1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (C) 2012-2018 ARM Limited or its affiliates. */ 3 4 #include <linux/kernel.h> 5 #include <linux/fips.h> 6 7 #include "cc_driver.h" 8 #include "cc_fips.h" 9 10 static void fips_dsr(unsigned long devarg); 11 12 struct cc_fips_handle { 13 struct tasklet_struct tasklet; 14 }; 15 16 /* The function called once at driver entry point to check 17 * whether TEE FIPS error occurred. 18 */ 19 static bool cc_get_tee_fips_status(struct cc_drvdata *drvdata) 20 { 21 u32 reg; 22 23 reg = cc_ioread(drvdata, CC_REG(GPR_HOST)); 24 return (reg == (CC_FIPS_SYNC_TEE_STATUS | CC_FIPS_SYNC_MODULE_OK)); 25 } 26 27 /* 28 * This function should push the FIPS REE library status towards the TEE library 29 * by writing the error state to HOST_GPR0 register. 30 */ 31 void cc_set_ree_fips_status(struct cc_drvdata *drvdata, bool status) 32 { 33 int val = CC_FIPS_SYNC_REE_STATUS; 34 35 if (drvdata->hw_rev < CC_HW_REV_712) 36 return; 37 38 val |= (status ? CC_FIPS_SYNC_MODULE_OK : CC_FIPS_SYNC_MODULE_ERROR); 39 40 cc_iowrite(drvdata, CC_REG(HOST_GPR0), val); 41 } 42 43 void cc_fips_fini(struct cc_drvdata *drvdata) 44 { 45 struct cc_fips_handle *fips_h = drvdata->fips_handle; 46 47 if (drvdata->hw_rev < CC_HW_REV_712 || !fips_h) 48 return; 49 50 /* Kill tasklet */ 51 tasklet_kill(&fips_h->tasklet); 52 drvdata->fips_handle = NULL; 53 } 54 55 void fips_handler(struct cc_drvdata *drvdata) 56 { 57 struct cc_fips_handle *fips_handle_ptr = drvdata->fips_handle; 58 59 if (drvdata->hw_rev < CC_HW_REV_712) 60 return; 61 62 tasklet_schedule(&fips_handle_ptr->tasklet); 63 } 64 65 static inline void tee_fips_error(struct device *dev) 66 { 67 if (fips_enabled) 68 panic("ccree: TEE reported cryptographic error in fips mode!\n"); 69 else 70 dev_err(dev, "TEE reported error!\n"); 71 } 72 73 /* Deferred service handler, run as interrupt-fired tasklet */ 74 static void fips_dsr(unsigned long devarg) 75 { 76 struct cc_drvdata *drvdata = (struct cc_drvdata *)devarg; 77 struct device *dev = drvdata_to_dev(drvdata); 78 u32 irq, state, val; 79 80 irq = (drvdata->irq & (CC_GPR0_IRQ_MASK)); 81 82 if (irq) { 83 state = cc_ioread(drvdata, CC_REG(GPR_HOST)); 84 85 if (state != (CC_FIPS_SYNC_TEE_STATUS | CC_FIPS_SYNC_MODULE_OK)) 86 tee_fips_error(dev); 87 } 88 89 /* after verifing that there is nothing to do, 90 * unmask AXI completion interrupt. 91 */ 92 val = (CC_REG(HOST_IMR) & ~irq); 93 cc_iowrite(drvdata, CC_REG(HOST_IMR), val); 94 } 95 96 /* The function called once at driver entry point .*/ 97 int cc_fips_init(struct cc_drvdata *p_drvdata) 98 { 99 struct cc_fips_handle *fips_h; 100 struct device *dev = drvdata_to_dev(p_drvdata); 101 102 if (p_drvdata->hw_rev < CC_HW_REV_712) 103 return 0; 104 105 fips_h = devm_kzalloc(dev, sizeof(*fips_h), GFP_KERNEL); 106 if (!fips_h) 107 return -ENOMEM; 108 109 p_drvdata->fips_handle = fips_h; 110 111 dev_dbg(dev, "Initializing fips tasklet\n"); 112 tasklet_init(&fips_h->tasklet, fips_dsr, (unsigned long)p_drvdata); 113 114 if (!cc_get_tee_fips_status(p_drvdata)) 115 tee_fips_error(dev); 116 117 return 0; 118 } 119