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linux/arch/powerpc/kernel/misc.S

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treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-27 14:55:01 +08:00
/* SPDX-License-Identifier: GPL-2.0-or-later */
[POWERPC] Consolidate some of kernel/misc*.S There were some common functions (mainly i/o). Also some small white space cleanups and remove a couple of small unused functions. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-06-28 09:55:49 +08:00
/*
* This file contains miscellaneous low-level functions.
* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
*
* Largely rewritten by Cort Dougan (cort@cs.nmt.edu)
* and Paul Mackerras.
*
* PPC64 updates by Dave Engebretsen (engebret@us.ibm.com)
*
[POWERPC] Make setjmp/longjmp code usable outside of xmon This makes the setjmp/longjmp code used by xmon, generically available to other code. It also removes the requirement for debugger hooks to be only called on 0x300 (data storage) exception. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-01-18 12:50:30 +08:00
* setjmp/longjmp code by Paul Mackerras.
[POWERPC] Consolidate some of kernel/misc*.S There were some common functions (mainly i/o). Also some small white space cleanups and remove a couple of small unused functions. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-06-28 09:55:49 +08:00
*/
#include <asm/ppc_asm.h>
[POWERPC] kernel_execve is identical in 32 and 64 bit so consolidate it into misc.S. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-11-28 08:13:02 +08:00
#include <asm/unistd.h>
[POWERPC] Make setjmp/longjmp code usable outside of xmon This makes the setjmp/longjmp code used by xmon, generically available to other code. It also removes the requirement for debugger hooks to be only called on 0x300 (data storage) exception. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-01-18 12:50:30 +08:00
#include <asm/asm-compat.h>
#include <asm/asm-offsets.h>
ppc: move exports to definitions Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-14 12:33:46 +08:00
#include <asm/export.h>
[POWERPC] Consolidate some of kernel/misc*.S There were some common functions (mainly i/o). Also some small white space cleanups and remove a couple of small unused functions. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-06-28 09:55:49 +08:00
.text
/*
* Returns (address we are running at) - (address we were linked at)
* for use before the text and data are mapped to KERNELBASE.
* add_reloc_offset(x) returns x + reloc_offset().
*/
powerpc/misc: merge reloc_offset() and add_reloc_offset() reloc_offset() is the same as add_reloc_offset(0) Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-04-17 19:23:10 +08:00
_GLOBAL(reloc_offset)
li r3, 0
[POWERPC] Consolidate some of kernel/misc*.S There were some common functions (mainly i/o). Also some small white space cleanups and remove a couple of small unused functions. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-06-28 09:55:49 +08:00
_GLOBAL(add_reloc_offset)
mflr r0
bl 1f
1: mflr r5
powerpc: Use LOAD_REG_IMMEDIATE only for constants on 64-bit Using LOAD_REG_IMMEDIATE to get the address of kernel symbols generates 5 instructions where LOAD_REG_ADDR can do it in one, and will generate R_PPC64_ADDR16_* relocations in the output when we get to making the kernel as a position-independent executable, which we'd rather not have to handle. This changes various bits of assembly code to use LOAD_REG_ADDR when we need to get the address of a symbol, or to use suitable position-independent code for cases where we can't access the TOC for various reasons, or if we're not running at the address we were linked at. It also cleans up a few minor things; there's no reason to save and restore SRR0/1 around RTAS calls, __mmu_off can get the return address from LR more conveniently than the caller can supply it in R4 (and we already assume elsewhere that EA == RA if the MMU is on in early boot), and enable_64b_mode was using 5 instructions where 2 would do. Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-08-30 09:41:12 +08:00
PPC_LL r4,(2f-1b)(r5)
[POWERPC] Consolidate some of kernel/misc*.S There were some common functions (mainly i/o). Also some small white space cleanups and remove a couple of small unused functions. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-06-28 09:55:49 +08:00
subf r5,r4,r5
add r3,r3,r5
mtlr r0
blr
powerpc/32: Blacklist functions running with MMU disabled for kprobe kprobe does not handle events happening in real mode, all functions running with MMU disabled have to be blacklisted. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/3bf57066d05518644dee0840af69d36ab5086729.1585670437.git.christophe.leroy@c-s.fr
2020-04-01 00:03:44 +08:00
_ASM_NOKPROBE_SYMBOL(reloc_offset)
_ASM_NOKPROBE_SYMBOL(add_reloc_offset)
[POWERPC] kernel_execve is identical in 32 and 64 bit so consolidate it into misc.S. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-11-28 08:13:02 +08:00
powerpc: Use LOAD_REG_IMMEDIATE only for constants on 64-bit Using LOAD_REG_IMMEDIATE to get the address of kernel symbols generates 5 instructions where LOAD_REG_ADDR can do it in one, and will generate R_PPC64_ADDR16_* relocations in the output when we get to making the kernel as a position-independent executable, which we'd rather not have to handle. This changes various bits of assembly code to use LOAD_REG_ADDR when we need to get the address of a symbol, or to use suitable position-independent code for cases where we can't access the TOC for various reasons, or if we're not running at the address we were linked at. It also cleans up a few minor things; there's no reason to save and restore SRR0/1 around RTAS calls, __mmu_off can get the return address from LR more conveniently than the caller can supply it in R4 (and we already assume elsewhere that EA == RA if the MMU is on in early boot), and enable_64b_mode was using 5 instructions where 2 would do. Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-08-30 09:41:12 +08:00
.align 3
2: PPC_LONG 1b
[POWERPC] Make setjmp/longjmp code usable outside of xmon This makes the setjmp/longjmp code used by xmon, generically available to other code. It also removes the requirement for debugger hooks to be only called on 0x300 (data storage) exception. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-01-18 12:50:30 +08:00
_GLOBAL(setjmp)
mflr r0
PPC_STL r0,0(r3)
PPC_STL r1,SZL(r3)
PPC_STL r2,2*SZL(r3)
powerpc/32: Use stmw/lmw for registers save/restore in asm arch/powerpc/Makefile activates -mmultiple on BE PPC32 configs in order to use multiple word instructions in functions entry/exit. The patch does the same for the asm parts, for consistency. On processors like the 8xx on which insn fetching is pretty slow, this speeds up registers save/restore. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> [mpe: PPC32 is BE only, so drop the endian checks] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-04-18 01:08:18 +08:00
#ifdef CONFIG_PPC32
mfcr r12
stmw r12, 3*SZL(r3)
#else
[POWERPC] Make setjmp/longjmp code usable outside of xmon This makes the setjmp/longjmp code used by xmon, generically available to other code. It also removes the requirement for debugger hooks to be only called on 0x300 (data storage) exception. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-01-18 12:50:30 +08:00
mfcr r0
PPC_STL r0,3*SZL(r3)
PPC_STL r13,4*SZL(r3)
PPC_STL r14,5*SZL(r3)
PPC_STL r15,6*SZL(r3)
PPC_STL r16,7*SZL(r3)
PPC_STL r17,8*SZL(r3)
PPC_STL r18,9*SZL(r3)
PPC_STL r19,10*SZL(r3)
PPC_STL r20,11*SZL(r3)
PPC_STL r21,12*SZL(r3)
PPC_STL r22,13*SZL(r3)
PPC_STL r23,14*SZL(r3)
PPC_STL r24,15*SZL(r3)
PPC_STL r25,16*SZL(r3)
PPC_STL r26,17*SZL(r3)
PPC_STL r27,18*SZL(r3)
PPC_STL r28,19*SZL(r3)
PPC_STL r29,20*SZL(r3)
PPC_STL r30,21*SZL(r3)
PPC_STL r31,22*SZL(r3)
powerpc/32: Use stmw/lmw for registers save/restore in asm arch/powerpc/Makefile activates -mmultiple on BE PPC32 configs in order to use multiple word instructions in functions entry/exit. The patch does the same for the asm parts, for consistency. On processors like the 8xx on which insn fetching is pretty slow, this speeds up registers save/restore. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> [mpe: PPC32 is BE only, so drop the endian checks] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-04-18 01:08:18 +08:00
#endif
[POWERPC] Make setjmp/longjmp code usable outside of xmon This makes the setjmp/longjmp code used by xmon, generically available to other code. It also removes the requirement for debugger hooks to be only called on 0x300 (data storage) exception. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-01-18 12:50:30 +08:00
li r3,0
blr
_GLOBAL(longjmp)
powerpc/32: Use stmw/lmw for registers save/restore in asm arch/powerpc/Makefile activates -mmultiple on BE PPC32 configs in order to use multiple word instructions in functions entry/exit. The patch does the same for the asm parts, for consistency. On processors like the 8xx on which insn fetching is pretty slow, this speeds up registers save/restore. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> [mpe: PPC32 is BE only, so drop the endian checks] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-04-18 01:08:18 +08:00
#ifdef CONFIG_PPC32
lmw r12, 3*SZL(r3)
mtcrf 0x38, r12
#else
powerpc: Avoid an unnecessary test and branch in longjmp() Doing the test at exit of the function avoids an unnecessary test and branch inside longjmp(). Semantics are unchanged. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Reviewed-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-04-18 01:08:16 +08:00
PPC_LL r13,4*SZL(r3)
[POWERPC] Make setjmp/longjmp code usable outside of xmon This makes the setjmp/longjmp code used by xmon, generically available to other code. It also removes the requirement for debugger hooks to be only called on 0x300 (data storage) exception. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-01-18 12:50:30 +08:00
PPC_LL r14,5*SZL(r3)
PPC_LL r15,6*SZL(r3)
PPC_LL r16,7*SZL(r3)
PPC_LL r17,8*SZL(r3)
PPC_LL r18,9*SZL(r3)
PPC_LL r19,10*SZL(r3)
PPC_LL r20,11*SZL(r3)
PPC_LL r21,12*SZL(r3)
PPC_LL r22,13*SZL(r3)
PPC_LL r23,14*SZL(r3)
PPC_LL r24,15*SZL(r3)
PPC_LL r25,16*SZL(r3)
PPC_LL r26,17*SZL(r3)
PPC_LL r27,18*SZL(r3)
PPC_LL r28,19*SZL(r3)
PPC_LL r29,20*SZL(r3)
PPC_LL r30,21*SZL(r3)
PPC_LL r31,22*SZL(r3)
PPC_LL r0,3*SZL(r3)
mtcrf 0x38,r0
powerpc/32: Use stmw/lmw for registers save/restore in asm arch/powerpc/Makefile activates -mmultiple on BE PPC32 configs in order to use multiple word instructions in functions entry/exit. The patch does the same for the asm parts, for consistency. On processors like the 8xx on which insn fetching is pretty slow, this speeds up registers save/restore. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> [mpe: PPC32 is BE only, so drop the endian checks] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-04-18 01:08:18 +08:00
#endif
[POWERPC] Make setjmp/longjmp code usable outside of xmon This makes the setjmp/longjmp code used by xmon, generically available to other code. It also removes the requirement for debugger hooks to be only called on 0x300 (data storage) exception. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-01-18 12:50:30 +08:00
PPC_LL r0,0(r3)
PPC_LL r1,SZL(r3)
PPC_LL r2,2*SZL(r3)
mtlr r0
powerpc: Avoid an unnecessary test and branch in longjmp() Doing the test at exit of the function avoids an unnecessary test and branch inside longjmp(). Semantics are unchanged. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Reviewed-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-04-18 01:08:16 +08:00
mr. r3, r4
bnelr
li r3, 1
[POWERPC] Make setjmp/longjmp code usable outside of xmon This makes the setjmp/longjmp code used by xmon, generically available to other code. It also removes the requirement for debugger hooks to be only called on 0x300 (data storage) exception. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-01-18 12:50:30 +08:00
blr
powerpc: Reimplement __get_SP() as a function not a define Li Zhong points out an issue with our current __get_SP() implementation. If ftrace function tracing is enabled (ie -pg profiling using _mcount) we spill a stack frame on 64bit all the time. If a function calls __get_SP() and later calls a function that is tail call optimised, we will pop the stack frame and the value returned by __get_SP() is no longer valid. An example from Li can be found in save_stack_trace -> save_context_stack: c0000000000432c0 <.save_stack_trace>: c0000000000432c0: mflr r0 c0000000000432c4: std r0,16(r1) c0000000000432c8: stdu r1,-128(r1) <-- stack frame for _mcount c0000000000432cc: std r3,112(r1) c0000000000432d0: bl <._mcount> c0000000000432d4: nop c0000000000432d8: mr r4,r1 <-- __get_SP() c0000000000432dc: ld r5,632(r13) c0000000000432e0: ld r3,112(r1) c0000000000432e4: li r6,1 c0000000000432e8: addi r1,r1,128 <-- pop stack frame c0000000000432ec: ld r0,16(r1) c0000000000432f0: mtlr r0 c0000000000432f4: b <.save_context_stack> <-- tail call optimized save_context_stack ends up with a stack pointer below the current one, and it is likely to be scribbled over. Fix this by making __get_SP() a function which returns the callers stack frame. Also replace inline assembly which grabs the stack pointer in save_stack_trace and show_stack with __get_SP(). This also fixes an issue with perf_arch_fetch_caller_regs(). It currently unwinds the stack once, which will skip a valid stack frame on a leaf function. With the __get_SP() fixes in this patch, we never need to unwind the stack frame to get to the first interesting frame. We have to export __get_SP() because perf_arch_fetch_caller_regs() (which is used in modules) calls it from a header file. Reported-by: Li Zhong <zhong@linux.vnet.ibm.com> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-10-13 16:41:38 +08:00
powerpc: Rename current_stack_pointer() to current_stack_frame() current_stack_pointer(), which was called __get_SP(), used to just return the value in r1. But that caused problems in some cases, so it was turned into a function in commit bfe9a2cfe91a ("powerpc: Reimplement __get_SP() as a function not a define"). Because it's a function in a separate compilation unit to all its callers, it has the effect of causing a stack frame to be created, and then returns the address of that frame. This is good in some cases like those described in the above commit, but in other cases it's overkill, we just need to know what stack page we're on. On some other arches current_stack_pointer is just a register global giving the stack pointer, and we'd like to do that too. So rename our current_stack_pointer() to current_stack_frame() to make that possible. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr> Link: https://lore.kernel.org/r/20200220115141.2707-1-mpe@ellerman.id.au
2020-02-20 19:51:37 +08:00
_GLOBAL(current_stack_frame)
powerpc: Reimplement __get_SP() as a function not a define Li Zhong points out an issue with our current __get_SP() implementation. If ftrace function tracing is enabled (ie -pg profiling using _mcount) we spill a stack frame on 64bit all the time. If a function calls __get_SP() and later calls a function that is tail call optimised, we will pop the stack frame and the value returned by __get_SP() is no longer valid. An example from Li can be found in save_stack_trace -> save_context_stack: c0000000000432c0 <.save_stack_trace>: c0000000000432c0: mflr r0 c0000000000432c4: std r0,16(r1) c0000000000432c8: stdu r1,-128(r1) <-- stack frame for _mcount c0000000000432cc: std r3,112(r1) c0000000000432d0: bl <._mcount> c0000000000432d4: nop c0000000000432d8: mr r4,r1 <-- __get_SP() c0000000000432dc: ld r5,632(r13) c0000000000432e0: ld r3,112(r1) c0000000000432e4: li r6,1 c0000000000432e8: addi r1,r1,128 <-- pop stack frame c0000000000432ec: ld r0,16(r1) c0000000000432f0: mtlr r0 c0000000000432f4: b <.save_context_stack> <-- tail call optimized save_context_stack ends up with a stack pointer below the current one, and it is likely to be scribbled over. Fix this by making __get_SP() a function which returns the callers stack frame. Also replace inline assembly which grabs the stack pointer in save_stack_trace and show_stack with __get_SP(). This also fixes an issue with perf_arch_fetch_caller_regs(). It currently unwinds the stack once, which will skip a valid stack frame on a leaf function. With the __get_SP() fixes in this patch, we never need to unwind the stack frame to get to the first interesting frame. We have to export __get_SP() because perf_arch_fetch_caller_regs() (which is used in modules) calls it from a header file. Reported-by: Li Zhong <zhong@linux.vnet.ibm.com> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-10-13 16:41:38 +08:00
PPC_LL r3,0(r1)
blr
powerpc: Rename current_stack_pointer() to current_stack_frame() current_stack_pointer(), which was called __get_SP(), used to just return the value in r1. But that caused problems in some cases, so it was turned into a function in commit bfe9a2cfe91a ("powerpc: Reimplement __get_SP() as a function not a define"). Because it's a function in a separate compilation unit to all its callers, it has the effect of causing a stack frame to be created, and then returns the address of that frame. This is good in some cases like those described in the above commit, but in other cases it's overkill, we just need to know what stack page we're on. On some other arches current_stack_pointer is just a register global giving the stack pointer, and we'd like to do that too. So rename our current_stack_pointer() to current_stack_frame() to make that possible. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr> Link: https://lore.kernel.org/r/20200220115141.2707-1-mpe@ellerman.id.au
2020-02-20 19:51:37 +08:00
EXPORT_SYMBOL(current_stack_frame)
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