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1// SPDX-License-Identifier: GPL-2.02/* Copyright (C) 2012-2019 ARM Limited (or its affiliates). */3 4#include <linux/kernel.h>5#include <linux/fips.h>6#include <linux/notifier.h>7 8#include "cc_driver.h"9#include "cc_fips.h"10 11static void fips_dsr(unsigned long devarg);12 13struct cc_fips_handle {14 struct tasklet_struct tasklet;15 struct notifier_block nb;16 struct cc_drvdata *drvdata;17};18 19/* The function called once at driver entry point to check20 * whether TEE FIPS error occurred.21 */22static bool cc_get_tee_fips_status(struct cc_drvdata *drvdata)23{24 u32 reg;25 26 reg = cc_ioread(drvdata, CC_REG(GPR_HOST));27 /* Did the TEE report status? */28 if (reg & CC_FIPS_SYNC_TEE_STATUS)29 /* Yes. Is it OK? */30 return (reg & CC_FIPS_SYNC_MODULE_OK);31 32 /* No. It's either not in use or will be reported later */33 return true;34}35 36/*37 * This function should push the FIPS REE library status towards the TEE library38 * by writing the error state to HOST_GPR0 register.39 */40void cc_set_ree_fips_status(struct cc_drvdata *drvdata, bool status)41{42 int val = CC_FIPS_SYNC_REE_STATUS;43 44 if (drvdata->hw_rev < CC_HW_REV_712)45 return;46 47 val |= (status ? CC_FIPS_SYNC_MODULE_OK : CC_FIPS_SYNC_MODULE_ERROR);48 49 cc_iowrite(drvdata, CC_REG(HOST_GPR0), val);50}51 52/* Push REE side FIPS test failure to TEE side */53static int cc_ree_fips_failure(struct notifier_block *nb, unsigned long unused1,54 void *unused2)55{56 struct cc_fips_handle *fips_h =57 container_of(nb, struct cc_fips_handle, nb);58 struct cc_drvdata *drvdata = fips_h->drvdata;59 struct device *dev = drvdata_to_dev(drvdata);60 61 cc_set_ree_fips_status(drvdata, false);62 dev_info(dev, "Notifying TEE of FIPS test failure...\n");63 64 return NOTIFY_OK;65}66 67void cc_fips_fini(struct cc_drvdata *drvdata)68{69 struct cc_fips_handle *fips_h = drvdata->fips_handle;70 71 if (drvdata->hw_rev < CC_HW_REV_712 || !fips_h)72 return;73 74 atomic_notifier_chain_unregister(&fips_fail_notif_chain, &fips_h->nb);75 76 /* Kill tasklet */77 tasklet_kill(&fips_h->tasklet);78 drvdata->fips_handle = NULL;79}80 81void fips_handler(struct cc_drvdata *drvdata)82{83 struct cc_fips_handle *fips_handle_ptr = drvdata->fips_handle;84 85 if (drvdata->hw_rev < CC_HW_REV_712)86 return;87 88 tasklet_schedule(&fips_handle_ptr->tasklet);89}90 91static inline void tee_fips_error(struct device *dev)92{93 if (fips_enabled)94 panic("ccree: TEE reported cryptographic error in fips mode!\n");95 else96 dev_err(dev, "TEE reported error!\n");97}98 99/*100 * This function check if cryptocell tee fips error occurred101 * and in such case triggers system error102 */103void cc_tee_handle_fips_error(struct cc_drvdata *p_drvdata)104{105 struct device *dev = drvdata_to_dev(p_drvdata);106 107 if (!cc_get_tee_fips_status(p_drvdata))108 tee_fips_error(dev);109}110 111/* Deferred service handler, run as interrupt-fired tasklet */112static void fips_dsr(unsigned long devarg)113{114 struct cc_drvdata *drvdata = (struct cc_drvdata *)devarg;115 u32 irq, val;116 117 irq = (drvdata->irq & (CC_GPR0_IRQ_MASK));118 119 if (irq) {120 cc_tee_handle_fips_error(drvdata);121 }122 123 /* after verifying that there is nothing to do,124 * unmask AXI completion interrupt.125 */126 val = (CC_REG(HOST_IMR) & ~irq);127 cc_iowrite(drvdata, CC_REG(HOST_IMR), val);128}129 130/* The function called once at driver entry point .*/131int cc_fips_init(struct cc_drvdata *p_drvdata)132{133 struct cc_fips_handle *fips_h;134 struct device *dev = drvdata_to_dev(p_drvdata);135 136 if (p_drvdata->hw_rev < CC_HW_REV_712)137 return 0;138 139 fips_h = devm_kzalloc(dev, sizeof(*fips_h), GFP_KERNEL);140 if (!fips_h)141 return -ENOMEM;142 143 p_drvdata->fips_handle = fips_h;144 145 dev_dbg(dev, "Initializing fips tasklet\n");146 tasklet_init(&fips_h->tasklet, fips_dsr, (unsigned long)p_drvdata);147 fips_h->drvdata = p_drvdata;148 fips_h->nb.notifier_call = cc_ree_fips_failure;149 atomic_notifier_chain_register(&fips_fail_notif_chain, &fips_h->nb);150 151 cc_tee_handle_fips_error(p_drvdata);152 153 return 0;154}155