drivers/misc/fsl_sec_mon.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright 2015 Freescale Semiconductor, Inc.
   4  */
   5
   6 #include <common.h>
   7 #include <fsl_sec_mon.h>
   8 #include <linux/delay.h>
   9
  10 static u32 get_sec_mon_state(void)
  11 {
  12         struct ccsr_sec_mon_regs *sec_mon_regs = (void *)
  13                                                 (CONFIG_SYS_SEC_MON_ADDR);
  14         return sec_mon_in32(&sec_mon_regs->hp_stat) & HPSR_SSM_ST_MASK;
  15 }
  16
  17 static int set_sec_mon_state_non_sec(void)
  18 {
  19         u32 sts;
  20         int timeout = 10;
  21         struct ccsr_sec_mon_regs *sec_mon_regs = (void *)
  22                                                 (CONFIG_SYS_SEC_MON_ADDR);
  23
  24         sts = get_sec_mon_state();
  25
  26         switch (sts) {
  27         /*
  28          * If initial state is check or Non-Secure, then set the Software
  29          * Security Violation Bit and transition to Non-Secure State.
  30          */
  31         case HPSR_SSM_ST_CHECK:
  32                 printf("SEC_MON state transitioning to Non Secure.\n");
  33                 sec_mon_setbits32(&sec_mon_regs->hp_com, HPCOMR_SW_SV);
  34
  35                 /* polling loop till SEC_MON is in Non Secure state */
  36                 while (timeout) {
  37                         sts = get_sec_mon_state();
  38
  39                         if ((sts & HPSR_SSM_ST_MASK) ==
  40                                 HPSR_SSM_ST_NON_SECURE)
  41                                 break;
  42
  43                         udelay(10);
  44                         timeout--;
  45                 }
  46
  47                 if (timeout == 0) {
  48                         printf("SEC_MON state transition timeout.\n");
  49                         return -1;
  50                 }
  51                 break;
  52
  53         /*
  54          * If initial state is Trusted, Secure or Soft-Fail, then first set
  55          * the Software Security Violation Bit and transition to Soft-Fail
  56          * State.
  57          */
  58         case HPSR_SSM_ST_TRUST:
  59         case HPSR_SSM_ST_SECURE:
  60         case HPSR_SSM_ST_SOFT_FAIL:
  61                 printf("SEC_MON state transitioning to Soft Fail.\n");
  62                 sec_mon_setbits32(&sec_mon_regs->hp_com, HPCOMR_SW_SV);
  63
  64                 /* polling loop till SEC_MON is in Soft-Fail state */
  65                 while (timeout) {
  66                         sts = get_sec_mon_state();
  67
  68                         if ((sts & HPSR_SSM_ST_MASK) ==
  69                                 HPSR_SSM_ST_SOFT_FAIL)
  70                                 break;
  71
  72                         udelay(10);
  73                         timeout--;
  74                 }
  75
  76                 if (timeout == 0) {
  77                         printf("SEC_MON state transition timeout.\n");
  78                         return -1;
  79                 }
  80
  81                 timeout = 10;
  82
  83                 /*
  84                  * If SSM Soft Fail to Non-Secure State Transition
  85                  * disable is not set, then set SSM_ST bit and
  86                  * transition to Non-Secure State.
  87                  */
  88                 if ((sec_mon_in32(&sec_mon_regs->hp_com) &
  89                         HPCOMR_SSM_SFNS_DIS) == 0) {
  90                         printf("SEC_MON state transitioning to Non Secure.\n");
  91                         sec_mon_setbits32(&sec_mon_regs->hp_com, HPCOMR_SSM_ST);
  92
  93                         /* polling loop till SEC_MON is in Non Secure*/
  94                         while (timeout) {
  95                                 sts = get_sec_mon_state();
  96
  97                                 if ((sts & HPSR_SSM_ST_MASK) ==
  98                                         HPSR_SSM_ST_NON_SECURE)
  99                                         break;
 100
 101                                 udelay(10);
 102                                 timeout--;
 103                         }
 104
 105                         if (timeout == 0) {
 106                                 printf("SEC_MON state transition timeout.\n");
 107                                 return -1;
 108                         }
 109                 }
 110                 break;
 111         default:
 112                 printf("SEC_MON already in Non Secure state.\n");
 113                 return 0;
 114         }
 115         return 0;
 116 }
 117
 118 static int set_sec_mon_state_soft_fail(void)
 119 {
 120         u32 sts;
 121         int timeout = 10;
 122         struct ccsr_sec_mon_regs *sec_mon_regs = (void *)
 123                                                 (CONFIG_SYS_SEC_MON_ADDR);
 124
 125         printf("SEC_MON state transitioning to Soft Fail.\n");
 126         sec_mon_setbits32(&sec_mon_regs->hp_com, HPCOMR_SW_FSV);
 127
 128         /* polling loop till SEC_MON is in Soft-Fail state */
 129         while (timeout) {
 130                 sts = get_sec_mon_state();
 131
 132                 if ((sts & HPSR_SSM_ST_MASK) ==
 133                         HPSR_SSM_ST_SOFT_FAIL)
 134                         break;
 135
 136                 udelay(10);
 137                 timeout--;
 138         }
 139
 140         if (timeout == 0) {
 141                 printf("SEC_MON state transition timeout.\n");
 142                 return -1;
 143         }
 144         return 0;
 145 }
 146
 147 int set_sec_mon_state(u32 state)
 148 {
 149         int ret = -1;
 150
 151         switch (state) {
 152         case HPSR_SSM_ST_NON_SECURE:
 153                 ret = set_sec_mon_state_non_sec();
 154                 break;
 155         case HPSR_SSM_ST_SOFT_FAIL:
 156                 ret = set_sec_mon_state_soft_fail();
 157                 break;
 158         default:
 159                 printf("SEC_MON state transition not supported.\n");
 160                 return 0;
 161         }
 162
 163         return ret;
 164 }