env/env.c

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