lib/sbi/sbi_system.c

   1 /*
   2  * SPDX-License-Identifier: BSD-2-Clause
   3  *
   4  * Copyright (c) 2019 Western Digital Corporation or its affiliates.
   5  *
   6  * Authors:
   7  *   Anup Patel <anup.patel@wdc.com>
   8  *   Nick Kossifidis <mick@ics.forth.gr>
   9  */
  10
  11 #include <sbi/riscv_asm.h>
  12 #include <sbi/sbi_bitops.h>
  13 #include <sbi/sbi_domain.h>
  14 #include <sbi/sbi_hart.h>
  15 #include <sbi/sbi_hsm.h>
  16 #include <sbi/sbi_platform.h>
  17 #include <sbi/sbi_system.h>
  18 #include <sbi/sbi_ipi.h>
  19 #include <sbi/sbi_init.h>
  20
  21 static SBI_LIST_HEAD(reset_devices_list);
  22
  23 const struct sbi_system_reset_device *sbi_system_reset_get_device(
  24                                         u32 reset_type, u32 reset_reason)
  25 {
  26         struct sbi_system_reset_device *reset_dev = NULL;
  27         struct sbi_dlist *pos;
  28         /** lowest priority - any non zero is our candidate */
  29         int priority = 0;
  30
  31         /* Check each reset device registered for supported reset type */
  32         sbi_list_for_each(pos, &(reset_devices_list)) {
  33                 struct sbi_system_reset_device *dev =
  34                         to_system_reset_device(pos);
  35                 if (dev->system_reset_check) {
  36                         int status = dev->system_reset_check(reset_type,
  37                                                              reset_reason);
  38                         /** reset_type not supported */
  39                         if (status == 0)
  40                                 continue;
  41
  42                         if (status > priority) {
  43                                 reset_dev = dev;
  44                                 priority = status;
  45                         }
  46                 }
  47         }
  48
  49         return reset_dev;
  50 }
  51
  52 void sbi_system_reset_add_device(struct sbi_system_reset_device *dev)
  53 {
  54         if (!dev || !dev->system_reset_check)
  55                 return;
  56
  57         sbi_list_add(&(dev->node), &(reset_devices_list));
  58 }
  59
  60 bool sbi_system_reset_supported(u32 reset_type, u32 reset_reason)
  61 {
  62         return !!sbi_system_reset_get_device(reset_type, reset_reason);
  63 }
  64
  65 void __noreturn sbi_system_reset(u32 reset_type, u32 reset_reason)
  66 {
  67         ulong hbase = 0, hmask;
  68         u32 cur_hartid = current_hartid();
  69         struct sbi_domain *dom = sbi_domain_thishart_ptr();
  70         struct sbi_scratch *scratch = sbi_scratch_thishart_ptr();
  71
  72         /* Send HALT IPI to every hart other than the current hart */
  73         while (!sbi_hsm_hart_interruptible_mask(dom, hbase, &hmask)) {
  74                 if (hbase <= cur_hartid)
  75                         hmask &= ~(1UL << (cur_hartid - hbase));
  76                 if (hmask)
  77                         sbi_ipi_send_halt(hmask, hbase);
  78                 hbase += BITS_PER_LONG;
  79         }
  80
  81         /* Stop current HART */
  82         sbi_hsm_hart_stop(scratch, false);
  83
  84         /* Platform specific reset if domain allowed system reset */
  85         if (dom->system_reset_allowed) {
  86                 const struct sbi_system_reset_device *dev =
  87                         sbi_system_reset_get_device(reset_type, reset_reason);
  88                 if (dev)
  89                         dev->system_reset(reset_type, reset_reason);
  90         }
  91
  92         /* If platform specific reset did not work then do sbi_exit() */
  93         sbi_exit(scratch);
  94 }
  95
  96 static const struct sbi_system_suspend_device *suspend_dev = NULL;
  97
  98 const struct sbi_system_suspend_device *sbi_system_suspend_get_device(void)
  99 {
 100         return suspend_dev;
 101 }
 102
 103 void sbi_system_suspend_set_device(struct sbi_system_suspend_device *dev)
 104 {
 105         if (!dev || suspend_dev)
 106                 return;
 107
 108         suspend_dev = dev;
 109 }
 110
 111 bool sbi_system_suspend_supported(u32 sleep_type)
 112 {
 113         return suspend_dev && suspend_dev->system_suspend_check &&
 114                suspend_dev->system_suspend_check(sleep_type);
 115 }
 116
 117 int sbi_system_suspend(u32 sleep_type, ulong resume_addr, ulong opaque)
 118 {
 119         int ret = SBI_ENOTSUPP;
 120         const struct sbi_domain *dom = sbi_domain_thishart_ptr();
 121         struct sbi_scratch *scratch = sbi_scratch_thishart_ptr();
 122         void (*jump_warmboot)(void) = (void (*)(void))scratch->warmboot_addr;
 123         unsigned int hartid = current_hartid();
 124         unsigned long prev_mode;
 125         unsigned long i;
 126
 127         if (!dom || !dom->system_suspend_allowed)
 128                 return SBI_EFAIL;
 129
 130         if (!suspend_dev || !suspend_dev->system_suspend)
 131                 return SBI_EFAIL;
 132
 133         if (!sbi_system_suspend_supported(sleep_type))
 134                 return SBI_ENOTSUPP;
 135
 136         prev_mode = (csr_read(CSR_MSTATUS) & MSTATUS_MPP) >> MSTATUS_MPP_SHIFT;
 137         if (prev_mode != PRV_S && prev_mode != PRV_U)
 138                 return SBI_EFAIL;
 139
 140         sbi_hartmask_for_each_hart(i, &dom->assigned_harts) {
 141                 if (i == hartid)
 142                         continue;
 143                 if (__sbi_hsm_hart_get_state(i) != SBI_HSM_STATE_STOPPED)
 144                         return SBI_EFAIL;
 145         }
 146
 147         if (!sbi_domain_check_addr(dom, resume_addr, prev_mode,
 148                                    SBI_DOMAIN_EXECUTE))
 149                 return SBI_EINVALID_ADDR;
 150
 151         if (!sbi_hsm_hart_change_state(scratch, SBI_HSM_STATE_STARTED,
 152                                        SBI_HSM_STATE_SUSPENDED))
 153                 return SBI_EFAIL;
 154
 155         /* Prepare for resume */
 156         scratch->next_mode = prev_mode;
 157         scratch->next_addr = resume_addr;
 158         scratch->next_arg1 = opaque;
 159
 160         __sbi_hsm_suspend_non_ret_save(scratch);
 161
 162         /* Suspend */
 163         ret = suspend_dev->system_suspend(sleep_type, scratch->warmboot_addr);
 164         if (ret != SBI_OK) {
 165                 if (!sbi_hsm_hart_change_state(scratch, SBI_HSM_STATE_SUSPENDED,
 166                                                SBI_HSM_STATE_STARTED))
 167                         sbi_hart_hang();
 168                 return ret;
 169         }
 170
 171         /* Resume */
 172         jump_warmboot();
 173
 174         __builtin_unreachable();
 175 }