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author | Rijo Thomas <Rijo-john.Thomas@amd.com> | 2019-12-04 09:18:59 +0300 |
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committer | Herbert Xu <herbert@gondor.apana.org.au> | 2019-12-20 09:58:32 +0300 |
commit | b93566f1bb54e02a1ff1e3b4782073be1886744e (patch) | |
tree | 67a4ddf206b02c1b6e7d3b7752e36ec512a2cb62 /drivers/crypto/ccp/psp-dev.c | |
parent | 9b67d08dbc1751ab15d972a63a4d9132e7e7442f (diff) | |
download | linux-b93566f1bb54e02a1ff1e3b4782073be1886744e.tar.xz |
crypto: ccp - create a generic psp-dev file
The PSP (Platform Security Processor) provides support for key management
commands in Secure Encrypted Virtualization (SEV) mode, along with
software-based Trusted Execution Environment (TEE) to enable third-party
Trusted Applications.
Therefore, introduce psp-dev.c and psp-dev.h files, which can invoke
SEV (or TEE) initialization based on platform feature support.
TEE interface support will be introduced in a later patch.
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Jens Wiklander <jens.wiklander@linaro.org>
Co-developed-by: Devaraj Rangasamy <Devaraj.Rangasamy@amd.com>
Signed-off-by: Devaraj Rangasamy <Devaraj.Rangasamy@amd.com>
Signed-off-by: Rijo Thomas <Rijo-john.Thomas@amd.com>
Acked-by: Gary R Hook <gary.hook@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'drivers/crypto/ccp/psp-dev.c')
-rw-r--r-- | drivers/crypto/ccp/psp-dev.c | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c new file mode 100644 index 000000000000..2cd7a5ea4156 --- /dev/null +++ b/drivers/crypto/ccp/psp-dev.c @@ -0,0 +1,194 @@ +// 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" + +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); + } + + /* 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 psp_check_sev_support(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; + } + + if (!(val & 1)) { + /* Device does not support the SEV feature */ + dev_dbg(psp->dev, "psp does not support SEV\n"); + return -ENODEV; + } + + 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_check_sev_support(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 = sev_dev_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); + + sp_free_psp_irq(sp, psp); +} + +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(); +} |