| /* SPDX-License-Identifier: GPL-2.0 */ |
| #ifndef _ASM_UM_BARRIER_H_ |
| #define _ASM_UM_BARRIER_H_ |
| |
| #include <asm/alternative.h> |
| |
| /* |
| * Force strict CPU ordering. |
| * And yes, this is required on UP too when we're talking |
| * to devices. |
| */ |
| #ifdef CONFIG_X86_32 |
| |
| #define mb() alternative("lock; addl $0,0(%%esp)", "mfence", X86_FEATURE_XMM2) |
| #define rmb() alternative("lock; addl $0,0(%%esp)", "lfence", X86_FEATURE_XMM2) |
| #define wmb() alternative("lock; addl $0,0(%%esp)", "sfence", X86_FEATURE_XMM) |
| |
| #else /* CONFIG_X86_32 */ |
| |
| #define mb() asm volatile("mfence" : : : "memory") |
| #define rmb() asm volatile("lfence" : : : "memory") |
| #define wmb() asm volatile("sfence" : : : "memory") |
| |
| #endif /* CONFIG_X86_32 */ |
| |
| #include <asm-generic/barrier.h> |
| |
| #endif |
