diff options
| author | Arthur Heymans <arthur@aheymans.xyz> | 2019-11-25 19:58:36 +0100 |
|---|---|---|
| committer | Patrick Georgi <pgeorgi@google.com> | 2020-08-17 06:22:41 +0000 |
| commit | a6a2f9372c492c2e6ca4404b372054b1fd82e1ee (patch) | |
| tree | 809849d881e1ec1006ed033f54edfa7eba2cc44c | |
| parent | 65605276a4cd08fd2e38f87cd80e3362265f9091 (diff) | |
arch/x86/exit_car.S: Make sure _cbmem_top_ptr hits dram
INVD is called below so if postcar is running in a cached environment
it needs to happen.
NOTE: postcar cannot execute in a cached environment if clflush is not
supported!
Change-Id: I37681ee1f1d2ae5f9dd824b5baf7b23b2883b1dc
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/37212
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
| -rw-r--r-- | src/arch/x86/exit_car.S | 10 | ||||
| -rw-r--r-- | src/include/cpu/x86/cache.h | 2 |
2 files changed, 11 insertions, 1 deletions
diff --git a/src/arch/x86/exit_car.S b/src/arch/x86/exit_car.S index 806dc9c069..dc356b2cf9 100644 --- a/src/arch/x86/exit_car.S +++ b/src/arch/x86/exit_car.S @@ -2,6 +2,7 @@ #include <cpu/x86/mtrr.h> #include <cpu/x86/cr.h> +#include <cpu/x86/cache.h> .section ".module_parameters", "aw", @progbits /* stack_top indicates the stack to pull MTRR information from. */ @@ -54,7 +55,14 @@ _start: movl 4(%esp), %eax movl %eax, _cbmem_top_ptr #endif - + /* Make sure _cbmem_top_ptr hits dram before invd */ + movl $1, %eax + cpuid + btl $CPUID_FEATURE_CLFLUSH_BIT, %edx + jz skip_clflush + clflush _cbmem_top_ptr + +skip_clflush: /* chipset_teardown_car() is expected to disable cache-as-ram. */ call chipset_teardown_car diff --git a/src/include/cpu/x86/cache.h b/src/include/cpu/x86/cache.h index 01b202eb1a..62341104a4 100644 --- a/src/include/cpu/x86/cache.h +++ b/src/include/cpu/x86/cache.h @@ -8,6 +8,8 @@ #define CR0_CacheDisable (CR0_CD) #define CR0_NoWriteThrough (CR0_NW) +#define CPUID_FEATURE_CLFLUSH_BIT 19 + #if !defined(__ASSEMBLER__) static inline void wbinvd(void) |