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 enum env_location env_load_location = ENVL_UNKNOWN;
  66
  67 static bool env_has_inited(enum env_location location)
  68 {
  69         return gd->env_has_init & BIT(location);
  70 }
  71
  72 static void env_set_inited(enum env_location location)
  73 {
  74         /*
  75          * We're using a 32-bits bitmask stored in gd (env_has_init)
  76          * using the above enum value as the bit index. We need to
  77          * make sure that we're not overflowing it.
  78          */
  79         BUILD_BUG_ON(ARRAY_SIZE(env_locations) > BITS_PER_LONG);
  80
  81         gd->env_has_init |= BIT(location);
  82 }
  83
  84 /**
  85  * env_get_location() - Returns the best env location for a board
  86  * @op: operations performed on the environment
  87  * @prio: priority between the multiple environments, 0 being the
  88  *        highest priority
  89  *
  90  * This will return the preferred environment for the given priority.
  91  *
  92  * All implementations are free to use the operation, the priority and
  93  * any other data relevant to their choice, but must take into account
  94  * the fact that the lowest prority (0) is the most important location
  95  * in the system. The following locations should be returned by order
  96  * of descending priorities, from the highest to the lowest priority.
  97  *
  98  * Returns:
  99  * an enum env_location value on success, a negative error code otherwise
 100  */
 101 static enum env_location env_get_location(enum env_operation op, int prio)
 102 {
 103         switch (op) {
 104         case ENVOP_GET_CHAR:
 105         case ENVOP_INIT:
 106         case ENVOP_LOAD:
 107                 if (prio >= ARRAY_SIZE(env_locations))
 108                         return ENVL_UNKNOWN;
 109
 110                 env_load_location = env_locations[prio];
 111                 return env_load_location;
 112
 113         case ENVOP_SAVE:
 114                 return env_load_location;
 115         }
 116
 117         return ENVL_UNKNOWN;
 118 }
 119
 120
 121 /**
 122  * env_driver_lookup() - Finds the most suited environment location
 123  * @op: operations performed on the environment
 124  * @prio: priority between the multiple environments, 0 being the
 125  *        highest priority
 126  *
 127  * This will try to find the available environment with the highest
 128  * priority in the system.
 129  *
 130  * Returns:
 131  * NULL on error, a pointer to a struct env_driver otherwise
 132  */
 133 static struct env_driver *env_driver_lookup(enum env_operation op, int prio)
 134 {
 135         enum env_location loc = env_get_location(op, prio);
 136         struct env_driver *drv;
 137
 138         if (loc == ENVL_UNKNOWN)
 139                 return NULL;
 140
 141         drv = _env_driver_lookup(loc);
 142         if (!drv) {
 143                 debug("%s: No environment driver for location %d\n", __func__,
 144                       loc);
 145                 return NULL;
 146         }
 147
 148         return drv;
 149 }
 150
 151 int env_get_char(int index)
 152 {
 153         struct env_driver *drv;
 154         int prio;
 155
 156         if (gd->env_valid == ENV_INVALID)
 157                 return default_environment[index];
 158
 159         for (prio = 0; (drv = env_driver_lookup(ENVOP_GET_CHAR, prio)); prio++) {
 160                 int ret;
 161
 162                 if (!drv->get_char)
 163                         continue;
 164
 165                 if (!env_has_inited(drv->location))
 166                         continue;
 167
 168                 ret = drv->get_char(index);
 169                 if (!ret)
 170                         return 0;
 171
 172                 debug("%s: Environment %s failed to load (err=%d)\n", __func__,
 173                       drv->name, ret);
 174         }
 175
 176         return -ENODEV;
 177 }
 178
 179 int env_load(void)
 180 {
 181         struct env_driver *drv;
 182         int prio;
 183
 184         for (prio = 0; (drv = env_driver_lookup(ENVOP_LOAD, prio)); prio++) {
 185                 int ret;
 186
 187                 if (!drv->load)
 188                         continue;
 189
 190                 if (!env_has_inited(drv->location))
 191                         continue;
 192
 193                 printf("Loading Environment from %s... ", drv->name);
 194                 ret = drv->load();
 195                 if (ret)
 196                         printf("Failed (%d)\n", ret);
 197                 else
 198                         printf("OK\n");
 199
 200                 if (!ret)
 201                         return 0;
 202         }
 203
 204         return -ENODEV;
 205 }
 206
 207 int env_save(void)
 208 {
 209         struct env_driver *drv;
 210         int prio;
 211
 212         for (prio = 0; (drv = env_driver_lookup(ENVOP_SAVE, prio)); prio++) {
 213                 int ret;
 214
 215                 if (!drv->save)
 216                         continue;
 217
 218                 if (!env_has_inited(drv->location))
 219                         continue;
 220
 221                 printf("Saving Environment to %s... ", drv->name);
 222                 ret = drv->save();
 223                 if (ret)
 224                         printf("Failed (%d)\n", ret);
 225                 else
 226                         printf("OK\n");
 227
 228                 if (!ret)
 229                         return 0;
 230         }
 231
 232         return -ENODEV;
 233 }
 234
 235 int env_init(void)
 236 {
 237         struct env_driver *drv;
 238         int ret = -ENOENT;
 239         int prio;
 240
 241         for (prio = 0; (drv = env_driver_lookup(ENVOP_INIT, prio)); prio++) {
 242                 if (!drv->init || !(ret = drv->init()))
 243                         env_set_inited(drv->location);
 244
 245                 debug("%s: Environment %s init done (ret=%d)\n", __func__,
 246                       drv->name, ret);
 247         }
 248
 249         if (!prio)
 250                 return -ENODEV;
 251
 252         if (ret == -ENOENT) {
 253                 gd->env_addr = (ulong)&default_environment[0];
 254                 gd->env_valid = ENV_VALID;
 255
 256                 return 0;
 257         }
 258
 259         return ret;
 260 }