52 lines
1.8 KiB
Diff
52 lines
1.8 KiB
Diff
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# HG changeset patch
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# User Wei Huang <wei.huang2@amd.com>
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# Date 1302076933 -3600
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# Node ID 42fa70e0761bbb0596618ca5323664f31a2faa76
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# Parent 8fb61c9ebe499b576687907d164da07802414925
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x86, amd, MTRR: remove k8_enable_fixed_iorrs()
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AMD64 defines two special bits (bit 3 and 4) RdMem and WrMem in fixed
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MTRR type. Their values are supposed to be 0 after BIOS hands the
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control to OS according to AMD BKDG. Unless OS specificially turn them
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on, they are kept 0 all the time. As a result, k8_enable_fixed_iorrs()
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is unnecessary and removed from upstream kernel (see
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https://patchwork.kernel.org/patch/11425/). This patch does the same
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thing.
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Signed-off-by: Wei Huang <wei.huang2@amd.com>
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--- a/xen/arch/x86/cpu/mtrr/generic.c
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+++ b/xen/arch/x86/cpu/mtrr/generic.c
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@@ -116,20 +116,6 @@ void mtrr_wrmsr(unsigned int msr, uint64
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}
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/**
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- * Enable and allow read/write of extended fixed-range MTRR bits on K8 CPUs
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- * see AMD publication no. 24593, chapter 3.2.1 for more information
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- */
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-static inline void k8_enable_fixed_iorrs(void)
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-{
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- uint64_t msr_content;
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-
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- rdmsrl(MSR_K8_SYSCFG, msr_content);
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- mtrr_wrmsr(MSR_K8_SYSCFG, msr_content
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- | K8_MTRRFIXRANGE_DRAM_ENABLE
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- | K8_MTRRFIXRANGE_DRAM_MODIFY);
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-}
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-
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-/**
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* Checks and updates an fixed-range MTRR if it differs from the value it
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* should have. If K8 extenstions are wanted, update the K8 SYSCFG MSR also.
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* see AMD publication no. 24593, chapter 7.8.1, page 233 for more information
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@@ -145,10 +131,6 @@ static void set_fixed_range(int msr, int
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val = ((uint64_t)msrwords[1] << 32) | msrwords[0];
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if (msr_content != val) {
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- if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
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- boot_cpu_data.x86 == 15 &&
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- ((msrwords[0] | msrwords[1]) & K8_MTRR_RDMEM_WRMEM_MASK))
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- k8_enable_fixed_iorrs();
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mtrr_wrmsr(msr, val);
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*changed = TRUE;
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}
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