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-rw-r--r--arch/i386/kernel/cpu/mtrr/generic.c85
-rw-r--r--include/asm-i386/msr-index.h5
2 files changed, 65 insertions, 25 deletions
diff --git a/arch/i386/kernel/cpu/mtrr/generic.c b/arch/i386/kernel/cpu/mtrr/generic.c
index 150cf50..000c07e 100644
--- a/arch/i386/kernel/cpu/mtrr/generic.c
+++ b/arch/i386/kernel/cpu/mtrr/generic.c
@@ -20,6 +20,18 @@ struct mtrr_state {
mtrr_type def_type;
};
+struct fixed_range_block {
+ int base_msr; /* start address of an MTRR block */
+ int ranges; /* number of MTRRs in this block */
+};
+
+static struct fixed_range_block fixed_range_blocks[] = {
+ { MTRRfix64K_00000_MSR, 1 }, /* one 64k MTRR */
+ { MTRRfix16K_80000_MSR, 2 }, /* two 16k MTRRs */
+ { MTRRfix4K_C0000_MSR, 8 }, /* eight 4k MTRRs */
+ {}
+};
+
static unsigned long smp_changes_mask;
static struct mtrr_state mtrr_state = {};
@@ -152,6 +164,44 @@ void mtrr_wrmsr(unsigned msr, unsigned a, unsigned b)
smp_processor_id(), msr, a, b);
}
+/**
+ * Enable and allow read/write of extended fixed-range MTRR bits on K8 CPUs
+ * see AMD publication no. 24593, chapter 3.2.1 for more information
+ */
+static inline void k8_enable_fixed_iorrs(void)
+{
+ unsigned lo, hi;
+
+ rdmsr(MSR_K8_SYSCFG, lo, hi);
+ mtrr_wrmsr(MSR_K8_SYSCFG, lo
+ | K8_MTRRFIXRANGE_DRAM_ENABLE
+ | K8_MTRRFIXRANGE_DRAM_MODIFY, hi);
+}
+
+/**
+ * Checks and updates an fixed-range MTRR if it differs from the value it
+ * should have. If K8 extenstions are wanted, update the K8 SYSCFG MSR also.
+ * see AMD publication no. 24593, chapter 7.8.1, page 233 for more information
+ * \param msr MSR address of the MTTR which should be checked and updated
+ * \param changed pointer which indicates whether the MTRR needed to be changed
+ * \param msrwords pointer to the MSR values which the MSR should have
+ */
+static void set_fixed_range(int msr, int * changed, unsigned int * msrwords)
+{
+ unsigned lo, hi;
+
+ rdmsr(msr, lo, hi);
+
+ if (lo != msrwords[0] || hi != msrwords[1]) {
+ if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
+ boot_cpu_data.x86 == 15 &&
+ ((msrwords[0] | msrwords[1]) & K8_MTRR_RDMEM_WRMEM_MASK))
+ k8_enable_fixed_iorrs();
+ mtrr_wrmsr(msr, msrwords[0], msrwords[1]);
+ *changed = TRUE;
+ }
+}
+
int generic_get_free_region(unsigned long base, unsigned long size, int replace_reg)
/* [SUMMARY] Get a free MTRR.
<base> The starting (base) address of the region.
@@ -201,36 +251,21 @@ static void generic_get_mtrr(unsigned int reg, unsigned long *base,
*type = base_lo & 0xff;
}
+/**
+ * Checks and updates the fixed-range MTRRs if they differ from the saved set
+ * \param frs pointer to fixed-range MTRR values, saved by get_fixed_ranges()
+ */
static int set_fixed_ranges(mtrr_type * frs)
{
- unsigned int *p = (unsigned int *) frs;
+ unsigned long long *saved = (unsigned long long *) frs;
int changed = FALSE;
- int i;
- unsigned int lo, hi;
+ int block=-1, range;
- rdmsr(MTRRfix64K_00000_MSR, lo, hi);
- if (p[0] != lo || p[1] != hi) {
- mtrr_wrmsr(MTRRfix64K_00000_MSR, p[0], p[1]);
- changed = TRUE;
- }
-
- for (i = 0; i < 2; i++) {
- rdmsr(MTRRfix16K_80000_MSR + i, lo, hi);
- if (p[2 + i * 2] != lo || p[3 + i * 2] != hi) {
- mtrr_wrmsr(MTRRfix16K_80000_MSR + i, p[2 + i * 2],
- p[3 + i * 2]);
- changed = TRUE;
- }
- }
+ while (fixed_range_blocks[++block].ranges)
+ for (range=0; range < fixed_range_blocks[block].ranges; range++)
+ set_fixed_range(fixed_range_blocks[block].base_msr + range,
+ &changed, (unsigned int *) saved++);
- for (i = 0; i < 8; i++) {
- rdmsr(MTRRfix4K_C0000_MSR + i, lo, hi);
- if (p[6 + i * 2] != lo || p[7 + i * 2] != hi) {
- mtrr_wrmsr(MTRRfix4K_C0000_MSR + i, p[6 + i * 2],
- p[7 + i * 2]);
- changed = TRUE;
- }
- }
return changed;
}
diff --git a/include/asm-i386/msr-index.h b/include/asm-i386/msr-index.h
index f119080..a02eb29 100644
--- a/include/asm-i386/msr-index.h
+++ b/include/asm-i386/msr-index.h
@@ -87,6 +87,11 @@
#define MSR_K7_CLK_CTL 0xc001001b
#define MSR_K8_TOP_MEM2 0xc001001d
#define MSR_K8_SYSCFG 0xc0010010
+
+#define K8_MTRRFIXRANGE_DRAM_ENABLE 0x00040000 /* MtrrFixDramEn bit */
+#define K8_MTRRFIXRANGE_DRAM_MODIFY 0x00080000 /* MtrrFixDramModEn bit */
+#define K8_MTRR_RDMEM_WRMEM_MASK 0x18181818 /* Mask: RdMem|WrMem */
+
#define MSR_K7_HWCR 0xc0010015
#define MSR_K8_HWCR 0xc0010015
#define MSR_K7_FID_VID_CTL 0xc0010041
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