src/drivers/smmstore/smi.c

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2
   3 #include <console/console.h>
   4 #include <commonlib/region.h>
   5 #include <cpu/x86/smm.h>
   6 #include <smmstore.h>
   7 #include <stddef.h>
   8 #include <stdint.h>
   9
  10 /*
  11  * Check that the given range is legal.
  12  *
  13  * Legal means:
  14  *  - not pointing into SMRAM
  15  *
  16  * returns 0 on success, -1 on failure
  17  */
  18 static int range_check(void *start, size_t size)
  19 {
  20         if (smm_points_to_smram(start, size))
  21                 return -1;
  22
  23         return 0;
  24 }
  25
  26 static uint32_t smmstorev1_exec(uint8_t command, void *param)
  27 {
  28         uint32_t ret = SMMSTORE_RET_FAILURE;
  29
  30         switch (command) {
  31         case SMMSTORE_CMD_READ: {
  32                 printk(BIOS_DEBUG, "Reading from SMM store\n");
  33                 struct smmstore_params_read *params = param;
  34
  35                 if (range_check(params, sizeof(*params)) != 0)
  36                         break;
  37
  38                 if (range_check(params->buf, params->bufsize) != 0)
  39                         break;
  40
  41                 if (smmstore_read_region(params->buf, &params->bufsize) == 0)
  42                         ret = SMMSTORE_RET_SUCCESS;
  43                 break;
  44         }
  45
  46         case SMMSTORE_CMD_APPEND: {
  47                 printk(BIOS_DEBUG, "Appending into SMM store\n");
  48                 struct smmstore_params_append *params = param;
  49
  50                 if (range_check(params, sizeof(*params)) != 0)
  51                         break;
  52                 if (range_check(params->key, params->keysize) != 0)
  53                         break;
  54                 if (range_check(params->val, params->valsize) != 0)
  55                         break;
  56
  57                 if (smmstore_append_data(params->key, params->keysize,
  58                                          params->val, params->valsize) == 0)
  59                         ret = SMMSTORE_RET_SUCCESS;
  60                 break;
  61         }
  62
  63         case SMMSTORE_CMD_CLEAR: {
  64                 if (smmstore_clear_region() == 0)
  65                         ret = SMMSTORE_RET_SUCCESS;
  66                 break;
  67         }
  68         default:
  69                 printk(BIOS_DEBUG,
  70                        "Unknown SMM store v1 command: 0x%02x\n", command);
  71                 ret = SMMSTORE_RET_UNSUPPORTED;
  72                 break;
  73         }
  74
  75         return ret;
  76 }
  77
  78 static uint32_t smmstorev2_exec(uint8_t command, void *param)
  79 {
  80         uint32_t ret = SMMSTORE_RET_FAILURE;
  81         static bool initialized = false;
  82
  83         if (!initialized) {
  84                 uintptr_t base;
  85                 size_t size;
  86                 smm_get_smmstore_com_buffer(&base, &size);
  87
  88                 if (smmstore_init((void *)base, size))
  89                         return SMMSTORE_RET_FAILURE;
  90                 initialized = true;
  91         }
  92
  93         switch (command) {
  94         case SMMSTORE_CMD_RAW_READ: {
  95                 printk(BIOS_DEBUG, "Raw read from SMM store, param = %p\n", param);
  96                 struct smmstore_params_raw_read *params = param;
  97
  98                 if (range_check(params, sizeof(*params)) != 0)
  99                         break;
 100
 101                 if (smmstore_rawread_region(params->block_id, params->bufoffset,
 102                                             params->bufsize) == 0)
 103                         ret = SMMSTORE_RET_SUCCESS;
 104                 break;
 105         }
 106         case SMMSTORE_CMD_RAW_WRITE: {
 107                 printk(BIOS_DEBUG, "Raw write to SMM store, param = %p\n", param);
 108                 struct smmstore_params_raw_write *params = param;
 109
 110                 if (range_check(params, sizeof(*params)) != 0)
 111                         break;
 112
 113                 if (smmstore_rawwrite_region(params->block_id, params->bufoffset,
 114                                              params->bufsize) == 0)
 115                         ret = SMMSTORE_RET_SUCCESS;
 116                 break;
 117         }
 118         case SMMSTORE_CMD_RAW_CLEAR: {
 119                 printk(BIOS_DEBUG, "Raw clear SMM store, param = %p\n", param);
 120                 struct smmstore_params_raw_clear *params = param;
 121
 122                 if (range_check(params, sizeof(*params)) != 0)
 123                         break;
 124
 125                 if (smmstore_rawclear_region(params->block_id) == 0)
 126                         ret = SMMSTORE_RET_SUCCESS;
 127                 break;
 128         }
 129         default:
 130                 printk(BIOS_DEBUG,
 131                         "Unknown SMM store v2 command: 0x%02x\n", command);
 132                 ret = SMMSTORE_RET_UNSUPPORTED;
 133                 break;
 134         }
 135
 136         return ret;
 137 }
 138
 139 uint32_t smmstore_exec(uint8_t command, void *param)
 140 {
 141         if (command != SMMSTORE_CMD_CLEAR && !param)
 142                 return SMMSTORE_RET_FAILURE;
 143
 144         if (CONFIG(SMMSTORE_V2))
 145                 return smmstorev2_exec(command, param);
 146         else
 147                 return smmstorev1_exec(command, param);
 148 }