/*
 *  AMD CPU Microcode Update Driver for Linux
 *
 *  This driver allows to upgrade microcode on F10h AMD
 *  CPUs and later.
 *
 *  Copyright (C) 2008-2011 Advanced Micro Devices Inc.
 *
 *  Author: Peter Oruba <peter.oruba@amd.com>
 *
 *  Based on work by:
 *  Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
 *
 *  early loader:
 *  Copyright (C) 2013 Advanced Micro Devices, Inc.
 *
 *  Author: Jacob Shin <jacob.shin@amd.com>
 *  Fixes: Borislav Petkov <bp@suse.de>
 *
 *  Licensed under the terms of the GNU General Public
 *  License version 2. See file COPYING for details.
 */
#define pr_fmt(fmt) "microcode: " fmt

#include <linux/earlycpio.h>
#include <linux/firmware.h>
#include <linux/uaccess.h>
#include <linux/vmalloc.h>
#include <linux/initrd.h>
#include <linux/kernel.h>
#include <linux/pci.h>

#include <asm/microcode_amd.h>
#include <asm/microcode.h>
#include <asm/processor.h>
#include <asm/setup.h>
#include <asm/cpu.h>
#include <asm/msr.h>

static struct equiv_cpu_entry *equiv_cpu_table;

struct ucode_patch {
        struct list_head plist;
        void *data;
        u32 patch_id;
        u16 equiv_cpu;
};

static LIST_HEAD(pcache);

/*
 * This points to the current valid container of microcode patches which we will
 * save from the initrd before jettisoning its contents.
 */
static u8 *container;
static size_t container_size;

static u32 ucode_new_rev;
u8 amd_ucode_patch[PATCH_MAX_SIZE];
static u16 this_equiv_id;

static struct cpio_data ucode_cpio;

/*
 * 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;
        char *path;
        void *start;
        size_t size;

#ifdef CONFIG_X86_32
        struct boot_params *p;

        /*
         * On 32-bit, early load occurs before paging is turned on so we need
         * to use physical addresses.
         */
        p       = (struct boot_params *)__pa_nodebug(&boot_params);
        path    = (char *)__pa_nodebug(ucode_path);
        start   = (void *)p->hdr.ramdisk_image;
        size    = p->hdr.ramdisk_size;
#else
        path    = ucode_path;
        start   = (void *)(boot_params.hdr.ramdisk_image + PAGE_OFFSET);
        size    = boot_params.hdr.ramdisk_size;
#endif

        return find_cpio_data(path, start, size, &offset);
}

static size_t compute_container_size(u8 *data, u32 total_size)
{
        size_t size = 0;
        u32 *header = (u32 *)data;

        if (header[0] != UCODE_MAGIC ||
            header[1] != UCODE_EQUIV_CPU_TABLE_TYPE || /* type */
            header[2] == 0)                            /* size */
                return size;

        size = header[2] + CONTAINER_HDR_SZ;
        total_size -= size;
        data += size;

        while (total_size) {
                u16 patch_size;

                header = (u32 *)data;

                if (header[0] != UCODE_UCODE_TYPE)
                        break;

                /*
                 * Sanity-check patch size.
                 */
                patch_size = header[1];
                if (patch_size > PATCH_MAX_SIZE)
                        break;

                size       += patch_size + SECTION_HDR_SIZE;
                data       += patch_size + SECTION_HDR_SIZE;
                total_size -= patch_size + SECTION_HDR_SIZE;
        }

        return size;
}

/*
 * 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 apply_ucode_in_initrd(void *ucode, size_t size, bool save_patch)
{
        struct equiv_cpu_entry *eq;
        size_t *cont_sz;
        u32 *header;
        u8  *data, **cont;
        u8 (*patch)[PATCH_MAX_SIZE];
        u16 eq_id = 0;
        int offset, left;
        u32 rev, eax, ebx, ecx, edx;
        u32 *new_rev;

#ifdef CONFIG_X86_32
        new_rev = (u32 *)__pa_nodebug(&ucode_new_rev);
        cont_sz = (size_t *)__pa_nodebug(&container_size);
        cont    = (u8 **)__pa_nodebug(&container);
        patch   = (u8 (*)[PATCH_MAX_SIZE])__pa_nodebug(&amd_ucode_patch);
#else
        new_rev = &ucode_new_rev;
        cont_sz = &container_size;
        cont    = &container;
        patch   = &amd_ucode_patch;
#endif

        data   = ucode;
        left   = size;
        header = (u32 *)data;

        /* find equiv cpu table */
        if (header[0] != UCODE_MAGIC ||
            header[1] != UCODE_EQUIV_CPU_TABLE_TYPE || /* type */
            header[2] == 0)                            /* size */
                return;

        eax = 0x00000001;
        ecx = 0;
        native_cpuid(&eax, &ebx, &ecx, &edx);

        while (left > 0) {
                eq = (struct equiv_cpu_entry *)(data + CONTAINER_HDR_SZ);

                *cont = data;

                /* Advance past the container header */
                offset = header[2] + CONTAINER_HDR_SZ;
                data  += offset;
                left  -= offset;

                eq_id = find_equiv_id(eq, eax);
                if (eq_id) {
                        this_equiv_id = eq_id;
                        *cont_sz = compute_container_size(*cont, left + offset);

                        /*
                         * truncate how much we need to iterate over in the
                         * ucode update loop below
                         */
                        left = *cont_sz - offset;
                        break;
                }

                /*
                 * support multiple container files appended together. if this
                 * one does not have a matching equivalent cpu entry, we fast
                 * forward to the next container file.
                 */
                while (left > 0) {
                        header = (u32 *)data;
                        if (header[0] == UCODE_MAGIC &&
                            header[1] == UCODE_EQUIV_CPU_TABLE_TYPE)
                                break;

                        offset = header[1] + SECTION_HDR_SIZE;
                        data  += offset;
                        left  -= offset;
                }

                /* mark where the next microcode container file starts */
                offset    = data - (u8 *)ucode;
                ucode     = data;
        }

        if (!eq_id) {
                *cont = NULL;
                *cont_sz = 0;
                return;
        }

        if (check_current_patch_level(&rev, true))
                return;

        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)) {
                                rev = mc->hdr.patch_id;
                                *new_rev = rev;

                                if (save_patch)
                                        memcpy(patch, mc,
                                               min_t(u32, header[1], PATCH_MAX_SIZE));
                        }
                }

                offset  = header[1] + SECTION_HDR_SIZE;
                data   += offset;
                left   -= offset;
        }
}

static bool __init load_builtin_amd_microcode(struct cpio_data *cp,
                                              unsigned int family)
{
#ifdef CONFIG_X86_64
        char fw_name[36] = "amd-ucode/microcode_amd.bin";

        if (family >= 0x15)
                snprintf(fw_name, sizeof(fw_name),
                         "amd-ucode/microcode_amd_fam%.2xh.bin", family);

        return get_builtin_firmware(cp, fw_name);
#else
        return false;
#endif
}

void __init load_ucode_amd_bsp(unsigned int family)
{
        struct cpio_data cp;
        void **data;
        size_t *size;

#ifdef CONFIG_X86_32
        data =  (void **)__pa_nodebug(&ucode_cpio.data);
        size = (size_t *)__pa_nodebug(&ucode_cpio.size);
#else
        data = &ucode_cpio.data;
        size = &ucode_cpio.size;
#endif

        cp = find_ucode_in_initrd();
        if (!cp.data) {
                if (!load_builtin_amd_microcode(&cp, family))
                        return;
        }

        *data = cp.data;
        *size = cp.size;

        apply_ucode_in_initrd(cp.data, cp.size, true);
}

#ifdef CONFIG_X86_32
/*
 * 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_ucode_patch,
 * which is used upon resume from suspend.
 */
void load_ucode_amd_ap(void)
{
        struct microcode_amd *mc;
        size_t *usize;
        void **ucode;

        mc = (struct microcode_amd *)__pa_nodebug(amd_ucode_patch);
        if (mc->hdr.patch_id && mc->hdr.processor_rev_id) {
                __apply_microcode_amd(mc);
                return;
        }

        ucode = (void *)__pa_nodebug(&container);
        usize = (size_t *)__pa_nodebug(&container_size);

        if (!*ucode || !*usize)
                return;

        apply_ucode_in_initrd(*ucode, *usize, false);
}

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);
}

static void __init get_bsp_sig(void)
{
        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);
}
#else
void load_ucode_amd_ap(void)
{
        unsigned int cpu = smp_processor_id();
        struct equiv_cpu_entry *eq;
        struct microcode_amd *mc;
        u32 rev, eax;
        u16 eq_id;

        /* Exit if called on the BSP. */
        if (!cpu)
                return;

        if (!container)
                return;

        /*
         * 64-bit runs with paging enabled, thus early==false.
         */
        if (check_current_patch_level(&rev, false))
                return;

        eax = cpuid_eax(0x00000001);
        eq  = (struct equiv_cpu_entry *)(container + CONTAINER_HDR_SZ);

        eq_id = find_equiv_id(eq, eax);
        if (!eq_id)
                return;

        if (eq_id == this_equiv_id) {
                mc = (struct microcode_amd *)amd_ucode_patch;

                if (mc && rev < mc->hdr.patch_id) {
                        if (!__apply_microcode_amd(mc))
                                ucode_new_rev = mc->hdr.patch_id;
                }

        } else {
                if (!ucode_cpio.data)
                        return;

                /*
                 * AP has a different equivalence ID than BSP, looks like
                 * mixed-steppings silicon so go through the ucode blob anew.
                 */
                apply_ucode_in_initrd(ucode_cpio.data, ucode_cpio.size, false);
        }
}
#endif

int __init save_microcode_in_initrd_amd(void)
{
        unsigned long cont;
        int retval = 0;
        enum ucode_state ret;
        u8 *cont_va;
        u32 eax;

        if (!container)
                return -EINVAL;

#ifdef CONFIG_X86_32
        get_bsp_sig();
        cont    = (unsigned long)container;
        cont_va = __va(container);
#else
        /*
         * We need the physical address of the container for both bitness since
         * boot_params.hdr.ramdisk_image is a physical address.
         */
        cont    = __pa(container);
        cont_va = container;
#endif

        /*
         * Take into account the fact that the ramdisk might get relocated and
         * therefore we need to recompute the container's position in virtual
         * memory space.
         */
        if (relocated_ramdisk)
                container = (u8 *)(__va(relocated_ramdisk) +
                             (cont - boot_params.hdr.ramdisk_image));
        else
                container = cont_va;

        eax   = cpuid_eax(0x00000001);
        eax   = ((eax >> 8) & 0xf) + ((eax >> 20) & 0xff);

        ret = load_microcode_amd(smp_processor_id(), eax, container, container_size);
        if (ret != UCODE_OK)
                retval = -EINVAL;

        /*
         * This will be freed any msec now, stash patches for the current
         * family and switch to patch cache for cpu hotplug, etc later.
         */
        container = NULL;
        container_size = 0;

        return retval;
}

void reload_ucode_amd(void)
{
        struct microcode_amd *mc;
        u32 rev;

        /*
         * early==false because this is a syscore ->resume path and by
         * that time paging is long enabled.
         */
        if (check_current_patch_level(&rev, false))
                return;

        mc = (struct microcode_amd *)amd_ucode_patch;

        if (mc && rev < mc->hdr.patch_id) {
                if (!__apply_microcode_amd(mc)) {
                        ucode_new_rev = mc->hdr.patch_id;
                        pr_info("reload patch_level=0x%08x\n", ucode_new_rev);
                }
        }
}
static u16 __find_equiv_id(unsigned int cpu)
{
        struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
        return find_equiv_id(equiv_cpu_table, uci->cpu_sig.sig);
}

static u32 find_cpu_family_by_equiv_cpu(u16 equiv_cpu)
{
        int i = 0;

        BUG_ON(!equiv_cpu_table);

        while (equiv_cpu_table[i].equiv_cpu != 0) {
                if (equiv_cpu == equiv_cpu_table[i].equiv_cpu)
                        return equiv_cpu_table[i].installed_cpu;
                i++;
        }
        return 0;
}

/*
 * a small, trivial cache of per-family ucode patches
 */
static struct ucode_patch *cache_find_patch(u16 equiv_cpu)
{
        struct ucode_patch *p;

        list_for_each_entry(p, &pcache, plist)
                if (p->equiv_cpu == equiv_cpu)
                        return p;
        return NULL;
}

static void update_cache(struct ucode_patch *new_patch)
{
        struct ucode_patch *p;

        list_for_each_entry(p, &pcache, plist) {
                if (p->equiv_cpu == new_patch->equiv_cpu) {
                        if (p->patch_id >= new_patch->patch_id)
                                /* we already have the latest patch */
                                return;

                        list_replace(&p->plist, &new_patch->plist);
                        kfree(p->data);
                        kfree(p);
                        return;
                }
        }
        /* no patch found, add it */
        list_add_tail(&new_patch->plist, &pcache);
}

static void free_cache(void)
{
        struct ucode_patch *p, *tmp;

        list_for_each_entry_safe(p, tmp, &pcache, plist) {
                __list_del(p->plist.prev, p->plist.next);
                kfree(p->data);
                kfree(p);
        }
}

static struct ucode_patch *find_patch(unsigned int cpu)
{
        u16 equiv_id;

        equiv_id = __find_equiv_id(cpu);
        if (!equiv_id)
                return NULL;

        return cache_find_patch(equiv_id);
}

static int collect_cpu_info_amd(int cpu, struct cpu_signature *csig)
{
        struct cpuinfo_x86 *c = &cpu_data(cpu);
        struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
        struct ucode_patch *p;

        csig->sig = cpuid_eax(0x00000001);
        csig->rev = c->microcode;

        /*
         * a patch could have been loaded early, set uci->mc so that
         * mc_bp_resume() can call apply_microcode()
         */
        p = find_patch(cpu);
        if (p && (p->patch_id == csig->rev))
                uci->mc = p->data;

        pr_info("CPU%d: patch_level=0x%08x\n", cpu, csig->rev);

        return 0;
}

static unsigned int verify_patch_size(u8 family, u32 patch_size,
                                      unsigned int size)
{
        u32 max_size;

#define F1XH_MPB_MAX_SIZE 2048
#define F14H_MPB_MAX_SIZE 1824
#define F15H_MPB_MAX_SIZE 4096
#define F16H_MPB_MAX_SIZE 3458

        switch (family) {
        case 0x14:
                max_size = F14H_MPB_MAX_SIZE;
                break;
        case 0x15:
                max_size = F15H_MPB_MAX_SIZE;
                break;
        case 0x16:
                max_size = F16H_MPB_MAX_SIZE;
                break;
        default:
                max_size = F1XH_MPB_MAX_SIZE;
                break;
        }

        if (patch_size > min_t(u32, size, max_size)) {
                pr_err("patch size mismatch\n");
                return 0;
        }

        return patch_size;
}

/*
 * Those patch levels cannot be updated to newer ones and thus should be final.
 */
static u32 final_levels[] = {
        0x01000098,
        0x0100009f,
        0x010000af,
        0, /* T-101 terminator */
};

/*
 * Check the current patch level on this CPU.
 *
 * @rev: Use it to return the patch level. It is set to 0 in the case of
 * error.
 *
 * Returns:
 *  - true: if update should stop
 *  - false: otherwise
 */
bool check_current_patch_level(u32 *rev, bool early)
{
        u32 lvl, dummy, i;
        bool ret = false;
        u32 *levels;

        native_rdmsr(MSR_AMD64_PATCH_LEVEL, lvl, dummy);

        if (IS_ENABLED(CONFIG_X86_32) && early)
                levels = (u32 *)__pa_nodebug(&final_levels);
        else
                levels = final_levels;

        for (i = 0; levels[i]; i++) {
                if (lvl == levels[i]) {
                        lvl = 0;
                        ret = true;
                        break;
                }
        }

        if (rev)
                *rev = lvl;

        return ret;
}

int __apply_microcode_amd(struct microcode_amd *mc_amd)
{
        u32 rev, dummy;

        native_wrmsrl(MSR_AMD64_PATCH_LOADER, (u64)(long)&mc_amd->hdr.data_code);

        /* verify patch application was successful */
        native_rdmsr(MSR_AMD64_PATCH_LEVEL, rev, dummy);
        if (rev != mc_amd->hdr.patch_id)
                return -1;

        return 0;
}

int apply_microcode_amd(int cpu)
{
        struct cpuinfo_x86 *c = &cpu_data(cpu);
        struct microcode_amd *mc_amd;
        struct ucode_cpu_info *uci;
        struct ucode_patch *p;
        u32 rev;

        BUG_ON(raw_smp_processor_id() != cpu);

        uci = ucode_cpu_info + cpu;

        p = find_patch(cpu);
        if (!p)
                return 0;

        mc_amd  = p->data;
        uci->mc = p->data;

        if (check_current_patch_level(&rev, false))
                return -1;

        /* need to apply patch? */
        if (rev >= mc_amd->hdr.patch_id) {
                c->microcode = rev;
                uci->cpu_sig.rev = rev;
                return 0;
        }

        if (__apply_microcode_amd(mc_amd)) {
                pr_err("CPU%d: update failed for patch_level=0x%08x\n",
                        cpu, mc_amd->hdr.patch_id);
                return -1;
        }
        pr_info("CPU%d: new patch_level=0x%08x\n", cpu,
                mc_amd->hdr.patch_id);

        uci->cpu_sig.rev = mc_amd->hdr.patch_id;
        c->microcode = mc_amd->hdr.patch_id;

        return 0;
}

static int install_equiv_cpu_table(const u8 *buf)
{
        unsigned int *ibuf = (unsigned int *)buf;
        unsigned int type = ibuf[1];
        unsigned int size = ibuf[2];

        if (type != UCODE_EQUIV_CPU_TABLE_TYPE || !size) {
                pr_err("empty section/"
                       "invalid type field in container file section header\n");
                return -EINVAL;
        }

        equiv_cpu_table = vmalloc(size);
        if (!equiv_cpu_table) {
                pr_err("failed to allocate equivalent CPU table\n");
                return -ENOMEM;
        }

        memcpy(equiv_cpu_table, buf + CONTAINER_HDR_SZ, size);

        /* add header length */
        return size + CONTAINER_HDR_SZ;
}

static void free_equiv_cpu_table(void)
{
        vfree(equiv_cpu_table);
        equiv_cpu_table = NULL;
}

static void cleanup(void)
{
        free_equiv_cpu_table();
        free_cache();
}

/*
 * We return the current size even if some of the checks failed so that
 * we can skip over the next patch. If we return a negative value, we
 * signal a grave error like a memory allocation has failed and the
 * driver cannot continue functioning normally. In such cases, we tear
 * down everything we've used up so far and exit.
 */
static int verify_and_add_patch(u8 family, u8 *fw, unsigned int leftover)
{
        struct microcode_header_amd *mc_hdr;
        struct ucode_patch *patch;
        unsigned int patch_size, crnt_size, ret;
        u32 proc_fam;
        u16 proc_id;

        patch_size  = *(u32 *)(fw + 4);
        crnt_size   = patch_size + SECTION_HDR_SIZE;
        mc_hdr      = (struct microcode_header_amd *)(fw + SECTION_HDR_SIZE);
        proc_id     = mc_hdr->processor_rev_id;

        proc_fam = find_cpu_family_by_equiv_cpu(proc_id);
        if (!proc_fam) {
                pr_err("No patch family for equiv ID: 0x%04x\n", proc_id);
                return crnt_size;
        }

        /* check if patch is for the current family */
        proc_fam = ((proc_fam >> 8) & 0xf) + ((proc_fam >> 20) & 0xff);
        if (proc_fam != family)
                return crnt_size;

        if (mc_hdr->nb_dev_id || mc_hdr->sb_dev_id) {
                pr_err("Patch-ID 0x%08x: chipset-specific code unsupported.\n",
                        mc_hdr->patch_id);
                return crnt_size;
        }

        ret = verify_patch_size(family, patch_size, leftover);
        if (!ret) {
                pr_err("Patch-ID 0x%08x: size mismatch.\n", mc_hdr->patch_id);
                return crnt_size;
        }

        patch = kzalloc(sizeof(*patch), GFP_KERNEL);
        if (!patch) {
                pr_err("Patch allocation failure.\n");
                return -EINVAL;
        }

        patch->data = kmemdup(fw + SECTION_HDR_SIZE, patch_size, GFP_KERNEL);
        if (!patch->data) {
                pr_err("Patch data allocation failure.\n");
                kfree(patch);
                return -EINVAL;
        }

        INIT_LIST_HEAD(&patch->plist);
        patch->patch_id  = mc_hdr->patch_id;
        patch->equiv_cpu = proc_id;

        pr_debug("%s: Added patch_id: 0x%08x, proc_id: 0x%04x\n",
                 __func__, patch->patch_id, proc_id);

        /* ... and add to cache. */
        update_cache(patch);

        return crnt_size;
}

static enum ucode_state __load_microcode_amd(u8 family, const u8 *data,
                                             size_t size)
{
        enum ucode_state ret = UCODE_ERROR;
        unsigned int leftover;
        u8 *fw = (u8 *)data;
        int crnt_size = 0;
        int offset;

        offset = install_equiv_cpu_table(data);
        if (offset < 0) {
                pr_err("failed to create equivalent cpu table\n");
                return ret;
        }
        fw += offset;
        leftover = size - offset;

        if (*(u32 *)fw != UCODE_UCODE_TYPE) {
                pr_err("invalid type field in container file section header\n");
                free_equiv_cpu_table();
                return ret;
        }

        while (leftover) {
                crnt_size = verify_and_add_patch(family, fw, leftover);
                if (crnt_size < 0)
                        return ret;

                fw       += crnt_size;
                leftover -= crnt_size;
        }

        return UCODE_OK;
}

enum ucode_state load_microcode_amd(int cpu, u8 family, const u8 *data, size_t size)
{
        enum ucode_state ret;

        /* free old equiv table */
        free_equiv_cpu_table();

        ret = __load_microcode_amd(family, data, size);

        if (ret != UCODE_OK)
                cleanup();

#ifdef CONFIG_X86_32
        /* save BSP's matching patch for early load */
        if (cpu_data(cpu).cpu_index == boot_cpu_data.cpu_index) {
                struct ucode_patch *p = find_patch(cpu);
                if (p) {
                        memset(amd_ucode_patch, 0, PATCH_MAX_SIZE);
                        memcpy(amd_ucode_patch, p->data, min_t(u32, ksize(p->data),
                                                               PATCH_MAX_SIZE));
                }
        }
#endif
        return ret;
}

/*
 * AMD microcode firmware naming convention, up to family 15h they are in
 * the legacy file:
 *
 *    amd-ucode/microcode_amd.bin
 *
 * This legacy file is always smaller than 2K in size.
 *
 * Beginning with family 15h, they are in family-specific firmware files:
 *
 *    amd-ucode/microcode_amd_fam15h.bin
 *    amd-ucode/microcode_amd_fam16h.bin
 *    ...
 *
 * These might be larger than 2K.
 */
static enum ucode_state request_microcode_amd(int cpu, struct device *device,
                                              bool refresh_fw)
{
        char fw_name[36] = "amd-ucode/microcode_amd.bin";
        struct cpuinfo_x86 *c = &cpu_data(cpu);
        enum ucode_state ret = UCODE_NFOUND;
        const struct firmware *fw;

        /* reload ucode container only on the boot cpu */
        if (!refresh_fw || c->cpu_index != boot_cpu_data.cpu_index)
                return UCODE_OK;

        if (c->x86 >= 0x15)
                snprintf(fw_name, sizeof(fw_name), "amd-ucode/microcode_amd_fam%.2xh.bin", c->x86);

        if (request_firmware_direct(&fw, (const char *)fw_name, device)) {
                pr_debug("failed to load file %s\n", fw_name);
                goto out;
        }

        ret = UCODE_ERROR;
        if (*(u32 *)fw->data != UCODE_MAGIC) {
                pr_err("invalid magic value (0x%08x)\n", *(u32 *)fw->data);
                goto fw_release;
        }

        ret = load_microcode_amd(cpu, c->x86, fw->data, fw->size);

 fw_release:
        release_firmware(fw);

 out:
        return ret;
}

static enum ucode_state
request_microcode_user(int cpu, const void __user *buf, size_t size)
{
        return UCODE_ERROR;
}

static void microcode_fini_cpu_amd(int cpu)
{
        struct ucode_cpu_info *uci = ucode_cpu_info + cpu;

        uci->mc = NULL;
}

static struct microcode_ops microcode_amd_ops = {
        .request_microcode_user           = request_microcode_user,
        .request_microcode_fw             = request_microcode_amd,
        .collect_cpu_info                 = collect_cpu_info_amd,
        .apply_microcode                  = apply_microcode_amd,
        .microcode_fini_cpu               = microcode_fini_cpu_amd,
};

struct microcode_ops * __init init_amd_microcode(void)
{
        struct cpuinfo_x86 *c = &boot_cpu_data;

        if (c->x86_vendor != X86_VENDOR_AMD || c->x86 < 0x10) {
                pr_warn("AMD CPU family 0x%x not supported\n", c->x86);
                return NULL;
        }

        if (ucode_new_rev)
                pr_info_once("microcode updated early to new patch_level=0x%08x\n",
                             ucode_new_rev);

        return &microcode_amd_ops;
}

void __exit exit_amd_microcode(void)
{
        cleanup();
}