drivers/crypto/ccree/cc_fips.c

   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         /* Did the TEE report status? */
  25         if (reg & CC_FIPS_SYNC_TEE_STATUS)
  26                 /* Yes. Is it OK? */
  27                 return (reg & CC_FIPS_SYNC_MODULE_OK);
  28
  29         /* No. It's either not in use or will be reported later */
  30         return true;
  31 }
  32
  33 /*
  34  * This function should push the FIPS REE library status towards the TEE library
  35  * by writing the error state to HOST_GPR0 register.
  36  */
  37 void cc_set_ree_fips_status(struct cc_drvdata *drvdata, bool status)
  38 {
  39         int val = CC_FIPS_SYNC_REE_STATUS;
  40
  41         if (drvdata->hw_rev < CC_HW_REV_712)
  42                 return;
  43
  44         val |= (status ? CC_FIPS_SYNC_MODULE_OK : CC_FIPS_SYNC_MODULE_ERROR);
  45
  46         cc_iowrite(drvdata, CC_REG(HOST_GPR0), val);
  47 }
  48
  49 void cc_fips_fini(struct cc_drvdata *drvdata)
  50 {
  51         struct cc_fips_handle *fips_h = drvdata->fips_handle;
  52
  53         if (drvdata->hw_rev < CC_HW_REV_712 || !fips_h)
  54                 return;
  55
  56         /* Kill tasklet */
  57         tasklet_kill(&fips_h->tasklet);
  58
  59         kfree(fips_h);
  60         drvdata->fips_handle = NULL;
  61 }
  62
  63 void fips_handler(struct cc_drvdata *drvdata)
  64 {
  65         struct cc_fips_handle *fips_handle_ptr = drvdata->fips_handle;
  66
  67         if (drvdata->hw_rev < CC_HW_REV_712)
  68                 return;
  69
  70         tasklet_schedule(&fips_handle_ptr->tasklet);
  71 }
  72
  73 static inline void tee_fips_error(struct device *dev)
  74 {
  75         if (fips_enabled)
  76                 panic("ccree: TEE reported cryptographic error in fips mode!\n");
  77         else
  78                 dev_err(dev, "TEE reported error!\n");
  79 }
  80
  81 /*
  82  * This function check if cryptocell tee fips error occurred
  83  * and in such case triggers system error
  84  */
  85 void cc_tee_handle_fips_error(struct cc_drvdata *p_drvdata)
  86 {
  87         struct device *dev = drvdata_to_dev(p_drvdata);
  88
  89         if (!cc_get_tee_fips_status(p_drvdata))
  90                 tee_fips_error(dev);
  91 }
  92
  93 /* Deferred service handler, run as interrupt-fired tasklet */
  94 static void fips_dsr(unsigned long devarg)
  95 {
  96         struct cc_drvdata *drvdata = (struct cc_drvdata *)devarg;
  97         u32 irq, val;
  98
  99         irq = (drvdata->irq & (CC_GPR0_IRQ_MASK));
 100
 101         if (irq) {
 102                 cc_tee_handle_fips_error(drvdata);
 103         }
 104
 105         /* after verifing that there is nothing to do,
 106          * unmask AXI completion interrupt.
 107          */
 108         val = (CC_REG(HOST_IMR) & ~irq);
 109         cc_iowrite(drvdata, CC_REG(HOST_IMR), val);
 110 }
 111
 112 /* The function called once at driver entry point .*/
 113 int cc_fips_init(struct cc_drvdata *p_drvdata)
 114 {
 115         struct cc_fips_handle *fips_h;
 116         struct device *dev = drvdata_to_dev(p_drvdata);
 117
 118         if (p_drvdata->hw_rev < CC_HW_REV_712)
 119                 return 0;
 120
 121         fips_h = kzalloc(sizeof(*fips_h), GFP_KERNEL);
 122         if (!fips_h)
 123                 return -ENOMEM;
 124
 125         p_drvdata->fips_handle = fips_h;
 126
 127         dev_dbg(dev, "Initializing fips tasklet\n");
 128         tasklet_init(&fips_h->tasklet, fips_dsr, (unsigned long)p_drvdata);
 129
 130         cc_tee_handle_fips_error(p_drvdata);
 131
 132         return 0;
 133 }