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Commit fa54a981 authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

powerpc/lib: Use patch_site to patch copy_32 functions once cache is enabled 



The symbol memcpy_nocache_branch defined in order to allow patching
of memset function once cache is enabled leads to confusing reports
by perf tool.

Using the new patch_site functionality solves this issue.

Signed-off-by: default avatarChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent cd813e1c

arch/powerpc/include/asm/asm-prototypes.h

+1 −0
Original line number Diff line number Diff line
@@ -146,6 +146,7 @@ void _kvmppc_save_tm_pr(struct kvm_vcpu *vcpu, u64 guest_msr); 
/* Patch sites */

extern s32 patch__call_flush_count_cache;

extern s32 patch__flush_count_cache_return;

extern s32 patch__memset_nocache, patch__memcpy_nocache;



extern long flush_count_cache;

arch/powerpc/kernel/setup_32.c

+3 −4
Original line number Diff line number Diff line
@@ -97,11 +97,10 @@ notrace unsigned long __init early_init(unsigned long dt_ptr) 
 * We do the initial parsing of the flat device-tree and prepares

 * for the MMU to be fully initialized.

 */

extern unsigned int memset_nocache_branch; /* Insn to be replaced by NOP */



notrace void __init machine_init(u64 dt_ptr)

{

	unsigned int *addr = &memset_nocache_branch;

	unsigned int *addr = (unsigned int *)((unsigned long)&patch__memset_nocache +

					       patch__memset_nocache);

	unsigned long insn;



	/* Configure static keys first, now that we're relocated. */
@@ -110,7 +109,7 @@ notrace void __init machine_init(u64 dt_ptr) 
	/* Enable early debugging if any specified (see udbg.h) */

	udbg_early_init();



	patch_instruction((unsigned int *)&memcpy, PPC_INST_NOP);

	patch_instruction_site(&patch__memcpy_nocache, PPC_INST_NOP);



	insn = create_cond_branch(addr, branch_target(addr), 0x820000);

	patch_instruction(addr, insn);	/* replace b by bne cr0 */

arch/powerpc/lib/copy_32.S

+6 −3
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
#include <asm/errno.h>

#include <asm/ppc_asm.h>

#include <asm/export.h>

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



#define COPY_16_BYTES		\

	lwz	r7,4(r4);	\
@@ -107,8 +108,8 @@ _GLOBAL(memset) 
	 * Skip optimised bloc until cache is enabled. Will be replaced

	 * by 'bne' during boot to use normal procedure if r4 is not zero

	 */

_GLOBAL(memset_nocache_branch)

	b	2f

5:	b	2f

	patch_site	5b, patch__memset_nocache



	clrlwi	r7,r6,32-LG_CACHELINE_BYTES

	add	r8,r7,r5
@@ -168,7 +169,9 @@ _GLOBAL(memmove) 
	/* fall through */



_GLOBAL(memcpy)

	b	generic_memcpy

1:	b	generic_memcpy

	patch_site	1b, patch__memcpy_nocache



	add	r7,r3,r5		/* test if the src & dst overlap */

	add	r8,r4,r5

	cmplw	0,r4,r7