diff options
Diffstat (limited to 'drivers/crypto/ccree/cc_fips.c')
-rw-r--r-- | drivers/crypto/ccree/cc_fips.c | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/drivers/crypto/ccree/cc_fips.c b/drivers/crypto/ccree/cc_fips.c new file mode 100644 index 000000000..702aefc21 --- /dev/null +++ b/drivers/crypto/ccree/cc_fips.c @@ -0,0 +1,154 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (C) 2012-2019 ARM Limited (or its affiliates). */ + +#include <linux/kernel.h> +#include <linux/fips.h> +#include <linux/notifier.h> + +#include "cc_driver.h" +#include "cc_fips.h" + +static void fips_dsr(unsigned long devarg); + +struct cc_fips_handle { + struct tasklet_struct tasklet; + struct notifier_block nb; + struct cc_drvdata *drvdata; +}; + +/* The function called once at driver entry point to check + * whether TEE FIPS error occurred. + */ +static bool cc_get_tee_fips_status(struct cc_drvdata *drvdata) +{ + u32 reg; + + reg = cc_ioread(drvdata, CC_REG(GPR_HOST)); + /* Did the TEE report status? */ + if (reg & CC_FIPS_SYNC_TEE_STATUS) + /* Yes. Is it OK? */ + return (reg & CC_FIPS_SYNC_MODULE_OK); + + /* No. It's either not in use or will be reported later */ + return true; +} + +/* + * This function should push the FIPS REE library status towards the TEE library + * by writing the error state to HOST_GPR0 register. + */ +void cc_set_ree_fips_status(struct cc_drvdata *drvdata, bool status) +{ + int val = CC_FIPS_SYNC_REE_STATUS; + + if (drvdata->hw_rev < CC_HW_REV_712) + return; + + val |= (status ? CC_FIPS_SYNC_MODULE_OK : CC_FIPS_SYNC_MODULE_ERROR); + + cc_iowrite(drvdata, CC_REG(HOST_GPR0), val); +} + +/* Push REE side FIPS test failure to TEE side */ +static int cc_ree_fips_failure(struct notifier_block *nb, unsigned long unused1, + void *unused2) +{ + struct cc_fips_handle *fips_h = + container_of(nb, struct cc_fips_handle, nb); + struct cc_drvdata *drvdata = fips_h->drvdata; + struct device *dev = drvdata_to_dev(drvdata); + + cc_set_ree_fips_status(drvdata, false); + dev_info(dev, "Notifying TEE of FIPS test failure...\n"); + + return NOTIFY_OK; +} + +void cc_fips_fini(struct cc_drvdata *drvdata) +{ + struct cc_fips_handle *fips_h = drvdata->fips_handle; + + if (drvdata->hw_rev < CC_HW_REV_712 || !fips_h) + return; + + atomic_notifier_chain_unregister(&fips_fail_notif_chain, &fips_h->nb); + + /* Kill tasklet */ + tasklet_kill(&fips_h->tasklet); + drvdata->fips_handle = NULL; +} + +void fips_handler(struct cc_drvdata *drvdata) +{ + struct cc_fips_handle *fips_handle_ptr = drvdata->fips_handle; + + if (drvdata->hw_rev < CC_HW_REV_712) + return; + + tasklet_schedule(&fips_handle_ptr->tasklet); +} + +static inline void tee_fips_error(struct device *dev) +{ + if (fips_enabled) + panic("ccree: TEE reported cryptographic error in fips mode!\n"); + else + dev_err(dev, "TEE reported error!\n"); +} + +/* + * This function check if cryptocell tee fips error occurred + * and in such case triggers system error + */ +void cc_tee_handle_fips_error(struct cc_drvdata *p_drvdata) +{ + struct device *dev = drvdata_to_dev(p_drvdata); + + if (!cc_get_tee_fips_status(p_drvdata)) + tee_fips_error(dev); +} + +/* Deferred service handler, run as interrupt-fired tasklet */ +static void fips_dsr(unsigned long devarg) +{ + struct cc_drvdata *drvdata = (struct cc_drvdata *)devarg; + u32 irq, val; + + irq = (drvdata->irq & (CC_GPR0_IRQ_MASK)); + + if (irq) { + cc_tee_handle_fips_error(drvdata); + } + + /* after verifying that there is nothing to do, + * unmask AXI completion interrupt. + */ + val = (CC_REG(HOST_IMR) & ~irq); + cc_iowrite(drvdata, CC_REG(HOST_IMR), val); +} + +/* The function called once at driver entry point .*/ +int cc_fips_init(struct cc_drvdata *p_drvdata) +{ + struct cc_fips_handle *fips_h; + struct device *dev = drvdata_to_dev(p_drvdata); + + if (p_drvdata->hw_rev < CC_HW_REV_712) + return 0; + + fips_h = devm_kzalloc(dev, sizeof(*fips_h), GFP_KERNEL); + if (!fips_h) + return -ENOMEM; + + p_drvdata->fips_handle = fips_h; + + dev_dbg(dev, "Initializing fips tasklet\n"); + tasklet_init(&fips_h->tasklet, fips_dsr, (unsigned long)p_drvdata); + fips_h->drvdata = p_drvdata; + fips_h->nb.notifier_call = cc_ree_fips_failure; + atomic_notifier_chain_register(&fips_fail_notif_chain, &fips_h->nb); + + cc_tee_handle_fips_error(p_drvdata); + + return 0; +} |