x86, microcode, amd: Early microcode patch loading support for AMD

Add early microcode patch loading support for AMD.

Signed-off-by: Jacob Shin <jacob.shin@amd.com>
Link: http://lkml.kernel.org/r/1369940959-2077-5-git-send-email-jacob.shin@amd.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>

1 files changed, 222 insertions, 0 deletions

diff --git a/arch/x86/kernel/microcode_amd_early.c b/arch/x86/kernel/microcode_amd_early.c
new file mode 100644
index 000000000000..7e54d97c714a
--- /dev/null
+++ b/arch/x86/kernel/microcode_amd_early.c
@@ -0,0 +1,222 @@
+/*
+ * Copyright (C) 2013 Advanced Micro Devices, Inc.
+ *
+ * Author: Jacob Shin <jacob.shin@amd.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/earlycpio.h>
+
+#include <asm/cpu.h>
+#include <asm/setup.h>
+#include <asm/microcode_amd.h>
+
+static bool ucode_loaded;
+static u32 ucode_new_rev;
+
+/*
+ * Microcode patch container file is prepended to the initrd in cpio format.
+ * See Documentation/x86/early-microcode.txt
+ */
+static __initdata char ucode_path[] = "kernel/x86/microcode/AuthenticAMD.bin";
+
+static struct cpio_data __init find_ucode_in_initrd(void)
+{
+	long offset = 0;
+	struct cpio_data cd;
+
+#ifdef CONFIG_X86_32
+	/*
+	 * On 32-bit, early load occurs before paging is turned on so we need
+	 * to use physical addresses.
+	 */
+	if (!(read_cr0() & X86_CR0_PG)) {
+		struct boot_params *p;
+		p  = (struct boot_params *)__pa_nodebug(&boot_params);
+		cd = find_cpio_data((char *)__pa_nodebug(ucode_path),
+			(void *)p->hdr.ramdisk_image, p->hdr.ramdisk_size,
+			&offset);
+	} else
+#endif
+		cd = find_cpio_data(ucode_path,
+			(void *)(boot_params.hdr.ramdisk_image + PAGE_OFFSET),
+			boot_params.hdr.ramdisk_size, &offset);
+
+	if (*(u32 *)cd.data != UCODE_MAGIC) {
+		cd.data = NULL;
+		cd.size = 0;
+	}
+
+	return cd;
+}
+
+/*
+ * Early load occurs before we can vmalloc(). So we look for the microcode
+ * patch container file in initrd, traverse equivalent cpu table, look for a
+ * matching microcode patch, and update, all in initrd memory in place.
+ * When vmalloc() is available for use later -- on 64-bit during first AP load,
+ * and on 32-bit during save_microcode_in_initrd_amd() -- we can call
+ * load_microcode_amd() to save equivalent cpu table and microcode patches in
+ * kernel heap memory.
+ */
+static void __init apply_ucode_in_initrd(void)
+{
+	struct cpio_data cd;
+	struct equiv_cpu_entry *eq;
+	u32 *header;
+	u8  *data;
+	u16 eq_id;
+	int offset, left;
+	u32 rev, dummy;
+	u32 *new_rev;
+
+#ifdef CONFIG_X86_32
+	new_rev = (u32 *)__pa_nodebug(&ucode_new_rev);
+#else
+	new_rev = &ucode_new_rev;
+#endif
+	cd = find_ucode_in_initrd();
+	if (!cd.data)
+		return;
+
+	data   = cd.data;
+	left   = cd.size;
+	header = (u32 *)data;
+
+	/* find equiv cpu table */
+
+	if (header[1] != UCODE_EQUIV_CPU_TABLE_TYPE || /* type */
+	    header[2] == 0)                            /* size */
+		return;
+
+	eq     = (struct equiv_cpu_entry *)(data + CONTAINER_HDR_SZ);
+	offset = header[2] + CONTAINER_HDR_SZ;
+	data  += offset;
+	left  -= offset;
+
+	eq_id  = find_equiv_id(eq, cpuid_eax(0x00000001));
+	if (!eq_id)
+		return;
+
+	/* find ucode and update if needed */
+
+	rdmsr(MSR_AMD64_PATCH_LEVEL, rev, dummy);
+
+	while (left > 0) {
+		struct microcode_amd *mc;
+
+		header = (u32 *)data;
+		if (header[0] != UCODE_UCODE_TYPE || /* type */
+		    header[1] == 0)                  /* size */
+			break;
+
+		mc = (struct microcode_amd *)(data + SECTION_HDR_SIZE);
+		if (eq_id == mc->hdr.processor_rev_id && rev < mc->hdr.patch_id)
+			if (__apply_microcode_amd(mc) == 0) {
+				if (!(*new_rev))
+					*new_rev = mc->hdr.patch_id;
+				break;
+			}
+
+		offset  = header[1] + SECTION_HDR_SIZE;
+		data   += offset;
+		left   -= offset;
+	}
+}
+
+void __init load_ucode_amd_bsp(void)
+{
+	apply_ucode_in_initrd();
+}
+
+#ifdef CONFIG_X86_32
+u8 __cpuinitdata amd_bsp_mpb[MPB_MAX_SIZE];
+
+/*
+ * On 32-bit, since AP's early load occurs before paging is turned on, we
+ * cannot traverse cpu_equiv_table and pcache in kernel heap memory. So during
+ * cold boot, AP will apply_ucode_in_initrd() just like the BSP. During
+ * save_microcode_in_initrd_amd() BSP's patch is copied to amd_bsp_mpb, which
+ * is used upon resume from suspend.
+ */
+void __cpuinit load_ucode_amd_ap(void)
+{
+	struct microcode_amd *mc;
+
+	mc = (struct microcode_amd *)__pa_nodebug(amd_bsp_mpb);
+	if (mc->hdr.patch_id && mc->hdr.processor_rev_id)
+		__apply_microcode_amd(mc);
+	else
+		apply_ucode_in_initrd();
+}
+
+static void __init collect_cpu_sig_on_bsp(void *arg)
+{
+	unsigned int cpu = smp_processor_id();
+	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
+	uci->cpu_sig.sig = cpuid_eax(0x00000001);
+}
+#else
+static void __cpuinit collect_cpu_info_amd_early(struct cpuinfo_x86 *c,
+						 struct ucode_cpu_info *uci)
+{
+	u32 rev, eax;
+
+	rdmsr(MSR_AMD64_PATCH_LEVEL, rev, eax);
+	eax = cpuid_eax(0x00000001);
+
+	uci->cpu_sig.sig = eax;
+	uci->cpu_sig.rev = rev;
+	c->microcode = rev;
+	c->x86 = ((eax >> 8) & 0xf) + ((eax >> 20) & 0xff);
+}
+
+void __cpuinit load_ucode_amd_ap(void)
+{
+	unsigned int cpu = smp_processor_id();
+
+	collect_cpu_info_amd_early(&cpu_data(cpu), ucode_cpu_info + cpu);
+
+	if (cpu && !ucode_loaded) {
+		struct cpio_data cd = find_ucode_in_initrd();
+		if (load_microcode_amd(0, cd.data, cd.size) != UCODE_OK)
+			return;
+		ucode_loaded = true;
+	}
+
+	apply_microcode_amd(cpu);
+}
+#endif
+
+int __init save_microcode_in_initrd_amd(void)
+{
+	enum ucode_state ret;
+	struct cpio_data cd;
+#ifdef CONFIG_X86_32
+	unsigned int bsp = boot_cpu_data.cpu_index;
+	struct ucode_cpu_info *uci = ucode_cpu_info + bsp;
+
+	if (!uci->cpu_sig.sig)
+		smp_call_function_single(bsp, collect_cpu_sig_on_bsp, NULL, 1);
+#endif
+	if (ucode_new_rev)
+		pr_info("microcode: updated early to new patch_level=0x%08x\n",
+			ucode_new_rev);
+
+	if (ucode_loaded)
+		return 0;
+
+	cd = find_ucode_in_initrd();
+	if (!cd.data)
+		return -EINVAL;
+
+	ret = load_microcode_amd(0, cd.data, cd.size);
+	if (ret != UCODE_OK)
+		return -EINVAL;
+
+	ucode_loaded = true;
+	return 0;
+}