1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_X86_SYNC_CORE_H
3 #define _ASM_X86_SYNC_CORE_H
4
5 #include <linux/preempt.h>
6 #include <asm/processor.h>
7 #include <asm/cpufeature.h>
8
9 /*
10 * Ensure that a core serializing instruction is issued before returning
11 * to user-mode. x86 implements return to user-space through sysexit,
12 * sysrel, and sysretq, which are not core serializing.
13 */
14 static inline void sync_core_before_usermode(void)
15 {
16 /* With PTI, we unconditionally serialize before running user code. */
17 if (static_cpu_has(X86_FEATURE_PTI))
18 return;
19 /*
20 * Return from interrupt and NMI is done through iret, which is core
21 * serializing.
22 */
23 if (in_irq() || in_nmi())
24 return;
25 sync_core();
26 }
27
28 #endif /* _ASM_X86_SYNC_CORE_H */