[PATCH 2/2] powerpc/lib/feature-fixups: use raw_patch_instruction()

From: Christophe Leroy
Date: Fri Nov 24 2017 - 02:31:40 EST


feature fixups need to use patch_instruction() early in the boot,
even before the code is relocated to its final address, requiring
patch_instruction() to use PTRRELOC() in order to address data.

But feature fixups applies on code before it is set to read only,
even for modules. Therefore, feature fixups can use
raw_patch_instruction() instead.

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx>
---
arch/powerpc/include/asm/code-patching.h | 1 +
arch/powerpc/lib/code-patching.c | 4 ++--
arch/powerpc/lib/feature-fixups.c | 8 ++++----
3 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/include/asm/code-patching.h b/arch/powerpc/include/asm/code-patching.h
index abef812de7f8..1090024e8519 100644
--- a/arch/powerpc/include/asm/code-patching.h
+++ b/arch/powerpc/include/asm/code-patching.h
@@ -31,6 +31,7 @@ unsigned int create_cond_branch(const unsigned int *addr,
unsigned long target, int flags);
int patch_branch(unsigned int *addr, unsigned long target, int flags);
int patch_instruction(unsigned int *addr, unsigned int instr);
+int raw_patch_instruction(unsigned int *addr, unsigned int instr);

int instr_is_relative_branch(unsigned int instr);
int instr_is_branch_to_addr(const unsigned int *instr, unsigned long addr);
diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c
index 80954c910b66..b7c555df5cd6 100644
--- a/arch/powerpc/lib/code-patching.c
+++ b/arch/powerpc/lib/code-patching.c
@@ -38,7 +38,7 @@ static int __patch_instruction(unsigned int *exec_addr, unsigned int instr,
return 0;
}

-static int raw_patch_instruction(unsigned int *addr, unsigned int instr)
+int raw_patch_instruction(unsigned int *addr, unsigned int instr)
{
return __patch_instruction(addr, instr, addr);
}
@@ -155,7 +155,7 @@ int patch_instruction(unsigned int *addr, unsigned int instr)
* when text_poke_area is not ready, but we still need
* to allow patching. We just do the plain old patching
*/
- if (!this_cpu_read(*PTRRELOC(&text_poke_area)))
+ if (!this_cpu_read(text_poke_area))
return raw_patch_instruction(addr, instr);

local_irq_save(flags);
diff --git a/arch/powerpc/lib/feature-fixups.c b/arch/powerpc/lib/feature-fixups.c
index 41cf5ae273cf..0872d60ede10 100644
--- a/arch/powerpc/lib/feature-fixups.c
+++ b/arch/powerpc/lib/feature-fixups.c
@@ -62,7 +62,7 @@ static int patch_alt_instruction(unsigned int *src, unsigned int *dest,
}
}

- patch_instruction(dest, instr);
+ raw_patch_instruction(dest, instr);

return 0;
}
@@ -91,7 +91,7 @@ static int patch_feature_section(unsigned long value, struct fixup_entry *fcur)
}

for (; dest < end; dest++)
- patch_instruction(dest, PPC_INST_NOP);
+ raw_patch_instruction(dest, PPC_INST_NOP);

return 0;
}
@@ -129,7 +129,7 @@ void do_lwsync_fixups(unsigned long value, void *fixup_start, void *fixup_end)

for (; start < end; start++) {
dest = (void *)start + *start;
- patch_instruction(dest, PPC_INST_LWSYNC);
+ raw_patch_instruction(dest, PPC_INST_LWSYNC);
}
}

@@ -147,7 +147,7 @@ static void do_final_fixups(void)
length = (__end_interrupts - _stext) / sizeof(int);

while (length--) {
- patch_instruction(dest, *src);
+ raw_patch_instruction(dest, *src);
src++;
dest++;
}
--
2.13.3