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| author | Arthur Heymans <arthur@aheymans.xyz> | 2021-11-30 21:03:14 +0100 |
|---|---|---|
| committer | Arthur Heymans <arthur@aheymans.xyz> | 2022-06-02 05:48:08 +0000 |
| commit | e771b9a65fe668bd04dd8dbdab8af4819a987d95 (patch) | |
| tree | 76c053a12724b1d431ac274aabb91caa2c898e4d /src/include | |
| parent | 7235cc19d6baef83c6bced1698db17aa7aaeec11 (diff) | |
cpu/x86/mp.h: Implement a pre-SSE2 mfence
Taken from the Linux Kernel.
Tested: Qemu using '-cpu pentium3' now boots.
Change-Id: I376f86f4d7992344dd68374ba67ad3580070f4d8
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/59766
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Diffstat (limited to 'src/include')
| -rw-r--r-- | src/include/cpu/x86/mp.h | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/src/include/cpu/x86/mp.h b/src/include/cpu/x86/mp.h index 8105477c49..aea3ca1e3d 100644 --- a/src/include/cpu/x86/mp.h +++ b/src/include/cpu/x86/mp.h @@ -13,7 +13,11 @@ struct bus; static inline void mfence(void) { - __asm__ __volatile__("mfence\t\n": : :"memory"); + /* mfence came with the introduction of SSE2. */ + if (CONFIG(SSE2)) + __asm__ __volatile__("mfence\t\n": : :"memory"); + else + __asm__ __volatile__("lock; addl $0,0(%%esp)": : : "memory"); } /* The sequence of the callbacks are in calling order. */ |