imported SEABIOS source tree

[palacios.git] / bios / seabios / src / mtrr.c

diff --git a/bios/seabios/src/mtrr.c b/bios/seabios/src/mtrr.c
new file mode 100644 (file)
index 0000000..0548043
--- /dev/null
+++ b/bios/seabios/src/mtrr.c
@@ -0,0 +1,103 @@
+// Initialize MTRRs - mostly useful on KVM.
+//
+// Copyright (C) 2006 Fabrice Bellard
+//
+// This file may be distributed under the terms of the GNU LGPLv3 license.
+
+#include "util.h" // dprintf
+#include "biosvar.h" // GET_EBDA
+#include "xen.h" // usingXen
+
+#define MSR_MTRRcap                    0x000000fe
+#define MSR_MTRRfix64K_00000           0x00000250
+#define MSR_MTRRfix16K_80000           0x00000258
+#define MSR_MTRRfix16K_A0000           0x00000259
+#define MSR_MTRRfix4K_C0000            0x00000268
+#define MSR_MTRRfix4K_C8000            0x00000269
+#define MSR_MTRRfix4K_D0000            0x0000026a
+#define MSR_MTRRfix4K_D8000            0x0000026b
+#define MSR_MTRRfix4K_E0000            0x0000026c
+#define MSR_MTRRfix4K_E8000            0x0000026d
+#define MSR_MTRRfix4K_F0000            0x0000026e
+#define MSR_MTRRfix4K_F8000            0x0000026f
+#define MSR_MTRRdefType                0x000002ff
+
+#define MTRRphysBase_MSR(reg) (0x200 + 2 * (reg))
+#define MTRRphysMask_MSR(reg) (0x200 + 2 * (reg) + 1)
+
+#define MTRR_MEMTYPE_UC 0
+#define MTRR_MEMTYPE_WC 1
+#define MTRR_MEMTYPE_WT 4
+#define MTRR_MEMTYPE_WP 5
+#define MTRR_MEMTYPE_WB 6
+
+void mtrr_setup(void)
+{
+    if (!CONFIG_MTRR_INIT || CONFIG_COREBOOT || usingXen())
+        return;
+
+    u32 eax, ebx, ecx, edx, cpuid_features;
+    cpuid(1, &eax, &ebx, &ecx, &cpuid_features);
+    if (!(cpuid_features & CPUID_MTRR))
+        return;
+    if (!(cpuid_features & CPUID_MSR))
+        return;
+
+    dprintf(3, "init mtrr\n");
+
+    u32 mtrr_cap = rdmsr(MSR_MTRRcap);
+    int vcnt = mtrr_cap & 0xff;
+    int fix = mtrr_cap & 0x100;
+    if (!vcnt || !fix)
+       return;
+
+    // Disable MTRRs
+    wrmsr_smp(MSR_MTRRdefType, 0);
+
+    // Set fixed MTRRs
+    union u64b {
+        u8 valb[8];
+        u64 val;
+    } u;
+    u.val = 0;
+    int i;
+    for (i = 0; i < 8; i++)
+        if (RamSize >= 65536 * (i + 1))
+            u.valb[i] = MTRR_MEMTYPE_WB;
+    wrmsr_smp(MSR_MTRRfix64K_00000, u.val);
+    u.val = 0;
+    for (i = 0; i < 8; i++)
+        if (RamSize >= 0x80000 + 16384 * (i + 1))
+            u.valb[i] = MTRR_MEMTYPE_WB;
+    wrmsr_smp(MSR_MTRRfix16K_80000, u.val);
+    wrmsr_smp(MSR_MTRRfix16K_A0000, 0);   // 0xA0000-0xC0000 is uncached
+    int j;
+    for (j = 0; j < 8; j++) {
+        u.val = 0;
+        for (i = 0; i < 8; i++)
+            if (RamSize >= 0xC0000 + j * 0x8000 + 4096 * (i + 1))
+                u.valb[i] = MTRR_MEMTYPE_WP;
+        wrmsr_smp(MSR_MTRRfix4K_C0000 + j, u.val);
+    }
+
+    // Set variable MTRRs
+    int phys_bits = 36;
+    cpuid(0x80000000u, &eax, &ebx, &ecx, &edx);
+    if (eax >= 0x80000008) {
+            /* Get physical bits from leaf 0x80000008 (if available) */
+            cpuid(0x80000008u, &eax, &ebx, &ecx, &edx);
+            phys_bits = eax & 0xff;
+    }
+    u64 phys_mask = ((1ull << phys_bits) - 1);
+    for (i=0; i<vcnt; i++) {
+        wrmsr_smp(MTRRphysBase_MSR(i), 0);
+        wrmsr_smp(MTRRphysMask_MSR(i), 0);
+    }
+    /* Mark 3.5-4GB as UC, anything not specified defaults to WB */
+    wrmsr_smp(MTRRphysBase_MSR(0), BUILD_MAX_HIGHMEM | MTRR_MEMTYPE_UC);
+    wrmsr_smp(MTRRphysMask_MSR(0)
+              , (-((1ull<<32)-BUILD_MAX_HIGHMEM) & phys_mask) | 0x800);
+
+    // Enable fixed and variable MTRRs; set default type.
+    wrmsr_smp(MSR_MTRRdefType, 0xc00 | MTRR_MEMTYPE_WB);
+}