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| author | Christophe Leroy <christophe.leroy@csgroup.eu> | 2022-03-14 13:27:35 +0300 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2022-04-05 10:59:38 +0300 |
| commit | 5517d500829c683a358a8de04ecb2e28af629ae5 (patch) | |
| tree | da7f5fefbdd46e59e7a62647e0b10277e0245b3e /include | |
| parent | 8fd4ddda2f49a66bf5dd3d0c01966c4b1971308b (diff) | |
| download | linux-5517d500829c683a358a8de04ecb2e28af629ae5.tar.xz | |
static_call: Properly initialise DEFINE_STATIC_CALL_RET0()
When a static call is updated with __static_call_return0() as target,
arch_static_call_transform() set it to use an optimised set of
instructions which are meant to lay in the same cacheline.
But when initialising a static call with DEFINE_STATIC_CALL_RET0(),
we get a branch to the real __static_call_return0() function instead
of getting the optimised setup:
c00d8120 <__SCT__perf_snapshot_branch_stack>:
c00d8120: 4b ff ff f4 b c00d8114 <__static_call_return0>
c00d8124: 3d 80 c0 0e lis r12,-16370
c00d8128: 81 8c 81 3c lwz r12,-32452(r12)
c00d812c: 7d 89 03 a6 mtctr r12
c00d8130: 4e 80 04 20 bctr
c00d8134: 38 60 00 00 li r3,0
c00d8138: 4e 80 00 20 blr
c00d813c: 00 00 00 00 .long 0x0
Add ARCH_DEFINE_STATIC_CALL_RET0_TRAMP() defined by each architecture
to setup the optimised configuration, and rework
DEFINE_STATIC_CALL_RET0() to call it:
c00d8120 <__SCT__perf_snapshot_branch_stack>:
c00d8120: 48 00 00 14 b c00d8134 <__SCT__perf_snapshot_branch_stack+0x14>
c00d8124: 3d 80 c0 0e lis r12,-16370
c00d8128: 81 8c 81 3c lwz r12,-32452(r12)
c00d812c: 7d 89 03 a6 mtctr r12
c00d8130: 4e 80 04 20 bctr
c00d8134: 38 60 00 00 li r3,0
c00d8138: 4e 80 00 20 blr
c00d813c: 00 00 00 00 .long 0x0
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/1e0a61a88f52a460f62a58ffc2a5f847d1f7d9d8.1647253456.git.christophe.leroy@csgroup.eu
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/static_call.h | 20 |
1 files changed, 17 insertions, 3 deletions
diff --git a/include/linux/static_call.h b/include/linux/static_call.h index fcc5b48989b3..3c50b0fdda16 100644 --- a/include/linux/static_call.h +++ b/include/linux/static_call.h @@ -196,6 +196,14 @@ extern long __static_call_return0(void); }; \ ARCH_DEFINE_STATIC_CALL_NULL_TRAMP(name) +#define DEFINE_STATIC_CALL_RET0(name, _func) \ + DECLARE_STATIC_CALL(name, _func); \ + struct static_call_key STATIC_CALL_KEY(name) = { \ + .func = __static_call_return0, \ + .type = 1, \ + }; \ + ARCH_DEFINE_STATIC_CALL_RET0_TRAMP(name) + #define static_call_cond(name) (void)__static_call(name) #define EXPORT_STATIC_CALL(name) \ @@ -231,6 +239,12 @@ static inline int static_call_init(void) { return 0; } }; \ ARCH_DEFINE_STATIC_CALL_NULL_TRAMP(name) +#define DEFINE_STATIC_CALL_RET0(name, _func) \ + DECLARE_STATIC_CALL(name, _func); \ + struct static_call_key STATIC_CALL_KEY(name) = { \ + .func = __static_call_return0, \ + }; \ + ARCH_DEFINE_STATIC_CALL_RET0_TRAMP(name) #define static_call_cond(name) (void)__static_call(name) @@ -284,6 +298,9 @@ static inline long __static_call_return0(void) .func = NULL, \ } +#define DEFINE_STATIC_CALL_RET0(name, _func) \ + __DEFINE_STATIC_CALL(name, _func, __static_call_return0) + static inline void __static_call_nop(void) { } /* @@ -327,7 +344,4 @@ static inline int static_call_text_reserved(void *start, void *end) #define DEFINE_STATIC_CALL(name, _func) \ __DEFINE_STATIC_CALL(name, _func, _func) -#define DEFINE_STATIC_CALL_RET0(name, _func) \ - __DEFINE_STATIC_CALL(name, _func, __static_call_return0) - #endif /* _LINUX_STATIC_CALL_H */ |