Messages in this thread Patch in this message | | | From | Uros Bizjak <> | Subject | [PATCH 1/2] x86/percpu: Define raw_cpu_try_cmpxchg and this_cpu_try_cmpxchg | Date | Wed, 30 Aug 2023 17:13:56 +0200 |
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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.
Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Uros Bizjak <ubizjak@gmail.com> --- 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 34734d730463..c8309f260d98 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) \ ({ \ @@ -343,6 +362,9 @@ 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) @@ -350,6 +372,9 @@ 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. @@ -364,6 +389,7 @@ 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) @@ -373,6 +399,7 @@ 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, -- 2.41.0
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