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-rw-r--r--arch/x86/cpu/cpu.c27
1 files changed, 20 insertions, 7 deletions
diff --git a/arch/x86/cpu/cpu.c b/arch/x86/cpu/cpu.c
index af927b94e0..b4e0fd9bc2 100644
--- a/arch/x86/cpu/cpu.c
+++ b/arch/x86/cpu/cpu.c
@@ -363,13 +363,26 @@ int x86_cpu_init_f(void)
mtrr_cap = native_read_msr(MTRR_CAP_MSR);
if (mtrr_cap & MTRR_CAP_FIX) {
/* Mark the VGA RAM area as uncacheable */
- native_write_msr(MTRR_FIX_16K_A0000_MSR, 0, 0);
-
- /* Mark the PCI ROM area as uncacheable */
- native_write_msr(MTRR_FIX_4K_C0000_MSR, 0, 0);
- native_write_msr(MTRR_FIX_4K_C8000_MSR, 0, 0);
- native_write_msr(MTRR_FIX_4K_D0000_MSR, 0, 0);
- native_write_msr(MTRR_FIX_4K_D8000_MSR, 0, 0);
+ native_write_msr(MTRR_FIX_16K_A0000_MSR,
+ MTRR_FIX_TYPE(MTRR_TYPE_UNCACHEABLE),
+ MTRR_FIX_TYPE(MTRR_TYPE_UNCACHEABLE));
+
+ /*
+ * Mark the PCI ROM area as cacheable to improve ROM
+ * execution performance.
+ */
+ native_write_msr(MTRR_FIX_4K_C0000_MSR,
+ MTRR_FIX_TYPE(MTRR_TYPE_WRBACK),
+ MTRR_FIX_TYPE(MTRR_TYPE_WRBACK));
+ native_write_msr(MTRR_FIX_4K_C8000_MSR,
+ MTRR_FIX_TYPE(MTRR_TYPE_WRBACK),
+ MTRR_FIX_TYPE(MTRR_TYPE_WRBACK));
+ native_write_msr(MTRR_FIX_4K_D0000_MSR,
+ MTRR_FIX_TYPE(MTRR_TYPE_WRBACK),
+ MTRR_FIX_TYPE(MTRR_TYPE_WRBACK));
+ native_write_msr(MTRR_FIX_4K_D8000_MSR,
+ MTRR_FIX_TYPE(MTRR_TYPE_WRBACK),
+ MTRR_FIX_TYPE(MTRR_TYPE_WRBACK));
/* Enable the fixed range MTRRs */
msr_setbits_64(MTRR_DEF_TYPE_MSR, MTRR_DEF_TYPE_FIX_EN);
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