[PATCH v2 2/5] powerpc/feature-fixups: Refactor entry fixups patching

From: Christophe Leroy
Date: Fri Dec 02 2022 - 03:34:49 EST


Several fonctions have the same loop for patching instructions.

Introduce function do_patch_entry_fixups() to refactor those loops.

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
---
arch/powerpc/lib/feature-fixups.c | 84 ++++++++++++-------------------
1 file changed, 32 insertions(+), 52 deletions(-)

diff --git a/arch/powerpc/lib/feature-fixups.c b/arch/powerpc/lib/feature-fixups.c
index 31f40f544de5..93b3f8ea38aa 100644
--- a/arch/powerpc/lib/feature-fixups.c
+++ b/arch/powerpc/lib/feature-fixups.c
@@ -118,9 +118,33 @@ void do_feature_fixups(unsigned long value, void *fixup_start, void *fixup_end)
}

#ifdef CONFIG_PPC_BOOK3S_64
+static int do_patch_entry_fixups(long *start, long *end, unsigned int *instrs,
+ bool do_fallback, void *fallback)
+{
+ int i;
+
+ for (i = 0; start < end; start++, i++) {
+ unsigned int *dest = (void *)start + *start;
+
+ pr_devel("patching dest %lx\n", (unsigned long)dest);
+
+ // See comment in do_entry_flush_fixups() RE order of patching
+ if (do_fallback) {
+ patch_instruction(dest, ppc_inst(instrs[0]));
+ patch_instruction(dest + 2, ppc_inst(instrs[2]));
+ patch_branch(dest + 1, (unsigned long)fallback, BRANCH_SET_LINK);
+ } else {
+ patch_instruction(dest + 1, ppc_inst(instrs[1]));
+ patch_instruction(dest + 2, ppc_inst(instrs[2]));
+ patch_instruction(dest, ppc_inst(instrs[0]));
+ }
+ }
+ return i;
+}
+
static void do_stf_entry_barrier_fixups(enum stf_barrier_type types)
{
- unsigned int instrs[3], *dest;
+ unsigned int instrs[3];
long *start, *end;
int i;

@@ -144,23 +168,8 @@ static void do_stf_entry_barrier_fixups(enum stf_barrier_type types)
instrs[i++] = PPC_RAW_ORI(_R31, _R31, 0); /* speculation barrier */
}

- for (i = 0; start < end; start++, i++) {
- dest = (void *)start + *start;
-
- pr_devel("patching dest %lx\n", (unsigned long)dest);
-
- // See comment in do_entry_flush_fixups() RE order of patching
- if (types & STF_BARRIER_FALLBACK) {
- patch_instruction(dest, ppc_inst(instrs[0]));
- patch_instruction(dest + 2, ppc_inst(instrs[2]));
- patch_branch(dest + 1,
- (unsigned long)&stf_barrier_fallback, BRANCH_SET_LINK);
- } else {
- patch_instruction(dest + 1, ppc_inst(instrs[1]));
- patch_instruction(dest + 2, ppc_inst(instrs[2]));
- patch_instruction(dest, ppc_inst(instrs[0]));
- }
- }
+ i = do_patch_entry_fixups(start, end, instrs, types & STF_BARRIER_FALLBACK,
+ &stf_barrier_fallback);

printk(KERN_DEBUG "stf-barrier: patched %d entry locations (%s barrier)\n", i,
(types == STF_BARRIER_NONE) ? "no" :
@@ -325,7 +334,7 @@ void do_uaccess_flush_fixups(enum l1d_flush_type types)
static int __do_entry_flush_fixups(void *data)
{
enum l1d_flush_type types = *(enum l1d_flush_type *)data;
- unsigned int instrs[3], *dest;
+ unsigned int instrs[3];
long *start, *end;
int i;

@@ -375,42 +384,13 @@ static int __do_entry_flush_fixups(void *data)

start = PTRRELOC(&__start___entry_flush_fixup);
end = PTRRELOC(&__stop___entry_flush_fixup);
- for (i = 0; start < end; start++, i++) {
- dest = (void *)start + *start;
-
- pr_devel("patching dest %lx\n", (unsigned long)dest);
-
- if (types == L1D_FLUSH_FALLBACK) {
- patch_instruction(dest, ppc_inst(instrs[0]));
- patch_instruction(dest + 2, ppc_inst(instrs[2]));
- patch_branch(dest + 1,
- (unsigned long)&entry_flush_fallback, BRANCH_SET_LINK);
- } else {
- patch_instruction(dest + 1, ppc_inst(instrs[1]));
- patch_instruction(dest + 2, ppc_inst(instrs[2]));
- patch_instruction(dest, ppc_inst(instrs[0]));
- }
- }
+ i = do_patch_entry_fixups(start, end, instrs, types == L1D_FLUSH_FALLBACK,
+ &entry_flush_fallback);

start = PTRRELOC(&__start___scv_entry_flush_fixup);
end = PTRRELOC(&__stop___scv_entry_flush_fixup);
- for (; start < end; start++, i++) {
- dest = (void *)start + *start;
-
- pr_devel("patching dest %lx\n", (unsigned long)dest);
-
- if (types == L1D_FLUSH_FALLBACK) {
- patch_instruction(dest, ppc_inst(instrs[0]));
- patch_instruction(dest + 2, ppc_inst(instrs[2]));
- patch_branch(dest + 1,
- (unsigned long)&scv_entry_flush_fallback, BRANCH_SET_LINK);
- } else {
- patch_instruction(dest + 1, ppc_inst(instrs[1]));
- patch_instruction(dest + 2, ppc_inst(instrs[2]));
- patch_instruction(dest, ppc_inst(instrs[0]));
- }
- }
-
+ i += do_patch_entry_fixups(start, end, instrs, types == L1D_FLUSH_FALLBACK,
+ &scv_entry_flush_fallback);

printk(KERN_DEBUG "entry-flush: patched %d locations (%s flush)\n", i,
(types == L1D_FLUSH_NONE) ? "no" :
--
2.38.1