powerpc/lib/feature-fixups: use raw_patch_instruction()

commit 8183d99 upstream.

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@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reported-by: David Gounaris <david.gounaris@infinera.com>
Tested-by: David Gounaris <david.gounaris@infinera.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: chleroy

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_relative_link_branch(unsigned int instr);

arch/powerpc/lib/code-patching.c

@@ -39,7 +39,7 @@ 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);
 }
@@ -156,7 +156,7 @@ static int do_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);

arch/powerpc/lib/feature-fixups.c

@@ -63,7 +63,7 @@ static int patch_alt_instruction(unsigned int *src, unsigned int *dest,
 		}
 	}
 
-	patch_instruction(dest, instr);
+	raw_patch_instruction(dest, instr);
 
 	return 0;
 }
@@ -92,7 +92,7 @@ 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;
 }
@@ -292,7 +292,7 @@ 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);
 	}
 }
 
@@ -310,7 +310,7 @@ 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++;
 	}