diff options
| author | Duncan Laurie <dlaurie@chromium.org> | 2013-06-10 09:53:33 -0700 |
|---|---|---|
| committer | Stefan Reinauer <stefan.reinauer@coreboot.org> | 2013-11-26 19:08:48 +0100 |
| commit | e807c34a5e34e8dd7cb959458de593ea1070fde4 (patch) | |
| tree | 5b7ea1d5fb675add375221c745c585e9f6484a26 | |
| parent | 35bd3fedfeafe96b5fb938c1b47e2b0380fdbfb7 (diff) | |
cmos post: Guard with spinlock
The CMOS post code storage mechanism does back-to-back
CMOS reads and writes that may be interleaved during
CPU bringup, leading to corruption of the log or of other
parts of CMOS.
Change-Id: I704813cc917a659fe034b71c2ff9eb9b80f7c949
Signed-off-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/58102
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/4227
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
| -rw-r--r-- | src/arch/x86/include/arch/smp/spinlock.h | 14 | ||||
| -rw-r--r-- | src/console/post.c | 15 |
2 files changed, 26 insertions, 3 deletions
diff --git a/src/arch/x86/include/arch/smp/spinlock.h b/src/arch/x86/include/arch/smp/spinlock.h index 5c1dd94c36..32be2f25fb 100644 --- a/src/arch/x86/include/arch/smp/spinlock.h +++ b/src/arch/x86/include/arch/smp/spinlock.h @@ -1,6 +1,8 @@ #ifndef ARCH_SMP_SPINLOCK_H #define ARCH_SMP_SPINLOCK_H +#ifndef __PRE_RAM__ + /* * Your basic SMP spinlocks, allowing only a single CPU anywhere */ @@ -61,4 +63,16 @@ static inline __attribute__((always_inline)) void cpu_relax(void) __asm__ __volatile__("rep;nop": : :"memory"); } +#else /* !__PRE_RAM__ */ + +#define DECLARE_SPIN_LOCK(x) +#define barrier() do {} while(0) +#define spin_is_locked(lock) 0 +#define spin_unlock_wait(lock) do {} while(0) +#define spin_lock(lock) do {} while(0) +#define spin_unlock(lock) do {} while(0) +#define cpu_relax() do {} while(0) + +#endif /* !__PRE_RAM__ */ + #endif /* ARCH_SMP_SPINLOCK_H */ diff --git a/src/console/post.c b/src/console/post.c index f55683e4d1..11c631d4dc 100644 --- a/src/console/post.c +++ b/src/console/post.c @@ -23,6 +23,7 @@ #include <console/console.h> #if CONFIG_CMOS_POST #include <pc80/mc146818rtc.h> +#include <smp/spinlock.h> #endif #include <elog.h> @@ -44,10 +45,14 @@ void __attribute__((weak)) mainboard_post(uint8_t value) #if CONFIG_CMOS_POST +DECLARE_SPIN_LOCK(cmos_post_lock) + #if !defined(__PRE_RAM__) void cmos_post_log(void) { - u8 code; + u8 code = 0; + + spin_lock(&cmos_post_lock); /* Get post code from other bank */ switch (cmos_read(CMOS_POST_BANK_OFFSET)) { @@ -57,10 +62,10 @@ void cmos_post_log(void) case CMOS_POST_BANK_1_MAGIC: code = cmos_read(CMOS_POST_BANK_0_OFFSET); break; - default: - return; } + spin_unlock(&cmos_post_lock); + /* Check last post code in previous boot against normal list */ switch (code) { case POST_OS_BOOT: @@ -80,6 +85,8 @@ void cmos_post_log(void) static void cmos_post_code(u8 value) { + spin_lock(&cmos_post_lock); + switch (cmos_read(CMOS_POST_BANK_OFFSET)) { case CMOS_POST_BANK_0_MAGIC: cmos_write(value, CMOS_POST_BANK_0_OFFSET); @@ -88,6 +95,8 @@ static void cmos_post_code(u8 value) cmos_write(value, CMOS_POST_BANK_1_OFFSET); break; } + + spin_unlock(&cmos_post_lock); } #endif /* CONFIG_CMOS_POST */ |