The following commit has been merged into the x86/asm branch of tip:
Commit-ID: 5f863897d964e834a0da35b1e483b5bb8faca522
Gitweb: https://git.kernel.org/tip/5f863897d964e834a0da35b1e483b5bb8faca522
Author: Uros Bizjak <ubizjak@xxxxxxxxx>
AuthorDate: Wed, 30 Aug 2023 17:13:56 +02:00
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Fri, 15 Sep 2023 13:18:23 +02:00
x86/percpu: Define raw_cpu_try_cmpxchg and this_cpu_try_cmpxchg()
Define target-specific raw_cpu_try_cmpxchg_N() and
this_cpu_try_cmpxchg_N() macros. These definitions override
the generic fallback definitions and enable target-specific
optimized implementations.
Signed-off-by: Uros Bizjak <ubizjak@xxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230830151623.3900-1-ubizjak@xxxxxxxxx
---
arch/x86/include/asm/percpu.h | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)
diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h
index 4c36419..a87db61 100644
--- a/arch/x86/include/asm/percpu.h
+++ b/arch/x86/include/asm/percpu.h
@@ -210,6 +210,25 @@ do { \
(typeof(_var))(unsigned long) pco_old__; \
})
+#define percpu_try_cmpxchg_op(size, qual, _var, _ovalp, _nval) \
+({ \
+ bool success; \
+ __pcpu_type_##size *pco_oval__ = (__pcpu_type_##size *)(_ovalp); \
+ __pcpu_type_##size pco_old__ = *pco_oval__; \
+ __pcpu_type_##size pco_new__ = __pcpu_cast_##size(_nval); \
+ asm qual (__pcpu_op2_##size("cmpxchg", "%[nval]", \
+ __percpu_arg([var])) \
+ CC_SET(z) \
+ : CC_OUT(z) (success), \
+ [oval] "+a" (pco_old__), \
+ [var] "+m" (_var) \
+ : [nval] __pcpu_reg_##size(, pco_new__) \
+ : "memory"); \
+ if (unlikely(!success)) \
+ *pco_oval__ = pco_old__; \
+ likely(success); \
+})
+
#if defined(CONFIG_X86_32) && !defined(CONFIG_UML)
#define percpu_cmpxchg64_op(size, qual, _var, _oval, _nval) \
({ \
@@ -410,6 +429,9 @@ do { \
#define raw_cpu_cmpxchg_1(pcp, oval, nval) percpu_cmpxchg_op(1, , pcp, oval, nval)
#define raw_cpu_cmpxchg_2(pcp, oval, nval) percpu_cmpxchg_op(2, , pcp, oval, nval)
#define raw_cpu_cmpxchg_4(pcp, oval, nval) percpu_cmpxchg_op(4, , pcp, oval, nval)
+#define raw_cpu_try_cmpxchg_1(pcp, ovalp, nval) percpu_try_cmpxchg_op(1, , pcp, ovalp, nval)
+#define raw_cpu_try_cmpxchg_2(pcp, ovalp, nval) percpu_try_cmpxchg_op(2, , pcp, ovalp, nval)
+#define raw_cpu_try_cmpxchg_4(pcp, ovalp, nval) percpu_try_cmpxchg_op(4, , pcp, ovalp, nval)
#define this_cpu_add_return_1(pcp, val) percpu_add_return_op(1, volatile, pcp, val)
#define this_cpu_add_return_2(pcp, val) percpu_add_return_op(2, volatile, pcp, val)
@@ -417,6 +439,9 @@ do { \
#define this_cpu_cmpxchg_1(pcp, oval, nval) percpu_cmpxchg_op(1, volatile, pcp, oval, nval)
#define this_cpu_cmpxchg_2(pcp, oval, nval) percpu_cmpxchg_op(2, volatile, pcp, oval, nval)
#define this_cpu_cmpxchg_4(pcp, oval, nval) percpu_cmpxchg_op(4, volatile, pcp, oval, nval)
+#define this_cpu_try_cmpxchg_1(pcp, ovalp, nval) percpu_try_cmpxchg_op(1, volatile, pcp, ovalp, nval)
+#define this_cpu_try_cmpxchg_2(pcp, ovalp, nval) percpu_try_cmpxchg_op(2, volatile, pcp, ovalp, nval)
+#define this_cpu_try_cmpxchg_4(pcp, ovalp, nval) percpu_try_cmpxchg_op(4, volatile, pcp, ovalp, nval)
/*
* Per cpu atomic 64 bit operations are only available under 64 bit.
@@ -431,6 +456,7 @@ do { \
#define raw_cpu_add_return_8(pcp, val) percpu_add_return_op(8, , pcp, val)
#define raw_cpu_xchg_8(pcp, nval) raw_percpu_xchg_op(pcp, nval)
#define raw_cpu_cmpxchg_8(pcp, oval, nval) percpu_cmpxchg_op(8, , pcp, oval, nval)
+#define raw_cpu_try_cmpxchg_8(pcp, ovalp, nval) percpu_try_cmpxchg_op(8, , pcp, ovalp, nval)
#define this_cpu_read_8(pcp) percpu_from_op(8, volatile, "mov", pcp)
#define this_cpu_write_8(pcp, val) percpu_to_op(8, volatile, "mov", (pcp), val)
@@ -440,6 +466,7 @@ do { \
#define this_cpu_add_return_8(pcp, val) percpu_add_return_op(8, volatile, pcp, val)
#define this_cpu_xchg_8(pcp, nval) percpu_xchg_op(8, volatile, pcp, nval)
#define this_cpu_cmpxchg_8(pcp, oval, nval) percpu_cmpxchg_op(8, volatile, pcp, oval, nval)
+#define this_cpu_try_cmpxchg_8(pcp, ovalp, nval) percpu_try_cmpxchg_op(8, volatile, pcp, ovalp, nval)
#endif
static __always_inline bool x86_this_cpu_constant_test_bit(unsigned int nr,
|