From 06d0bbc6d0f56dacac3a79900e9a9a0d5972d818 Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Tue, 24 Jul 2018 01:07:52 +1000 Subject: powerpc/asm: Add a patch_site macro & helpers for patching instructions Add a macro and some helper C functions for patching single asm instructions. The gas macro means we can do something like: 1: nop patch_site 1b, patch__foo Which is less visually distracting than defining a GLOBAL symbol at 1, and also doesn't pollute the symbol table which can confuse eg. perf. These are obviously similar to our existing feature sections, but are not automatically patched based on CPU/MMU features, rather they are designed to be manually patched by C code at some arbitrary point. Signed-off-by: Michael Ellerman --- arch/powerpc/lib/code-patching.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'arch/powerpc/lib/code-patching.c') diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c index e0d881ab304e..850f3b8f4da5 100644 --- a/arch/powerpc/lib/code-patching.c +++ b/arch/powerpc/lib/code-patching.c @@ -195,6 +195,22 @@ int patch_branch(unsigned int *addr, unsigned long target, int flags) return patch_instruction(addr, create_branch(addr, target, flags)); } +int patch_branch_site(s32 *site, unsigned long target, int flags) +{ + unsigned int *addr; + + addr = (unsigned int *)((unsigned long)site + *site); + return patch_instruction(addr, create_branch(addr, target, flags)); +} + +int patch_instruction_site(s32 *site, unsigned int instr) +{ + unsigned int *addr; + + addr = (unsigned int *)((unsigned long)site + *site); + return patch_instruction(addr, instr); +} + bool is_offset_in_branch_range(long offset) { /* -- cgit v1.2.3