env/env.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (C) 2017 Google, Inc
   4  * Written by Simon Glass <sjg@chromium.org>
   5  */
   6
   7 #include <common.h>
   8 #include <environment.h>
   9
  10 DECLARE_GLOBAL_DATA_PTR;
  11
  12 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
  13 void env_fix_drivers(void)
  14 {
  15         struct env_driver *drv;
  16         const int n_ents = ll_entry_count(struct env_driver, env_driver);
  17         struct env_driver *entry;
  18
  19         drv = ll_entry_start(struct env_driver, env_driver);
  20         for (entry = drv; entry != drv + n_ents; entry++) {
  21                 if (entry->name)
  22                         entry->name += gd->reloc_off;
  23                 if (entry->load)
  24                         entry->load += gd->reloc_off;
  25                 if (entry->save)
  26                         entry->save += gd->reloc_off;
  27                 if (entry->init)
  28                         entry->init += gd->reloc_off;
  29         }
  30 }
  31 #endif
  32
  33 static struct env_driver *_env_driver_lookup(enum env_location loc)
  34 {
  35         struct env_driver *drv;
  36         const int n_ents = ll_entry_count(struct env_driver, env_driver);
  37         struct env_driver *entry;
  38
  39         drv = ll_entry_start(struct env_driver, env_driver);
  40         for (entry = drv; entry != drv + n_ents; entry++) {
  41                 if (loc == entry->location)
  42                         return entry;
  43         }
  44
  45         /* Not found */
  46         return NULL;
  47 }
  48
  49 static enum env_location env_locations[] = {
  50 #ifdef CONFIG_ENV_IS_IN_EEPROM
  51         ENVL_EEPROM,
  52 #endif
  53 #ifdef CONFIG_ENV_IS_IN_EXT4
  54         ENVL_EXT4,
  55 #endif
  56 #ifdef CONFIG_ENV_IS_IN_FAT
  57         ENVL_FAT,
  58 #endif
  59 #ifdef CONFIG_ENV_IS_IN_FLASH
  60         ENVL_FLASH,
  61 #endif
  62 #ifdef CONFIG_ENV_IS_IN_MMC
  63         ENVL_MMC,
  64 #endif
  65 #ifdef CONFIG_ENV_IS_IN_NAND
  66         ENVL_NAND,
  67 #endif
  68 #ifdef CONFIG_ENV_IS_IN_NVRAM
  69         ENVL_NVRAM,
  70 #endif
  71 #ifdef CONFIG_ENV_IS_IN_REMOTE
  72         ENVL_REMOTE,
  73 #endif
  74 #ifdef CONFIG_ENV_IS_IN_SPI_FLASH
  75         ENVL_SPI_FLASH,
  76 #endif
  77 #ifdef CONFIG_ENV_IS_IN_UBI
  78         ENVL_UBI,
  79 #endif
  80 #ifdef CONFIG_ENV_IS_NOWHERE
  81         ENVL_NOWHERE,
  82 #endif
  83 };
  84
  85 static bool env_has_inited(enum env_location location)
  86 {
  87         return gd->env_has_init & BIT(location);
  88 }
  89
  90 static void env_set_inited(enum env_location location)
  91 {
  92         /*
  93          * We're using a 32-bits bitmask stored in gd (env_has_init)
  94          * using the above enum value as the bit index. We need to
  95          * make sure that we're not overflowing it.
  96          */
  97         BUILD_BUG_ON(ARRAY_SIZE(env_locations) > BITS_PER_LONG);
  98
  99         gd->env_has_init |= BIT(location);
 100 }
 101
 102 /**
 103  * env_get_location() - Returns the best env location for a board
 104  * @op: operations performed on the environment
 105  * @prio: priority between the multiple environments, 0 being the
 106  *        highest priority
 107  *
 108  * This will return the preferred environment for the given priority.
 109  * This is overridable by boards if they need to.
 110  *
 111  * All implementations are free to use the operation, the priority and
 112  * any other data relevant to their choice, but must take into account
 113  * the fact that the lowest prority (0) is the most important location
 114  * in the system. The following locations should be returned by order
 115  * of descending priorities, from the highest to the lowest priority.
 116  *
 117  * Returns:
 118  * an enum env_location value on success, a negative error code otherwise
 119  */
 120 __weak enum env_location env_get_location(enum env_operation op, int prio)
 121 {
 122         if (prio >= ARRAY_SIZE(env_locations))
 123                 return ENVL_UNKNOWN;
 124
 125         gd->env_load_prio = prio;
 126
 127         return env_locations[prio];
 128 }
 129
 130
 131 /**
 132  * env_driver_lookup() - Finds the most suited environment location
 133  * @op: operations performed on the environment
 134  * @prio: priority between the multiple environments, 0 being the
 135  *        highest priority
 136  *
 137  * This will try to find the available environment with the highest
 138  * priority in the system.
 139  *
 140  * Returns:
 141  * NULL on error, a pointer to a struct env_driver otherwise
 142  */
 143 static struct env_driver *env_driver_lookup(enum env_operation op, int prio)
 144 {
 145         enum env_location loc = env_get_location(op, prio);
 146         struct env_driver *drv;
 147
 148         if (loc == ENVL_UNKNOWN)
 149                 return NULL;
 150
 151         drv = _env_driver_lookup(loc);
 152         if (!drv) {
 153                 debug("%s: No environment driver for location %d\n", __func__,
 154                       loc);
 155                 return NULL;
 156         }
 157
 158         return drv;
 159 }
 160
 161 __weak int env_get_char_spec(int index)
 162 {
 163         return *(uchar *)(gd->env_addr + index);
 164 }
 165
 166 int env_get_char(int index)
 167 {
 168         if (gd->env_valid == ENV_INVALID)
 169                 return default_environment[index];
 170         else
 171                 return env_get_char_spec(index);
 172 }
 173
 174 int env_load(void)
 175 {
 176         struct env_driver *drv;
 177         int prio;
 178
 179         for (prio = 0; (drv = env_driver_lookup(ENVOP_LOAD, prio)); prio++) {
 180                 int ret;
 181
 182                 if (!drv->load)
 183                         continue;
 184
 185                 if (!env_has_inited(drv->location))
 186                         continue;
 187
 188                 printf("Loading Environment from %s... ", drv->name);
 189                 /*
 190                  * In error case, the error message must be printed during
 191                  * drv->load() in some underlying API, and it must be exactly
 192                  * one message.
 193                  */
 194                 ret = drv->load();
 195                 if (ret) {
 196                         debug("Failed (%d)\n", ret);
 197                 } else {
 198                         printf("OK\n");
 199                         return 0;
 200                 }
 201         }
 202
 203         /*
 204          * In case of invalid environment, we set the 'default' env location
 205          * to the highest priority. In this way, next calls to env_save()
 206          * will restore the environment at the right place.
 207          */
 208         env_get_location(ENVOP_LOAD, 0);
 209
 210         return -ENODEV;
 211 }
 212
 213 int env_save(void)
 214 {
 215         struct env_driver *drv;
 216
 217         drv = env_driver_lookup(ENVOP_SAVE, gd->env_load_prio);
 218         if (drv) {
 219                 int ret;
 220
 221                 if (!drv->save)
 222                         return -ENODEV;
 223
 224                 if (!env_has_inited(drv->location))
 225                         return -ENODEV;
 226
 227                 printf("Saving Environment to %s... ", drv->name);
 228                 ret = drv->save();
 229                 if (ret)
 230                         printf("Failed (%d)\n", ret);
 231                 else
 232                         printf("OK\n");
 233
 234                 if (!ret)
 235                         return 0;
 236         }
 237
 238         return -ENODEV;
 239 }
 240
 241 int env_init(void)
 242 {
 243         struct env_driver *drv;
 244         int ret = -ENOENT;
 245         int prio;
 246
 247         for (prio = 0; (drv = env_driver_lookup(ENVOP_INIT, prio)); prio++) {
 248                 if (!drv->init || !(ret = drv->init()))
 249                         env_set_inited(drv->location);
 250
 251                 debug("%s: Environment %s init done (ret=%d)\n", __func__,
 252                       drv->name, ret);
 253         }
 254
 255         if (!prio)
 256                 return -ENODEV;
 257
 258         if (ret == -ENOENT) {
 259                 gd->env_addr = (ulong)&default_environment[0];
 260                 gd->env_valid = ENV_VALID;
 261
 262                 return 0;
 263         }
 264
 265         return ret;
 266 }