diff options
| -rw-r--r-- | src/cpu/intel/car/cache_as_ram_ht.inc | 31 |
1 files changed, 30 insertions, 1 deletions
diff --git a/src/cpu/intel/car/cache_as_ram_ht.inc b/src/cpu/intel/car/cache_as_ram_ht.inc index a6cbd6bac5..641a2f3304 100644 --- a/src/cpu/intel/car/cache_as_ram_ht.inc +++ b/src/cpu/intel/car/cache_as_ram_ht.inc @@ -83,11 +83,40 @@ clear_mtrrs: orl $MTRRdefTypeEn, %eax wrmsr - /* Enable L2 cache. */ + /* Enable L2 cache Write-Back (WBINVD and FLUSH#). + * + * MSR is set when DisplayFamily_DisplayModel is one of: + * 06_0x, 06_17, 06_1C + * + * Description says this bit enables use of WBINVD and FLUSH#. + * Should this be set only after the system bus and/or memory + * controller can successfully handle write cycles? + */ + +#define EAX_FAMILY(a) (a << 8) /* for family <= 0fH */ +#define EAX_MODEL(a) (((a & 0xf0) << 12) | ((a & 0xf) << 4)) + + movl $1, %eax + cpuid + movl %eax, %ebx + andl $EAX_FAMILY(0x0f), %eax + cmpl $EAX_FAMILY(0x06), %eax + jne no_msr_11e + movl %ebx, %eax + andl $EAX_MODEL(0xff), %eax + cmpl $EAX_MODEL(0x17), %eax + je has_msr_11e + cmpl $EAX_MODEL(0x1c), %eax + je has_msr_11e + andl $EAX_MODEL(0xf0), %eax + cmpl $EAX_MODEL(0x00), %eax + jne no_msr_11e +has_msr_11e: movl $0x11e, %ecx rdmsr orl $(1 << 8), %eax wrmsr +no_msr_11e: /* Enable cache (CR0.CD = 0, CR0.NW = 0). */ movl %cr0, %eax |