env: Support multiple environments

Now that we have everything in place to support multiple environment, let's
make sure the current code can use it.

The priority used between the various environment is the same one that was
used in the code previously.

At read / init times, the highest priority environment is going to be
detected, and we'll use the same one without lookup during writes. This
should implement the same behaviour than we currently have.

Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

env/env.c

@@ -26,6 +26,44 @@ static struct env_driver *_env_driver_lookup(enum env_location loc)
 	return NULL;
 }
 
+static enum env_location env_locations[] = {
+#ifdef CONFIG_ENV_IS_IN_EEPROM
+	ENVL_EEPROM,
+#endif
+#ifdef CONFIG_ENV_IS_IN_EXT4
+	ENVL_EXT4,
+#endif
+#ifdef CONFIG_ENV_IS_IN_FAT
+	ENVL_FAT,
+#endif
+#ifdef CONFIG_ENV_IS_IN_FLASH
+	ENVL_FLASH,
+#endif
+#ifdef CONFIG_ENV_IS_IN_MMC
+	ENVL_MMC,
+#endif
+#ifdef CONFIG_ENV_IS_IN_NAND
+	ENVL_NAND,
+#endif
+#ifdef CONFIG_ENV_IS_IN_NVRAM
+	ENVL_NVRAM,
+#endif
+#ifdef CONFIG_ENV_IS_IN_REMOTE
+	ENVL_REMOTE,
+#endif
+#ifdef CONFIG_ENV_IS_IN_SPI_FLASH
+	ENVL_SPI_FLASH,
+#endif
+#ifdef CONFIG_ENV_IS_IN_UBI
+	ENVL_UBI,
+#endif
+#ifdef CONFIG_ENV_IS_NOWHERE
+	ENVL_NOWHERE,
+#endif
+};
+
+static enum env_location env_load_location = ENVL_UNKNOWN;
+
 /**
  * env_get_location() - Returns the best env location for a board
  * @op: operations performed on the environment
@@ -45,38 +83,21 @@ static struct env_driver *_env_driver_lookup(enum env_location loc)
  */
 static enum env_location env_get_location(enum env_operation op, int prio)
 {
-	/*
-	 * We support a single environment, so any environment asked
-	 * with a priority that is not zero is out of our supported
-	 * bounds.
-	 */
-	if (prio >= 1)
-		return ENVL_UNKNOWN;
-
-	if IS_ENABLED(CONFIG_ENV_IS_IN_EEPROM)
-		return ENVL_EEPROM;
-	else if IS_ENABLED(CONFIG_ENV_IS_IN_FAT)
-		return ENVL_FAT;
-	else if IS_ENABLED(CONFIG_ENV_IS_IN_EXT4)
-		return ENVL_EXT4;
-	else if IS_ENABLED(CONFIG_ENV_IS_IN_FLASH)
-		return ENVL_FLASH;
-	else if IS_ENABLED(CONFIG_ENV_IS_IN_MMC)
-		return ENVL_MMC;
-	else if IS_ENABLED(CONFIG_ENV_IS_IN_NAND)
-		return ENVL_NAND;
-	else if IS_ENABLED(CONFIG_ENV_IS_IN_NVRAM)
-		return ENVL_NVRAM;
-	else if IS_ENABLED(CONFIG_ENV_IS_IN_REMOTE)
-		return ENVL_REMOTE;
-	else if IS_ENABLED(CONFIG_ENV_IS_IN_SPI_FLASH)
-		return ENVL_SPI_FLASH;
-	else if IS_ENABLED(CONFIG_ENV_IS_IN_UBI)
-		return ENVL_UBI;
-	else if IS_ENABLED(CONFIG_ENV_IS_NOWHERE)
-		return ENVL_NOWHERE;
-	else
-		return ENVL_UNKNOWN;
+	switch (op) {
+	case ENVOP_GET_CHAR:
+	case ENVOP_INIT:
+	case ENVOP_LOAD:
+		if (prio >= ARRAY_SIZE(env_locations))
+			return ENVL_UNKNOWN;
+
+		env_load_location = env_locations[prio];
+		return env_load_location;
+
+	case ENVOP_SAVE:
+		return env_load_location;
+	}
+
+	return ENVL_UNKNOWN;
 }