--- /dev/null
+/*
+ * 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;
+}