staging: rtl8188eu: rename HalSetBrateCfg() - style

[linux/fpc-iii.git] / drivers / crypto / ccp / psp-dev.c

/*
 * AMD Platform Security Processor (PSP) interface
 *
 * Copyright (C) 2016-2017 Advanced Micro Devices, Inc.
 *
 * Author: Brijesh Singh <brijesh.singh@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/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 "sp-dev.h"
#include "psp-dev.h"

#define SEV_VERSION_GREATER_OR_EQUAL(_maj, _min)        \
                ((psp_master->api_major) >= _maj &&     \
                 (psp_master->api_minor) >= _min)

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

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

static struct psp_device *psp_alloc_struct(struct sp_device *sp)
{
        struct device *dev = sp->dev;
        struct psp_device *psp;

        psp = devm_kzalloc(dev, sizeof(*psp), GFP_KERNEL);
        if (!psp)
                return NULL;

        psp->dev = dev;
        psp->sp = sp;

        snprintf(psp->name, sizeof(psp->name), "psp-%u", sp->ord);

        return psp;
}

static irqreturn_t psp_irq_handler(int irq, void *data)
{
        struct psp_device *psp = data;
        unsigned int status;
        int reg;

        /* Read the interrupt status: */
        status = ioread32(psp->io_regs + psp->vdata->intsts_reg);

        /* Check if it is command completion: */
        if (!(status & PSP_CMD_COMPLETE))
                goto done;

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

done:
        /* Clear the interrupt status by writing the same value we read. */
        iowrite32(status, psp->io_regs + psp->vdata->intsts_reg);

        return IRQ_HANDLED;
}

static void sev_wait_cmd_ioc(struct psp_device *psp, unsigned int *reg)
{
        wait_event(psp->sev_int_queue, psp->sev_int_rcvd);
        *reg = ioread32(psp->io_regs + psp->vdata->cmdresp_reg);
}

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);
        default:                                return 0;
        }

        return 0;
}

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

        if (!psp)
                return -ENODEV;

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

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

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

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

        psp->sev_int_rcvd = 0;

        reg = cmd;
        reg <<= PSP_CMDRESP_CMD_SHIFT;
        reg |= PSP_CMDRESP_IOC;
        iowrite32(reg, psp->io_regs + psp->vdata->cmdresp_reg);

        /* wait for command completion */
        sev_wait_cmd_ioc(psp, &reg);

        if (psp_ret)
                *psp_ret = reg & PSP_CMDRESP_ERR_MASK;

        if (reg & PSP_CMDRESP_ERR_MASK) {
                dev_dbg(psp->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,
                             sev_cmd_buffer_len(cmd), false);

        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;
        int rc = 0;

        if (!psp)
                return -ENODEV;

        if (psp->sev_state == SEV_STATE_INIT)
                return 0;

        rc = __sev_do_cmd_locked(SEV_CMD_INIT, &psp->init_cmd_buf, error);
        if (rc)
                return rc;

        psp->sev_state = SEV_STATE_INIT;
        dev_dbg(psp->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)
{
        int ret;

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

        psp_master->sev_state = SEV_STATE_UNINIT;
        dev_dbg(psp_master->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)
{
        int rc;

        rc = __sev_do_cmd_locked(SEV_CMD_PLATFORM_STATUS,
                                 &psp_master->status_cmd_buf, error);
        if (rc)
                return rc;

        *state = psp_master->status_cmd_buf.state;
        return rc;
}

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

        /*
         * 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 = &psp_master->status_cmd_buf;
        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)
{
        int rc;

        if (psp_master->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)
{
        struct sev_user_data_pek_csr input;
        struct sev_data_pek_csr *data;
        void *blob = NULL;
        int ret;

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

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

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

        /* allocate a physically contiguous buffer to store the CSR blob */
        if (!access_ok(VERIFY_WRITE, input.address, input.length) ||
            input.length > SEV_FW_BLOB_MAX_SIZE) {
                ret = -EFAULT;
                goto e_free;
        }

        blob = kmalloc(input.length, GFP_KERNEL);
        if (!blob) {
                ret = -ENOMEM;
                goto e_free;
        }

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

cmd:
        if (psp_master->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((void __user *)input.address, blob, input.length))
                        ret = -EFAULT;
        }

e_free_blob:
        kfree(blob);
e_free:
        kfree(data);
        return ret;
}

void *psp_copy_user_blob(u64 __user 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 *)(uintptr_t)uaddr, len);
}
EXPORT_SYMBOL_GPL(psp_copy_user_blob);

static int sev_get_api_version(void)
{
        struct sev_user_data_status *status;
        int error, ret;

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

        psp_master->api_major = status->api_major;
        psp_master->api_minor = status->api_minor;
        psp_master->build = status->build;

        return 0;
}

/* 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;

        ret = request_firmware(&firmware, SEV_FW_FILE, dev);
        if (ret < 0)
                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)
{
        struct sev_user_data_pek_cert_import input;
        struct sev_data_pek_cert_import *data;
        void *pek_blob, *oca_blob;
        int ret;

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

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

        /* 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)) {
                ret = PTR_ERR(pek_blob);
                goto e_free;
        }

        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 (psp_master->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);
e_free:
        kfree(data);
        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)
{
        struct sev_user_data_pdh_cert_export input;
        void *pdh_blob = NULL, *cert_blob = NULL;
        struct sev_data_pdh_cert_export *data;
        int ret;

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

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

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

        /* Allocate a physically contiguous buffer to store the PDH blob. */
        if ((input.pdh_cert_len > SEV_FW_BLOB_MAX_SIZE) ||
            !access_ok(VERIFY_WRITE, input.pdh_cert_address, input.pdh_cert_len)) {
                ret = -EFAULT;
                goto e_free;
        }

        /* Allocate a physically contiguous buffer to store the cert chain blob. */
        if ((input.cert_chain_len > SEV_FW_BLOB_MAX_SIZE) ||
            !access_ok(VERIFY_WRITE, input.cert_chain_address, input.cert_chain_len)) {
                ret = -EFAULT;
                goto e_free;
        }

        pdh_blob = kmalloc(input.pdh_cert_len, GFP_KERNEL);
        if (!pdh_blob) {
                ret = -ENOMEM;
                goto e_free;
        }

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

        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((void __user *)input.pdh_cert_address,
                                 pdh_blob, input.pdh_cert_len)) {
                        ret = -EFAULT;
                        goto e_free_cert;
                }
        }

        if (cert_blob) {
                if (copy_to_user((void __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);
e_free:
        kfree(data);
        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;

        if (!psp_master)
                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);
                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);
                break;
        case SEV_PDH_GEN:
                ret = sev_ioctl_do_pek_pdh_gen(SEV_CMD_PDH_GEN, &input);
                break;
        case SEV_PEK_CSR:
                ret = sev_ioctl_do_pek_csr(&input);
                break;
        case SEV_PEK_CERT_IMPORT:
                ret = sev_ioctl_do_pek_import(&input);
                break;
        case SEV_PDH_CERT_EXPORT:
                ret = sev_ioctl_do_pdh_export(&input);
                break;
        case SEV_GET_ID:
                ret = sev_ioctl_do_get_id(&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)
{
        struct sev_misc_dev *misc_dev = container_of(ref, struct sev_misc_dev, refcount);

        misc_deregister(&misc_dev->misc);
}

static int sev_misc_init(struct psp_device *psp)
{
        struct device *dev = psp->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 = devm_kzalloc(dev, 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(&psp->sev_int_queue);
        psp->sev_misc = misc_dev;
        dev_dbg(dev, "registered SEV device\n");

        return 0;
}

static int sev_init(struct psp_device *psp)
{
        /* Check if device supports SEV feature */
        if (!(ioread32(psp->io_regs + psp->vdata->feature_reg) & 1)) {
                dev_dbg(psp->dev, "device does not support SEV\n");
                return 1;
        }

        return sev_misc_init(psp);
}

int psp_dev_init(struct sp_device *sp)
{
        struct device *dev = sp->dev;
        struct psp_device *psp;
        int ret;

        ret = -ENOMEM;
        psp = psp_alloc_struct(sp);
        if (!psp)
                goto e_err;

        sp->psp_data = psp;

        psp->vdata = (struct psp_vdata *)sp->dev_vdata->psp_vdata;
        if (!psp->vdata) {
                ret = -ENODEV;
                dev_err(dev, "missing driver data\n");
                goto e_err;
        }

        psp->io_regs = sp->io_map;

        /* Disable and clear interrupts until ready */
        iowrite32(0, psp->io_regs + psp->vdata->inten_reg);
        iowrite32(-1, psp->io_regs + psp->vdata->intsts_reg);

        /* Request an irq */
        ret = sp_request_psp_irq(psp->sp, psp_irq_handler, psp->name, psp);
        if (ret) {
                dev_err(dev, "psp: unable to allocate an IRQ\n");
                goto e_err;
        }

        ret = sev_init(psp);
        if (ret)
                goto e_irq;

        if (sp->set_psp_master_device)
                sp->set_psp_master_device(sp);

        /* Enable interrupt */
        iowrite32(-1, psp->io_regs + psp->vdata->inten_reg);

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

        return 0;

e_irq:
        sp_free_psp_irq(psp->sp, psp);
e_err:
        sp->psp_data = NULL;

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

        return ret;
}

void psp_dev_destroy(struct sp_device *sp)
{
        struct psp_device *psp = sp->psp_data;

        if (!psp)
                return;

        if (psp->sev_misc)
                kref_put(&misc_dev->refcount, sev_exit);

        sp_free_psp_irq(sp, 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 psp_pci_init(void)
{
        struct sp_device *sp;
        int error, rc;

        sp = sp_get_psp_master_device();
        if (!sp)
                return;

        psp_master = sp->psp_data;

        if (sev_get_api_version())
                goto err;

        if (SEV_VERSION_GREATER_OR_EQUAL(0, 15) &&
            sev_update_firmware(psp_master->dev) == 0)
                sev_get_api_version();

        /* Initialize the platform */
        rc = sev_platform_init(&error);
        if (rc) {
                dev_err(sp->dev, "SEV: failed to INIT error %#x\n", error);
                goto err;
        }

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

        return;

err:
        psp_master = NULL;
}

void psp_pci_exit(void)
{
        if (!psp_master)
                return;

        sev_platform_shutdown(NULL);
}