diff options
| author | Uros Bizjak <ubizjak@gmail.com> | 2025-09-07 20:33:38 +0200 |
|---|---|---|
| committer | Borislav Petkov (AMD) <bp@alien8.de> | 2025-09-08 15:38:06 +0200 |
| commit | c6c973dbfa5e34b1572bcd1852adcad1b5d08fab (patch) | |
| tree | d7f0dfbf593ee77c79d6d3efe69c5877c446de98 /arch/x86/include/asm/percpu.h | |
| parent | 13bdfb53aa04eeb8022af87288c5bc0a5d13a834 (diff) | |
x86/asm: Remove code depending on __GCC_ASM_FLAG_OUTPUTS__
The minimum supported GCC version is 8.1, which supports flag output operands
and always defines __GCC_ASM_FLAG_OUTPUTS__ macro.
Remove code depending on __GCC_ASM_FLAG_OUTPUTS__ and use the "=@ccCOND" flag
output operand directly.
Use the equivalent "=@ccz" instead of "=@cce" flag output operand for
CMPXCHG8B and CMPXCHG16B instructions. These instructions set a single flag
bit - the Zero flag - and "=@ccz" is used to distinguish the CC user from
comparison instructions, where set ZERO flag indeed means that the values are
equal.
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20250905121723.GCaLrU04lP2A50PT-B@fat_crate.local
Diffstat (limited to 'arch/x86/include/asm/percpu.h')
| -rw-r--r-- | arch/x86/include/asm/percpu.h | 12 |
1 files changed, 4 insertions, 8 deletions
diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h index b0d03b6c279b..332428caaed2 100644 --- a/arch/x86/include/asm/percpu.h +++ b/arch/x86/include/asm/percpu.h @@ -309,8 +309,7 @@ do { \ \ asm qual (__pcpu_op_##size("cmpxchg") "%[nval], " \ __percpu_arg([var]) \ - CC_SET(z) \ - : CC_OUT(z) (success), \ + : "=@ccz" (success), \ [oval] "+a" (pco_old__), \ [var] "+m" (__my_cpu_var(_var)) \ : [nval] __pcpu_reg_##size(, pco_new__) \ @@ -367,8 +366,7 @@ do { \ asm_inline qual ( \ ALTERNATIVE("call this_cpu_cmpxchg8b_emu", \ "cmpxchg8b " __percpu_arg([var]), X86_FEATURE_CX8) \ - CC_SET(z) \ - : ALT_OUTPUT_SP(CC_OUT(z) (success), \ + : ALT_OUTPUT_SP("=@ccz" (success), \ [var] "+m" (__my_cpu_var(_var)), \ "+a" (old__.low), "+d" (old__.high)) \ : "b" (new__.low), "c" (new__.high), \ @@ -436,8 +434,7 @@ do { \ asm_inline qual ( \ ALTERNATIVE("call this_cpu_cmpxchg16b_emu", \ "cmpxchg16b " __percpu_arg([var]), X86_FEATURE_CX16) \ - CC_SET(z) \ - : ALT_OUTPUT_SP(CC_OUT(z) (success), \ + : ALT_OUTPUT_SP("=@ccz" (success), \ [var] "+m" (__my_cpu_var(_var)), \ "+a" (old__.low), "+d" (old__.high)) \ : "b" (new__.low), "c" (new__.high), \ @@ -585,8 +582,7 @@ do { \ bool oldbit; \ \ asm volatile("btl %[nr], " __percpu_arg([var]) \ - CC_SET(c) \ - : CC_OUT(c) (oldbit) \ + : "=@ccc" (oldbit) \ : [var] "m" (__my_cpu_var(_var)), \ [nr] "rI" (_nr)); \ oldbit; \ |