Commit 245067d1674d451855692fcd4647daf9fd47f82d
Committed by
Linus Torvalds
Linus Torvalds
1 parent
4bb0d3ec3e
Exists in
master
and in
4 other branches
[PATCH] i386: cleanup serialize msr
i386 arch cleanup. Introduce the serialize macro to serialize processor state. Why the microcode update needs it I am not quite sure, since wrmsr() is already a serializing instruction, but it is a microcode update, so I will keep the semantic the same, since this could be a timing workaround. As far as I can tell, this has always been there since the original microcode update source. Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Showing 3 changed files with 15 additions and 2 deletions Side-by-side Diff
arch/i386/kernel/microcode.c
| ... | ... | @@ -164,7 +164,8 @@ |
| 164 | 164 | } |
| 165 | 165 | |
| 166 | 166 | wrmsr(MSR_IA32_UCODE_REV, 0, 0); |
| 167 | - __asm__ __volatile__ ("cpuid" : : : "ax", "bx", "cx", "dx"); | |
| 167 | + /* see notes above for revision 1.07. Apparent chip bug */ | |
| 168 | + serialize_cpu(); | |
| 168 | 169 | /* get the current revision from MSR 0x8B */ |
| 169 | 170 | rdmsr(MSR_IA32_UCODE_REV, val[0], uci->rev); |
| 170 | 171 | pr_debug("microcode: collect_cpu_info : sig=0x%x, pf=0x%x, rev=0x%x\n", |
| ... | ... | @@ -377,7 +378,9 @@ |
| 377 | 378 | (unsigned long) uci->mc->bits >> 16 >> 16); |
| 378 | 379 | wrmsr(MSR_IA32_UCODE_REV, 0, 0); |
| 379 | 380 | |
| 380 | - __asm__ __volatile__ ("cpuid" : : : "ax", "bx", "cx", "dx"); | |
| 381 | + /* see notes above for revision 1.07. Apparent chip bug */ | |
| 382 | + serialize_cpu(); | |
| 383 | + | |
| 381 | 384 | /* get the current revision from MSR 0x8B */ |
| 382 | 385 | rdmsr(MSR_IA32_UCODE_REV, val[0], val[1]); |
| 383 | 386 |
include/asm-i386/processor.h
| ... | ... | @@ -277,6 +277,11 @@ |
| 277 | 277 | outb((data), 0x23); \ |
| 278 | 278 | } while (0) |
| 279 | 279 | |
| 280 | +static inline void serialize_cpu(void) | |
| 281 | +{ | |
| 282 | + __asm__ __volatile__ ("cpuid" : : : "ax", "bx", "cx", "dx"); | |
| 283 | +} | |
| 284 | + | |
| 280 | 285 | static inline void __monitor(const void *eax, unsigned long ecx, |
| 281 | 286 | unsigned long edx) |
| 282 | 287 | { |
include/asm-x86_64/processor.h
| ... | ... | @@ -437,6 +437,11 @@ |
| 437 | 437 | outb((data), 0x23); \ |
| 438 | 438 | } while (0) |
| 439 | 439 | |
| 440 | +static inline void serialize_cpu(void) | |
| 441 | +{ | |
| 442 | + __asm__ __volatile__ ("cpuid" : : : "ax", "bx", "cx", "dx"); | |
| 443 | +} | |
| 444 | + | |
| 440 | 445 | static inline void __monitor(const void *eax, unsigned long ecx, |
| 441 | 446 | unsigned long edx) |
| 442 | 447 | { |