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// 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 "sp-dev.h"
#include "psp-dev.h"
#include "sev-dev.h"
#include "tee-dev.h"
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;
/* Read the interrupt status: */
status = ioread32(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);
if (psp->tee_irq_handler)
psp->tee_irq_handler(irq, psp->tee_irq_data, status);
}
/* Clear the interrupt status by writing the same value we read. */
iowrite32(status, psp->io_regs + psp->vdata->intsts_reg);
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_CAPABILITY_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_CAPABILITY_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_CAPABILITY_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;
}
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;
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;
}
ret = psp_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;
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);
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);
}
void psp_set_tee_irq_handler(struct psp_device *psp, psp_irq_handler_t handler,
void *data)
{
psp->tee_irq_data = data;
psp->tee_irq_handler = handler;
}
void psp_clear_tee_irq_handler(struct psp_device *psp)
{
psp_set_tee_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();
}
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