1 // SPDX-License-Identifier: GPL-2.0 2 /* 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 11 static void fips_dsr(unsigned long devarg); 12 13 struct 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 check 20 * whether TEE FIPS error occurred. 21 */ 22 static 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 library 38 * by writing the error state to HOST_GPR0 register. 39 */ 40 void 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 */ 53 static 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 67 void 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 81 void 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 91 static 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 else 96 dev_err(dev, "TEE reported error!\n"); 97 } 98 99 /* 100 * This function check if cryptocell tee fips error occurred 101 * and in such case triggers system error 102 */ 103 void 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 */ 112 static 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 .*/ 131 int 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