33eb8ab4ec
Macros __arch{,_try}_cmpxchg64_emu() are almost identical to their
local variants __arch{,_try}_cmpxchg64_emu_local(), differing only
by lock prefixes.
Merge these two macros by introducing additional macro parameters
to pass lock location and lock prefix from their respective static
inline functions.
No functional change intended.
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20240417175830.161561-1-ubizjak@gmail.com
155 lines
4.1 KiB
C
155 lines
4.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ASM_X86_CMPXCHG_32_H
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#define _ASM_X86_CMPXCHG_32_H
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/*
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* Note: if you use __cmpxchg64(), or their variants,
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* you need to test for the feature in boot_cpu_data.
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*/
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union __u64_halves {
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u64 full;
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struct {
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u32 low, high;
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};
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};
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#define __arch_cmpxchg64(_ptr, _old, _new, _lock) \
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({ \
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union __u64_halves o = { .full = (_old), }, \
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n = { .full = (_new), }; \
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\
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asm volatile(_lock "cmpxchg8b %[ptr]" \
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: [ptr] "+m" (*(_ptr)), \
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"+a" (o.low), "+d" (o.high) \
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: "b" (n.low), "c" (n.high) \
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: "memory"); \
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\
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o.full; \
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})
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static __always_inline u64 __cmpxchg64(volatile u64 *ptr, u64 old, u64 new)
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{
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return __arch_cmpxchg64(ptr, old, new, LOCK_PREFIX);
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}
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static __always_inline u64 __cmpxchg64_local(volatile u64 *ptr, u64 old, u64 new)
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{
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return __arch_cmpxchg64(ptr, old, new,);
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}
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#define __arch_try_cmpxchg64(_ptr, _oldp, _new, _lock) \
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({ \
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union __u64_halves o = { .full = *(_oldp), }, \
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n = { .full = (_new), }; \
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bool ret; \
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\
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asm volatile(_lock "cmpxchg8b %[ptr]" \
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CC_SET(e) \
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: CC_OUT(e) (ret), \
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[ptr] "+m" (*(_ptr)), \
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"+a" (o.low), "+d" (o.high) \
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: "b" (n.low), "c" (n.high) \
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: "memory"); \
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\
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if (unlikely(!ret)) \
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*(_oldp) = o.full; \
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\
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likely(ret); \
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})
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static __always_inline bool __try_cmpxchg64(volatile u64 *ptr, u64 *oldp, u64 new)
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{
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return __arch_try_cmpxchg64(ptr, oldp, new, LOCK_PREFIX);
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}
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static __always_inline bool __try_cmpxchg64_local(volatile u64 *ptr, u64 *oldp, u64 new)
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{
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return __arch_try_cmpxchg64(ptr, oldp, new,);
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}
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#ifdef CONFIG_X86_CMPXCHG64
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#define arch_cmpxchg64 __cmpxchg64
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#define arch_cmpxchg64_local __cmpxchg64_local
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#define arch_try_cmpxchg64 __try_cmpxchg64
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#define arch_try_cmpxchg64_local __try_cmpxchg64_local
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#else
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/*
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* Building a kernel capable running on 80386 and 80486. It may be necessary
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* to simulate the cmpxchg8b on the 80386 and 80486 CPU.
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*/
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#define __arch_cmpxchg64_emu(_ptr, _old, _new, _lock_loc, _lock) \
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({ \
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union __u64_halves o = { .full = (_old), }, \
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n = { .full = (_new), }; \
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\
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asm volatile(ALTERNATIVE(_lock_loc \
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"call cmpxchg8b_emu", \
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_lock "cmpxchg8b %[ptr]", X86_FEATURE_CX8) \
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: [ptr] "+m" (*(_ptr)), \
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"+a" (o.low), "+d" (o.high) \
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: "b" (n.low), "c" (n.high), "S" (_ptr) \
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: "memory"); \
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\
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o.full; \
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})
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static __always_inline u64 arch_cmpxchg64(volatile u64 *ptr, u64 old, u64 new)
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{
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return __arch_cmpxchg64_emu(ptr, old, new, LOCK_PREFIX_HERE, "lock; ");
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}
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#define arch_cmpxchg64 arch_cmpxchg64
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static __always_inline u64 arch_cmpxchg64_local(volatile u64 *ptr, u64 old, u64 new)
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{
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return __arch_cmpxchg64_emu(ptr, old, new, ,);
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}
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#define arch_cmpxchg64_local arch_cmpxchg64_local
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#define __arch_try_cmpxchg64_emu(_ptr, _oldp, _new, _lock_loc, _lock) \
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({ \
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union __u64_halves o = { .full = *(_oldp), }, \
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n = { .full = (_new), }; \
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bool ret; \
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\
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asm volatile(ALTERNATIVE(_lock_loc \
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"call cmpxchg8b_emu", \
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_lock "cmpxchg8b %[ptr]", X86_FEATURE_CX8) \
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CC_SET(e) \
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: CC_OUT(e) (ret), \
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[ptr] "+m" (*(_ptr)), \
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"+a" (o.low), "+d" (o.high) \
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: "b" (n.low), "c" (n.high), "S" (_ptr) \
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: "memory"); \
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\
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if (unlikely(!ret)) \
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*(_oldp) = o.full; \
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\
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likely(ret); \
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})
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static __always_inline bool arch_try_cmpxchg64(volatile u64 *ptr, u64 *oldp, u64 new)
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{
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return __arch_try_cmpxchg64_emu(ptr, oldp, new, LOCK_PREFIX_HERE, "lock; ");
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}
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#define arch_try_cmpxchg64 arch_try_cmpxchg64
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static __always_inline bool arch_try_cmpxchg64_local(volatile u64 *ptr, u64 *oldp, u64 new)
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{
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return __arch_try_cmpxchg64_emu(ptr, oldp, new, ,);
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}
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#define arch_try_cmpxchg64_local arch_try_cmpxchg64_local
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#endif
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#define system_has_cmpxchg64() boot_cpu_has(X86_FEATURE_CX8)
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#endif /* _ASM_X86_CMPXCHG_32_H */
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