blob: 124a2e0c89993786843b88daa609b5dfd86917ef [file] [log] [blame]
// 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 "platform-access.h"
#include "dbc.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);
ret = psp_mailbox_command(psp, PSP_CMD_TEE_EXTENDED_CMD, (void *)req,
timeout_msecs, &reg);
if (ret) {
return ret;
} else if (FIELD_GET(PSP_CMDRESP_STS, reg)) {
req->header.status = FIELD_GET(PSP_CMDRESP_STS, reg);
return -EIO;
}
print_hex_dump_debug("<-psp ", DUMP_PREFIX_OFFSET, 16, 2, req,
req->header.payload_size, false);
return 0;
}
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;
/* Read the interrupt status: */
status = ioread32(psp->io_regs + psp->vdata->intsts_reg);
/* Clear the interrupt status by writing the same value we read. */
iowrite32(status, psp->io_regs + psp->vdata->intsts_reg);
/* invoke subdevice interrupt handlers */
if (status) {
if (psp->sev_irq_handler)
psp->sev_irq_handler(irq, psp->sev_irq_data, status);
}
return IRQ_HANDLED;
}
static unsigned int psp_get_capability(struct psp_device *psp)
{
unsigned int val = ioread32(psp->io_regs + psp->vdata->feature_reg);
/*
* Check for a access to the registers. If this read returns
* 0xffffffff, it's likely that the system is running a broken
* BIOS which disallows access to the device. Stop here and
* fail the PSP initialization (but not the load, as the CCP
* could get properly initialized).
*/
if (val == 0xffffffff) {
dev_notice(psp->dev, "psp: unable to access the device: you might be running a broken BIOS.\n");
return -ENODEV;
}
psp->capability = val;
/* Detect if TSME and SME are both enabled */
if (PSP_CAPABILITY(psp, PSP_SECURITY_REPORTING) &&
psp->capability & (PSP_SECURITY_TSME_STATUS << PSP_CAPABILITY_PSP_SECURITY_OFFSET) &&
cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT))
dev_notice(psp->dev, "psp: Both TSME and SME are active, SME is unnecessary when TSME is active.\n");
return 0;
}
static int psp_check_sev_support(struct psp_device *psp)
{
/* Check if device supports SEV feature */
if (!PSP_CAPABILITY(psp, SEV)) {
dev_dbg(psp->dev, "psp does not support SEV\n");
return -ENODEV;
}
return 0;
}
static int psp_check_tee_support(struct psp_device *psp)
{
/* Check if device supports TEE feature */
if (!PSP_CAPABILITY(psp, TEE)) {
dev_dbg(psp->dev, "psp does not support TEE\n");
return -ENODEV;
}
return 0;
}
static int psp_init(struct psp_device *psp)
{
int ret;
if (!psp_check_sev_support(psp)) {
ret = sev_dev_init(psp);
if (ret)
return ret;
}
if (!psp_check_tee_support(psp)) {
ret = tee_dev_init(psp);
if (ret)
return ret;
}
if (psp->vdata->platform_access) {
ret = platform_access_dev_init(psp);
if (ret)
return ret;
}
/* dbc must come after platform access as it tests the feature */
if (PSP_FEATURE(psp, DBC) ||
PSP_CAPABILITY(psp, DBC_THRU_EXT)) {
ret = dbc_dev_init(psp);
if (ret)
return ret;
}
return 0;
}
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;
mutex_init(&psp->mailbox_mutex);
ret = psp_get_capability(psp);
if (ret)
goto e_disable;
/* 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;
}
/* master device must be set for platform access */
if (psp->sp->set_psp_master_device)
psp->sp->set_psp_master_device(psp->sp);
ret = psp_init(psp);
if (ret)
goto e_irq;
/* Enable interrupt */
iowrite32(-1, psp->io_regs + psp->vdata->inten_reg);
dev_notice(dev, "psp enabled\n");
return 0;
e_irq:
if (sp->clear_psp_master_device)
sp->clear_psp_master_device(sp);
sp_free_psp_irq(psp->sp, psp);
e_err:
sp->psp_data = NULL;
dev_notice(dev, "psp initialization failed\n");
return ret;
e_disable:
sp->psp_data = NULL;
return ret;
}
void psp_dev_destroy(struct sp_device *sp)
{
struct psp_device *psp = sp->psp_data;
if (!psp)
return;
sev_dev_destroy(psp);
tee_dev_destroy(psp);
dbc_dev_destroy(psp);
platform_access_dev_destroy(psp);
sp_free_psp_irq(sp, psp);
if (sp->clear_psp_master_device)
sp->clear_psp_master_device(sp);
}
void psp_set_sev_irq_handler(struct psp_device *psp, psp_irq_handler_t handler,
void *data)
{
psp->sev_irq_data = data;
psp->sev_irq_handler = handler;
}
void psp_clear_sev_irq_handler(struct psp_device *psp)
{
psp_set_sev_irq_handler(psp, NULL, NULL);
}
struct psp_device *psp_get_master_device(void)
{
struct sp_device *sp = sp_get_psp_master_device();
return sp ? sp->psp_data : NULL;
}
void psp_pci_init(void)
{
psp_master = psp_get_master_device();
if (!psp_master)
return;
sev_pci_init();
}
void psp_pci_exit(void)
{
if (!psp_master)
return;
sev_pci_exit();
}