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         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
  53         kfree(fips_h);
  54         drvdata->fips_handle = NULL;
  55 }
  56
  57 void fips_handler(struct cc_drvdata *drvdata)
  58 {
  59         struct cc_fips_handle *fips_handle_ptr = drvdata->fips_handle;
  60
  61         if (drvdata->hw_rev < CC_HW_REV_712)
  62                 return;
  63
  64         tasklet_schedule(&fips_handle_ptr->tasklet);
  65 }
  66
  67 static inline void tee_fips_error(struct device *dev)
  68 {
  69         if (fips_enabled)
  70                 panic("ccree: TEE reported cryptographic error in fips mode!\n");
  71         else
  72                 dev_err(dev, "TEE reported error!\n");
  73 }
  74
  75 /* Deferred service handler, run as interrupt-fired tasklet */
  76 static void fips_dsr(unsigned long devarg)
  77 {
  78         struct cc_drvdata *drvdata = (struct cc_drvdata *)devarg;
  79         struct device *dev = drvdata_to_dev(drvdata);
  80         u32 irq, state, val;
  81
  82         irq = (drvdata->irq & (CC_GPR0_IRQ_MASK));
  83
  84         if (irq) {
  85                 state = cc_ioread(drvdata, CC_REG(GPR_HOST));
  86
  87                 if (state != (CC_FIPS_SYNC_TEE_STATUS | CC_FIPS_SYNC_MODULE_OK))
  88                         tee_fips_error(dev);
  89         }
  90
  91         /* after verifing that there is nothing to do,
  92          * unmask AXI completion interrupt.
  93          */
  94         val = (CC_REG(HOST_IMR) & ~irq);
  95         cc_iowrite(drvdata, CC_REG(HOST_IMR), val);
  96 }
  97
  98 /* The function called once at driver entry point .*/
  99 int cc_fips_init(struct cc_drvdata *p_drvdata)
 100 {
 101         struct cc_fips_handle *fips_h;
 102         struct device *dev = drvdata_to_dev(p_drvdata);
 103
 104         if (p_drvdata->hw_rev < CC_HW_REV_712)
 105                 return 0;
 106
 107         fips_h = kzalloc(sizeof(*fips_h), GFP_KERNEL);
 108         if (!fips_h)
 109                 return -ENOMEM;
 110
 111         p_drvdata->fips_handle = fips_h;
 112
 113         dev_dbg(dev, "Initializing fips tasklet\n");
 114         tasklet_init(&fips_h->tasklet, fips_dsr, (unsigned long)p_drvdata);
 115
 116         if (!cc_get_tee_fips_status(p_drvdata))
 117                 tee_fips_error(dev);
 118
 119         return 0;
 120 }