drivers/crypto/ccp/psp-dev.c

Source file repositories/reference/linux-study-clean/drivers/crypto/ccp/psp-dev.c

File Facts

System
Linux kernel
Corpus path
drivers/crypto/ccp/psp-dev.c
Extension
.c
Size
7924 bytes
Lines
382
Domain
Driver Families
Bucket
drivers/crypto
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

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

#include <linux/kernel.h>
#include <linux/irqreturn.h>
#include <linux/mutex.h>
#include <linux/bitfield.h>
#include <linux/delay.h>

#include "sp-dev.h"
#include "psp-dev.h"
#include "sev-dev.h"
#include "tee-dev.h"
#include "sfs.h"
#include "platform-access.h"
#include "dbc.h"
#include "hsti.h"

struct psp_device *psp_master;

#define PSP_C2PMSG_17_CMDRESP_CMD	GENMASK(19, 16)

static int psp_mailbox_poll(const void __iomem *cmdresp_reg, unsigned int *cmdresp,
			    unsigned int timeout_msecs)
{
	while (true) {
		*cmdresp = ioread32(cmdresp_reg);
		if (FIELD_GET(PSP_CMDRESP_RESP, *cmdresp))
			return 0;

		if (!timeout_msecs--)
			break;

		usleep_range(1000, 1100);
	}

	return -ETIMEDOUT;
}

int psp_mailbox_command(struct psp_device *psp, enum psp_cmd cmd, void *cmdbuff,
			unsigned int timeout_msecs, unsigned int *cmdresp)
{
	void __iomem *cmdresp_reg, *cmdbuff_lo_reg, *cmdbuff_hi_reg;
	int ret;

	if (!psp || !psp->vdata || !psp->vdata->cmdresp_reg ||
	    !psp->vdata->cmdbuff_addr_lo_reg || !psp->vdata->cmdbuff_addr_hi_reg)
		return -ENODEV;

	cmdresp_reg    = psp->io_regs + psp->vdata->cmdresp_reg;
	cmdbuff_lo_reg = psp->io_regs + psp->vdata->cmdbuff_addr_lo_reg;
	cmdbuff_hi_reg = psp->io_regs + psp->vdata->cmdbuff_addr_hi_reg;

	mutex_lock(&psp->mailbox_mutex);

	/* Ensure mailbox is ready for a command */
	ret = -EBUSY;
	if (psp_mailbox_poll(cmdresp_reg, cmdresp, 0))
		goto unlock;

	if (cmdbuff) {
		iowrite32(lower_32_bits(__psp_pa(cmdbuff)), cmdbuff_lo_reg);
		iowrite32(upper_32_bits(__psp_pa(cmdbuff)), cmdbuff_hi_reg);
	}

	*cmdresp = FIELD_PREP(PSP_C2PMSG_17_CMDRESP_CMD, cmd);
	iowrite32(*cmdresp, cmdresp_reg);

	ret = psp_mailbox_poll(cmdresp_reg, cmdresp, timeout_msecs);

unlock:
	mutex_unlock(&psp->mailbox_mutex);

	return ret;
}

int psp_extended_mailbox_cmd(struct psp_device *psp, unsigned int timeout_msecs,
			     struct psp_ext_request *req)
{
	unsigned int reg;
	int ret;

	print_hex_dump_debug("->psp ", DUMP_PREFIX_OFFSET, 16, 2, req,
			     req->header.payload_size, false);

Annotation

Implementation Notes