mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-18 17:54:13 +08:00
5917dae83c
Optimize code generated for percpu access by checking for increment and
decrements.
tj: fix incorrect usage of __builtin_constant_p() and restructure
percpu_add_op() macro.
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
352 lines
12 KiB
C
352 lines
12 KiB
C
#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_arg(x) "%%"__stringify(__percpu_seg)":%P" #x
|
|
#define __my_cpu_offset percpu_read(this_cpu_off)
|
|
#else
|
|
#define __percpu_arg(x) "%P" #x
|
|
#endif
|
|
|
|
/*
|
|
* 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); \
|
|
} \
|
|
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 a 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) && \
|
|
((val) == 1 || (val) == -1)) ? (val) : 0; \
|
|
if (0) { \
|
|
pao_T__ pao_tmp__; \
|
|
pao_tmp__ = (val); \
|
|
} \
|
|
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, constraint) \
|
|
({ \
|
|
typeof(var) pfo_ret__; \
|
|
switch (sizeof(var)) { \
|
|
case 1: \
|
|
asm(op "b "__percpu_arg(1)",%0" \
|
|
: "=q" (pfo_ret__) \
|
|
: constraint); \
|
|
break; \
|
|
case 2: \
|
|
asm(op "w "__percpu_arg(1)",%0" \
|
|
: "=r" (pfo_ret__) \
|
|
: constraint); \
|
|
break; \
|
|
case 4: \
|
|
asm(op "l "__percpu_arg(1)",%0" \
|
|
: "=r" (pfo_ret__) \
|
|
: constraint); \
|
|
break; \
|
|
case 8: \
|
|
asm(op "q "__percpu_arg(1)",%0" \
|
|
: "=r" (pfo_ret__) \
|
|
: constraint); \
|
|
break; \
|
|
default: __bad_percpu_size(); \
|
|
} \
|
|
pfo_ret__; \
|
|
})
|
|
|
|
/*
|
|
* percpu_read() makes gcc load the percpu variable every time it is
|
|
* accessed while percpu_read_stable() allows the value to be cached.
|
|
* percpu_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 percpu_read(var) percpu_from_op("mov", var, "m" (var))
|
|
#define percpu_read_stable(var) percpu_from_op("mov", var, "p" (&(var)))
|
|
#define percpu_write(var, val) percpu_to_op("mov", var, val)
|
|
#define percpu_add(var, val) percpu_add_op(var, val)
|
|
#define percpu_sub(var, val) percpu_add_op(var, -(val))
|
|
#define percpu_and(var, val) percpu_to_op("and", var, val)
|
|
#define percpu_or(var, val) percpu_to_op("or", var, val)
|
|
#define percpu_xor(var, val) percpu_to_op("xor", var, val)
|
|
|
|
#define __this_cpu_read_1(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
|
|
#define __this_cpu_read_2(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
|
|
#define __this_cpu_read_4(pcp) percpu_from_op("mov", (pcp), "m"(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_xor_1(pcp, val) percpu_to_op("xor", (pcp), val)
|
|
#define __this_cpu_xor_2(pcp, val) percpu_to_op("xor", (pcp), val)
|
|
#define __this_cpu_xor_4(pcp, val) percpu_to_op("xor", (pcp), val)
|
|
|
|
#define this_cpu_read_1(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
|
|
#define this_cpu_read_2(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
|
|
#define this_cpu_read_4(pcp) percpu_from_op("mov", (pcp), "m"(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_xor_1(pcp, val) percpu_to_op("xor", (pcp), val)
|
|
#define this_cpu_xor_2(pcp, val) percpu_to_op("xor", (pcp), val)
|
|
#define this_cpu_xor_4(pcp, val) percpu_to_op("xor", (pcp), val)
|
|
|
|
#define irqsafe_cpu_add_1(pcp, val) percpu_add_op((pcp), val)
|
|
#define irqsafe_cpu_add_2(pcp, val) percpu_add_op((pcp), val)
|
|
#define irqsafe_cpu_add_4(pcp, val) percpu_add_op((pcp), val)
|
|
#define irqsafe_cpu_and_1(pcp, val) percpu_to_op("and", (pcp), val)
|
|
#define irqsafe_cpu_and_2(pcp, val) percpu_to_op("and", (pcp), val)
|
|
#define irqsafe_cpu_and_4(pcp, val) percpu_to_op("and", (pcp), val)
|
|
#define irqsafe_cpu_or_1(pcp, val) percpu_to_op("or", (pcp), val)
|
|
#define irqsafe_cpu_or_2(pcp, val) percpu_to_op("or", (pcp), val)
|
|
#define irqsafe_cpu_or_4(pcp, val) percpu_to_op("or", (pcp), val)
|
|
#define irqsafe_cpu_xor_1(pcp, val) percpu_to_op("xor", (pcp), val)
|
|
#define irqsafe_cpu_xor_2(pcp, val) percpu_to_op("xor", (pcp), val)
|
|
#define irqsafe_cpu_xor_4(pcp, val) percpu_to_op("xor", (pcp), val)
|
|
|
|
/*
|
|
* 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 __this_cpu_read_8(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
|
|
#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_xor_8(pcp, val) percpu_to_op("xor", (pcp), val)
|
|
|
|
#define this_cpu_read_8(pcp) percpu_from_op("mov", (pcp), "m"(pcp))
|
|
#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_xor_8(pcp, val) percpu_to_op("xor", (pcp), val)
|
|
|
|
#define irqsafe_cpu_add_8(pcp, val) percpu_add_op((pcp), val)
|
|
#define irqsafe_cpu_and_8(pcp, val) percpu_to_op("and", (pcp), val)
|
|
#define irqsafe_cpu_or_8(pcp, val) percpu_to_op("or", (pcp), val)
|
|
#define irqsafe_cpu_xor_8(pcp, val) percpu_to_op("xor", (pcp), val)
|
|
|
|
#endif
|
|
|
|
/* This is not atomic against other CPUs -- CPU preemption needs to be off */
|
|
#define x86_test_and_clear_bit_percpu(bit, var) \
|
|
({ \
|
|
int old__; \
|
|
asm volatile("btr %2,"__percpu_arg(1)"\n\tsbbl %0,%0" \
|
|
: "=r" (old__), "+m" (var) \
|
|
: "dIr" (bit)); \
|
|
old__; \
|
|
})
|
|
|
|
#include <asm-generic/percpu.h>
|
|
|
|
/* We can use this directly for local CPU (faster). */
|
|
DECLARE_PER_CPU(unsigned long, this_cpu_off);
|
|
|
|
#endif /* !__ASSEMBLY__ */
|
|
|
|
#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 }; \
|
|
__typeof__(_type) *_name##_early_ptr __refdata = _name##_early_map
|
|
|
|
#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 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))
|
|
|
|
#else /* !CONFIG_SMP */
|
|
#define DEFINE_EARLY_PER_CPU(_type, _name, _initvalue) \
|
|
DEFINE_PER_CPU(_type, _name) = _initvalue
|
|
|
|
#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 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 */
|