[PATCHv2 1/5] FWU: Add FWU metadata access driver for MTD storage regions

[jassisinghbrar@gmail.com]

From: Sughosh Ganu <sughosh.ganu@linaro.org>

In the FWU Multi Bank Update feature, the information about the
updatable images is stored as part of the metadata, on a separate
region. Add a driver for reading from and writing to the metadata
when the updatable images and the metadata are stored on a raw
MTD region.

Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
---
 drivers/fwu-mdata/Kconfig   |  17 +-
 drivers/fwu-mdata/Makefile  |   1 +
 drivers/fwu-mdata/raw_mtd.c | 305 ++++++++++++++++++++++++++++++++++++
 3 files changed, 322 insertions(+), 1 deletion(-)
 create mode 100644 drivers/fwu-mdata/raw_mtd.c

diff --git a/drivers/fwu-mdata/Kconfig b/drivers/fwu-mdata/Kconfig
index 36c4479a59..841c6f5b2d 100644
--- a/drivers/fwu-mdata/Kconfig
+++ b/drivers/fwu-mdata/Kconfig
@@ -6,11 +6,26 @@ config FWU_MDATA
 	  FWU Metadata partitions reside on the same storage device
 	  which contains the other FWU updatable firmware images.
 
+choice
+	prompt "Storage Layout Scheme"
+	depends on FWU_MDATA
+	default FWU_MDATA_GPT_BLK
+
 config FWU_MDATA_GPT_BLK
-	bool "FWU Metadata access for GPT partitioned Block devices"
+	bool "GPT Partitioned Block devices"
 	select PARTITION_TYPE_GUID
 	select PARTITION_UUIDS
 	depends on FWU_MDATA && BLK && EFI_PARTITION
 	help
 	  Enable support for accessing FWU Metadata on GPT partitioned
 	  block devices.
+
+config FWU_MDATA_MTD
+	bool "Raw MTD devices"
+	depends on MTD
+	help
+	  Enable support for accessing FWU Metadata on non-partitioned
+	  (or non-GPT partitioned, e.g. partition nodes in devicetree)
+	  MTD devices.
+
+endchoice
diff --git a/drivers/fwu-mdata/Makefile b/drivers/fwu-mdata/Makefile
index 3fee64c10c..06c49747ba 100644
--- a/drivers/fwu-mdata/Makefile
+++ b/drivers/fwu-mdata/Makefile
@@ -6,3 +6,4 @@
 
 obj-$(CONFIG_FWU_MDATA) += fwu-mdata-uclass.o
 obj-$(CONFIG_FWU_MDATA_GPT_BLK) += gpt_blk.o
+obj-$(CONFIG_FWU_MDATA_MTD) += raw_mtd.o
diff --git a/drivers/fwu-mdata/raw_mtd.c b/drivers/fwu-mdata/raw_mtd.c
new file mode 100644
index 0000000000..ff2064b442
--- /dev/null
+++ b/drivers/fwu-mdata/raw_mtd.c
@@ -0,0 +1,305 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2022, Linaro Limited
+ */
+
+#define LOG_CATEGORY UCLASS_FWU_MDATA
+
+#include <efi_loader.h>
+#include <fwu.h>
+#include <fwu_mdata.h>
+#include <memalign.h>
+#include <spi.h>
+#include <spi_flash.h>
+#include <flash.h>
+
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <u-boot/crc.h>
+
+/* Internal helper structure to move data around */
+struct fwu_mdata_mtd_priv {
+	struct mtd_info *mtd;
+	u32 pri_offset;
+	u32 sec_offset;
+};
+
+enum fwu_mtd_op {
+	FWU_MTD_READ,
+	FWU_MTD_WRITE,
+};
+
+#define FWU_MDATA_PRIMARY	true
+#define FWU_MDATA_SECONDARY	false
+
+static bool mtd_is_aligned_with_block_size(struct mtd_info *mtd, u64 size)
+{
+	return !do_div(size, mtd->erasesize);
+}
+
+static int mtd_io_data(struct mtd_info *mtd, u32 offs, u32 size, void *data,
+		       enum fwu_mtd_op op)
+{
+	struct mtd_oob_ops io_op ={};
+	u64 lock_offs, lock_len;
+	size_t len;
+	void *buf;
+	int ret;
+
+	if (!mtd_is_aligned_with_block_size(mtd, offs)) {
+		log_err("Offset unaligned with a block (0x%x)\n", mtd->erasesize);
+		return -EINVAL;
+	}
+
+	lock_offs = offs;
+	/* This will expand erase size to align with the block size */
+	lock_len = round_up(size, mtd->erasesize);
+
+	ret = mtd_unlock(mtd, lock_offs, lock_len);
+	if (ret && ret != -EOPNOTSUPP)
+		return ret;
+
+	if (op == FWU_MTD_WRITE) {
+		struct erase_info erase_op = {};
+
+		erase_op.mtd = mtd;
+		erase_op.addr = lock_offs;
+		erase_op.len = lock_len;
+		erase_op.scrub = 0;
+
+		ret = mtd_erase(mtd, &erase_op);
+		if (ret)
+			goto lock;
+	}
+
+	/* Also, expand the write size to align with the write size */
+	len = round_up(size, mtd->writesize);
+
+	buf = memalign(ARCH_DMA_MINALIGN, len);
+	if (!buf) {
+		ret = -ENOMEM;
+		goto lock;
+	}
+	memset(buf, 0xff, len);
+
+	io_op.mode = MTD_OPS_AUTO_OOB;
+	io_op.len = len;
+	io_op.ooblen = 0;
+	io_op.datbuf = buf;
+	io_op.oobbuf = NULL;
+
+	if (op == FWU_MTD_WRITE) {
+		memcpy(buf, data, size);
+		ret = mtd_write_oob(mtd, offs, &io_op);
+	} else {
+		ret = mtd_read_oob(mtd, offs, &io_op);
+		if (!ret)
+			memcpy(data, buf, size);
+	}
+	free(buf);
+
+lock:
+	mtd_lock(mtd, lock_offs, lock_len);
+
+	return ret;
+}
+
+static int fwu_mtd_load_mdata(struct mtd_info *mtd, struct fwu_mdata *mdata,
+			      u32 offs, bool primary)
+{
+	size_t size = sizeof(struct fwu_mdata);
+	int ret;
+
+	ret = mtd_io_data(mtd, offs, size, mdata, FWU_MTD_READ);
+	if (ret >= 0)
+		ret = fwu_verify_mdata(mdata, primary);
+
+	return ret;
+}
+
+static int fwu_mtd_save_primary_mdata(struct fwu_mdata_mtd_priv *mtd_priv,
+				     struct fwu_mdata *mdata)
+{
+	return mtd_io_data(mtd_priv->mtd, mtd_priv->pri_offset,
+			   sizeof(struct fwu_mdata), mdata, FWU_MTD_WRITE);
+}
+
+static int fwu_mtd_save_secondary_mdata(struct fwu_mdata_mtd_priv *mtd_priv,
+				       struct fwu_mdata *mdata)
+{
+	return mtd_io_data(mtd_priv->mtd, mtd_priv->sec_offset,
+			   sizeof(struct fwu_mdata), mdata, FWU_MTD_WRITE);
+}
+
+static int fwu_mtd_get_valid_mdata(struct fwu_mdata_mtd_priv *mtd_priv,
+				  struct fwu_mdata *mdata)
+{
+	int ret;
+
+	ret = fwu_mtd_load_mdata(mtd_priv->mtd, mdata,
+							 mtd_priv->pri_offset, FWU_MDATA_PRIMARY);
+	if (!ret)
+		return 0;
+
+	log_debug("Failed to load primary mdata. Trying secondary...\n");
+
+	ret = fwu_mtd_load_mdata(mtd_priv->mtd, mdata,
+							 mtd_priv->sec_offset, FWU_MDATA_SECONDARY);
+	if (ret) {
+		log_debug("Failed to load secondary mdata.\n");
+		return -1;
+	}
+
+	return 0;
+}
+
+static int fwu_mtd_update_mdata(struct udevice *dev, struct fwu_mdata *mdata)
+{
+	struct fwu_mdata_mtd_priv *mtd_priv = dev_get_priv(dev);
+	int ret;
+
+	/* First write the primary mdata */
+	ret = fwu_mtd_save_primary_mdata(mtd_priv, mdata);
+	if (ret < 0) {
+		log_debug("Failed to update the primary mdata.\n");
+		return ret;
+	}
+
+	/* And now the replica */
+	ret = fwu_mtd_save_secondary_mdata(mtd_priv, mdata);
+	if (ret < 0) {
+		log_debug("Failed to update the secondary mdata.\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int fwu_mtd_check_mdata(struct udevice *dev)
+{
+	struct fwu_mdata_mtd_priv *mtd_priv = dev_get_priv(dev);
+	struct fwu_mdata primary, secondary;
+	bool pri = false, sec = false;
+	int ret;
+
+	ret = fwu_mtd_load_mdata(mtd_priv->mtd, &primary,
+							 mtd_priv->pri_offset, FWU_MDATA_PRIMARY);
+	if (ret < 0)
+		log_debug("Failed to read the primary mdata: %d\n", ret);
+	else
+		pri = true;
+
+	ret = fwu_mtd_load_mdata(mtd_priv->mtd, &secondary,
+							 mtd_priv->sec_offset, FWU_MDATA_SECONDARY);
+	if (ret < 0)
+		log_debug("Failed to read the secondary mdata: %d\n", ret);
+	else
+		sec = true;
+
+	if (pri && sec) {
+		if (memcmp(&primary, &secondary, sizeof(struct fwu_mdata))) {
+			log_debug("The primary and the secondary mdata are different\n");
+			ret = -1;
+		}
+	} else if (pri) {
+		ret = fwu_mtd_save_secondary_mdata(mtd_priv, &primary);
+		if (ret < 0)
+			log_debug("Restoring secondary mdata partition failed\n");
+	} else if (sec) {
+		ret = fwu_mtd_save_primary_mdata(mtd_priv, &secondary);
+		if (ret < 0)
+			log_debug("Restoring primary mdata partition failed\n");
+	}
+
+	return ret;
+}
+
+static int fwu_mtd_get_mdata(struct udevice *dev, struct fwu_mdata *mdata)
+{
+	struct fwu_mdata_mtd_priv *mtd_priv = dev_get_priv(dev);
+
+	return fwu_mtd_get_valid_mdata(mtd_priv, mdata);
+}
+
+/**
+ * fwu_mdata_mtd_of_to_plat() - Translate from DT to fwu mdata device
+ */
+static int fwu_mdata_mtd_of_to_plat(struct udevice *dev)
+{
+	struct fwu_mdata_mtd_priv *mtd_priv = dev_get_priv(dev);
+	const fdt32_t *phandle_p = NULL;
+	struct udevice *mtd_dev;
+	struct mtd_info *mtd;
+	int ret, size;
+	u32 phandle;
+
+	/* Find the FWU mdata storage device */
+	phandle_p = ofnode_get_property(dev_ofnode(dev),
+					"fwu-mdata-store", &size);
+	if (!phandle_p) {
+		log_err("FWU meta data store not defined in device-tree\n");
+		return -ENOENT;
+	}
+
+	phandle = fdt32_to_cpu(*phandle_p);
+
+	ret = device_get_global_by_ofnode(ofnode_get_by_phandle(phandle),
+									  &mtd_dev);
+	if (ret) {
+		log_err("FWU: failed to get mtd device\n");
+		return ret;
+	}
+
+	mtd_probe_devices();
+
+	mtd_for_each_device(mtd) {
+		if (mtd->dev == mtd_dev) {
+			mtd_priv->mtd = mtd;
+			log_debug("Found the FWU mdata mtd device %s\n", mtd->name);
+			break;
+		}
+	}
+	if (!mtd_priv->mtd) {
+		log_err("Failed to find mtd device by fwu-mdata-store\n");
+		return -ENOENT;
+	}
+
+	/* Get the offset of primary and seconday mdata */
+	ret = ofnode_read_u32_index(dev_ofnode(dev), "mdata-offsets", 0,
+				    &mtd_priv->pri_offset);
+	if (ret)
+		return ret;
+	ret = ofnode_read_u32_index(dev_ofnode(dev), "mdata-offsets", 1,
+				    &mtd_priv->sec_offset);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int fwu_mdata_mtd_probe(struct udevice *dev)
+{
+	/* Ensure the metadata can be read. */
+	return fwu_mtd_check_mdata(dev);
+}
+
+static struct fwu_mdata_ops fwu_mtd_ops = {
+	.check_mdata = fwu_mtd_check_mdata,
+	.get_mdata = fwu_mtd_get_mdata,
+	.update_mdata = fwu_mtd_update_mdata,
+};
+
+static const struct udevice_id fwu_mdata_ids[] = {
+	{ .compatible = "u-boot,fwu-mdata-mtd" },
+	{ }
+};
+
+U_BOOT_DRIVER(fwu_mdata_mtd) = {
+	.name		= "fwu-mdata-mtd",
+	.id		= UCLASS_FWU_MDATA,
+	.of_match	= fwu_mdata_ids,
+	.ops		= &fwu_mtd_ops,
+	.probe		= fwu_mdata_mtd_probe,
+	.of_to_plat	= fwu_mdata_mtd_of_to_plat,
+	.priv_auto	= sizeof(struct fwu_mdata_mtd_priv),
+};
-- 
2.25.1