env: Add support for storing env variables in SCSI devices

Allow SCSI to be able to store environment variables.

Signed-off-by: Varadarajan Narayanan <quic_varada@quicinc.com>
Acked-by: Casey Connolly <casey.connolly@linaro.org>

env/Kconfig

@@ -74,7 +74,7 @@ config ENV_IS_DEFAULT
 		     !ENV_IS_IN_MMC && !ENV_IS_IN_NAND && \
 		     !ENV_IS_IN_NVRAM && !ENV_IS_IN_ONENAND && \
 		     !ENV_IS_IN_REMOTE && !ENV_IS_IN_SPI_FLASH && \
-		     !ENV_IS_IN_UBI && !ENV_IS_IN_MTD
+		     !ENV_IS_IN_UBI && !ENV_IS_IN_MTD && !ENV_IS_IN_SCSI
 	select ENV_IS_NOWHERE
 
 config ENV_IS_NOWHERE
@@ -297,6 +297,13 @@ config ENV_IS_IN_NAND
 	  Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
 	  using CONFIG_ENV_OFFSET_OOB.
 
+config ENV_IS_IN_SCSI
+	bool "Environment in an SCSI device"
+	depends on SCSI
+	help
+	  Define this if you have an SCSI device which you want to use for the
+	  environment.
+
 config ENV_RANGE
 	hex "Length of the region in which the environment can be written"
 	depends on ENV_IS_IN_NAND
@@ -731,6 +738,12 @@ config ENV_MMC_USE_DT
 	  The 2 defines CONFIG_ENV_OFFSET, CONFIG_ENV_OFFSET_REDUND
 	  are not used as fallback.
 
+config SCSI_ENV_PART_UUID
+	string "SCSI partition UUID for saving environment"
+	depends on ENV_IS_IN_SCSI
+	help
+	  UUID of the SCSI partition that you want to store the environment in.
+
 config USE_DEFAULT_ENV_FILE
 	bool "Create default environment from file"
 	help

env/Makefile

@@ -28,5 +28,6 @@ obj-$(CONFIG_$(PHASE_)ENV_IS_IN_NAND) += nand.o
 obj-$(CONFIG_$(PHASE_)ENV_IS_IN_SPI_FLASH) += sf.o
 obj-$(CONFIG_$(PHASE_)ENV_IS_IN_MTD) += mtd.o
 obj-$(CONFIG_$(PHASE_)ENV_IS_IN_FLASH) += flash.o
+obj-$(CONFIG_$(PHASE_)ENV_IS_IN_SCSI) += scsi.o
 
 CFLAGS_embedded.o := -Wa,--no-warn -DENV_CRC=$(shell tools/envcrc 2>/dev/null)

env/env.c

@@ -46,6 +46,9 @@ static enum env_location env_locations[] = {
 #ifdef CONFIG_ENV_IS_IN_MMC
 	ENVL_MMC,
 #endif
+#ifdef CONFIG_ENV_IS_IN_SCSI
+	ENVL_SCSI,
+#endif
 #ifdef CONFIG_ENV_IS_IN_NAND
 	ENVL_NAND,
 #endif

env/scsi.c

@@ -0,0 +1,115 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2008-2011 Freescale Semiconductor, Inc.
+ */
+
+/* #define DEBUG */
+
+#include <asm/global_data.h>
+
+#include <command.h>
+#include <env.h>
+#include <env_internal.h>
+#include <fdtdec.h>
+#include <linux/stddef.h>
+#include <malloc.h>
+#include <memalign.h>
+#include <part.h>
+#include <search.h>
+#include <scsi.h>
+#include <errno.h>
+#include <dm/ofnode.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+static env_t envbuf;
+
+struct env_scsi_info {
+	struct blk_desc *blk;
+	struct disk_partition part;
+	int count;
+};
+
+static struct env_scsi_info env_part;
+
+static inline struct env_scsi_info *env_scsi_get_part(void)
+{
+	struct env_scsi_info *ep = &env_part;
+
+	if (scsi_get_blk_by_uuid(CONFIG_SCSI_ENV_PART_UUID, &ep->blk, &ep->part))
+		return NULL;
+
+	ep->count = CONFIG_ENV_SIZE / ep->part.blksz;
+
+	return ep;
+}
+
+static int env_scsi_save(void)
+{
+	struct env_scsi_info *ep = env_scsi_get_part();
+	int ret;
+
+	if (!ep)
+		return -ENOENT;
+
+	ret = env_export(&envbuf);
+	if (ret)
+		return ret;
+
+	if (blk_dwrite(ep->blk, ep->part.start, ep->count, &envbuf) != ep->count)
+		return -EIO;
+
+	return 0;
+}
+
+static int env_scsi_erase(void)
+{
+	struct env_scsi_info *ep = env_scsi_get_part();
+
+	if (!ep)
+		return -ENOENT;
+
+	return (int)blk_derase(ep->blk, ep->part.start, ep->count);
+}
+
+#if defined(ENV_IS_EMBEDDED)
+static int env_scsi_load(void)
+{
+	return 0;
+}
+#else
+static int env_scsi_load(void)
+{
+	struct env_scsi_info *ep = env_scsi_get_part();
+	int ret;
+
+	if (!ep) {
+		env_set_default(CONFIG_SCSI_ENV_PART_UUID " partition not found", 0);
+		return -ENOENT;
+	}
+
+	if (blk_dread(ep->blk, ep->part.start, ep->count, &envbuf) != ep->count) {
+		env_set_default(CONFIG_SCSI_ENV_PART_UUID " partition read failed", 0);
+		return -EIO;
+	}
+
+	ret = env_import((char *)&envbuf, 1, H_EXTERNAL);
+	if (ret) {
+		debug("ENV import failed\n");
+		env_set_default("Cannot load environment", 0);
+	} else {
+		gd->env_addr = (ulong)envbuf.data;
+	}
+
+	return ret;
+}
+#endif
+
+U_BOOT_ENV_LOCATION(scsi) = {
+	.location	= ENVL_SCSI,
+	ENV_NAME("SCSI")
+	.load		= env_scsi_load,
+#if defined(CONFIG_CMD_SAVEENV) && !defined(CONFIG_XPL_BUILD)
+	.save		= env_save_ptr(env_scsi_save),
+	.erase		= ENV_ERASE_PTR(env_scsi_erase),
+#endif
+};

include/env_internal.h

@@ -115,6 +115,7 @@ enum env_location {
 	ENVL_SPI_FLASH,
 	ENVL_MTD,
 	ENVL_UBI,
+	ENVL_SCSI,
 	ENVL_NOWHERE,
 
 	ENVL_COUNT,