path: root/drivers/crypto/ccp/psp-dev.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * AMD Platform Security Processor (PSP) interface
 *
 * Copyright (C) 2016,2018 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 "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"
#define SEV_FW_NAME_SIZE	64

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

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");

static bool psp_dead;
static int psp_timeout;

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 int sev_wait_cmd_ioc(struct psp_device *psp,
			    unsigned int *reg, unsigned int timeout)
{
	int ret;

	ret = wait_event_timeout(psp->sev_int_queue,
			psp->sev_int_rcvd, timeout * HZ);
	if (!ret)
		return -ETIMEDOUT;

	*reg = ioread32(psp->io_regs + psp->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