mirror of
https://github.com/torvalds/linux.git
synced 2024-11-26 06:02:05 +00:00
acf02be3c7
Use atomic_try_cmpxchg_acquire(*ptr, &old, new) instead of atomic_cmpxchg_acquire(*ptr, old, new) == old in kexec_trylock(). x86 CMPXCHG instruction returns success in ZF flag, so this change saves a compare after cmpxchg. Link: https://lkml.kernel.org/r/20240719103937.53742-1-ubizjak@gmail.com Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Acked-by: Baoquan He <bhe@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
43 lines
1.3 KiB
C
43 lines
1.3 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef LINUX_KEXEC_INTERNAL_H
|
|
#define LINUX_KEXEC_INTERNAL_H
|
|
|
|
#include <linux/kexec.h>
|
|
|
|
struct kexec_segment;
|
|
|
|
struct kimage *do_kimage_alloc_init(void);
|
|
int sanity_check_segment_list(struct kimage *image);
|
|
void kimage_free_page_list(struct list_head *list);
|
|
void kimage_free(struct kimage *image);
|
|
int kimage_load_segment(struct kimage *image, struct kexec_segment *segment);
|
|
void kimage_terminate(struct kimage *image);
|
|
int kimage_is_destination_range(struct kimage *image,
|
|
unsigned long start, unsigned long end);
|
|
|
|
/*
|
|
* Whatever is used to serialize accesses to the kexec_crash_image needs to be
|
|
* NMI safe, as __crash_kexec() can happen during nmi_panic(), so here we use a
|
|
* "simple" atomic variable that is acquired with a cmpxchg().
|
|
*/
|
|
extern atomic_t __kexec_lock;
|
|
static inline bool kexec_trylock(void)
|
|
{
|
|
int old = 0;
|
|
return atomic_try_cmpxchg_acquire(&__kexec_lock, &old, 1);
|
|
}
|
|
static inline void kexec_unlock(void)
|
|
{
|
|
atomic_set_release(&__kexec_lock, 0);
|
|
}
|
|
|
|
#ifdef CONFIG_KEXEC_FILE
|
|
#include <linux/purgatory.h>
|
|
void kimage_file_post_load_cleanup(struct kimage *image);
|
|
extern char kexec_purgatory[];
|
|
extern size_t kexec_purgatory_size;
|
|
#else /* CONFIG_KEXEC_FILE */
|
|
static inline void kimage_file_post_load_cleanup(struct kimage *image) { }
|
|
#endif /* CONFIG_KEXEC_FILE */
|
|
#endif /* LINUX_KEXEC_INTERNAL_H */
|