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linux-next/arch/x86/include/asm/percpu.h

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License cleanup: add SPDX GPL-2.0 license identifier to files with no license Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-01 22:07:57 +08:00
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_PERCPU_H
#define _ASM_X86_PERCPU_H
#ifdef CONFIG_X86_64
#define __percpu_seg gs
#define __percpu_mov_op movq
#else
#define __percpu_seg fs
#define __percpu_mov_op movl
#endif
#ifdef __ASSEMBLY__
/*
* PER_CPU finds an address of a per-cpu variable.
*
* Args:
* var - variable name
* reg - 32bit register
*
* The resulting address is stored in the "reg" argument.
*
* Example:
* PER_CPU(cpu_gdt_descr, %ebx)
*/
#ifdef CONFIG_SMP
#define PER_CPU(var, reg) \
__percpu_mov_op %__percpu_seg:this_cpu_off, reg; \
lea var(reg), reg
#define PER_CPU_VAR(var) %__percpu_seg:var
#else /* ! SMP */
#define PER_CPU(var, reg) __percpu_mov_op $var, reg
#define PER_CPU_VAR(var) var
#endif /* SMP */
#ifdef CONFIG_X86_64_SMP
#define INIT_PER_CPU_VAR(var) init_per_cpu__##var
#else
#define INIT_PER_CPU_VAR(var) var
#endif
#else /* ...!ASSEMBLY */
#include <linux/kernel.h>
#include <linux/stringify.h>
#ifdef CONFIG_SMP
#define __percpu_prefix "%%"__stringify(__percpu_seg)":"
#define __my_cpu_offset this_cpu_read(this_cpu_off)
/*
* Compared to the generic __my_cpu_offset version, the following
* saves one instruction and avoids clobbering a temp register.
*/
#define arch_raw_cpu_ptr(ptr) \
({ \
unsigned long tcp_ptr__; \
asm volatile("add " __percpu_arg(1) ", %0" \
: "=r" (tcp_ptr__) \
: "m" (this_cpu_off), "0" (ptr)); \
(typeof(*(ptr)) __kernel __force *)tcp_ptr__; \
})
#else
#define __percpu_prefix ""
#endif
#define __percpu_arg(x) __percpu_prefix "%" #x
/*
* Initialized pointers to per-cpu variables needed for the boot
* processor need to use these macros to get the proper address
* offset from __per_cpu_load on SMP.
*
* There also must be an entry in vmlinux_64.lds.S
*/
#define DECLARE_INIT_PER_CPU(var) \
extern typeof(var) init_per_cpu_var(var)
#ifdef CONFIG_X86_64_SMP
#define init_per_cpu_var(var) init_per_cpu__##var
#else
#define init_per_cpu_var(var) var
#endif
/* For arch-specific code, we can use direct single-insn ops (they
* don't give an lvalue though). */
extern void __bad_percpu_size(void);
#define percpu_to_op(op, var, val) \
do { \
typedef typeof(var) pto_T__; \
if (0) { \
pto_T__ pto_tmp__; \
pto_tmp__ = (val); \
(void)pto_tmp__; \
} \
switch (sizeof(var)) { \
case 1: \
asm(op "b %1,"__percpu_arg(0) \
: "+m" (var) \
: "qi" ((pto_T__)(val))); \
break; \
case 2: \
asm(op "w %1,"__percpu_arg(0) \
: "+m" (var) \
: "ri" ((pto_T__)(val))); \
break; \
case 4: \
asm(op "l %1,"__percpu_arg(0) \
: "+m" (var) \
: "ri" ((pto_T__)(val))); \
break; \
case 8: \
asm(op "q %1,"__percpu_arg(0) \
: "+m" (var) \
: "re" ((pto_T__)(val))); \
break; \
default: __bad_percpu_size(); \
} \
} while (0)
/*
* Generate a percpu add to memory instruction and optimize code
* if one is added or subtracted.
*/
#define percpu_add_op(var, val) \
do { \
typedef typeof(var) pao_T__; \
const int pao_ID__ = (__builtin_constant_p(val) && \
percpu: fix this_cpu_sub() subtrahend casting for unsigneds this_cpu_sub() is implemented as negation and addition. This patch casts the adjustment to the counter type before negation to sign extend the adjustment. This helps in cases where the counter type is wider than an unsigned adjustment. An alternative to this patch is to declare such operations unsupported, but it seemed useful to avoid surprises. This patch specifically helps the following example: unsigned int delta = 1 preempt_disable() this_cpu_write(long_counter, 0) this_cpu_sub(long_counter, delta) preempt_enable() Before this change long_counter on a 64 bit machine ends with value 0xffffffff, rather than 0xffffffffffffffff. This is because this_cpu_sub(pcp, delta) boils down to this_cpu_add(pcp, -delta), which is basically: long_counter = 0 + 0xffffffff Also apply the same cast to: __this_cpu_sub() __this_cpu_sub_return() this_cpu_sub_return() All percpu_test.ko passes, especially the following cases which previously failed: l -= ui_one; __this_cpu_sub(long_counter, ui_one); CHECK(l, long_counter, -1); l -= ui_one; this_cpu_sub(long_counter, ui_one); CHECK(l, long_counter, -1); CHECK(l, long_counter, 0xffffffffffffffff); ul -= ui_one; __this_cpu_sub(ulong_counter, ui_one); CHECK(ul, ulong_counter, -1); CHECK(ul, ulong_counter, 0xffffffffffffffff); ul = this_cpu_sub_return(ulong_counter, ui_one); CHECK(ul, ulong_counter, 2); ul = __this_cpu_sub_return(ulong_counter, ui_one); CHECK(ul, ulong_counter, 1); Signed-off-by: Greg Thelen <gthelen@google.com> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-10-31 04:56:20 +08:00
((val) == 1 || (val) == -1)) ? \
(int)(val) : 0; \
if (0) { \
pao_T__ pao_tmp__; \
pao_tmp__ = (val); \
(void)pao_tmp__; \
} \
switch (sizeof(var)) { \
case 1: \
if (pao_ID__ == 1) \
asm("incb "__percpu_arg(0) : "+m" (var)); \
else if (pao_ID__ == -1) \
asm("decb "__percpu_arg(0) : "+m" (var)); \
else \
asm("addb %1, "__percpu_arg(0) \
: "+m" (var) \
: "qi" ((pao_T__)(val))); \
break; \
case 2: \
if (pao_ID__ == 1) \
asm("incw "__percpu_arg(0) : "+m" (var)); \
else if (pao_ID__ == -1) \
asm("decw "__percpu_arg(0) : "+m" (var)); \
else \
asm("addw %1, "__percpu_arg(0) \
: "+m" (var) \
: "ri" ((pao_T__)(val))); \
break; \
case 4: \
if (pao_ID__ == 1) \
asm("incl "__percpu_arg(0) : "+m" (var)); \
else if (pao_ID__ == -1) \
asm("decl "__percpu_arg(0) : "+m" (var)); \
else \
asm("addl %1, "__percpu_arg(0) \
: "+m" (var) \
: "ri" ((pao_T__)(val))); \
break; \
case 8: \
if (pao_ID__ == 1) \
asm("incq "__percpu_arg(0) : "+m" (var)); \
else if (pao_ID__ == -1) \
asm("decq "__percpu_arg(0) : "+m" (var)); \
else \
asm("addq %1, "__percpu_arg(0) \
: "+m" (var) \
: "re" ((pao_T__)(val))); \
break; \
default: __bad_percpu_size(); \
} \
} while (0)
#define percpu_from_op(op, var) \
({ \
typeof(var) pfo_ret__; \
switch (sizeof(var)) { \
case 1: \
asm(op "b "__percpu_arg(1)",%0" \
: "=q" (pfo_ret__) \
: "m" (var)); \
break; \
case 2: \
asm(op "w "__percpu_arg(1)",%0" \
: "=r" (pfo_ret__) \
: "m" (var)); \
break; \
case 4: \
asm(op "l "__percpu_arg(1)",%0" \
: "=r" (pfo_ret__) \
: "m" (var)); \
break; \
case 8: \
asm(op "q "__percpu_arg(1)",%0" \
: "=r" (pfo_ret__) \
: "m" (var)); \
break; \
default: __bad_percpu_size(); \
} \
pfo_ret__; \
})
#define percpu_stable_op(op, var) \
({ \
typeof(var) pfo_ret__; \
switch (sizeof(var)) { \
case 1: \
asm(op "b "__percpu_arg(P1)",%0" \
: "=q" (pfo_ret__) \
: "p" (&(var))); \
break; \
case 2: \
asm(op "w "__percpu_arg(P1)",%0" \
: "=r" (pfo_ret__) \
: "p" (&(var))); \
break; \
case 4: \
asm(op "l "__percpu_arg(P1)",%0" \
: "=r" (pfo_ret__) \
: "p" (&(var))); \
break; \
case 8: \
asm(op "q "__percpu_arg(P1)",%0" \
: "=r" (pfo_ret__) \
: "p" (&(var))); \
break; \
default: __bad_percpu_size(); \
} \
pfo_ret__; \
})
#define percpu_unary_op(op, var) \
({ \
switch (sizeof(var)) { \
case 1: \
asm(op "b "__percpu_arg(0) \
: "+m" (var)); \
break; \
case 2: \
asm(op "w "__percpu_arg(0) \
: "+m" (var)); \
break; \
case 4: \
asm(op "l "__percpu_arg(0) \
: "+m" (var)); \
break; \
case 8: \
asm(op "q "__percpu_arg(0) \
: "+m" (var)); \
break; \
default: __bad_percpu_size(); \
} \
})
/*
* Add return operation
*/
#define percpu_add_return_op(var, val) \
({ \
typeof(var) paro_ret__ = val; \
switch (sizeof(var)) { \
case 1: \
asm("xaddb %0, "__percpu_arg(1) \
: "+q" (paro_ret__), "+m" (var) \
: : "memory"); \
break; \
case 2: \
asm("xaddw %0, "__percpu_arg(1) \
: "+r" (paro_ret__), "+m" (var) \
: : "memory"); \
break; \
case 4: \
asm("xaddl %0, "__percpu_arg(1) \
: "+r" (paro_ret__), "+m" (var) \
: : "memory"); \
break; \
case 8: \
asm("xaddq %0, "__percpu_arg(1) \
: "+re" (paro_ret__), "+m" (var) \
: : "memory"); \
break; \
default: __bad_percpu_size(); \
} \
paro_ret__ += val; \
paro_ret__; \
})
/*
* xchg is implemented using cmpxchg without a lock prefix. xchg is
* expensive due to the implied lock prefix. The processor cannot prefetch
* cachelines if xchg is used.
*/
#define percpu_xchg_op(var, nval) \
({ \
typeof(var) pxo_ret__; \
typeof(var) pxo_new__ = (nval); \
switch (sizeof(var)) { \
case 1: \
percpu, x86: Fix percpu_xchg_op() These recent percpu commits: 2485b6464cf8: x86,percpu: Move out of place 64 bit ops into X86_64 section 8270137a0d50: cpuops: Use cmpxchg for xchg to avoid lock semantics Caused this 'perf top' crash: Kernel panic - not syncing: Fatal exception in interrupt Pid: 0, comm: swapper Tainted: G D 2.6.38-rc2-00181-gef71723 #413 Call Trace: <IRQ> [<ffffffff810465b5>] ? panic ? kmsg_dump ? kmsg_dump ? oops_end ? no_context ? __bad_area_nosemaphore ? perf_output_begin ? bad_area_nosemaphore ? do_page_fault ? __task_pid_nr_ns ? perf_event_tid ? __perf_event_header__init_id ? validate_chain ? perf_output_sample ? trace_hardirqs_off ? page_fault ? irq_work_run ? update_process_times ? tick_sched_timer ? tick_sched_timer ? __run_hrtimer ? hrtimer_interrupt ? account_system_vtime ? smp_apic_timer_interrupt ? apic_timer_interrupt ... Looking at assembly code, I found: list = this_cpu_xchg(irq_work_list, NULL); gives this wrong code : (gcc-4.1.2 cross compiler) ffffffff810bc45e: mov %gs:0xead0,%rax cmpxchg %rax,%gs:0xead0 jne ffffffff810bc45e <irq_work_run+0x3e> test %rax,%rax je ffffffff810bc4aa <irq_work_run+0x8a> Tell gcc we dirty eax/rax register in percpu_xchg_op() Compiler must use another register to store pxo_new__ We also dont need to reload percpu value after a jump, since a 'failed' cmpxchg already updated eax/rax Wrong generated code was : xor %rax,%rax /* load 0 into %rax */ 1: mov %gs:0xead0,%rax cmpxchg %rax,%gs:0xead0 jne 1b test %rax,%rax After patch : xor %rdx,%rdx /* load 0 into %rdx */ mov %gs:0xead0,%rax 1: cmpxchg %rdx,%gs:0xead0 jne 1b: test %rax,%rax Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Tejun Heo <tj@kernel.org> LKML-Reference: <1295973114.3588.312.camel@edumazet-laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-26 00:31:54 +08:00
asm("\n\tmov "__percpu_arg(1)",%%al" \
"\n1:\tcmpxchgb %2, "__percpu_arg(1) \
"\n\tjnz 1b" \
percpu, x86: Fix percpu_xchg_op() These recent percpu commits: 2485b6464cf8: x86,percpu: Move out of place 64 bit ops into X86_64 section 8270137a0d50: cpuops: Use cmpxchg for xchg to avoid lock semantics Caused this 'perf top' crash: Kernel panic - not syncing: Fatal exception in interrupt Pid: 0, comm: swapper Tainted: G D 2.6.38-rc2-00181-gef71723 #413 Call Trace: <IRQ> [<ffffffff810465b5>] ? panic ? kmsg_dump ? kmsg_dump ? oops_end ? no_context ? __bad_area_nosemaphore ? perf_output_begin ? bad_area_nosemaphore ? do_page_fault ? __task_pid_nr_ns ? perf_event_tid ? __perf_event_header__init_id ? validate_chain ? perf_output_sample ? trace_hardirqs_off ? page_fault ? irq_work_run ? update_process_times ? tick_sched_timer ? tick_sched_timer ? __run_hrtimer ? hrtimer_interrupt ? account_system_vtime ? smp_apic_timer_interrupt ? apic_timer_interrupt ... Looking at assembly code, I found: list = this_cpu_xchg(irq_work_list, NULL); gives this wrong code : (gcc-4.1.2 cross compiler) ffffffff810bc45e: mov %gs:0xead0,%rax cmpxchg %rax,%gs:0xead0 jne ffffffff810bc45e <irq_work_run+0x3e> test %rax,%rax je ffffffff810bc4aa <irq_work_run+0x8a> Tell gcc we dirty eax/rax register in percpu_xchg_op() Compiler must use another register to store pxo_new__ We also dont need to reload percpu value after a jump, since a 'failed' cmpxchg already updated eax/rax Wrong generated code was : xor %rax,%rax /* load 0 into %rax */ 1: mov %gs:0xead0,%rax cmpxchg %rax,%gs:0xead0 jne 1b test %rax,%rax After patch : xor %rdx,%rdx /* load 0 into %rdx */ mov %gs:0xead0,%rax 1: cmpxchg %rdx,%gs:0xead0 jne 1b: test %rax,%rax Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Tejun Heo <tj@kernel.org> LKML-Reference: <1295973114.3588.312.camel@edumazet-laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-26 00:31:54 +08:00
: "=&a" (pxo_ret__), "+m" (var) \
: "q" (pxo_new__) \
: "memory"); \
break; \
case 2: \
percpu, x86: Fix percpu_xchg_op() These recent percpu commits: 2485b6464cf8: x86,percpu: Move out of place 64 bit ops into X86_64 section 8270137a0d50: cpuops: Use cmpxchg for xchg to avoid lock semantics Caused this 'perf top' crash: Kernel panic - not syncing: Fatal exception in interrupt Pid: 0, comm: swapper Tainted: G D 2.6.38-rc2-00181-gef71723 #413 Call Trace: <IRQ> [<ffffffff810465b5>] ? panic ? kmsg_dump ? kmsg_dump ? oops_end ? no_context ? __bad_area_nosemaphore ? perf_output_begin ? bad_area_nosemaphore ? do_page_fault ? __task_pid_nr_ns ? perf_event_tid ? __perf_event_header__init_id ? validate_chain ? perf_output_sample ? trace_hardirqs_off ? page_fault ? irq_work_run ? update_process_times ? tick_sched_timer ? tick_sched_timer ? __run_hrtimer ? hrtimer_interrupt ? account_system_vtime ? smp_apic_timer_interrupt ? apic_timer_interrupt ... Looking at assembly code, I found: list = this_cpu_xchg(irq_work_list, NULL); gives this wrong code : (gcc-4.1.2 cross compiler) ffffffff810bc45e: mov %gs:0xead0,%rax cmpxchg %rax,%gs:0xead0 jne ffffffff810bc45e <irq_work_run+0x3e> test %rax,%rax je ffffffff810bc4aa <irq_work_run+0x8a> Tell gcc we dirty eax/rax register in percpu_xchg_op() Compiler must use another register to store pxo_new__ We also dont need to reload percpu value after a jump, since a 'failed' cmpxchg already updated eax/rax Wrong generated code was : xor %rax,%rax /* load 0 into %rax */ 1: mov %gs:0xead0,%rax cmpxchg %rax,%gs:0xead0 jne 1b test %rax,%rax After patch : xor %rdx,%rdx /* load 0 into %rdx */ mov %gs:0xead0,%rax 1: cmpxchg %rdx,%gs:0xead0 jne 1b: test %rax,%rax Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Tejun Heo <tj@kernel.org> LKML-Reference: <1295973114.3588.312.camel@edumazet-laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-26 00:31:54 +08:00
asm("\n\tmov "__percpu_arg(1)",%%ax" \
"\n1:\tcmpxchgw %2, "__percpu_arg(1) \
"\n\tjnz 1b" \
percpu, x86: Fix percpu_xchg_op() These recent percpu commits: 2485b6464cf8: x86,percpu: Move out of place 64 bit ops into X86_64 section 8270137a0d50: cpuops: Use cmpxchg for xchg to avoid lock semantics Caused this 'perf top' crash: Kernel panic - not syncing: Fatal exception in interrupt Pid: 0, comm: swapper Tainted: G D 2.6.38-rc2-00181-gef71723 #413 Call Trace: <IRQ> [<ffffffff810465b5>] ? panic ? kmsg_dump ? kmsg_dump ? oops_end ? no_context ? __bad_area_nosemaphore ? perf_output_begin ? bad_area_nosemaphore ? do_page_fault ? __task_pid_nr_ns ? perf_event_tid ? __perf_event_header__init_id ? validate_chain ? perf_output_sample ? trace_hardirqs_off ? page_fault ? irq_work_run ? update_process_times ? tick_sched_timer ? tick_sched_timer ? __run_hrtimer ? hrtimer_interrupt ? account_system_vtime ? smp_apic_timer_interrupt ? apic_timer_interrupt ... Looking at assembly code, I found: list = this_cpu_xchg(irq_work_list, NULL); gives this wrong code : (gcc-4.1.2 cross compiler) ffffffff810bc45e: mov %gs:0xead0,%rax cmpxchg %rax,%gs:0xead0 jne ffffffff810bc45e <irq_work_run+0x3e> test %rax,%rax je ffffffff810bc4aa <irq_work_run+0x8a> Tell gcc we dirty eax/rax register in percpu_xchg_op() Compiler must use another register to store pxo_new__ We also dont need to reload percpu value after a jump, since a 'failed' cmpxchg already updated eax/rax Wrong generated code was : xor %rax,%rax /* load 0 into %rax */ 1: mov %gs:0xead0,%rax cmpxchg %rax,%gs:0xead0 jne 1b test %rax,%rax After patch : xor %rdx,%rdx /* load 0 into %rdx */ mov %gs:0xead0,%rax 1: cmpxchg %rdx,%gs:0xead0 jne 1b: test %rax,%rax Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Tejun Heo <tj@kernel.org> LKML-Reference: <1295973114.3588.312.camel@edumazet-laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-26 00:31:54 +08:00
: "=&a" (pxo_ret__), "+m" (var) \
: "r" (pxo_new__) \
: "memory"); \
break; \
case 4: \
percpu, x86: Fix percpu_xchg_op() These recent percpu commits: 2485b6464cf8: x86,percpu: Move out of place 64 bit ops into X86_64 section 8270137a0d50: cpuops: Use cmpxchg for xchg to avoid lock semantics Caused this 'perf top' crash: Kernel panic - not syncing: Fatal exception in interrupt Pid: 0, comm: swapper Tainted: G D 2.6.38-rc2-00181-gef71723 #413 Call Trace: <IRQ> [<ffffffff810465b5>] ? panic ? kmsg_dump ? kmsg_dump ? oops_end ? no_context ? __bad_area_nosemaphore ? perf_output_begin ? bad_area_nosemaphore ? do_page_fault ? __task_pid_nr_ns ? perf_event_tid ? __perf_event_header__init_id ? validate_chain ? perf_output_sample ? trace_hardirqs_off ? page_fault ? irq_work_run ? update_process_times ? tick_sched_timer ? tick_sched_timer ? __run_hrtimer ? hrtimer_interrupt ? account_system_vtime ? smp_apic_timer_interrupt ? apic_timer_interrupt ... Looking at assembly code, I found: list = this_cpu_xchg(irq_work_list, NULL); gives this wrong code : (gcc-4.1.2 cross compiler) ffffffff810bc45e: mov %gs:0xead0,%rax cmpxchg %rax,%gs:0xead0 jne ffffffff810bc45e <irq_work_run+0x3e> test %rax,%rax je ffffffff810bc4aa <irq_work_run+0x8a> Tell gcc we dirty eax/rax register in percpu_xchg_op() Compiler must use another register to store pxo_new__ We also dont need to reload percpu value after a jump, since a 'failed' cmpxchg already updated eax/rax Wrong generated code was : xor %rax,%rax /* load 0 into %rax */ 1: mov %gs:0xead0,%rax cmpxchg %rax,%gs:0xead0 jne 1b test %rax,%rax After patch : xor %rdx,%rdx /* load 0 into %rdx */ mov %gs:0xead0,%rax 1: cmpxchg %rdx,%gs:0xead0 jne 1b: test %rax,%rax Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Tejun Heo <tj@kernel.org> LKML-Reference: <1295973114.3588.312.camel@edumazet-laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-26 00:31:54 +08:00
asm("\n\tmov "__percpu_arg(1)",%%eax" \
"\n1:\tcmpxchgl %2, "__percpu_arg(1) \
"\n\tjnz 1b" \
percpu, x86: Fix percpu_xchg_op() These recent percpu commits: 2485b6464cf8: x86,percpu: Move out of place 64 bit ops into X86_64 section 8270137a0d50: cpuops: Use cmpxchg for xchg to avoid lock semantics Caused this 'perf top' crash: Kernel panic - not syncing: Fatal exception in interrupt Pid: 0, comm: swapper Tainted: G D 2.6.38-rc2-00181-gef71723 #413 Call Trace: <IRQ> [<ffffffff810465b5>] ? panic ? kmsg_dump ? kmsg_dump ? oops_end ? no_context ? __bad_area_nosemaphore ? perf_output_begin ? bad_area_nosemaphore ? do_page_fault ? __task_pid_nr_ns ? perf_event_tid ? __perf_event_header__init_id ? validate_chain ? perf_output_sample ? trace_hardirqs_off ? page_fault ? irq_work_run ? update_process_times ? tick_sched_timer ? tick_sched_timer ? __run_hrtimer ? hrtimer_interrupt ? account_system_vtime ? smp_apic_timer_interrupt ? apic_timer_interrupt ... Looking at assembly code, I found: list = this_cpu_xchg(irq_work_list, NULL); gives this wrong code : (gcc-4.1.2 cross compiler) ffffffff810bc45e: mov %gs:0xead0,%rax cmpxchg %rax,%gs:0xead0 jne ffffffff810bc45e <irq_work_run+0x3e> test %rax,%rax je ffffffff810bc4aa <irq_work_run+0x8a> Tell gcc we dirty eax/rax register in percpu_xchg_op() Compiler must use another register to store pxo_new__ We also dont need to reload percpu value after a jump, since a 'failed' cmpxchg already updated eax/rax Wrong generated code was : xor %rax,%rax /* load 0 into %rax */ 1: mov %gs:0xead0,%rax cmpxchg %rax,%gs:0xead0 jne 1b test %rax,%rax After patch : xor %rdx,%rdx /* load 0 into %rdx */ mov %gs:0xead0,%rax 1: cmpxchg %rdx,%gs:0xead0 jne 1b: test %rax,%rax Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Tejun Heo <tj@kernel.org> LKML-Reference: <1295973114.3588.312.camel@edumazet-laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-26 00:31:54 +08:00
: "=&a" (pxo_ret__), "+m" (var) \
: "r" (pxo_new__) \
: "memory"); \
break; \
case 8: \
percpu, x86: Fix percpu_xchg_op() These recent percpu commits: 2485b6464cf8: x86,percpu: Move out of place 64 bit ops into X86_64 section 8270137a0d50: cpuops: Use cmpxchg for xchg to avoid lock semantics Caused this 'perf top' crash: Kernel panic - not syncing: Fatal exception in interrupt Pid: 0, comm: swapper Tainted: G D 2.6.38-rc2-00181-gef71723 #413 Call Trace: <IRQ> [<ffffffff810465b5>] ? panic ? kmsg_dump ? kmsg_dump ? oops_end ? no_context ? __bad_area_nosemaphore ? perf_output_begin ? bad_area_nosemaphore ? do_page_fault ? __task_pid_nr_ns ? perf_event_tid ? __perf_event_header__init_id ? validate_chain ? perf_output_sample ? trace_hardirqs_off ? page_fault ? irq_work_run ? update_process_times ? tick_sched_timer ? tick_sched_timer ? __run_hrtimer ? hrtimer_interrupt ? account_system_vtime ? smp_apic_timer_interrupt ? apic_timer_interrupt ... Looking at assembly code, I found: list = this_cpu_xchg(irq_work_list, NULL); gives this wrong code : (gcc-4.1.2 cross compiler) ffffffff810bc45e: mov %gs:0xead0,%rax cmpxchg %rax,%gs:0xead0 jne ffffffff810bc45e <irq_work_run+0x3e> test %rax,%rax je ffffffff810bc4aa <irq_work_run+0x8a> Tell gcc we dirty eax/rax register in percpu_xchg_op() Compiler must use another register to store pxo_new__ We also dont need to reload percpu value after a jump, since a 'failed' cmpxchg already updated eax/rax Wrong generated code was : xor %rax,%rax /* load 0 into %rax */ 1: mov %gs:0xead0,%rax cmpxchg %rax,%gs:0xead0 jne 1b test %rax,%rax After patch : xor %rdx,%rdx /* load 0 into %rdx */ mov %gs:0xead0,%rax 1: cmpxchg %rdx,%gs:0xead0 jne 1b: test %rax,%rax Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Tejun Heo <tj@kernel.org> LKML-Reference: <1295973114.3588.312.camel@edumazet-laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-26 00:31:54 +08:00
asm("\n\tmov "__percpu_arg(1)",%%rax" \
"\n1:\tcmpxchgq %2, "__percpu_arg(1) \
"\n\tjnz 1b" \
percpu, x86: Fix percpu_xchg_op() These recent percpu commits: 2485b6464cf8: x86,percpu: Move out of place 64 bit ops into X86_64 section 8270137a0d50: cpuops: Use cmpxchg for xchg to avoid lock semantics Caused this 'perf top' crash: Kernel panic - not syncing: Fatal exception in interrupt Pid: 0, comm: swapper Tainted: G D 2.6.38-rc2-00181-gef71723 #413 Call Trace: <IRQ> [<ffffffff810465b5>] ? panic ? kmsg_dump ? kmsg_dump ? oops_end ? no_context ? __bad_area_nosemaphore ? perf_output_begin ? bad_area_nosemaphore ? do_page_fault ? __task_pid_nr_ns ? perf_event_tid ? __perf_event_header__init_id ? validate_chain ? perf_output_sample ? trace_hardirqs_off ? page_fault ? irq_work_run ? update_process_times ? tick_sched_timer ? tick_sched_timer ? __run_hrtimer ? hrtimer_interrupt ? account_system_vtime ? smp_apic_timer_interrupt ? apic_timer_interrupt ... Looking at assembly code, I found: list = this_cpu_xchg(irq_work_list, NULL); gives this wrong code : (gcc-4.1.2 cross compiler) ffffffff810bc45e: mov %gs:0xead0,%rax cmpxchg %rax,%gs:0xead0 jne ffffffff810bc45e <irq_work_run+0x3e> test %rax,%rax je ffffffff810bc4aa <irq_work_run+0x8a> Tell gcc we dirty eax/rax register in percpu_xchg_op() Compiler must use another register to store pxo_new__ We also dont need to reload percpu value after a jump, since a 'failed' cmpxchg already updated eax/rax Wrong generated code was : xor %rax,%rax /* load 0 into %rax */ 1: mov %gs:0xead0,%rax cmpxchg %rax,%gs:0xead0 jne 1b test %rax,%rax After patch : xor %rdx,%rdx /* load 0 into %rdx */ mov %gs:0xead0,%rax 1: cmpxchg %rdx,%gs:0xead0 jne 1b: test %rax,%rax Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Tejun Heo <tj@kernel.org> LKML-Reference: <1295973114.3588.312.camel@edumazet-laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-26 00:31:54 +08:00
: "=&a" (pxo_ret__), "+m" (var) \
: "r" (pxo_new__) \
: "memory"); \
break; \
default: __bad_percpu_size(); \
} \
pxo_ret__; \
})
/*
* cmpxchg has no such implied lock semantics as a result it is much
* more efficient for cpu local operations.
*/
#define percpu_cmpxchg_op(var, oval, nval) \
({ \
typeof(var) pco_ret__; \
typeof(var) pco_old__ = (oval); \
typeof(var) pco_new__ = (nval); \
switch (sizeof(var)) { \
case 1: \
asm("cmpxchgb %2, "__percpu_arg(1) \
: "=a" (pco_ret__), "+m" (var) \
: "q" (pco_new__), "0" (pco_old__) \
: "memory"); \
break; \
case 2: \
asm("cmpxchgw %2, "__percpu_arg(1) \
: "=a" (pco_ret__), "+m" (var) \
: "r" (pco_new__), "0" (pco_old__) \
: "memory"); \
break; \
case 4: \
asm("cmpxchgl %2, "__percpu_arg(1) \
: "=a" (pco_ret__), "+m" (var) \
: "r" (pco_new__), "0" (pco_old__) \
: "memory"); \
break; \
case 8: \
asm("cmpxchgq %2, "__percpu_arg(1) \
: "=a" (pco_ret__), "+m" (var) \
: "r" (pco_new__), "0" (pco_old__) \
: "memory"); \
break; \
default: __bad_percpu_size(); \
} \
pco_ret__; \
})
/*
* this_cpu_read() makes gcc load the percpu variable every time it is
* accessed while this_cpu_read_stable() allows the value to be cached.
* this_cpu_read_stable() is more efficient and can be used if its value
* is guaranteed to be valid across cpus. The current users include
* get_current() and get_thread_info() both of which are actually
* per-thread variables implemented as per-cpu variables and thus
* stable for the duration of the respective task.
*/
#define this_cpu_read_stable(var) percpu_stable_op("mov", var)
#define raw_cpu_read_1(pcp) percpu_from_op("mov", pcp)
#define raw_cpu_read_2(pcp) percpu_from_op("mov", pcp)
#define raw_cpu_read_4(pcp) percpu_from_op("mov", pcp)
percpu: add raw_cpu_ops The kernel has never been audited to ensure that this_cpu operations are consistently used throughout the kernel. The code generated in many places can be improved through the use of this_cpu operations (which uses a segment register for relocation of per cpu offsets instead of performing address calculations). The patch set also addresses various consistency issues in general with the per cpu macros. A. The semantics of __this_cpu_ptr() differs from this_cpu_ptr only because checks are skipped. This is typically shown through a raw_ prefix. So this patch set changes the places where __this_cpu_ptr() is used to raw_cpu_ptr(). B. There has been the long term wish by some that __this_cpu operations would check for preemption. However, there are cases where preemption checks need to be skipped. This patch set adds raw_cpu operations that do not check for preemption and then adds preemption checks to the __this_cpu operations. C. The use of __get_cpu_var is always a reference to a percpu variable that can also be handled via a this_cpu operation. This patch set replaces all uses of __get_cpu_var with this_cpu operations. D. We can then use this_cpu RMW operations in various places replacing sequences of instructions by a single one. E. The use of this_cpu operations throughout will allow other arches than x86 to implement optimized references and RMV operations to work with per cpu local data. F. The use of this_cpu operations opens up the possibility to further optimize code that relies on synchronization through per cpu data. The patch set works in a couple of stages: I. Patch 1 adds the additional raw_cpu operations and raw_cpu_ptr(). Also converts the existing __this_cpu_xx_# primitive in the x86 code to raw_cpu_xx_#. II. Patch 2-4 use the raw_cpu operations in places that would give us false positives once they are enabled. III. Patch 5 adds preemption checks to __this_cpu operations to allow checking if preemption is properly disabled when these functions are used. IV. Patches 6-20 are patches that simply replace uses of __get_cpu_var with this_cpu_ptr. They do not depend on any changes to the percpu code. No preemption tests are skipped if they are applied. V. Patches 21-46 are conversion patches that use this_cpu operations in various kernel subsystems/drivers or arch code. VI. Patches 47/48 (not included in this series) remove no longer used functions (__this_cpu_ptr and __get_cpu_var). These should only be applied after all the conversion patches have made it and after we have done additional passes through the kernel to ensure that none of the uses of these functions remain. This patch (of 46): The patches following this one will add preemption checks to __this_cpu ops so we need to have an alternative way to use this_cpu operations without preemption checks. raw_cpu_ops will be the basis for all other ops since these will be the operations that do not implement any checks. Primitive operations are renamed by this patch from __this_cpu_xxx to raw_cpu_xxxx. Also change the uses of the x86 percpu primitives in preempt.h. These depend directly on asm/percpu.h (header #include nesting issue). Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Christoph Lameter <cl@linux.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Alex Shi <alex.shi@intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Bryan Wu <cooloney@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: David Daney <david.daney@cavium.com> Cc: David Miller <davem@davemloft.net> Cc: David S. Miller <davem@davemloft.net> Cc: Dimitri Sivanich <sivanich@sgi.com> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@linux.intel.com> Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no> Cc: Hedi Berriche <hedi@sgi.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: James Hogan <james.hogan@imgtec.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: John Stultz <john.stultz@linaro.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Mike Travis <travis@sgi.com> Cc: Neil Brown <neilb@suse.de> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Robert Richter <rric@kernel.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Wim Van Sebroeck <wim@iguana.be> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-08 06:39:34 +08:00
#define raw_cpu_write_1(pcp, val) percpu_to_op("mov", (pcp), val)
#define raw_cpu_write_2(pcp, val) percpu_to_op("mov", (pcp), val)
#define raw_cpu_write_4(pcp, val) percpu_to_op("mov", (pcp), val)
#define raw_cpu_add_1(pcp, val) percpu_add_op((pcp), val)
#define raw_cpu_add_2(pcp, val) percpu_add_op((pcp), val)
#define raw_cpu_add_4(pcp, val) percpu_add_op((pcp), val)
#define raw_cpu_and_1(pcp, val) percpu_to_op("and", (pcp), val)
#define raw_cpu_and_2(pcp, val) percpu_to_op("and", (pcp), val)
#define raw_cpu_and_4(pcp, val) percpu_to_op("and", (pcp), val)
#define raw_cpu_or_1(pcp, val) percpu_to_op("or", (pcp), val)
#define raw_cpu_or_2(pcp, val) percpu_to_op("or", (pcp), val)
#define raw_cpu_or_4(pcp, val) percpu_to_op("or", (pcp), val)
#define raw_cpu_xchg_1(pcp, val) percpu_xchg_op(pcp, val)
#define raw_cpu_xchg_2(pcp, val) percpu_xchg_op(pcp, val)
#define raw_cpu_xchg_4(pcp, val) percpu_xchg_op(pcp, val)
#define this_cpu_read_1(pcp) percpu_from_op("mov", pcp)
#define this_cpu_read_2(pcp) percpu_from_op("mov", pcp)
#define this_cpu_read_4(pcp) percpu_from_op("mov", pcp)
#define this_cpu_write_1(pcp, val) percpu_to_op("mov", (pcp), val)
#define this_cpu_write_2(pcp, val) percpu_to_op("mov", (pcp), val)
#define this_cpu_write_4(pcp, val) percpu_to_op("mov", (pcp), val)
#define this_cpu_add_1(pcp, val) percpu_add_op((pcp), val)
#define this_cpu_add_2(pcp, val) percpu_add_op((pcp), val)
#define this_cpu_add_4(pcp, val) percpu_add_op((pcp), val)
#define this_cpu_and_1(pcp, val) percpu_to_op("and", (pcp), val)
#define this_cpu_and_2(pcp, val) percpu_to_op("and", (pcp), val)
#define this_cpu_and_4(pcp, val) percpu_to_op("and", (pcp), val)
#define this_cpu_or_1(pcp, val) percpu_to_op("or", (pcp), val)
#define this_cpu_or_2(pcp, val) percpu_to_op("or", (pcp), val)
#define this_cpu_or_4(pcp, val) percpu_to_op("or", (pcp), val)
#define this_cpu_xchg_1(pcp, nval) percpu_xchg_op(pcp, nval)
#define this_cpu_xchg_2(pcp, nval) percpu_xchg_op(pcp, nval)
#define this_cpu_xchg_4(pcp, nval) percpu_xchg_op(pcp, nval)
percpu: add raw_cpu_ops The kernel has never been audited to ensure that this_cpu operations are consistently used throughout the kernel. The code generated in many places can be improved through the use of this_cpu operations (which uses a segment register for relocation of per cpu offsets instead of performing address calculations). The patch set also addresses various consistency issues in general with the per cpu macros. A. The semantics of __this_cpu_ptr() differs from this_cpu_ptr only because checks are skipped. This is typically shown through a raw_ prefix. So this patch set changes the places where __this_cpu_ptr() is used to raw_cpu_ptr(). B. There has been the long term wish by some that __this_cpu operations would check for preemption. However, there are cases where preemption checks need to be skipped. This patch set adds raw_cpu operations that do not check for preemption and then adds preemption checks to the __this_cpu operations. C. The use of __get_cpu_var is always a reference to a percpu variable that can also be handled via a this_cpu operation. This patch set replaces all uses of __get_cpu_var with this_cpu operations. D. We can then use this_cpu RMW operations in various places replacing sequences of instructions by a single one. E. The use of this_cpu operations throughout will allow other arches than x86 to implement optimized references and RMV operations to work with per cpu local data. F. The use of this_cpu operations opens up the possibility to further optimize code that relies on synchronization through per cpu data. The patch set works in a couple of stages: I. Patch 1 adds the additional raw_cpu operations and raw_cpu_ptr(). Also converts the existing __this_cpu_xx_# primitive in the x86 code to raw_cpu_xx_#. II. Patch 2-4 use the raw_cpu operations in places that would give us false positives once they are enabled. III. Patch 5 adds preemption checks to __this_cpu operations to allow checking if preemption is properly disabled when these functions are used. IV. Patches 6-20 are patches that simply replace uses of __get_cpu_var with this_cpu_ptr. They do not depend on any changes to the percpu code. No preemption tests are skipped if they are applied. V. Patches 21-46 are conversion patches that use this_cpu operations in various kernel subsystems/drivers or arch code. VI. Patches 47/48 (not included in this series) remove no longer used functions (__this_cpu_ptr and __get_cpu_var). These should only be applied after all the conversion patches have made it and after we have done additional passes through the kernel to ensure that none of the uses of these functions remain. This patch (of 46): The patches following this one will add preemption checks to __this_cpu ops so we need to have an alternative way to use this_cpu operations without preemption checks. raw_cpu_ops will be the basis for all other ops since these will be the operations that do not implement any checks. Primitive operations are renamed by this patch from __this_cpu_xxx to raw_cpu_xxxx. Also change the uses of the x86 percpu primitives in preempt.h. These depend directly on asm/percpu.h (header #include nesting issue). Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Christoph Lameter <cl@linux.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Alex Shi <alex.shi@intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Bryan Wu <cooloney@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: David Daney <david.daney@cavium.com> Cc: David Miller <davem@davemloft.net> Cc: David S. Miller <davem@davemloft.net> Cc: Dimitri Sivanich <sivanich@sgi.com> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@linux.intel.com> Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no> Cc: Hedi Berriche <hedi@sgi.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: James Hogan <james.hogan@imgtec.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: John Stultz <john.stultz@linaro.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Mike Travis <travis@sgi.com> Cc: Neil Brown <neilb@suse.de> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Robert Richter <rric@kernel.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Wim Van Sebroeck <wim@iguana.be> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-08 06:39:34 +08:00
#define raw_cpu_add_return_1(pcp, val) percpu_add_return_op(pcp, val)
#define raw_cpu_add_return_2(pcp, val) percpu_add_return_op(pcp, val)
#define raw_cpu_add_return_4(pcp, val) percpu_add_return_op(pcp, val)
#define raw_cpu_cmpxchg_1(pcp, oval, nval) percpu_cmpxchg_op(pcp, oval, nval)
#define raw_cpu_cmpxchg_2(pcp, oval, nval) percpu_cmpxchg_op(pcp, oval, nval)
#define raw_cpu_cmpxchg_4(pcp, oval, nval) percpu_cmpxchg_op(pcp, oval, nval)
percpu: add raw_cpu_ops The kernel has never been audited to ensure that this_cpu operations are consistently used throughout the kernel. The code generated in many places can be improved through the use of this_cpu operations (which uses a segment register for relocation of per cpu offsets instead of performing address calculations). The patch set also addresses various consistency issues in general with the per cpu macros. A. The semantics of __this_cpu_ptr() differs from this_cpu_ptr only because checks are skipped. This is typically shown through a raw_ prefix. So this patch set changes the places where __this_cpu_ptr() is used to raw_cpu_ptr(). B. There has been the long term wish by some that __this_cpu operations would check for preemption. However, there are cases where preemption checks need to be skipped. This patch set adds raw_cpu operations that do not check for preemption and then adds preemption checks to the __this_cpu operations. C. The use of __get_cpu_var is always a reference to a percpu variable that can also be handled via a this_cpu operation. This patch set replaces all uses of __get_cpu_var with this_cpu operations. D. We can then use this_cpu RMW operations in various places replacing sequences of instructions by a single one. E. The use of this_cpu operations throughout will allow other arches than x86 to implement optimized references and RMV operations to work with per cpu local data. F. The use of this_cpu operations opens up the possibility to further optimize code that relies on synchronization through per cpu data. The patch set works in a couple of stages: I. Patch 1 adds the additional raw_cpu operations and raw_cpu_ptr(). Also converts the existing __this_cpu_xx_# primitive in the x86 code to raw_cpu_xx_#. II. Patch 2-4 use the raw_cpu operations in places that would give us false positives once they are enabled. III. Patch 5 adds preemption checks to __this_cpu operations to allow checking if preemption is properly disabled when these functions are used. IV. Patches 6-20 are patches that simply replace uses of __get_cpu_var with this_cpu_ptr. They do not depend on any changes to the percpu code. No preemption tests are skipped if they are applied. V. Patches 21-46 are conversion patches that use this_cpu operations in various kernel subsystems/drivers or arch code. VI. Patches 47/48 (not included in this series) remove no longer used functions (__this_cpu_ptr and __get_cpu_var). These should only be applied after all the conversion patches have made it and after we have done additional passes through the kernel to ensure that none of the uses of these functions remain. This patch (of 46): The patches following this one will add preemption checks to __this_cpu ops so we need to have an alternative way to use this_cpu operations without preemption checks. raw_cpu_ops will be the basis for all other ops since these will be the operations that do not implement any checks. Primitive operations are renamed by this patch from __this_cpu_xxx to raw_cpu_xxxx. Also change the uses of the x86 percpu primitives in preempt.h. These depend directly on asm/percpu.h (header #include nesting issue). Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Christoph Lameter <cl@linux.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Alex Shi <alex.shi@intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Bryan Wu <cooloney@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: David Daney <david.daney@cavium.com> Cc: David Miller <davem@davemloft.net> Cc: David S. Miller <davem@davemloft.net> Cc: Dimitri Sivanich <sivanich@sgi.com> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@linux.intel.com> Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no> Cc: Hedi Berriche <hedi@sgi.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: James Hogan <james.hogan@imgtec.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: John Stultz <john.stultz@linaro.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Mike Travis <travis@sgi.com> Cc: Neil Brown <neilb@suse.de> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Robert Richter <rric@kernel.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Wim Van Sebroeck <wim@iguana.be> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-08 06:39:34 +08:00
#define this_cpu_add_return_1(pcp, val) percpu_add_return_op(pcp, val)
#define this_cpu_add_return_2(pcp, val) percpu_add_return_op(pcp, val)
#define this_cpu_add_return_4(pcp, val) percpu_add_return_op(pcp, val)
#define this_cpu_cmpxchg_1(pcp, oval, nval) percpu_cmpxchg_op(pcp, oval, nval)
#define this_cpu_cmpxchg_2(pcp, oval, nval) percpu_cmpxchg_op(pcp, oval, nval)
#define this_cpu_cmpxchg_4(pcp, oval, nval) percpu_cmpxchg_op(pcp, oval, nval)
#ifdef CONFIG_X86_CMPXCHG64
#define percpu_cmpxchg8b_double(pcp1, pcp2, o1, o2, n1, n2) \
({ \
bool __ret; \
typeof(pcp1) __o1 = (o1), __n1 = (n1); \
typeof(pcp2) __o2 = (o2), __n2 = (n2); \
asm volatile("cmpxchg8b "__percpu_arg(1) \
CC_SET(z) \
: CC_OUT(z) (__ret), "+m" (pcp1), "+m" (pcp2), "+a" (__o1), "+d" (__o2) \
: "b" (__n1), "c" (__n2)); \
__ret; \
})
percpu: add raw_cpu_ops The kernel has never been audited to ensure that this_cpu operations are consistently used throughout the kernel. The code generated in many places can be improved through the use of this_cpu operations (which uses a segment register for relocation of per cpu offsets instead of performing address calculations). The patch set also addresses various consistency issues in general with the per cpu macros. A. The semantics of __this_cpu_ptr() differs from this_cpu_ptr only because checks are skipped. This is typically shown through a raw_ prefix. So this patch set changes the places where __this_cpu_ptr() is used to raw_cpu_ptr(). B. There has been the long term wish by some that __this_cpu operations would check for preemption. However, there are cases where preemption checks need to be skipped. This patch set adds raw_cpu operations that do not check for preemption and then adds preemption checks to the __this_cpu operations. C. The use of __get_cpu_var is always a reference to a percpu variable that can also be handled via a this_cpu operation. This patch set replaces all uses of __get_cpu_var with this_cpu operations. D. We can then use this_cpu RMW operations in various places replacing sequences of instructions by a single one. E. The use of this_cpu operations throughout will allow other arches than x86 to implement optimized references and RMV operations to work with per cpu local data. F. The use of this_cpu operations opens up the possibility to further optimize code that relies on synchronization through per cpu data. The patch set works in a couple of stages: I. Patch 1 adds the additional raw_cpu operations and raw_cpu_ptr(). Also converts the existing __this_cpu_xx_# primitive in the x86 code to raw_cpu_xx_#. II. Patch 2-4 use the raw_cpu operations in places that would give us false positives once they are enabled. III. Patch 5 adds preemption checks to __this_cpu operations to allow checking if preemption is properly disabled when these functions are used. IV. Patches 6-20 are patches that simply replace uses of __get_cpu_var with this_cpu_ptr. They do not depend on any changes to the percpu code. No preemption tests are skipped if they are applied. V. Patches 21-46 are conversion patches that use this_cpu operations in various kernel subsystems/drivers or arch code. VI. Patches 47/48 (not included in this series) remove no longer used functions (__this_cpu_ptr and __get_cpu_var). These should only be applied after all the conversion patches have made it and after we have done additional passes through the kernel to ensure that none of the uses of these functions remain. This patch (of 46): The patches following this one will add preemption checks to __this_cpu ops so we need to have an alternative way to use this_cpu operations without preemption checks. raw_cpu_ops will be the basis for all other ops since these will be the operations that do not implement any checks. Primitive operations are renamed by this patch from __this_cpu_xxx to raw_cpu_xxxx. Also change the uses of the x86 percpu primitives in preempt.h. These depend directly on asm/percpu.h (header #include nesting issue). Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Christoph Lameter <cl@linux.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Alex Shi <alex.shi@intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Bryan Wu <cooloney@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: David Daney <david.daney@cavium.com> Cc: David Miller <davem@davemloft.net> Cc: David S. Miller <davem@davemloft.net> Cc: Dimitri Sivanich <sivanich@sgi.com> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@linux.intel.com> Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no> Cc: Hedi Berriche <hedi@sgi.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: James Hogan <james.hogan@imgtec.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: John Stultz <john.stultz@linaro.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Mike Travis <travis@sgi.com> Cc: Neil Brown <neilb@suse.de> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Robert Richter <rric@kernel.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Wim Van Sebroeck <wim@iguana.be> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-08 06:39:34 +08:00
#define raw_cpu_cmpxchg_double_4 percpu_cmpxchg8b_double
#define this_cpu_cmpxchg_double_4 percpu_cmpxchg8b_double
#endif /* CONFIG_X86_CMPXCHG64 */
/*
* Per cpu atomic 64 bit operations are only available under 64 bit.
* 32 bit must fall back to generic operations.
*/
#ifdef CONFIG_X86_64
#define raw_cpu_read_8(pcp) percpu_from_op("mov", pcp)
percpu: add raw_cpu_ops The kernel has never been audited to ensure that this_cpu operations are consistently used throughout the kernel. The code generated in many places can be improved through the use of this_cpu operations (which uses a segment register for relocation of per cpu offsets instead of performing address calculations). The patch set also addresses various consistency issues in general with the per cpu macros. A. The semantics of __this_cpu_ptr() differs from this_cpu_ptr only because checks are skipped. This is typically shown through a raw_ prefix. So this patch set changes the places where __this_cpu_ptr() is used to raw_cpu_ptr(). B. There has been the long term wish by some that __this_cpu operations would check for preemption. However, there are cases where preemption checks need to be skipped. This patch set adds raw_cpu operations that do not check for preemption and then adds preemption checks to the __this_cpu operations. C. The use of __get_cpu_var is always a reference to a percpu variable that can also be handled via a this_cpu operation. This patch set replaces all uses of __get_cpu_var with this_cpu operations. D. We can then use this_cpu RMW operations in various places replacing sequences of instructions by a single one. E. The use of this_cpu operations throughout will allow other arches than x86 to implement optimized references and RMV operations to work with per cpu local data. F. The use of this_cpu operations opens up the possibility to further optimize code that relies on synchronization through per cpu data. The patch set works in a couple of stages: I. Patch 1 adds the additional raw_cpu operations and raw_cpu_ptr(). Also converts the existing __this_cpu_xx_# primitive in the x86 code to raw_cpu_xx_#. II. Patch 2-4 use the raw_cpu operations in places that would give us false positives once they are enabled. III. Patch 5 adds preemption checks to __this_cpu operations to allow checking if preemption is properly disabled when these functions are used. IV. Patches 6-20 are patches that simply replace uses of __get_cpu_var with this_cpu_ptr. They do not depend on any changes to the percpu code. No preemption tests are skipped if they are applied. V. Patches 21-46 are conversion patches that use this_cpu operations in various kernel subsystems/drivers or arch code. VI. Patches 47/48 (not included in this series) remove no longer used functions (__this_cpu_ptr and __get_cpu_var). These should only be applied after all the conversion patches have made it and after we have done additional passes through the kernel to ensure that none of the uses of these functions remain. This patch (of 46): The patches following this one will add preemption checks to __this_cpu ops so we need to have an alternative way to use this_cpu operations without preemption checks. raw_cpu_ops will be the basis for all other ops since these will be the operations that do not implement any checks. Primitive operations are renamed by this patch from __this_cpu_xxx to raw_cpu_xxxx. Also change the uses of the x86 percpu primitives in preempt.h. These depend directly on asm/percpu.h (header #include nesting issue). Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Christoph Lameter <cl@linux.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Alex Shi <alex.shi@intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Bryan Wu <cooloney@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: David Daney <david.daney@cavium.com> Cc: David Miller <davem@davemloft.net> Cc: David S. Miller <davem@davemloft.net> Cc: Dimitri Sivanich <sivanich@sgi.com> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@linux.intel.com> Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no> Cc: Hedi Berriche <hedi@sgi.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: James Hogan <james.hogan@imgtec.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: John Stultz <john.stultz@linaro.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Mike Travis <travis@sgi.com> Cc: Neil Brown <neilb@suse.de> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Robert Richter <rric@kernel.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Wim Van Sebroeck <wim@iguana.be> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-08 06:39:34 +08:00
#define raw_cpu_write_8(pcp, val) percpu_to_op("mov", (pcp), val)
#define raw_cpu_add_8(pcp, val) percpu_add_op((pcp), val)
#define raw_cpu_and_8(pcp, val) percpu_to_op("and", (pcp), val)
#define raw_cpu_or_8(pcp, val) percpu_to_op("or", (pcp), val)
#define raw_cpu_add_return_8(pcp, val) percpu_add_return_op(pcp, val)
#define raw_cpu_xchg_8(pcp, nval) percpu_xchg_op(pcp, nval)
#define raw_cpu_cmpxchg_8(pcp, oval, nval) percpu_cmpxchg_op(pcp, oval, nval)
#define this_cpu_read_8(pcp) percpu_from_op("mov", pcp)
percpu: add raw_cpu_ops The kernel has never been audited to ensure that this_cpu operations are consistently used throughout the kernel. The code generated in many places can be improved through the use of this_cpu operations (which uses a segment register for relocation of per cpu offsets instead of performing address calculations). The patch set also addresses various consistency issues in general with the per cpu macros. A. The semantics of __this_cpu_ptr() differs from this_cpu_ptr only because checks are skipped. This is typically shown through a raw_ prefix. So this patch set changes the places where __this_cpu_ptr() is used to raw_cpu_ptr(). B. There has been the long term wish by some that __this_cpu operations would check for preemption. However, there are cases where preemption checks need to be skipped. This patch set adds raw_cpu operations that do not check for preemption and then adds preemption checks to the __this_cpu operations. C. The use of __get_cpu_var is always a reference to a percpu variable that can also be handled via a this_cpu operation. This patch set replaces all uses of __get_cpu_var with this_cpu operations. D. We can then use this_cpu RMW operations in various places replacing sequences of instructions by a single one. E. The use of this_cpu operations throughout will allow other arches than x86 to implement optimized references and RMV operations to work with per cpu local data. F. The use of this_cpu operations opens up the possibility to further optimize code that relies on synchronization through per cpu data. The patch set works in a couple of stages: I. Patch 1 adds the additional raw_cpu operations and raw_cpu_ptr(). Also converts the existing __this_cpu_xx_# primitive in the x86 code to raw_cpu_xx_#. II. Patch 2-4 use the raw_cpu operations in places that would give us false positives once they are enabled. III. Patch 5 adds preemption checks to __this_cpu operations to allow checking if preemption is properly disabled when these functions are used. IV. Patches 6-20 are patches that simply replace uses of __get_cpu_var with this_cpu_ptr. They do not depend on any changes to the percpu code. No preemption tests are skipped if they are applied. V. Patches 21-46 are conversion patches that use this_cpu operations in various kernel subsystems/drivers or arch code. VI. Patches 47/48 (not included in this series) remove no longer used functions (__this_cpu_ptr and __get_cpu_var). These should only be applied after all the conversion patches have made it and after we have done additional passes through the kernel to ensure that none of the uses of these functions remain. This patch (of 46): The patches following this one will add preemption checks to __this_cpu ops so we need to have an alternative way to use this_cpu operations without preemption checks. raw_cpu_ops will be the basis for all other ops since these will be the operations that do not implement any checks. Primitive operations are renamed by this patch from __this_cpu_xxx to raw_cpu_xxxx. Also change the uses of the x86 percpu primitives in preempt.h. These depend directly on asm/percpu.h (header #include nesting issue). Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Christoph Lameter <cl@linux.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Alex Shi <alex.shi@intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Bryan Wu <cooloney@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: David Daney <david.daney@cavium.com> Cc: David Miller <davem@davemloft.net> Cc: David S. Miller <davem@davemloft.net> Cc: Dimitri Sivanich <sivanich@sgi.com> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@linux.intel.com> Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no> Cc: Hedi Berriche <hedi@sgi.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: James Hogan <james.hogan@imgtec.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: John Stultz <john.stultz@linaro.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Mike Travis <travis@sgi.com> Cc: Neil Brown <neilb@suse.de> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Robert Richter <rric@kernel.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Wim Van Sebroeck <wim@iguana.be> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-08 06:39:34 +08:00
#define this_cpu_write_8(pcp, val) percpu_to_op("mov", (pcp), val)
#define this_cpu_add_8(pcp, val) percpu_add_op((pcp), val)
#define this_cpu_and_8(pcp, val) percpu_to_op("and", (pcp), val)
#define this_cpu_or_8(pcp, val) percpu_to_op("or", (pcp), val)
#define this_cpu_add_return_8(pcp, val) percpu_add_return_op(pcp, val)
#define this_cpu_xchg_8(pcp, nval) percpu_xchg_op(pcp, nval)
#define this_cpu_cmpxchg_8(pcp, oval, nval) percpu_cmpxchg_op(pcp, oval, nval)
/*
* Pretty complex macro to generate cmpxchg16 instruction. The instruction
* is not supported on early AMD64 processors so we must be able to emulate
* it in software. The address used in the cmpxchg16 instruction must be
* aligned to a 16 byte boundary.
*/
#define percpu_cmpxchg16b_double(pcp1, pcp2, o1, o2, n1, n2) \
({ \
bool __ret; \
typeof(pcp1) __o1 = (o1), __n1 = (n1); \
typeof(pcp2) __o2 = (o2), __n2 = (n2); \
alternative_io("leaq %P1,%%rsi\n\tcall this_cpu_cmpxchg16b_emu\n\t", \
"cmpxchg16b " __percpu_arg(1) "\n\tsetz %0\n\t", \
X86_FEATURE_CX16, \
ASM_OUTPUT2("=a" (__ret), "+m" (pcp1), \
"+m" (pcp2), "+d" (__o2)), \
"b" (__n1), "c" (__n2), "a" (__o1) : "rsi"); \
__ret; \
})
percpu: add raw_cpu_ops The kernel has never been audited to ensure that this_cpu operations are consistently used throughout the kernel. The code generated in many places can be improved through the use of this_cpu operations (which uses a segment register for relocation of per cpu offsets instead of performing address calculations). The patch set also addresses various consistency issues in general with the per cpu macros. A. The semantics of __this_cpu_ptr() differs from this_cpu_ptr only because checks are skipped. This is typically shown through a raw_ prefix. So this patch set changes the places where __this_cpu_ptr() is used to raw_cpu_ptr(). B. There has been the long term wish by some that __this_cpu operations would check for preemption. However, there are cases where preemption checks need to be skipped. This patch set adds raw_cpu operations that do not check for preemption and then adds preemption checks to the __this_cpu operations. C. The use of __get_cpu_var is always a reference to a percpu variable that can also be handled via a this_cpu operation. This patch set replaces all uses of __get_cpu_var with this_cpu operations. D. We can then use this_cpu RMW operations in various places replacing sequences of instructions by a single one. E. The use of this_cpu operations throughout will allow other arches than x86 to implement optimized references and RMV operations to work with per cpu local data. F. The use of this_cpu operations opens up the possibility to further optimize code that relies on synchronization through per cpu data. The patch set works in a couple of stages: I. Patch 1 adds the additional raw_cpu operations and raw_cpu_ptr(). Also converts the existing __this_cpu_xx_# primitive in the x86 code to raw_cpu_xx_#. II. Patch 2-4 use the raw_cpu operations in places that would give us false positives once they are enabled. III. Patch 5 adds preemption checks to __this_cpu operations to allow checking if preemption is properly disabled when these functions are used. IV. Patches 6-20 are patches that simply replace uses of __get_cpu_var with this_cpu_ptr. They do not depend on any changes to the percpu code. No preemption tests are skipped if they are applied. V. Patches 21-46 are conversion patches that use this_cpu operations in various kernel subsystems/drivers or arch code. VI. Patches 47/48 (not included in this series) remove no longer used functions (__this_cpu_ptr and __get_cpu_var). These should only be applied after all the conversion patches have made it and after we have done additional passes through the kernel to ensure that none of the uses of these functions remain. This patch (of 46): The patches following this one will add preemption checks to __this_cpu ops so we need to have an alternative way to use this_cpu operations without preemption checks. raw_cpu_ops will be the basis for all other ops since these will be the operations that do not implement any checks. Primitive operations are renamed by this patch from __this_cpu_xxx to raw_cpu_xxxx. Also change the uses of the x86 percpu primitives in preempt.h. These depend directly on asm/percpu.h (header #include nesting issue). Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Christoph Lameter <cl@linux.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Alex Shi <alex.shi@intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Bryan Wu <cooloney@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: David Daney <david.daney@cavium.com> Cc: David Miller <davem@davemloft.net> Cc: David S. Miller <davem@davemloft.net> Cc: Dimitri Sivanich <sivanich@sgi.com> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@linux.intel.com> Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no> Cc: Hedi Berriche <hedi@sgi.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: James Hogan <james.hogan@imgtec.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: John Stultz <john.stultz@linaro.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Mike Travis <travis@sgi.com> Cc: Neil Brown <neilb@suse.de> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Robert Richter <rric@kernel.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Wim Van Sebroeck <wim@iguana.be> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-08 06:39:34 +08:00
#define raw_cpu_cmpxchg_double_8 percpu_cmpxchg16b_double
#define this_cpu_cmpxchg_double_8 percpu_cmpxchg16b_double
#endif
static __always_inline bool x86_this_cpu_constant_test_bit(unsigned int nr,
const unsigned long __percpu *addr)
{
unsigned long __percpu *a =
(unsigned long __percpu *)addr + nr / BITS_PER_LONG;
#ifdef CONFIG_X86_64
percpu: add raw_cpu_ops The kernel has never been audited to ensure that this_cpu operations are consistently used throughout the kernel. The code generated in many places can be improved through the use of this_cpu operations (which uses a segment register for relocation of per cpu offsets instead of performing address calculations). The patch set also addresses various consistency issues in general with the per cpu macros. A. The semantics of __this_cpu_ptr() differs from this_cpu_ptr only because checks are skipped. This is typically shown through a raw_ prefix. So this patch set changes the places where __this_cpu_ptr() is used to raw_cpu_ptr(). B. There has been the long term wish by some that __this_cpu operations would check for preemption. However, there are cases where preemption checks need to be skipped. This patch set adds raw_cpu operations that do not check for preemption and then adds preemption checks to the __this_cpu operations. C. The use of __get_cpu_var is always a reference to a percpu variable that can also be handled via a this_cpu operation. This patch set replaces all uses of __get_cpu_var with this_cpu operations. D. We can then use this_cpu RMW operations in various places replacing sequences of instructions by a single one. E. The use of this_cpu operations throughout will allow other arches than x86 to implement optimized references and RMV operations to work with per cpu local data. F. The use of this_cpu operations opens up the possibility to further optimize code that relies on synchronization through per cpu data. The patch set works in a couple of stages: I. Patch 1 adds the additional raw_cpu operations and raw_cpu_ptr(). Also converts the existing __this_cpu_xx_# primitive in the x86 code to raw_cpu_xx_#. II. Patch 2-4 use the raw_cpu operations in places that would give us false positives once they are enabled. III. Patch 5 adds preemption checks to __this_cpu operations to allow checking if preemption is properly disabled when these functions are used. IV. Patches 6-20 are patches that simply replace uses of __get_cpu_var with this_cpu_ptr. They do not depend on any changes to the percpu code. No preemption tests are skipped if they are applied. V. Patches 21-46 are conversion patches that use this_cpu operations in various kernel subsystems/drivers or arch code. VI. Patches 47/48 (not included in this series) remove no longer used functions (__this_cpu_ptr and __get_cpu_var). These should only be applied after all the conversion patches have made it and after we have done additional passes through the kernel to ensure that none of the uses of these functions remain. This patch (of 46): The patches following this one will add preemption checks to __this_cpu ops so we need to have an alternative way to use this_cpu operations without preemption checks. raw_cpu_ops will be the basis for all other ops since these will be the operations that do not implement any checks. Primitive operations are renamed by this patch from __this_cpu_xxx to raw_cpu_xxxx. Also change the uses of the x86 percpu primitives in preempt.h. These depend directly on asm/percpu.h (header #include nesting issue). Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Christoph Lameter <cl@linux.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Alex Shi <alex.shi@intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Bryan Wu <cooloney@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: David Daney <david.daney@cavium.com> Cc: David Miller <davem@davemloft.net> Cc: David S. Miller <davem@davemloft.net> Cc: Dimitri Sivanich <sivanich@sgi.com> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@linux.intel.com> Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no> Cc: Hedi Berriche <hedi@sgi.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: James Hogan <james.hogan@imgtec.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: John Stultz <john.stultz@linaro.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Mike Travis <travis@sgi.com> Cc: Neil Brown <neilb@suse.de> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Robert Richter <rric@kernel.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Wim Van Sebroeck <wim@iguana.be> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-08 06:39:34 +08:00
return ((1UL << (nr % BITS_PER_LONG)) & raw_cpu_read_8(*a)) != 0;
#else
percpu: add raw_cpu_ops The kernel has never been audited to ensure that this_cpu operations are consistently used throughout the kernel. The code generated in many places can be improved through the use of this_cpu operations (which uses a segment register for relocation of per cpu offsets instead of performing address calculations). The patch set also addresses various consistency issues in general with the per cpu macros. A. The semantics of __this_cpu_ptr() differs from this_cpu_ptr only because checks are skipped. This is typically shown through a raw_ prefix. So this patch set changes the places where __this_cpu_ptr() is used to raw_cpu_ptr(). B. There has been the long term wish by some that __this_cpu operations would check for preemption. However, there are cases where preemption checks need to be skipped. This patch set adds raw_cpu operations that do not check for preemption and then adds preemption checks to the __this_cpu operations. C. The use of __get_cpu_var is always a reference to a percpu variable that can also be handled via a this_cpu operation. This patch set replaces all uses of __get_cpu_var with this_cpu operations. D. We can then use this_cpu RMW operations in various places replacing sequences of instructions by a single one. E. The use of this_cpu operations throughout will allow other arches than x86 to implement optimized references and RMV operations to work with per cpu local data. F. The use of this_cpu operations opens up the possibility to further optimize code that relies on synchronization through per cpu data. The patch set works in a couple of stages: I. Patch 1 adds the additional raw_cpu operations and raw_cpu_ptr(). Also converts the existing __this_cpu_xx_# primitive in the x86 code to raw_cpu_xx_#. II. Patch 2-4 use the raw_cpu operations in places that would give us false positives once they are enabled. III. Patch 5 adds preemption checks to __this_cpu operations to allow checking if preemption is properly disabled when these functions are used. IV. Patches 6-20 are patches that simply replace uses of __get_cpu_var with this_cpu_ptr. They do not depend on any changes to the percpu code. No preemption tests are skipped if they are applied. V. Patches 21-46 are conversion patches that use this_cpu operations in various kernel subsystems/drivers or arch code. VI. Patches 47/48 (not included in this series) remove no longer used functions (__this_cpu_ptr and __get_cpu_var). These should only be applied after all the conversion patches have made it and after we have done additional passes through the kernel to ensure that none of the uses of these functions remain. This patch (of 46): The patches following this one will add preemption checks to __this_cpu ops so we need to have an alternative way to use this_cpu operations without preemption checks. raw_cpu_ops will be the basis for all other ops since these will be the operations that do not implement any checks. Primitive operations are renamed by this patch from __this_cpu_xxx to raw_cpu_xxxx. Also change the uses of the x86 percpu primitives in preempt.h. These depend directly on asm/percpu.h (header #include nesting issue). Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Christoph Lameter <cl@linux.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Alex Shi <alex.shi@intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Bryan Wu <cooloney@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: David Daney <david.daney@cavium.com> Cc: David Miller <davem@davemloft.net> Cc: David S. Miller <davem@davemloft.net> Cc: Dimitri Sivanich <sivanich@sgi.com> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@linux.intel.com> Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no> Cc: Hedi Berriche <hedi@sgi.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: James Hogan <james.hogan@imgtec.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: John Stultz <john.stultz@linaro.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Mike Travis <travis@sgi.com> Cc: Neil Brown <neilb@suse.de> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Robert Richter <rric@kernel.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Wim Van Sebroeck <wim@iguana.be> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-08 06:39:34 +08:00
return ((1UL << (nr % BITS_PER_LONG)) & raw_cpu_read_4(*a)) != 0;
#endif
}
static inline bool x86_this_cpu_variable_test_bit(int nr,
const unsigned long __percpu *addr)
{
bool oldbit;
asm volatile("btl "__percpu_arg(2)",%1"
CC_SET(c)
: CC_OUT(c) (oldbit)
: "m" (*(unsigned long __percpu *)addr), "Ir" (nr));
return oldbit;
}
#define x86_this_cpu_test_bit(nr, addr) \
(__builtin_constant_p((nr)) \
? x86_this_cpu_constant_test_bit((nr), (addr)) \
: x86_this_cpu_variable_test_bit((nr), (addr)))
#include <asm-generic/percpu.h>
/* We can use this directly for local CPU (faster). */
DECLARE_PER_CPU_READ_MOSTLY(unsigned long, this_cpu_off);
#endif /* !__ASSEMBLY__ */
x86: cleanup early per cpu variables/accesses v4 * Introduce a new PER_CPU macro called "EARLY_PER_CPU". This is used by some per_cpu variables that are initialized and accessed before there are per_cpu areas allocated. ["Early" in respect to per_cpu variables is "earlier than the per_cpu areas have been setup".] This patchset adds these new macros: DEFINE_EARLY_PER_CPU(_type, _name, _initvalue) EXPORT_EARLY_PER_CPU_SYMBOL(_name) DECLARE_EARLY_PER_CPU(_type, _name) early_per_cpu_ptr(_name) early_per_cpu_map(_name, _idx) early_per_cpu(_name, _cpu) The DEFINE macro defines the per_cpu variable as well as the early map and pointer. It also initializes the per_cpu variable and map elements to "_initvalue". The early_* macros provide access to the initial map (usually setup during system init) and the early pointer. This pointer is initialized to point to the early map but is then NULL'ed when the actual per_cpu areas are setup. After that the per_cpu variable is the correct access to the variable. The early_per_cpu() macro is not very efficient but does show how to access the variable if you have a function that can be called both "early" and "late". It tests the early ptr to be NULL, and if not then it's still valid. Otherwise, the per_cpu variable is used instead: #define early_per_cpu(_name, _cpu) \ (early_per_cpu_ptr(_name) ? \ early_per_cpu_ptr(_name)[_cpu] : \ per_cpu(_name, _cpu)) A better method is to actually check the pointer manually. In the case below, numa_set_node can be called both "early" and "late": void __cpuinit numa_set_node(int cpu, int node) { int *cpu_to_node_map = early_per_cpu_ptr(x86_cpu_to_node_map); if (cpu_to_node_map) cpu_to_node_map[cpu] = node; else per_cpu(x86_cpu_to_node_map, cpu) = node; } * Add a flag "arch_provides_topology_pointers" that indicates pointers to topology cpumask_t maps are available. Otherwise, use the function returning the cpumask_t value. This is useful if cpumask_t set size is very large to avoid copying data on to/off of the stack. * The coverage of CONFIG_DEBUG_PER_CPU_MAPS has been increased while the non-debug case has been optimized a bit. * Remove an unreferenced compiler warning in drivers/base/topology.c * Clean up #ifdef in setup.c For inclusion into sched-devel/latest tree. Based on: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git + sched-devel/latest .../mingo/linux-2.6-sched-devel.git Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-13 03:21:12 +08:00
#ifdef CONFIG_SMP
/*
* Define the "EARLY_PER_CPU" macros. These are used for some per_cpu
* variables that are initialized and accessed before there are per_cpu
* areas allocated.
*/
#define DEFINE_EARLY_PER_CPU(_type, _name, _initvalue) \
DEFINE_PER_CPU(_type, _name) = _initvalue; \
__typeof__(_type) _name##_early_map[NR_CPUS] __initdata = \
{ [0 ... NR_CPUS-1] = _initvalue }; \
x86, percpu: silence section mismatch warnings related to EARLY_PER_CPU variables Quoting Mike Travis in "x86: cleanup early per cpu variables/accesses v4" (23ca4bba3e20c6c3cb11c1bb0ab4770b724d39ac): The DEFINE macro defines the per_cpu variable as well as the early map and pointer. It also initializes the per_cpu variable and map elements to "_initvalue". The early_* macros provide access to the initial map (usually setup during system init) and the early pointer. This pointer is initialized to point to the early map but is then NULL'ed when the actual per_cpu areas are setup. After that the per_cpu variable is the correct access to the variable. As these variables are NULL'ed before __init sections are dropped (in setup_per_cpu_maps), they can be safely annotated as __ref. This change silences following section mismatch warnings: WARNING: vmlinux.o(.data+0x46c0): Section mismatch in reference from the variable x86_cpu_to_apicid_early_ptr to the variable .init.data:x86_cpu_to_apicid_early_map The variable x86_cpu_to_apicid_early_ptr references the variable __initdata x86_cpu_to_apicid_early_map If the reference is valid then annotate the variable with __init* (see linux/init.h) or name the variable: *driver, *_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console, WARNING: vmlinux.o(.data+0x46c8): Section mismatch in reference from the variable x86_bios_cpu_apicid_early_ptr to the variable .init.data:x86_bios_cpu_apicid_early_map The variable x86_bios_cpu_apicid_early_ptr references the variable __initdata x86_bios_cpu_apicid_early_map If the reference is valid then annotate the variable with __init* (see linux/init.h) or name the variable: *driver, *_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console, WARNING: vmlinux.o(.data+0x46d0): Section mismatch in reference from the variable x86_cpu_to_node_map_early_ptr to the variable .init.data:x86_cpu_to_node_map_early_map The variable x86_cpu_to_node_map_early_ptr references the variable __initdata x86_cpu_to_node_map_early_map If the reference is valid then annotate the variable with __init* (see linux/init.h) or name the variable: *driver, *_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console, Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com> Cc: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-17 23:50:50 +08:00
__typeof__(_type) *_name##_early_ptr __refdata = _name##_early_map
x86: cleanup early per cpu variables/accesses v4 * Introduce a new PER_CPU macro called "EARLY_PER_CPU". This is used by some per_cpu variables that are initialized and accessed before there are per_cpu areas allocated. ["Early" in respect to per_cpu variables is "earlier than the per_cpu areas have been setup".] This patchset adds these new macros: DEFINE_EARLY_PER_CPU(_type, _name, _initvalue) EXPORT_EARLY_PER_CPU_SYMBOL(_name) DECLARE_EARLY_PER_CPU(_type, _name) early_per_cpu_ptr(_name) early_per_cpu_map(_name, _idx) early_per_cpu(_name, _cpu) The DEFINE macro defines the per_cpu variable as well as the early map and pointer. It also initializes the per_cpu variable and map elements to "_initvalue". The early_* macros provide access to the initial map (usually setup during system init) and the early pointer. This pointer is initialized to point to the early map but is then NULL'ed when the actual per_cpu areas are setup. After that the per_cpu variable is the correct access to the variable. The early_per_cpu() macro is not very efficient but does show how to access the variable if you have a function that can be called both "early" and "late". It tests the early ptr to be NULL, and if not then it's still valid. Otherwise, the per_cpu variable is used instead: #define early_per_cpu(_name, _cpu) \ (early_per_cpu_ptr(_name) ? \ early_per_cpu_ptr(_name)[_cpu] : \ per_cpu(_name, _cpu)) A better method is to actually check the pointer manually. In the case below, numa_set_node can be called both "early" and "late": void __cpuinit numa_set_node(int cpu, int node) { int *cpu_to_node_map = early_per_cpu_ptr(x86_cpu_to_node_map); if (cpu_to_node_map) cpu_to_node_map[cpu] = node; else per_cpu(x86_cpu_to_node_map, cpu) = node; } * Add a flag "arch_provides_topology_pointers" that indicates pointers to topology cpumask_t maps are available. Otherwise, use the function returning the cpumask_t value. This is useful if cpumask_t set size is very large to avoid copying data on to/off of the stack. * The coverage of CONFIG_DEBUG_PER_CPU_MAPS has been increased while the non-debug case has been optimized a bit. * Remove an unreferenced compiler warning in drivers/base/topology.c * Clean up #ifdef in setup.c For inclusion into sched-devel/latest tree. Based on: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git + sched-devel/latest .../mingo/linux-2.6-sched-devel.git Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-13 03:21:12 +08:00
#define DEFINE_EARLY_PER_CPU_READ_MOSTLY(_type, _name, _initvalue) \
DEFINE_PER_CPU_READ_MOSTLY(_type, _name) = _initvalue; \
__typeof__(_type) _name##_early_map[NR_CPUS] __initdata = \
{ [0 ... NR_CPUS-1] = _initvalue }; \
__typeof__(_type) *_name##_early_ptr __refdata = _name##_early_map
x86: cleanup early per cpu variables/accesses v4 * Introduce a new PER_CPU macro called "EARLY_PER_CPU". This is used by some per_cpu variables that are initialized and accessed before there are per_cpu areas allocated. ["Early" in respect to per_cpu variables is "earlier than the per_cpu areas have been setup".] This patchset adds these new macros: DEFINE_EARLY_PER_CPU(_type, _name, _initvalue) EXPORT_EARLY_PER_CPU_SYMBOL(_name) DECLARE_EARLY_PER_CPU(_type, _name) early_per_cpu_ptr(_name) early_per_cpu_map(_name, _idx) early_per_cpu(_name, _cpu) The DEFINE macro defines the per_cpu variable as well as the early map and pointer. It also initializes the per_cpu variable and map elements to "_initvalue". The early_* macros provide access to the initial map (usually setup during system init) and the early pointer. This pointer is initialized to point to the early map but is then NULL'ed when the actual per_cpu areas are setup. After that the per_cpu variable is the correct access to the variable. The early_per_cpu() macro is not very efficient but does show how to access the variable if you have a function that can be called both "early" and "late". It tests the early ptr to be NULL, and if not then it's still valid. Otherwise, the per_cpu variable is used instead: #define early_per_cpu(_name, _cpu) \ (early_per_cpu_ptr(_name) ? \ early_per_cpu_ptr(_name)[_cpu] : \ per_cpu(_name, _cpu)) A better method is to actually check the pointer manually. In the case below, numa_set_node can be called both "early" and "late": void __cpuinit numa_set_node(int cpu, int node) { int *cpu_to_node_map = early_per_cpu_ptr(x86_cpu_to_node_map); if (cpu_to_node_map) cpu_to_node_map[cpu] = node; else per_cpu(x86_cpu_to_node_map, cpu) = node; } * Add a flag "arch_provides_topology_pointers" that indicates pointers to topology cpumask_t maps are available. Otherwise, use the function returning the cpumask_t value. This is useful if cpumask_t set size is very large to avoid copying data on to/off of the stack. * The coverage of CONFIG_DEBUG_PER_CPU_MAPS has been increased while the non-debug case has been optimized a bit. * Remove an unreferenced compiler warning in drivers/base/topology.c * Clean up #ifdef in setup.c For inclusion into sched-devel/latest tree. Based on: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git + sched-devel/latest .../mingo/linux-2.6-sched-devel.git Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-13 03:21:12 +08:00
#define EXPORT_EARLY_PER_CPU_SYMBOL(_name) \
EXPORT_PER_CPU_SYMBOL(_name)
#define DECLARE_EARLY_PER_CPU(_type, _name) \
DECLARE_PER_CPU(_type, _name); \
extern __typeof__(_type) *_name##_early_ptr; \
extern __typeof__(_type) _name##_early_map[]
#define DECLARE_EARLY_PER_CPU_READ_MOSTLY(_type, _name) \
DECLARE_PER_CPU_READ_MOSTLY(_type, _name); \
extern __typeof__(_type) *_name##_early_ptr; \
extern __typeof__(_type) _name##_early_map[]
x86: cleanup early per cpu variables/accesses v4 * Introduce a new PER_CPU macro called "EARLY_PER_CPU". This is used by some per_cpu variables that are initialized and accessed before there are per_cpu areas allocated. ["Early" in respect to per_cpu variables is "earlier than the per_cpu areas have been setup".] This patchset adds these new macros: DEFINE_EARLY_PER_CPU(_type, _name, _initvalue) EXPORT_EARLY_PER_CPU_SYMBOL(_name) DECLARE_EARLY_PER_CPU(_type, _name) early_per_cpu_ptr(_name) early_per_cpu_map(_name, _idx) early_per_cpu(_name, _cpu) The DEFINE macro defines the per_cpu variable as well as the early map and pointer. It also initializes the per_cpu variable and map elements to "_initvalue". The early_* macros provide access to the initial map (usually setup during system init) and the early pointer. This pointer is initialized to point to the early map but is then NULL'ed when the actual per_cpu areas are setup. After that the per_cpu variable is the correct access to the variable. The early_per_cpu() macro is not very efficient but does show how to access the variable if you have a function that can be called both "early" and "late". It tests the early ptr to be NULL, and if not then it's still valid. Otherwise, the per_cpu variable is used instead: #define early_per_cpu(_name, _cpu) \ (early_per_cpu_ptr(_name) ? \ early_per_cpu_ptr(_name)[_cpu] : \ per_cpu(_name, _cpu)) A better method is to actually check the pointer manually. In the case below, numa_set_node can be called both "early" and "late": void __cpuinit numa_set_node(int cpu, int node) { int *cpu_to_node_map = early_per_cpu_ptr(x86_cpu_to_node_map); if (cpu_to_node_map) cpu_to_node_map[cpu] = node; else per_cpu(x86_cpu_to_node_map, cpu) = node; } * Add a flag "arch_provides_topology_pointers" that indicates pointers to topology cpumask_t maps are available. Otherwise, use the function returning the cpumask_t value. This is useful if cpumask_t set size is very large to avoid copying data on to/off of the stack. * The coverage of CONFIG_DEBUG_PER_CPU_MAPS has been increased while the non-debug case has been optimized a bit. * Remove an unreferenced compiler warning in drivers/base/topology.c * Clean up #ifdef in setup.c For inclusion into sched-devel/latest tree. Based on: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git + sched-devel/latest .../mingo/linux-2.6-sched-devel.git Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-13 03:21:12 +08:00
#define early_per_cpu_ptr(_name) (_name##_early_ptr)
#define early_per_cpu_map(_name, _idx) (_name##_early_map[_idx])
#define early_per_cpu(_name, _cpu) \
*(early_per_cpu_ptr(_name) ? \
&early_per_cpu_ptr(_name)[_cpu] : \
&per_cpu(_name, _cpu))
x86: cleanup early per cpu variables/accesses v4 * Introduce a new PER_CPU macro called "EARLY_PER_CPU". This is used by some per_cpu variables that are initialized and accessed before there are per_cpu areas allocated. ["Early" in respect to per_cpu variables is "earlier than the per_cpu areas have been setup".] This patchset adds these new macros: DEFINE_EARLY_PER_CPU(_type, _name, _initvalue) EXPORT_EARLY_PER_CPU_SYMBOL(_name) DECLARE_EARLY_PER_CPU(_type, _name) early_per_cpu_ptr(_name) early_per_cpu_map(_name, _idx) early_per_cpu(_name, _cpu) The DEFINE macro defines the per_cpu variable as well as the early map and pointer. It also initializes the per_cpu variable and map elements to "_initvalue". The early_* macros provide access to the initial map (usually setup during system init) and the early pointer. This pointer is initialized to point to the early map but is then NULL'ed when the actual per_cpu areas are setup. After that the per_cpu variable is the correct access to the variable. The early_per_cpu() macro is not very efficient but does show how to access the variable if you have a function that can be called both "early" and "late". It tests the early ptr to be NULL, and if not then it's still valid. Otherwise, the per_cpu variable is used instead: #define early_per_cpu(_name, _cpu) \ (early_per_cpu_ptr(_name) ? \ early_per_cpu_ptr(_name)[_cpu] : \ per_cpu(_name, _cpu)) A better method is to actually check the pointer manually. In the case below, numa_set_node can be called both "early" and "late": void __cpuinit numa_set_node(int cpu, int node) { int *cpu_to_node_map = early_per_cpu_ptr(x86_cpu_to_node_map); if (cpu_to_node_map) cpu_to_node_map[cpu] = node; else per_cpu(x86_cpu_to_node_map, cpu) = node; } * Add a flag "arch_provides_topology_pointers" that indicates pointers to topology cpumask_t maps are available. Otherwise, use the function returning the cpumask_t value. This is useful if cpumask_t set size is very large to avoid copying data on to/off of the stack. * The coverage of CONFIG_DEBUG_PER_CPU_MAPS has been increased while the non-debug case has been optimized a bit. * Remove an unreferenced compiler warning in drivers/base/topology.c * Clean up #ifdef in setup.c For inclusion into sched-devel/latest tree. Based on: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git + sched-devel/latest .../mingo/linux-2.6-sched-devel.git Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-13 03:21:12 +08:00
#else /* !CONFIG_SMP */
#define DEFINE_EARLY_PER_CPU(_type, _name, _initvalue) \
DEFINE_PER_CPU(_type, _name) = _initvalue
#define DEFINE_EARLY_PER_CPU_READ_MOSTLY(_type, _name, _initvalue) \
DEFINE_PER_CPU_READ_MOSTLY(_type, _name) = _initvalue
x86: cleanup early per cpu variables/accesses v4 * Introduce a new PER_CPU macro called "EARLY_PER_CPU". This is used by some per_cpu variables that are initialized and accessed before there are per_cpu areas allocated. ["Early" in respect to per_cpu variables is "earlier than the per_cpu areas have been setup".] This patchset adds these new macros: DEFINE_EARLY_PER_CPU(_type, _name, _initvalue) EXPORT_EARLY_PER_CPU_SYMBOL(_name) DECLARE_EARLY_PER_CPU(_type, _name) early_per_cpu_ptr(_name) early_per_cpu_map(_name, _idx) early_per_cpu(_name, _cpu) The DEFINE macro defines the per_cpu variable as well as the early map and pointer. It also initializes the per_cpu variable and map elements to "_initvalue". The early_* macros provide access to the initial map (usually setup during system init) and the early pointer. This pointer is initialized to point to the early map but is then NULL'ed when the actual per_cpu areas are setup. After that the per_cpu variable is the correct access to the variable. The early_per_cpu() macro is not very efficient but does show how to access the variable if you have a function that can be called both "early" and "late". It tests the early ptr to be NULL, and if not then it's still valid. Otherwise, the per_cpu variable is used instead: #define early_per_cpu(_name, _cpu) \ (early_per_cpu_ptr(_name) ? \ early_per_cpu_ptr(_name)[_cpu] : \ per_cpu(_name, _cpu)) A better method is to actually check the pointer manually. In the case below, numa_set_node can be called both "early" and "late": void __cpuinit numa_set_node(int cpu, int node) { int *cpu_to_node_map = early_per_cpu_ptr(x86_cpu_to_node_map); if (cpu_to_node_map) cpu_to_node_map[cpu] = node; else per_cpu(x86_cpu_to_node_map, cpu) = node; } * Add a flag "arch_provides_topology_pointers" that indicates pointers to topology cpumask_t maps are available. Otherwise, use the function returning the cpumask_t value. This is useful if cpumask_t set size is very large to avoid copying data on to/off of the stack. * The coverage of CONFIG_DEBUG_PER_CPU_MAPS has been increased while the non-debug case has been optimized a bit. * Remove an unreferenced compiler warning in drivers/base/topology.c * Clean up #ifdef in setup.c For inclusion into sched-devel/latest tree. Based on: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git + sched-devel/latest .../mingo/linux-2.6-sched-devel.git Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-13 03:21:12 +08:00
#define EXPORT_EARLY_PER_CPU_SYMBOL(_name) \
EXPORT_PER_CPU_SYMBOL(_name)
#define DECLARE_EARLY_PER_CPU(_type, _name) \
DECLARE_PER_CPU(_type, _name)
#define DECLARE_EARLY_PER_CPU_READ_MOSTLY(_type, _name) \
DECLARE_PER_CPU_READ_MOSTLY(_type, _name)
x86: cleanup early per cpu variables/accesses v4 * Introduce a new PER_CPU macro called "EARLY_PER_CPU". This is used by some per_cpu variables that are initialized and accessed before there are per_cpu areas allocated. ["Early" in respect to per_cpu variables is "earlier than the per_cpu areas have been setup".] This patchset adds these new macros: DEFINE_EARLY_PER_CPU(_type, _name, _initvalue) EXPORT_EARLY_PER_CPU_SYMBOL(_name) DECLARE_EARLY_PER_CPU(_type, _name) early_per_cpu_ptr(_name) early_per_cpu_map(_name, _idx) early_per_cpu(_name, _cpu) The DEFINE macro defines the per_cpu variable as well as the early map and pointer. It also initializes the per_cpu variable and map elements to "_initvalue". The early_* macros provide access to the initial map (usually setup during system init) and the early pointer. This pointer is initialized to point to the early map but is then NULL'ed when the actual per_cpu areas are setup. After that the per_cpu variable is the correct access to the variable. The early_per_cpu() macro is not very efficient but does show how to access the variable if you have a function that can be called both "early" and "late". It tests the early ptr to be NULL, and if not then it's still valid. Otherwise, the per_cpu variable is used instead: #define early_per_cpu(_name, _cpu) \ (early_per_cpu_ptr(_name) ? \ early_per_cpu_ptr(_name)[_cpu] : \ per_cpu(_name, _cpu)) A better method is to actually check the pointer manually. In the case below, numa_set_node can be called both "early" and "late": void __cpuinit numa_set_node(int cpu, int node) { int *cpu_to_node_map = early_per_cpu_ptr(x86_cpu_to_node_map); if (cpu_to_node_map) cpu_to_node_map[cpu] = node; else per_cpu(x86_cpu_to_node_map, cpu) = node; } * Add a flag "arch_provides_topology_pointers" that indicates pointers to topology cpumask_t maps are available. Otherwise, use the function returning the cpumask_t value. This is useful if cpumask_t set size is very large to avoid copying data on to/off of the stack. * The coverage of CONFIG_DEBUG_PER_CPU_MAPS has been increased while the non-debug case has been optimized a bit. * Remove an unreferenced compiler warning in drivers/base/topology.c * Clean up #ifdef in setup.c For inclusion into sched-devel/latest tree. Based on: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git + sched-devel/latest .../mingo/linux-2.6-sched-devel.git Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-13 03:21:12 +08:00
#define early_per_cpu(_name, _cpu) per_cpu(_name, _cpu)
#define early_per_cpu_ptr(_name) NULL
/* no early_per_cpu_map() */
#endif /* !CONFIG_SMP */
#endif /* _ASM_X86_PERCPU_H */