From 325c3376afad838eec8b9342e9e5eef270c5b184 Mon Sep 17 00:00:00 2001 From: Qiuxu Zhuo Date: Fri, 25 Oct 2024 10:45:53 +0800 Subject: x86/mce/mcelog: Use xchg() to get and clear the flags Using xchg() to atomically get and clear the MCE log buffer flags, streamlines the code and reduces the text size by 20 bytes. $ size dev-mcelog.o.* text data bss dec hex filename 3013 360 160 3533 dcd dev-mcelog.o.old 2993 360 160 3513 db9 dev-mcelog.o.new No functional changes intended. Signed-off-by: Qiuxu Zhuo Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Tony Luck Reviewed-by: Nikolay Borisov Reviewed-by: Sohil Mehta Link: https://lore.kernel.org/r/20241025024602.24318-2-qiuxu.zhuo@intel.com --- arch/x86/kernel/cpu/mce/dev-mcelog.c | 11 ++--------- 1 file changed, 2 insertions(+), 9 deletions(-) diff --git a/arch/x86/kernel/cpu/mce/dev-mcelog.c b/arch/x86/kernel/cpu/mce/dev-mcelog.c index af44fd5dbd7c..8d023239ce18 100644 --- a/arch/x86/kernel/cpu/mce/dev-mcelog.c +++ b/arch/x86/kernel/cpu/mce/dev-mcelog.c @@ -264,15 +264,8 @@ static long mce_chrdev_ioctl(struct file *f, unsigned int cmd, return put_user(sizeof(struct mce), p); case MCE_GET_LOG_LEN: return put_user(mcelog->len, p); - case MCE_GETCLEAR_FLAGS: { - unsigned flags; - - do { - flags = mcelog->flags; - } while (cmpxchg(&mcelog->flags, flags, 0) != flags); - - return put_user(flags, p); - } + case MCE_GETCLEAR_FLAGS: + return put_user(xchg(&mcelog->flags, 0), p); default: return -ENOTTY; } -- cgit v1.2.3