diff options
Diffstat (limited to 'drivers/crypto/ccp/psp-dev.c')
| -rw-r--r-- | drivers/crypto/ccp/psp-dev.c | 270 |
1 files changed, 270 insertions, 0 deletions
diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c new file mode 100644 index 000000000..4bf9eaab4 --- /dev/null +++ b/drivers/crypto/ccp/psp-dev.c @@ -0,0 +1,270 @@ +// 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); + + /* 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); + + if (psp->tee_irq_handler) + psp->tee_irq_handler(irq, psp->tee_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 0; + } + + return val; +} + +static int psp_check_sev_support(struct psp_device *psp, + unsigned int capability) +{ + /* Check if device supports SEV feature */ + if (!(capability & 1)) { + dev_dbg(psp->dev, "psp does not support SEV\n"); + return -ENODEV; + } + + return 0; +} + +static int psp_check_tee_support(struct psp_device *psp, + unsigned int capability) +{ + /* Check if device supports TEE feature */ + if (!(capability & 2)) { + dev_dbg(psp->dev, "psp does not support TEE\n"); + return -ENODEV; + } + + return 0; +} + +static int psp_check_support(struct psp_device *psp, + unsigned int capability) +{ + int sev_support = psp_check_sev_support(psp, capability); + int tee_support = psp_check_tee_support(psp, capability); + + /* Return error if device neither supports SEV nor TEE */ + if (sev_support && tee_support) + return -ENODEV; + + return 0; +} + +static int psp_init(struct psp_device *psp, unsigned int capability) +{ + int ret; + + if (!psp_check_sev_support(psp, capability)) { + ret = sev_dev_init(psp); + if (ret) + return ret; + } + + if (!psp_check_tee_support(psp, capability)) { + 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; + unsigned int capability; + 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; + + capability = psp_get_capability(psp); + if (!capability) + goto e_disable; + + ret = psp_check_support(psp, capability); + 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, capability); + 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(); +} |