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powerpc: Move code patching code into arch/powerpc/lib/code-patching.c
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We currently have a few routines for patching code in asm/system.h, because
they didn't fit anywhere else. I'd like to clean them up a little and add
some more, so first move them into a dedicated C file - they don't need to
be inlined.

While we're moving the code, drop create_function_call(), it's intended
caller never got merged and will be replaced in future with something
different.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
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Michael Ellerman authored and Paul Mackerras committed Jul 1, 2008
1 parent 73f38fe commit aaddd3e
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Showing 7 changed files with 63 additions and 48 deletions.
1 change: 1 addition & 0 deletions arch/powerpc/kernel/crash_dump.c
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Expand Up @@ -14,6 +14,7 @@
#include <linux/crash_dump.h>
#include <linux/bootmem.h>
#include <linux/lmb.h>
#include <asm/code-patching.h>
#include <asm/kdump.h>
#include <asm/prom.h>
#include <asm/firmware.h>
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2 changes: 2 additions & 0 deletions arch/powerpc/lib/Makefile
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Expand Up @@ -24,3 +24,5 @@ obj-$(CONFIG_SMP) += locks.o
endif

obj-$(CONFIG_PPC_LIB_RHEAP) += rheap.o

obj-y += code-patching.o
33 changes: 33 additions & 0 deletions arch/powerpc/lib/code-patching.c
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@@ -0,0 +1,33 @@
/*
* Copyright 2008 Michael Ellerman, IBM Corporation.
*
* 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.
*/

#include <linux/kernel.h>
#include <asm/code-patching.h>


void create_instruction(unsigned long addr, unsigned int instr)
{
unsigned int *p;
p = (unsigned int *)addr;
*p = instr;
asm ("dcbst 0, %0; sync; icbi 0,%0; sync; isync" : : "r" (p));
}

void create_branch(unsigned long addr, unsigned long target, int flags)
{
unsigned int instruction;

if (! (flags & BRANCH_ABSOLUTE))
target = target - addr;

/* Mask out the flags and target, so they don't step on each other. */
instruction = 0x48000000 | (flags & 0x3) | (target & 0x03FFFFFC);

create_instruction(addr, instruction);
}
1 change: 1 addition & 0 deletions arch/powerpc/platforms/86xx/mpc86xx_smp.c
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Expand Up @@ -15,6 +15,7 @@
#include <linux/init.h>
#include <linux/delay.h>

#include <asm/code-patching.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/pci-bridge.h>
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1 change: 1 addition & 0 deletions arch/powerpc/platforms/powermac/smp.c
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Expand Up @@ -36,6 +36,7 @@

#include <asm/ptrace.h>
#include <asm/atomic.h>
#include <asm/code-patching.h>
#include <asm/irq.h>
#include <asm/page.h>
#include <asm/pgtable.h>
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25 changes: 25 additions & 0 deletions include/asm-powerpc/code-patching.h
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@@ -0,0 +1,25 @@
#ifndef _ASM_POWERPC_CODE_PATCHING_H
#define _ASM_POWERPC_CODE_PATCHING_H

/*
* Copyright 2008, Michael Ellerman, IBM Corporation.
*
* 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.
*/

/* Flags for create_branch:
* "b" == create_branch(addr, target, 0);
* "ba" == create_branch(addr, target, BRANCH_ABSOLUTE);
* "bl" == create_branch(addr, target, BRANCH_SET_LINK);
* "bla" == create_branch(addr, target, BRANCH_ABSOLUTE | BRANCH_SET_LINK);
*/
#define BRANCH_SET_LINK 0x1
#define BRANCH_ABSOLUTE 0x2

extern void create_branch(unsigned long addr, unsigned long target, int flags);
extern void create_instruction(unsigned long addr, unsigned int instr);

#endif /* _ASM_POWERPC_CODE_PATCHING_H */
48 changes: 0 additions & 48 deletions include/asm-powerpc/system.h
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Expand Up @@ -526,54 +526,6 @@ extern void reloc_got2(unsigned long);

#define PTRRELOC(x) ((typeof(x)) add_reloc_offset((unsigned long)(x)))

static inline void create_instruction(unsigned long addr, unsigned int instr)
{
unsigned int *p;
p = (unsigned int *)addr;
*p = instr;
asm ("dcbst 0, %0; sync; icbi 0,%0; sync; isync" : : "r" (p));
}

/* Flags for create_branch:
* "b" == create_branch(addr, target, 0);
* "ba" == create_branch(addr, target, BRANCH_ABSOLUTE);
* "bl" == create_branch(addr, target, BRANCH_SET_LINK);
* "bla" == create_branch(addr, target, BRANCH_ABSOLUTE | BRANCH_SET_LINK);
*/
#define BRANCH_SET_LINK 0x1
#define BRANCH_ABSOLUTE 0x2

static inline void create_branch(unsigned long addr,
unsigned long target, int flags)
{
unsigned int instruction;

if (! (flags & BRANCH_ABSOLUTE))
target = target - addr;

/* Mask out the flags and target, so they don't step on each other. */
instruction = 0x48000000 | (flags & 0x3) | (target & 0x03FFFFFC);

create_instruction(addr, instruction);
}

static inline void create_function_call(unsigned long addr, void * func)
{
unsigned long func_addr;

#ifdef CONFIG_PPC64
/*
* On PPC64 the function pointer actually points to the function's
* descriptor. The first entry in the descriptor is the address
* of the function text.
*/
func_addr = *(unsigned long *)func;
#else
func_addr = (unsigned long)func;
#endif
create_branch(addr, func_addr, BRANCH_SET_LINK);
}

#ifdef CONFIG_VIRT_CPU_ACCOUNTING
extern void account_system_vtime(struct task_struct *);
#endif
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