diff mbox series

[v4,3/4] powerpc: Prepare arch_static_call_transform() for supporting inline static calls

Message ID 7a8b9245e773307c315c2548a4c6cad570ac2648.1733245362.git.christophe.leroy@csgroup.eu (mailing list archive)
State New
Headers show
Series Implement inline static calls on PPC32 - v4 | expand

Commit Message

Christophe Leroy Dec. 3, 2024, 7:44 p.m. UTC 
Reorganise arch_static_call_transform() in order to ease the support
of inline static calls in following patch:
- remove 'target' to nhide whether it is a 'return 0' or not.
- Don't bail out if 'tramp' is NULL, just do nothing until next patch.

Note that 'target' was 'tramp + PPC_SCT_RET0', is_short was perforce
true. So in the 'if (func && !is_short)' leg, target was perforce
equal to 'func'.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/static_call.c | 36 ++++++++++++++++++-------------
 1 file changed, 21 insertions(+), 15 deletions(-)
diff mbox series

Patch

diff --git a/arch/powerpc/kernel/static_call.c b/arch/powerpc/kernel/static_call.c
index 7cfd0710e757..1b106fbcc567 100644
--- a/arch/powerpc/kernel/static_call.c
+++ b/arch/powerpc/kernel/static_call.c
@@ -8,26 +8,32 @@  void arch_static_call_transform(void *site, void *tramp, void *func, bool tail)
 {
 	int err;
 	bool is_ret0 = (func == __static_call_return0);
-	unsigned long target = (unsigned long)(is_ret0 ? tramp + PPC_SCT_RET0 : func);
-	bool is_short = is_offset_in_branch_range((long)target - (long)tramp);
-
-	if (!tramp)
-		return;
+	unsigned long _tramp = (unsigned long)tramp;
+	unsigned long _func = (unsigned long)func;
+	unsigned long _ret0 = _tramp + PPC_SCT_RET0;
+	bool is_short = is_offset_in_branch_range((long)func - (long)(site ? : tramp));
 
 	mutex_lock(&text_mutex);
 
-	if (func && !is_short) {
-		err = patch_ulong(tramp + PPC_SCT_DATA, target);
-		if (err)
-			goto out;
+	if (tramp) {
+		if (func && !is_short) {
+			err = patch_ulong(tramp + PPC_SCT_DATA, _func);
+			if (err)
+				goto out;
+		}
+
+		if (!func)
+			err = patch_instruction(tramp, ppc_inst(PPC_RAW_BLR()));
+		else if (is_ret0)
+			err = patch_branch(tramp, _ret0, 0);
+		else if (is_short)
+			err = patch_branch(tramp, _func, 0);
+		else
+			err = patch_instruction(tramp, ppc_inst(PPC_RAW_NOP()));
+	} else {
+		err = 0;
 	}
 
-	if (!func)
-		err = patch_instruction(tramp, ppc_inst(PPC_RAW_BLR()));
-	else if (is_short)
-		err = patch_branch(tramp, target, 0);
-	else
-		err = patch_instruction(tramp, ppc_inst(PPC_RAW_NOP()));
 out:
 	mutex_unlock(&text_mutex);