1ac1ab12aSMathieu Desnoyers /* SPDX-License-Identifier: GPL-2.0 */ 2ac1ab12aSMathieu Desnoyers #ifndef _ASM_X86_SYNC_CORE_H 3ac1ab12aSMathieu Desnoyers #define _ASM_X86_SYNC_CORE_H 4ac1ab12aSMathieu Desnoyers 5ac1ab12aSMathieu Desnoyers #include <linux/preempt.h> 6ac1ab12aSMathieu Desnoyers #include <asm/processor.h> 7ac1ab12aSMathieu Desnoyers #include <asm/cpufeature.h> 8ac1ab12aSMathieu Desnoyers 9ac1ab12aSMathieu Desnoyers /* 10ac1ab12aSMathieu Desnoyers * Ensure that a core serializing instruction is issued before returning 11ac1ab12aSMathieu Desnoyers * to user-mode. x86 implements return to user-space through sysexit, 12ac1ab12aSMathieu Desnoyers * sysrel, and sysretq, which are not core serializing. 13ac1ab12aSMathieu Desnoyers */ 14ac1ab12aSMathieu Desnoyers static inline void sync_core_before_usermode(void) 15ac1ab12aSMathieu Desnoyers { 16ac1ab12aSMathieu Desnoyers /* With PTI, we unconditionally serialize before running user code. */ 17ac1ab12aSMathieu Desnoyers if (static_cpu_has(X86_FEATURE_PTI)) 18ac1ab12aSMathieu Desnoyers return; 19ac1ab12aSMathieu Desnoyers /* 20ac1ab12aSMathieu Desnoyers * Return from interrupt and NMI is done through iret, which is core 21ac1ab12aSMathieu Desnoyers * serializing. 22ac1ab12aSMathieu Desnoyers */ 23ac1ab12aSMathieu Desnoyers if (in_irq() || in_nmi()) 24ac1ab12aSMathieu Desnoyers return; 25ac1ab12aSMathieu Desnoyers sync_core(); 26ac1ab12aSMathieu Desnoyers } 27ac1ab12aSMathieu Desnoyers 28ac1ab12aSMathieu Desnoyers #endif /* _ASM_X86_SYNC_CORE_H */ 29