diff options
author | Peter Zijlstra <peterz@infradead.org> | 2023-05-31 16:08:39 +0300 |
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committer | Peter Zijlstra <peterz@infradead.org> | 2023-06-05 10:36:37 +0300 |
commit | 6d12c8d308e68b9b0fa98ca2df4f83db4b4c965d (patch) | |
tree | 442e57e61e0b36dd4b9bc4028450812344d1e198 /arch/x86/lib/cmpxchg8b_emu.S | |
parent | c5c0ba953b8c969c5d51bf1c57f239866a97c47c (diff) | |
download | linux-6d12c8d308e68b9b0fa98ca2df4f83db4b4c965d.tar.xz |
percpu: Wire up cmpxchg128
In order to replace cmpxchg_double() with the newly minted
cmpxchg128() family of functions, wire it up in this_cpu_cmpxchg().
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20230531132323.654945124@infradead.org
Diffstat (limited to 'arch/x86/lib/cmpxchg8b_emu.S')
-rw-r--r-- | arch/x86/lib/cmpxchg8b_emu.S | 67 |
1 files changed, 53 insertions, 14 deletions
diff --git a/arch/x86/lib/cmpxchg8b_emu.S b/arch/x86/lib/cmpxchg8b_emu.S index 6a912d58fecc..49805257b125 100644 --- a/arch/x86/lib/cmpxchg8b_emu.S +++ b/arch/x86/lib/cmpxchg8b_emu.S @@ -2,10 +2,16 @@ #include <linux/linkage.h> #include <asm/export.h> +#include <asm/percpu.h> +#include <asm/processor-flags.h> .text +#ifndef CONFIG_X86_CMPXCHG64 + /* + * Emulate 'cmpxchg8b (%esi)' on UP + * * Inputs: * %esi : memory location to compare * %eax : low 32 bits of old value @@ -15,32 +21,65 @@ */ SYM_FUNC_START(cmpxchg8b_emu) -# -# Emulate 'cmpxchg8b (%esi)' on UP except we don't -# set the whole ZF thing (caller will just compare -# eax:edx with the expected value) -# pushfl cli - cmpl (%esi), %eax - jne .Lnot_same - cmpl 4(%esi), %edx - jne .Lhalf_same + cmpl 0(%esi), %eax + jne .Lnot_same + cmpl 4(%esi), %edx + jne .Lnot_same + + movl %ebx, 0(%esi) + movl %ecx, 4(%esi) - movl %ebx, (%esi) - movl %ecx, 4(%esi) + orl $X86_EFLAGS_ZF, (%esp) popfl RET .Lnot_same: - movl (%esi), %eax -.Lhalf_same: - movl 4(%esi), %edx + movl 0(%esi), %eax + movl 4(%esi), %edx + + andl $(~X86_EFLAGS_ZF), (%esp) popfl RET SYM_FUNC_END(cmpxchg8b_emu) EXPORT_SYMBOL(cmpxchg8b_emu) + +#endif + +#ifndef CONFIG_UML + +SYM_FUNC_START(this_cpu_cmpxchg8b_emu) + + pushfl + cli + + cmpl PER_CPU_VAR(0(%esi)), %eax + jne .Lnot_same2 + cmpl PER_CPU_VAR(4(%esi)), %edx + jne .Lnot_same2 + + movl %ebx, PER_CPU_VAR(0(%esi)) + movl %ecx, PER_CPU_VAR(4(%esi)) + + orl $X86_EFLAGS_ZF, (%esp) + + popfl + RET + +.Lnot_same2: + movl PER_CPU_VAR(0(%esi)), %eax + movl PER_CPU_VAR(4(%esi)), %edx + + andl $(~X86_EFLAGS_ZF), (%esp) + + popfl + RET + +SYM_FUNC_END(this_cpu_cmpxchg8b_emu) + +#endif |