// SPDX-License-Identifier: GPL-2.0-only
/*
 * AMD Secure Encrypted Virtualization (SEV) interface
 *
 * Copyright (C) 2016,2019 Advanced Micro Devices, Inc.
 *
 * Author: Brijesh Singh <brijesh.singh@amd.com>
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/kthread.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/spinlock_types.h>
#include <linux/types.h>
#include <linux/mutex.h>
#include <linux/delay.h>
#include <linux/hw_random.h>
#include <linux/ccp.h>
#include <linux/firmware.h>
#include <linux/gfp.h>
#include <linux/cpufeature.h>

#include <asm/smp.h>

#include "psp-dev.h"
#include "sev-dev.h"

#define DEVICE_NAME             "sev"
#define SEV_FW_FILE             "amd/sev.fw"
#define SEV_FW_NAME_SIZE        64

static DEFINE_MUTEX(sev_cmd_mutex);
static struct sev_misc_dev *misc_dev;

static int psp_cmd_timeout = 100;
module_param(psp_cmd_timeout, int, 0644);
MODULE_PARM_DESC(psp_cmd_timeout, " default timeout value, in seconds, for PSP commands");

static int psp_probe_timeout = 5;
module_param(psp_probe_timeout, int, 0644);
MODULE_PARM_DESC(psp_probe_timeout, " default timeout value, in seconds, during PSP device probe");

MODULE_FIRMWARE("amd/amd_sev_fam17h_model0xh.sbin"); /* 1st gen EPYC */
MODULE_FIRMWARE("amd/amd_sev_fam17h_model3xh.sbin"); /* 2nd gen EPYC */
MODULE_FIRMWARE("amd/amd_sev_fam19h_model0xh.sbin"); /* 3rd gen EPYC */

static bool psp_dead;
static int psp_timeout;

/* Trusted Memory Region (TMR):
 *   The TMR is a 1MB area that must be 1MB aligned.  Use the page allocator
 *   to allocate the memory, which will return aligned memory for the specified
 *   allocation order.
 */
#define SEV_ES_TMR_SIZE         (1024 * 1024)
static void *sev_es_tmr;

static inline bool sev_version_greater_or_equal(u8 maj, u8 min)
{
        struct sev_device *sev = psp_master->sev_data;

        if (sev->api_major > maj)
                return true;

        if (sev->api_major == maj && sev->api_minor >= min)
                return true;

        return false;
}

static void sev_irq_handler(int irq, void *data, unsigned int status)
{
        struct sev_device *sev = data;
        int reg;

        /* Check if it is command completion: */
        if (!(status & SEV_CMD_COMPLETE))
                return;

        /* Check if it is SEV command completion: */
        reg = ioread32(sev->io_regs + sev->vdata->cmdresp_reg);
        if (reg & PSP_CMDRESP_RESP) {
                sev->int_rcvd = 1;
                wake_up(&sev->int_queue);
        }
}

static int sev_wait_cmd_ioc(struct sev_device *sev,
                            unsigned int *reg, unsigned int timeout)
{
        int ret;

        ret = wait_event_timeout(sev->int_queue,
                        sev->int_rcvd, timeout * HZ);
        if (!ret)
                return -ETIMEDOUT;

        *reg = ioread32(sev->io_regs + sev->vdata->cmdresp_reg);

        return 0;
}

static int sev_cmd_buffer_len(int cmd)
{
        switch (cmd) {
        case SEV_CMD_INIT:                      return sizeof(struct sev_data_init);
        case SEV_CMD_PLATFORM_STATUS:           return sizeof(struct sev_user_data_status);
        case SEV_CMD_PEK_CSR:                   return sizeof(struct sev_data_pek_csr);
        case SEV_CMD_PEK_CERT_IMPORT:           return sizeof(struct sev_data_pek_cert_import);
        case SEV_CMD_PDH_CERT_EXPORT:           return sizeof(struct sev_data_pdh_cert_export);
        case SEV_CMD_LAUNCH_START:              return sizeof(struct sev_data_launch_start);
        case SEV_CMD_LAUNCH_UPDATE_DATA:        return sizeof(struct sev_data_launch_update_data);
        case SEV_CMD_LAUNCH_UPDATE_VMSA:        return sizeof(struct sev_data_launch_update_vmsa);
        case SEV_CMD_LAUNCH_FINISH:             return sizeof(struct sev_data_launch_finish);
        case SEV_CMD_LAUNCH_MEASURE:            return sizeof(struct sev_data_launch_measure);
        case SEV_CMD_ACTIVATE:                  return sizeof(struct sev_data_activate);
        case SEV_CMD_DEACTIVATE:                return sizeof(struct sev_data_deactivate);
        case SEV_CMD_DECOMMISSION:              return sizeof(struct sev_data_decommission);
        case SEV_CMD_GUEST_STATUS:              return sizeof(struct sev_data_guest_status);
        case SEV_CMD_DBG_DECRYPT:               return sizeof(struct sev_data_dbg);
        case SEV_CMD_DBG_ENCRYPT:               return sizeof(struct sev_data_dbg);
        case SEV_CMD_SEND_START:                return sizeof(struct sev_data_send_start);
        case SEV_CMD_SEND_UPDATE_DATA:          return sizeof(struct sev_data_send_update_data);
        case SEV_CMD_SEND_UPDATE_VMSA:          return sizeof(struct sev_data_send_update_vmsa);
        case SEV_CMD_SEND_FINISH:               return sizeof(struct sev_data_send_finish);
        case SEV_CMD_RECEIVE_START:             return sizeof(struct sev_data_receive_start);
        case SEV_CMD_RECEIVE_FINISH:            return sizeof(struct sev_data_receive_finish);
        case SEV_CMD_RECEIVE_UPDATE_DATA:       return sizeof(struct sev_data_receive_update_data);
        case SEV_CMD_RECEIVE_UPDATE_VMSA:       return sizeof(struct sev_data_receive_update_vmsa);
        case SEV_CMD_LAUNCH_UPDATE_SECRET:      return sizeof(struct sev_data_launch_secret);
        case SEV_CMD_DOWNLOAD_FIRMWARE:         return sizeof(struct sev_data_download_firmware);
        case SEV_CMD_GET_ID:                    return sizeof(struct sev_data_get_id);
        case SEV_CMD_ATTESTATION_REPORT:        return sizeof(struct sev_data_attestation_report);
        case SEV_CMD_SEND_CANCEL:                       return sizeof(struct sev_data_send_cancel);
        default:                                return 0;
        }

        return 0;
}

static int __sev_do_cmd_locked(int cmd, void *data, int *psp_ret)
{
        struct psp_device *psp = psp_master;
        struct sev_device *sev;
        unsigned int phys_lsb, phys_msb;
        unsigned int reg, ret = 0;
        int buf_len;

        if (!psp || !psp->sev_data)
                return -ENODEV;

        if (psp_dead)
                return -EBUSY;

        sev = psp->sev_data;

        buf_len = sev_cmd_buffer_len(cmd);
        if (WARN_ON_ONCE(!data != !buf_len))
                return -EINVAL;

        /*
         * Copy the incoming data to driver's scratch buffer as __pa() will not
         * work for some memory, e.g. vmalloc'd addresses, and @data may not be
         * physically contiguous.
         */
        if (data)
                memcpy(sev->cmd_buf, data, buf_len);

        /* Get the physical address of the command buffer */
        phys_lsb = data ? lower_32_bits(__psp_pa(sev->cmd_buf)) : 0;
        phys_msb = data ? upper_32_bits(__psp_pa(sev->cmd_buf)) : 0;

        dev_dbg(sev->dev, "sev command id %#x buffer 0x%08x%08x timeout %us\n",
                cmd, phys_msb, phys_lsb, psp_timeout);

        print_hex_dump_debug("(in):  ", DUMP_PREFIX_OFFSET, 16, 2, data,
                             buf_len, false);

        iowrite32(phys_lsb, sev->io_regs + sev->vdata->cmdbuff_addr_lo_reg);
        iowrite32(phys_msb, sev->io_regs + sev->vdata->cmdbuff_addr_hi_reg);

        sev->int_rcvd = 0;

        reg = cmd;
        reg <<= SEV_CMDRESP_CMD_SHIFT;
        reg |= SEV_CMDRESP_IOC;
        iowrite32(reg, sev->io_regs + sev->vdata->cmdresp_reg);

        /* wait for command completion */
        ret = sev_wait_cmd_ioc(sev, &reg, psp_timeout);
        if (ret) {
                if (psp_ret)
                        *psp_ret = 0;

                dev_err(sev->dev, "sev command %#x timed out, disabling PSP\n", cmd);
                psp_dead = true;

                return ret;
        }

        psp_timeout = psp_cmd_timeout;

        if (psp_ret)
                *psp_ret = reg & PSP_CMDRESP_ERR_MASK;

        if (reg & PSP_CMDRESP_ERR_MASK) {
                dev_dbg(sev->dev, "sev command %#x failed (%#010x)\n",
                        cmd, reg & PSP_CMDRESP_ERR_MASK);
                ret = -EIO;
        }

        print_hex_dump_debug("(out): ", DUMP_PREFIX_OFFSET, 16, 2, data,
                             buf_len, false);

        /*
         * Copy potential output from the PSP back to data.  Do this even on
         * failure in case the caller wants to glean something from the error.
         */
        if (data)
                memcpy(data, sev->cmd_buf, buf_len);

        return ret;
}

static int sev_do_cmd(int cmd, void *data, int *psp_ret)
{
        int rc;

        mutex_lock(&sev_cmd_mutex);
        rc = __sev_do_cmd_locked(cmd, data, psp_ret);
        mutex_unlock(&sev_cmd_mutex);

        return rc;
}

static int __sev_platform_init_locked(int *error)
{
        struct psp_device *psp = psp_master;
        struct sev_data_init data;
        struct sev_device *sev;
        int rc = 0;

        if (!psp || !psp->sev_data)
                return -ENODEV;

        sev = psp->sev_data;

        if (sev->state == SEV_STATE_INIT)
                return 0;

        memset(&data, 0, sizeof(data));
        if (sev_es_tmr) {
                u64 tmr_pa;

                /*
                 * Do not include the encryption mask on the physical
                 * address of the TMR (firmware should clear it anyway).
                 */
                tmr_pa = __pa(sev_es_tmr);

                data.flags |= SEV_INIT_FLAGS_SEV_ES;
                data.tmr_address = tmr_pa;
                data.tmr_len = SEV_ES_TMR_SIZE;
        }

        rc = __sev_do_cmd_locked(SEV_CMD_INIT, &data, error);
        if (rc)
                return rc;

        sev->state = SEV_STATE_INIT;

        /* Prepare for first SEV guest launch after INIT */
        wbinvd_on_all_cpus();
        rc = __sev_do_cmd_locked(SEV_CMD_DF_FLUSH, NULL, error);
        if (rc)
                return rc;

        dev_dbg(sev->dev, "SEV firmware initialized\n");

        return rc;
}

int sev_platform_init(int *error)
{
        int rc;

        mutex_lock(&sev_cmd_mutex);
        rc = __sev_platform_init_locked(error);
        mutex_unlock(&sev_cmd_mutex);

        return rc;
}
EXPORT_SYMBOL_GPL(sev_platform_init);

static int __sev_platform_shutdown_locked(int *error)
{
        struct sev_device *sev = psp_master->sev_data;
        int ret;

        if (sev->state == SEV_STATE_UNINIT)
                return 0;

        ret = __sev_do_cmd_locked(SEV_CMD_SHUTDOWN, NULL, error);
        if (ret)
                return ret;

        sev->state = SEV_STATE_UNINIT;
        dev_dbg(sev->dev, "SEV firmware shutdown\n");

        return ret;
}

static int sev_platform_shutdown(int *error)
{
        int rc;

        mutex_lock(&sev_cmd_mutex);
        rc = __sev_platform_shutdown_locked(NULL);
        mutex_unlock(&sev_cmd_mutex);

        return rc;
}

static int sev_get_platform_state(int *state, int *error)
{
        struct sev_user_data_status data;
        int rc;

        rc = __sev_do_cmd_locked(SEV_CMD_PLATFORM_STATUS, &data, error);
        if (rc)
                return rc;

        *state = data.state;
        return rc;
}

static int sev_ioctl_do_reset(struct sev_issue_cmd *argp, bool writable)
{
        int state, rc;

        if (!writable)
                return -EPERM;

        /*
         * The SEV spec requires that FACTORY_RESET must be issued in
         * UNINIT state. Before we go further lets check if any guest is
         * active.
         *
         * If FW is in WORKING state then deny the request otherwise issue
         * SHUTDOWN command do INIT -> UNINIT before issuing the FACTORY_RESET.
         *
         */
        rc = sev_get_platform_state(&state, &argp->error);
        if (rc)
                return rc;

        if (state == SEV_STATE_WORKING)
                return -EBUSY;

        if (state == SEV_STATE_INIT) {
                rc = __sev_platform_shutdown_locked(&argp->error);
                if (rc)
                        return rc;
        }

        return __sev_do_cmd_locked(SEV_CMD_FACTORY_RESET, NULL, &argp->error);
}

static int sev_ioctl_do_platform_status(struct sev_issue_cmd *argp)
{
        struct sev_user_data_status data;
        int ret;

        ret = __sev_do_cmd_locked(SEV_CMD_PLATFORM_STATUS, &data, &argp->error);
        if (ret)
                return ret;

        if (copy_to_user((void __user *)argp->data, &data, sizeof(data)))
                ret = -EFAULT;

        return ret;
}

static int sev_ioctl_do_pek_pdh_gen(int cmd, struct sev_issue_cmd *argp, bool writable)
{
        struct sev_device *sev = psp_master->sev_data;
        int rc;

        if (!writable)
                return -EPERM;

        if (sev->state == SEV_STATE_UNINIT) {
                rc = __sev_platform_init_locked(&argp->error);
                if (rc)
                        return rc;
        }

        return __sev_do_cmd_locked(cmd, NULL, &argp->error);
}

static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable)
{
        struct sev_device *sev = psp_master->sev_data;
        struct sev_user_data_pek_csr input;
        struct sev_data_pek_csr data;
        void __user *input_address;
        void *blob = NULL;
        int ret;

        if (!writable)
                return -EPERM;

        if (copy_from_user(&input, (void __user *)argp->data, sizeof(input)))
                return -EFAULT;

        memset(&data, 0, sizeof(data));

        /* userspace wants to query CSR length */
        if (!input.address || !input.length)
                goto cmd;

        /* allocate a physically contiguous buffer to store the CSR blob */
        input_address = (void __user *)input.address;
        if (input.length > SEV_FW_BLOB_MAX_SIZE)
                return -EFAULT;

        blob = kmalloc(input.length, GFP_KERNEL);
        if (!blob)
                return -ENOMEM;

        data.address = __psp_pa(blob);
        data.len = input.length;

cmd:
        if (sev->state == SEV_STATE_UNINIT) {
                ret = __sev_platform_init_locked(&argp->error);
                if (ret)
                        goto e_free_blob;
        }

        ret = __sev_do_cmd_locked(SEV_CMD_PEK_CSR, &data, &argp->error);

         /* If we query the CSR length, FW responded with expected data. */
        input.length = data.len;

        if (copy_to_user((void __user *)argp->data, &input, sizeof(input))) {
                ret = -EFAULT;
                goto e_free_blob;
        }

        if (blob) {
                if (copy_to_user(input_address, blob, input.length))
                        ret = -EFAULT;
        }

e_free_blob:
        kfree(blob);
        return ret;
}

void *psp_copy_user_blob(u64 uaddr, u32 len)
{
        if (!uaddr || !len)
                return ERR_PTR(-EINVAL);

        /* verify that blob length does not exceed our limit */
        if (len > SEV_FW_BLOB_MAX_SIZE)
                return ERR_PTR(-EINVAL);

        return memdup_user((void __user *)uaddr, len);
}
EXPORT_SYMBOL_GPL(psp_copy_user_blob);

static int sev_get_api_version(void)
{
        struct sev_device *sev = psp_master->sev_data;
        struct sev_user_data_status status;
        int error = 0, ret;

        ret = sev_platform_status(&status, &error);
        if (ret) {
                dev_err(sev->dev,
                        "SEV: failed to get status. Error: %#x\n", error);
                return 1;
        }

        sev->api_major = status.api_major;
        sev->api_minor = status.api_minor;
        sev->build = status.build;
        sev->state = status.state;

        return 0;
}

static int sev_get_firmware(struct device *dev,
                            const struct firmware **firmware)
{
        char fw_name_specific[SEV_FW_NAME_SIZE];
        char fw_name_subset[SEV_FW_NAME_SIZE];

        snprintf(fw_name_specific, sizeof(fw_name_specific),
                 "amd/amd_sev_fam%.2xh_model%.2xh.sbin",
                 boot_cpu_data.x86, boot_cpu_data.x86_model);

        snprintf(fw_name_subset, sizeof(fw_name_subset),
                 "amd/amd_sev_fam%.2xh_model%.1xxh.sbin",
                 boot_cpu_data.x86, (boot_cpu_data.x86_model & 0xf0) >> 4);

        /* Check for SEV FW for a particular model.
         * Ex. amd_sev_fam17h_model00h.sbin for Family 17h Model 00h
         *
         * or
         *
         * Check for SEV FW common to a subset of models.
         * Ex. amd_sev_fam17h_model0xh.sbin for
         *     Family 17h Model 00h -- Family 17h Model 0Fh
         *
         * or
         *
         * Fall-back to using generic name: sev.fw
         */
        if ((firmware_request_nowarn(firmware, fw_name_specific, dev) >= 0) ||
            (firmware_request_nowarn(firmware, fw_name_subset, dev) >= 0) ||
            (firmware_request_nowarn(firmware, SEV_FW_FILE, dev) >= 0))
                return 0;

        return -ENOENT;
}

/* Don't fail if SEV FW couldn't be updated. Continue with existing SEV FW */
static int sev_update_firmware(struct device *dev)
{
        struct sev_data_download_firmware *data;
        const struct firmware *firmware;
        int ret, error, order;
        struct page *p;
        u64 data_size;

        if (sev_get_firmware(dev, &firmware) == -ENOENT) {
                dev_dbg(dev, "No SEV firmware file present\n");
                return -1;
        }

        /*
         * SEV FW expects the physical address given to it to be 32
         * byte aligned. Memory allocated has structure placed at the
         * beginning followed by the firmware being passed to the SEV
         * FW. Allocate enough memory for data structure + alignment
         * padding + SEV FW.
         */
        data_size = ALIGN(sizeof(struct sev_data_download_firmware), 32);

        order = get_order(firmware->size + data_size);
        p = alloc_pages(GFP_KERNEL, order);
        if (!p) {
                ret = -1;
                goto fw_err;
        }

        /*
         * Copy firmware data to a kernel allocated contiguous
         * memory region.
         */
        data = page_address(p);
        memcpy(page_address(p) + data_size, firmware->data, firmware->size);

        data->address = __psp_pa(page_address(p) + data_size);
        data->len = firmware->size;

        ret = sev_do_cmd(SEV_CMD_DOWNLOAD_FIRMWARE, data, &error);
        if (ret)
                dev_dbg(dev, "Failed to update SEV firmware: %#x\n", error);
        else
                dev_info(dev, "SEV firmware update successful\n");

        __free_pages(p, order);

fw_err:
        release_firmware(firmware);

        return ret;
}

static int sev_ioctl_do_pek_import(struct sev_issue_cmd *argp, bool writable)
{
        struct sev_device *sev = psp_master->sev_data;
        struct sev_user_data_pek_cert_import input;
        struct sev_data_pek_cert_import data;
        void *pek_blob, *oca_blob;
        int ret;

        if (!writable)
                return -EPERM;

        if (copy_from_user(&input, (void __user *)argp->data, sizeof(input)))
                return -EFAULT;

        /* copy PEK certificate blobs from userspace */
        pek_blob = psp_copy_user_blob(input.pek_cert_address, input.pek_cert_len);
        if (IS_ERR(pek_blob))
                return PTR_ERR(pek_blob);

        data.reserved = 0;
        data.pek_cert_address = __psp_pa(pek_blob);
        data.pek_cert_len = input.pek_cert_len;

        /* copy PEK certificate blobs from userspace */
        oca_blob = psp_copy_user_blob(input.oca_cert_address, input.oca_cert_len);
        if (IS_ERR(oca_blob)) {
                ret = PTR_ERR(oca_blob);
                goto e_free_pek;
        }

        data.oca_cert_address = __psp_pa(oca_blob);
        data.oca_cert_len = input.oca_cert_len;

        /* If platform is not in INIT state then transition it to INIT */
        if (sev->state != SEV_STATE_INIT) {
                ret = __sev_platform_init_locked(&argp->error);
                if (ret)
                        goto e_free_oca;
        }

        ret = __sev_do_cmd_locked(SEV_CMD_PEK_CERT_IMPORT, &data, &argp->error);

e_free_oca:
        kfree(oca_blob);
e_free_pek:
        kfree(pek_blob);
        return ret;
}

static int sev_ioctl_do_get_id2(struct sev_issue_cmd *argp)
{
        struct sev_user_data_get_id2 input;
        struct sev_data_get_id data;
        void __user *input_address;
        void *id_blob = NULL;
        int ret;

        /* SEV GET_ID is available from SEV API v0.16 and up */
        if (!sev_version_greater_or_equal(0, 16))
                return -ENOTSUPP;

        if (copy_from_user(&input, (void __user *)argp->data, sizeof(input)))
                return -EFAULT;

        input_address = (void __user *)input.address;

        if (input.address && input.length) {
                id_blob = kmalloc(input.length, GFP_KERNEL);
                if (!id_blob)
                        return -ENOMEM;

                data.address = __psp_pa(id_blob);
                data.len = input.length;
        } else {
                data.address = 0;
                data.len = 0;
        }

        ret = __sev_do_cmd_locked(SEV_CMD_GET_ID, &data, &argp->error);

        /*
         * Firmware will return the length of the ID value (either the minimum
         * required length or the actual length written), return it to the user.
         */
        input.length = data.len;

        if (copy_to_user((void __user *)argp->data, &input, sizeof(input))) {
                ret = -EFAULT;
                goto e_free;
        }

        if (id_blob) {
                if (copy_to_user(input_address, id_blob, data.len)) {
                        ret = -EFAULT;
                        goto e_free;
                }
        }

e_free:
        kfree(id_blob);

        return ret;
}

static int sev_ioctl_do_get_id(struct sev_issue_cmd *argp)
{
        struct sev_data_get_id *data;
        u64 data_size, user_size;
        void *id_blob, *mem;
        int ret;

        /* SEV GET_ID available from SEV API v0.16 and up */
        if (!sev_version_greater_or_equal(0, 16))
                return -ENOTSUPP;

        /* SEV FW expects the buffer it fills with the ID to be
         * 8-byte aligned. Memory allocated should be enough to
         * hold data structure + alignment padding + memory
         * where SEV FW writes the ID.
         */
        data_size = ALIGN(sizeof(struct sev_data_get_id), 8);
        user_size = sizeof(struct sev_user_data_get_id);

        mem = kzalloc(data_size + user_size, GFP_KERNEL);
        if (!mem)
                return -ENOMEM;

        data = mem;
        id_blob = mem + data_size;

        data->address = __psp_pa(id_blob);
        data->len = user_size;

        ret = __sev_do_cmd_locked(SEV_CMD_GET_ID, data, &argp->error);
        if (!ret) {
                if (copy_to_user((void __user *)argp->data, id_blob, data->len))
                        ret = -EFAULT;
        }

        kfree(mem);

        return ret;
}

static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable)
{
        struct sev_device *sev = psp_master->sev_data;
        struct sev_user_data_pdh_cert_export input;
        void *pdh_blob = NULL, *cert_blob = NULL;
        struct sev_data_pdh_cert_export data;
        void __user *input_cert_chain_address;
        void __user *input_pdh_cert_address;
        int ret;

        /* If platform is not in INIT state then transition it to INIT. */
        if (sev->state != SEV_STATE_INIT) {
                if (!writable)
                        return -EPERM;

                ret = __sev_platform_init_locked(&argp->error);
                if (ret)
                        return ret;
        }

        if (copy_from_user(&input, (void __user *)argp->data, sizeof(input)))
                return -EFAULT;

        memset(&data, 0, sizeof(data));

        /* Userspace wants to query the certificate length. */
        if (!input.pdh_cert_address ||
            !input.pdh_cert_len ||
            !input.cert_chain_address)
                goto cmd;

        input_pdh_cert_address = (void __user *)input.pdh_cert_address;
        input_cert_chain_address = (void __user *)input.cert_chain_address;

        /* Allocate a physically contiguous buffer to store the PDH blob. */
        if (input.pdh_cert_len > SEV_FW_BLOB_MAX_SIZE)
                return -EFAULT;

        /* Allocate a physically contiguous buffer to store the cert chain blob. */
        if (input.cert_chain_len > SEV_FW_BLOB_MAX_SIZE)
                return -EFAULT;

        pdh_blob = kmalloc(input.pdh_cert_len, GFP_KERNEL);
        if (!pdh_blob)
                return -ENOMEM;

        data.pdh_cert_address = __psp_pa(pdh_blob);
        data.pdh_cert_len = input.pdh_cert_len;

        cert_blob = kmalloc(input.cert_chain_len, GFP_KERNEL);
        if (!cert_blob) {
                ret = -ENOMEM;
                goto e_free_pdh;
        }

        data.cert_chain_address = __psp_pa(cert_blob);
        data.cert_chain_len = input.cert_chain_len;

cmd:
        ret = __sev_do_cmd_locked(SEV_CMD_PDH_CERT_EXPORT, &data, &argp->error);

        /* If we query the length, FW responded with expected data. */
        input.cert_chain_len = data.cert_chain_len;
        input.pdh_cert_len = data.pdh_cert_len;

        if (copy_to_user((void __user *)argp->data, &input, sizeof(input))) {
                ret = -EFAULT;
                goto e_free_cert;
        }

        if (pdh_blob) {
                if (copy_to_user(input_pdh_cert_address,
                                 pdh_blob, input.pdh_cert_len)) {
                        ret = -EFAULT;
                        goto e_free_cert;
                }
        }

        if (cert_blob) {
                if (copy_to_user(input_cert_chain_address,
                                 cert_blob, input.cert_chain_len))
                        ret = -EFAULT;
        }

e_free_cert:
        kfree(cert_blob);
e_free_pdh:
        kfree(pdh_blob);
        return ret;
}

static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg)
{
        void __user *argp = (void __user *)arg;
        struct sev_issue_cmd input;
        int ret = -EFAULT;
        bool writable = file->f_mode & FMODE_WRITE;

        if (!psp_master || !psp_master->sev_data)
                return -ENODEV;

        if (ioctl != SEV_ISSUE_CMD)
                return -EINVAL;

        if (copy_from_user(&input, argp, sizeof(struct sev_issue_cmd)))
                return -EFAULT;

        if (input.cmd > SEV_MAX)
                return -EINVAL;

        mutex_lock(&sev_cmd_mutex);

        switch (input.cmd) {

        case SEV_FACTORY_RESET:
                ret = sev_ioctl_do_reset(&input, writable);
                break;
        case SEV_PLATFORM_STATUS:
                ret = sev_ioctl_do_platform_status(&input);
                break;
        case SEV_PEK_GEN:
                ret = sev_ioctl_do_pek_pdh_gen(SEV_CMD_PEK_GEN, &input, writable);
                break;
        case SEV_PDH_GEN:
                ret = sev_ioctl_do_pek_pdh_gen(SEV_CMD_PDH_GEN, &input, writable);
                break;
        case SEV_PEK_CSR:
                ret = sev_ioctl_do_pek_csr(&input, writable);
                break;
        case SEV_PEK_CERT_IMPORT:
                ret = sev_ioctl_do_pek_import(&input, writable);
                break;
        case SEV_PDH_CERT_EXPORT:
                ret = sev_ioctl_do_pdh_export(&input, writable);
                break;
        case SEV_GET_ID:
                pr_warn_once("SEV_GET_ID command is deprecated, use SEV_GET_ID2\n");
                ret = sev_ioctl_do_get_id(&input);
                break;
        case SEV_GET_ID2:
                ret = sev_ioctl_do_get_id2(&input);
                break;
        default:
                ret = -EINVAL;
                goto out;
        }

        if (copy_to_user(argp, &input, sizeof(struct sev_issue_cmd)))
                ret = -EFAULT;
out:
        mutex_unlock(&sev_cmd_mutex);

        return ret;
}

static const struct file_operations sev_fops = {
        .owner  = THIS_MODULE,
        .unlocked_ioctl = sev_ioctl,
};

int sev_platform_status(struct sev_user_data_status *data, int *error)
{
        return sev_do_cmd(SEV_CMD_PLATFORM_STATUS, data, error);
}
EXPORT_SYMBOL_GPL(sev_platform_status);

int sev_guest_deactivate(struct sev_data_deactivate *data, int *error)
{
        return sev_do_cmd(SEV_CMD_DEACTIVATE, data, error);
}
EXPORT_SYMBOL_GPL(sev_guest_deactivate);

int sev_guest_activate(struct sev_data_activate *data, int *error)
{
        return sev_do_cmd(SEV_CMD_ACTIVATE, data, error);
}
EXPORT_SYMBOL_GPL(sev_guest_activate);

int sev_guest_decommission(struct sev_data_decommission *data, int *error)
{
        return sev_do_cmd(SEV_CMD_DECOMMISSION, data, error);
}
EXPORT_SYMBOL_GPL(sev_guest_decommission);

int sev_guest_df_flush(int *error)
{
        return sev_do_cmd(SEV_CMD_DF_FLUSH, NULL, error);
}
EXPORT_SYMBOL_GPL(sev_guest_df_flush);

static void sev_exit(struct kref *ref)
{
        misc_deregister(&misc_dev->misc);
        kfree(misc_dev);
        misc_dev = NULL;
}

static int sev_misc_init(struct sev_device *sev)
{
        struct device *dev = sev->dev;
        int ret;

        /*
         * SEV feature support can be detected on multiple devices but the SEV
         * FW commands must be issued on the master. During probe, we do not
         * know the master hence we create /dev/sev on the first device probe.
         * sev_do_cmd() finds the right master device to which to issue the
         * command to the firmware.
         */
        if (!misc_dev) {
                struct miscdevice *misc;

                misc_dev = kzalloc(sizeof(*misc_dev), GFP_KERNEL);
                if (!misc_dev)
                        return -ENOMEM;

                misc = &misc_dev->misc;
                misc->minor = MISC_DYNAMIC_MINOR;
                misc->name = DEVICE_NAME;
                misc->fops = &sev_fops;

                ret = misc_register(misc);
                if (ret)
                        return ret;

                kref_init(&misc_dev->refcount);
        } else {
                kref_get(&misc_dev->refcount);
        }

        init_waitqueue_head(&sev->int_queue);
        sev->misc = misc_dev;
        dev_dbg(dev, "registered SEV device\n");

        return 0;
}

int sev_dev_init(struct psp_device *psp)
{
        struct device *dev = psp->dev;
        struct sev_device *sev;
        int ret = -ENOMEM;

        if (!boot_cpu_has(X86_FEATURE_SEV)) {
                dev_info_once(dev, "SEV: memory encryption not enabled by BIOS\n");
                return 0;
        }

        sev = devm_kzalloc(dev, sizeof(*sev), GFP_KERNEL);
        if (!sev)
                goto e_err;

        sev->cmd_buf = (void *)devm_get_free_pages(dev, GFP_KERNEL, 0);
        if (!sev->cmd_buf)
                goto e_sev;

        psp->sev_data = sev;

        sev->dev = dev;
        sev->psp = psp;

        sev->io_regs = psp->io_regs;

        sev->vdata = (struct sev_vdata *)psp->vdata->sev;
        if (!sev->vdata) {
                ret = -ENODEV;
                dev_err(dev, "sev: missing driver data\n");
                goto e_buf;
        }

        psp_set_sev_irq_handler(psp, sev_irq_handler, sev);

        ret = sev_misc_init(sev);
        if (ret)
                goto e_irq;

        dev_notice(dev, "sev enabled\n");

        return 0;

e_irq:
        psp_clear_sev_irq_handler(psp);
e_buf:
        devm_free_pages(dev, (unsigned long)sev->cmd_buf);
e_sev:
        devm_kfree(dev, sev);
e_err:
        psp->sev_data = NULL;

        dev_notice(dev, "sev initialization failed\n");

        return ret;
}

static void sev_firmware_shutdown(struct sev_device *sev)
{
        sev_platform_shutdown(NULL);

        if (sev_es_tmr) {
                /* The TMR area was encrypted, flush it from the cache */
                wbinvd_on_all_cpus();

                free_pages((unsigned long)sev_es_tmr,
                           get_order(SEV_ES_TMR_SIZE));
                sev_es_tmr = NULL;
        }
}

void sev_dev_destroy(struct psp_device *psp)
{
        struct sev_device *sev = psp->sev_data;

        if (!sev)
                return;

        sev_firmware_shutdown(sev);

        if (sev->misc)
                kref_put(&misc_dev->refcount, sev_exit);

        psp_clear_sev_irq_handler(psp);
}

int sev_issue_cmd_external_user(struct file *filep, unsigned int cmd,
                                void *data, int *error)
{
        if (!filep || filep->f_op != &sev_fops)
                return -EBADF;

        return sev_do_cmd(cmd, data, error);
}
EXPORT_SYMBOL_GPL(sev_issue_cmd_external_user);

void sev_pci_init(void)
{
        struct sev_device *sev = psp_master->sev_data;
        struct page *tmr_page;
        int error, rc;

        if (!sev)
                return;

        psp_timeout = psp_probe_timeout;

        if (sev_get_api_version())
                goto err;

        if (sev_version_greater_or_equal(0, 15) &&
            sev_update_firmware(sev->dev) == 0)
                sev_get_api_version();

        /* Obtain the TMR memory area for SEV-ES use */
        tmr_page = alloc_pages(GFP_KERNEL, get_order(SEV_ES_TMR_SIZE));
        if (tmr_page) {
                sev_es_tmr = page_address(tmr_page);
        } else {
                sev_es_tmr = NULL;
                dev_warn(sev->dev,
                         "SEV: TMR allocation failed, SEV-ES support unavailable\n");
        }

        /* Initialize the platform */
        rc = sev_platform_init(&error);
        if (rc && (error == SEV_RET_SECURE_DATA_INVALID)) {
                /*
                 * INIT command returned an integrity check failure
                 * status code, meaning that firmware load and
                 * validation of SEV related persistent data has
                 * failed and persistent state has been erased.
                 * Retrying INIT command here should succeed.
                 */
                dev_dbg(sev->dev, "SEV: retrying INIT command");
                rc = sev_platform_init(&error);
        }

        if (rc) {
                dev_err(sev->dev, "SEV: failed to INIT error %#x\n", error);
                return;
        }

        dev_info(sev->dev, "SEV API:%d.%d build:%d\n", sev->api_major,
                 sev->api_minor, sev->build);

        return;

err:
        psp_master->sev_data = NULL;
}

void sev_pci_exit(void)
{
        struct sev_device *sev = psp_master->sev_data;

        if (!sev)
                return;

        sev_firmware_shutdown(sev);
}