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Diffstat (limited to 'arch/x86/cpu/ivybridge/microcode_intel.c')
-rw-r--r--arch/x86/cpu/ivybridge/microcode_intel.c151
1 files changed, 151 insertions, 0 deletions
diff --git a/arch/x86/cpu/ivybridge/microcode_intel.c b/arch/x86/cpu/ivybridge/microcode_intel.c
new file mode 100644
index 0000000000..8c11a6351f
--- /dev/null
+++ b/arch/x86/cpu/ivybridge/microcode_intel.c
@@ -0,0 +1,151 @@
+/*
+ * Copyright (c) 2014 Google, Inc
+ * Copyright (C) 2000 Ronald G. Minnich
+ *
+ * Microcode update for Intel PIII and later CPUs
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#include <common.h>
+#include <errno.h>
+#include <fdtdec.h>
+#include <libfdt.h>
+#include <asm/cpu.h>
+#include <asm/msr.h>
+#include <asm/processor.h>
+
+/**
+ * struct microcode_update - standard microcode header from Intel
+ *
+ * We read this information out of the device tree and use it to determine
+ * whether the update is applicable or not. We also use the same structure
+ * to read information from the CPU.
+ */
+struct microcode_update {
+ uint header_version;
+ uint update_revision;
+ uint date_code;
+ uint processor_signature;
+ uint checksum;
+ uint loader_revision;
+ uint processor_flags;
+ const void *data;
+ int size;
+};
+
+static int microcode_decode_node(const void *blob, int node,
+ struct microcode_update *update)
+{
+ update->data = fdt_getprop(blob, node, "data", &update->size);
+ if (!update->data)
+ return -EINVAL;
+
+ update->header_version = fdtdec_get_int(blob, node,
+ "intel,header-version", 0);
+ update->update_revision = fdtdec_get_int(blob, node,
+ "intel,update-revision", 0);
+ update->date_code = fdtdec_get_int(blob, node,
+ "intel,date-code", 0);
+ update->processor_signature = fdtdec_get_int(blob, node,
+ "intel.processor-signature", 0);
+ update->checksum = fdtdec_get_int(blob, node, "intel,checksum", 0);
+ update->loader_revision = fdtdec_get_int(blob, node,
+ "loader-revision", 0);
+ update->processor_flags = fdtdec_get_int(blob, node,
+ "processor-flags", 0);
+
+ return 0;
+}
+
+static uint32_t microcode_read_rev(void)
+{
+ /*
+ * Some Intel CPUs can be very finicky about the CPUID sequence used.
+ * So this is implemented in assembly so that it works reliably.
+ */
+ uint32_t low, high;
+
+ asm volatile (
+ "xorl %%eax, %%eax\n"
+ "xorl %%edx, %%edx\n"
+ "movl $0x8b, %%ecx\n"
+ "wrmsr\n"
+ "movl $0x01, %%eax\n"
+ "cpuid\n"
+ "movl $0x8b, %%ecx\n"
+ "rdmsr\n"
+ : /* outputs */
+ "=a" (low), "=d" (high)
+ : /* inputs */
+ : /* clobbers */
+ "ebx", "ecx"
+ );
+
+ return high;
+}
+
+static void microcode_read_cpu(struct microcode_update *cpu)
+{
+ /* CPUID sets MSR 0x8B iff a microcode update has been loaded. */
+ unsigned int x86_model, x86_family;
+ struct cpuid_result result;
+ uint32_t low, high;
+
+ wrmsr(0x8b, 0, 0);
+ result = cpuid(1);
+ rdmsr(0x8b, low, cpu->update_revision);
+ x86_model = (result.eax >> 4) & 0x0f;
+ x86_family = (result.eax >> 8) & 0x0f;
+ cpu->processor_signature = result.eax;
+
+ cpu->processor_flags = 0;
+ if ((x86_model >= 5) || (x86_family > 6)) {
+ rdmsr(0x17, low, high);
+ cpu->processor_flags = 1 << ((high >> 18) & 7);
+ }
+ debug("microcode: sig=%#x pf=%#x revision=%#x\n",
+ cpu->processor_signature, cpu->processor_flags,
+ cpu->update_revision);
+}
+
+/* Get a microcode update from the device tree and apply it */
+int microcode_update_intel(void)
+{
+ struct microcode_update cpu, update;
+ const void *blob = gd->fdt_blob;
+ int count;
+ int node;
+ int ret;
+
+ microcode_read_cpu(&cpu);
+ node = 0;
+ count = 0;
+ do {
+ node = fdtdec_next_compatible(blob, node,
+ COMPAT_INTEL_MICROCODE);
+ if (node < 0) {
+ debug("%s: Found %d updates\n", __func__, count);
+ return count ? 0 : -ENOENT;
+ }
+
+ ret = microcode_decode_node(blob, node, &update);
+ if (ret) {
+ debug("%s: Unable to decode update: %d\n", __func__,
+ ret);
+ return ret;
+ }
+ if (update.processor_signature == cpu.processor_signature &&
+ (update.processor_flags & cpu.processor_flags)) {
+ debug("%s: Update already exists\n", __func__);
+ return -EEXIST;
+ }
+
+ wrmsr(0x79, (ulong)update.data, 0);
+ debug("microcode: updated to revision 0x%x date=%04x-%02x-%02x\n",
+ microcode_read_rev(), update.date_code & 0xffff,
+ (update.date_code >> 24) & 0xff,
+ (update.date_code >> 16) & 0xff);
+ count++;
+ } while (1);
+}