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         switch (op) {
 123         case ENVOP_GET_CHAR:
 124         case ENVOP_INIT:
 125         case ENVOP_LOAD:
 126                 if (prio >= ARRAY_SIZE(env_locations))
 127                         return ENVL_UNKNOWN;
 128
 129                 gd->env_load_location = env_locations[prio];
 130                 return gd->env_load_location;
 131
 132         case ENVOP_SAVE:
 133                 return gd->env_load_location;
 134         }
 135
 136         return ENVL_UNKNOWN;
 137 }
 138
 139
 140 /**
 141  * env_driver_lookup() - Finds the most suited environment location
 142  * @op: operations performed on the environment
 143  * @prio: priority between the multiple environments, 0 being the
 144  *        highest priority
 145  *
 146  * This will try to find the available environment with the highest
 147  * priority in the system.
 148  *
 149  * Returns:
 150  * NULL on error, a pointer to a struct env_driver otherwise
 151  */
 152 static struct env_driver *env_driver_lookup(enum env_operation op, int prio)
 153 {
 154         enum env_location loc = env_get_location(op, prio);
 155         struct env_driver *drv;
 156
 157         if (loc == ENVL_UNKNOWN)
 158                 return NULL;
 159
 160         drv = _env_driver_lookup(loc);
 161         if (!drv) {
 162                 debug("%s: No environment driver for location %d\n", __func__,
 163                       loc);
 164                 return NULL;
 165         }
 166
 167         return drv;
 168 }
 169
 170 __weak int env_get_char_spec(int index)
 171 {
 172         return *(uchar *)(gd->env_addr + index);
 173 }
 174
 175 int env_get_char(int index)
 176 {
 177         if (gd->env_valid == ENV_INVALID)
 178                 return default_environment[index];
 179         else
 180                 return env_get_char_spec(index);
 181 }
 182
 183 int env_load(void)
 184 {
 185         struct env_driver *drv;
 186         int prio;
 187
 188         for (prio = 0; (drv = env_driver_lookup(ENVOP_LOAD, prio)); prio++) {
 189                 int ret;
 190
 191                 if (!drv->load)
 192                         continue;
 193
 194                 if (!env_has_inited(drv->location))
 195                         continue;
 196
 197                 printf("Loading Environment from %s... ", drv->name);
 198                 ret = drv->load();
 199                 if (ret)
 200                         printf("Failed (%d)\n", ret);
 201                 else
 202                         printf("OK\n");
 203
 204                 if (!ret)
 205                         return 0;
 206         }
 207
 208         return -ENODEV;
 209 }
 210
 211 int env_save(void)
 212 {
 213         struct env_driver *drv;
 214         int prio;
 215
 216         for (prio = 0; (drv = env_driver_lookup(ENVOP_SAVE, prio)); prio++) {
 217                 int ret;
 218
 219                 if (!drv->save)
 220                         continue;
 221
 222                 if (!env_has_inited(drv->location))
 223                         continue;
 224
 225                 printf("Saving Environment to %s... ", drv->name);
 226                 ret = drv->save();
 227                 if (ret)
 228                         printf("Failed (%d)\n", ret);
 229                 else
 230                         printf("OK\n");
 231
 232                 if (!ret)
 233                         return 0;
 234         }
 235
 236         return -ENODEV;
 237 }
 238
 239 int env_init(void)
 240 {
 241         struct env_driver *drv;
 242         int ret = -ENOENT;
 243         int prio;
 244
 245         for (prio = 0; (drv = env_driver_lookup(ENVOP_INIT, prio)); prio++) {
 246                 if (!drv->init || !(ret = drv->init()))
 247                         env_set_inited(drv->location);
 248
 249                 debug("%s: Environment %s init done (ret=%d)\n", __func__,
 250                       drv->name, ret);
 251         }
 252
 253         if (!prio)
 254                 return -ENODEV;
 255
 256         if (ret == -ENOENT) {
 257                 gd->env_addr = (ulong)&default_environment[0];
 258                 gd->env_valid = ENV_VALID;
 259
 260                 return 0;
 261         }
 262
 263         return ret;
 264 }