The following commit has been merged into the x86/asm branch of tip: Commit-ID: dc8bd769e70ecae0916bf1b05acad6120c6bd6f0 Gitweb: https://git.kernel.org/tip/dc8bd769e70ecae0916bf1b05acad6120c6bd6f0 Author: Uros Bizjak <ubizjak@xxxxxxxxx> AuthorDate: Sun, 23 Feb 2025 17:13:38 +01:00 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitterDate: Sun, 23 Feb 2025 19:18:18 +01:00 x86/ioperm: Use atomic64_inc_return() in ksys_ioperm() Use atomic64_inc_return(&ref) instead of atomic64_add_return(1, &ref) to use optimized implementation on targets that define atomic_inc_return() and to remove now unneeded initialization of the %eax/%edx register pair before the call to atomic64_inc_return(). On x86_32 the code improves from: 1b0: b9 00 00 00 00 mov $0x0,%ecx 1b1: R_386_32 .bss 1b5: 89 43 0c mov %eax,0xc(%ebx) 1b8: 31 d2 xor %edx,%edx 1ba: b8 01 00 00 00 mov $0x1,%eax 1bf: e8 fc ff ff ff call 1c0 <ksys_ioperm+0xa8> 1c0: R_386_PC32 atomic64_add_return_cx8 1c4: 89 03 mov %eax,(%ebx) 1c6: 89 53 04 mov %edx,0x4(%ebx) to: 1b0: be 00 00 00 00 mov $0x0,%esi 1b1: R_386_32 .bss 1b5: 89 43 0c mov %eax,0xc(%ebx) 1b8: e8 fc ff ff ff call 1b9 <ksys_ioperm+0xa1> 1b9: R_386_PC32 atomic64_inc_return_cx8 1bd: 89 03 mov %eax,(%ebx) 1bf: 89 53 04 mov %edx,0x4(%ebx) Signed-off-by: Uros Bizjak <ubizjak@xxxxxxxxx> Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Link: https://lore.kernel.org/r/20250223161355.3607-1-ubizjak@xxxxxxxxx --- arch/x86/kernel/ioport.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/ioport.c b/arch/x86/kernel/ioport.c index e2fab3c..6290dd1 100644 --- a/arch/x86/kernel/ioport.c +++ b/arch/x86/kernel/ioport.c @@ -144,7 +144,7 @@ long ksys_ioperm(unsigned long from, unsigned long num, int turn_on) * Update the sequence number to force a TSS update on return to * user mode. */ - iobm->sequence = atomic64_add_return(1, &io_bitmap_sequence); + iobm->sequence = atomic64_inc_return(&io_bitmap_sequence); return 0; }
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