FWU: Add FWU metadata access driver for MTD storage regions

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.
The code is divided into core under drivers/fwu-mdata/ and some helper
functions clubbed together under lib/fwu_updates/

Signed-off-by: Masami Hiramatsu <[e-mail]>
Signed-off-by: Jassi Brar <[e-mail]>

drivers/fwu-mdata/Kconfig

···
 	  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"
 	select PARTITION_TYPE_GUID
···
 	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

drivers/fwu-mdata/Makefile

···
 
 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

drivers/fwu-mdata/raw_mtd.c

···
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2023, Linaro Limited
+ */
+
+#define LOG_CATEGORY UCLASS_FWU_MDATA
+
+#include <fwu.h>
+#include <fwu_mdata.h>
+#include <memalign.h>
+
+#include <linux/errno.h>
+#include <linux/types.h>
+
+/* Internal helper structure to move data around */
+struct fwu_mdata_mtd_priv {
+	struct mtd_info *mtd;
+	char pri_label[50];
+	char sec_label[50];
+	u32 pri_offset;
+	u32 sec_offset;
+};
+
+enum fwu_mtd_op {
+	FWU_MTD_READ,
+	FWU_MTD_WRITE,
+};
+
+extern struct fwu_mtd_image_info fwu_mtd_images[];
+
+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_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;
+	}
+
+	/* This will expand erase size to align with the block size */
+	lock_len = round_up(size, mtd->erasesize);
+
+	ret = mtd_unlock(mtd, 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 = 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.datbuf = buf;
+
+	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, offs, lock_len);
+
+	return ret;
+}
+
+static int fwu_mtd_read_mdata(struct udevice *dev, struct fwu_mdata *mdata, bool primary)
+{
+	struct fwu_mdata_mtd_priv *mtd_priv = dev_get_priv(dev);
+	struct mtd_info *mtd = mtd_priv->mtd;
+	u32 offs = primary ? mtd_priv->pri_offset : mtd_priv->sec_offset;
+
+	return mtd_io_data(mtd, offs, sizeof(struct fwu_mdata), mdata, FWU_MTD_READ);
+}
+
+static int fwu_mtd_write_mdata(struct udevice *dev, struct fwu_mdata *mdata, bool primary)
+{
+	struct fwu_mdata_mtd_priv *mtd_priv = dev_get_priv(dev);
+	struct mtd_info *mtd = mtd_priv->mtd;
+	u32 offs = primary ? mtd_priv->pri_offset : mtd_priv->sec_offset;
+
+	return mtd_io_data(mtd, offs, sizeof(struct fwu_mdata), mdata, FWU_MTD_WRITE);
+}
+
+static int flash_partition_offset(struct udevice *dev, const char *part_name, fdt_addr_t *offset)
+{
+	ofnode node, parts_node;
+	fdt_addr_t size = 0;
+
+	parts_node = ofnode_by_compatible(dev_ofnode(dev), "fixed-partitions");
+	node = ofnode_by_prop_value(parts_node, "label", part_name, strlen(part_name) + 1);
+	if (!ofnode_valid(node)) {
+		log_err("Warning: Failed to find partition by label <%s>\n", part_name);
+		return -ENOENT;
+	}
+
+	*offset = ofnode_get_addr_size_index_notrans(node, 0, &size);
+
+	return (int)size;
+}
+
+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;
+	const char *label;
+	fdt_addr_t offset;
+	int ret, size;
+	u32 phandle;
+	ofnode bank;
+	int off_img;
+
+	/* 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 -ENODEV;
+	}
+
+	/* Get the offset of primary and secondary mdata */
+	ret = ofnode_read_string_index(dev_ofnode(dev), "mdata-parts", 0, &label);
+	if (ret)
+		return ret;
+	strncpy(mtd_priv->pri_label, label, 50);
+
+	ret = flash_partition_offset(mtd_dev, mtd_priv->pri_label, &offset);
+	if (ret <= 0)
+		return ret;
+	mtd_priv->pri_offset = offset;
+
+	ret = ofnode_read_string_index(dev_ofnode(dev), "mdata-parts", 1, &label);
+	if (ret)
+		return ret;
+	strncpy(mtd_priv->sec_label, label, 50);
+
+	ret = flash_partition_offset(mtd_dev, mtd_priv->sec_label, &offset);
+	if (ret <= 0)
+		return ret;
+	mtd_priv->sec_offset = offset;
+
+	off_img = 0;
+
+	ofnode_for_each_subnode(bank, dev_ofnode(dev)) {
+		int bank_num, bank_offset, bank_size;
+		const char *bank_name;
+		ofnode image;
+
+		ofnode_read_u32(bank, "id", &bank_num);
+		bank_name = ofnode_read_string(bank, "label");
+		bank_size = flash_partition_offset(mtd_dev, bank_name, &offset);
+		if (bank_size <= 0)
+			return bank_size;
+		bank_offset = offset;
+		log_debug("Bank%d: %s [0x%x - 0x%x]\n",
+			  bank_num, bank_name, bank_offset, bank_offset + bank_size);
+
+		ofnode_for_each_subnode(image, bank) {
+			int image_num, image_offset, image_size;
+			const char *uuid;
+
+			if (off_img == CONFIG_FWU_NUM_BANKS *
+						CONFIG_FWU_NUM_IMAGES_PER_BANK) {
+				log_err("DT provides more images than configured!\n");
+				break;
+			}
+
+			uuid = ofnode_read_string(image, "uuid");
+			ofnode_read_u32(image, "id", &image_num);
+			ofnode_read_u32(image, "offset", &image_offset);
+			ofnode_read_u32(image, "size", &image_size);
+
+			fwu_mtd_images[off_img].start = bank_offset + image_offset;
+			fwu_mtd_images[off_img].size = image_size;
+			fwu_mtd_images[off_img].bank_num = bank_num;
+			fwu_mtd_images[off_img].image_num = image_num;
+			strcpy(fwu_mtd_images[off_img].uuidbuf, uuid);
+			log_debug("\tImage%d: %s @0x%x\n\n",
+				  image_num, uuid, bank_offset + image_offset);
+			off_img++;
+		}
+	}
+
+	return 0;
+}
+
+static int fwu_mdata_mtd_probe(struct udevice *dev)
+{
+	/* Ensure the metadata can be read. */
+	return fwu_get_mdata(NULL);
+}
+
+static struct fwu_mdata_ops fwu_mtd_ops = {
+	.read_mdata = fwu_mtd_read_mdata,
+	.write_mdata = fwu_mtd_write_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),
+};

include/fwu.h

···
 
 #include <blk.h>
 #include <efi.h>
+#include <mtd.h>
+#include <uuid.h>
 
 #include <linux/types.h>
 
···
 
 struct fwu_mdata_gpt_blk_priv {
 	struct udevice *blk_dev;
+};
+
+struct fwu_mtd_image_info {
+	u32 start, size;
+	int bank_num, image_num;
+	char uuidbuf[UUID_STR_LEN + 1];
 };
 
 struct fwu_mdata_ops {
···
  *
  */
 int fwu_trial_state_ctr_start(void);
+
+/**
+ * fwu_gen_alt_info_from_mtd() - Parse dfu_alt_info from metadata in mtd
+ * @buf: Buffer into which the dfu_alt_info is filled
+ * @len: Maximum characters that can be written in buf
+ * @mtd: Pointer to underlying MTD device
+ *
+ * Parse dfu_alt_info from metadata in mtd. Used for setting the env.
+ *
+ * Return: 0 if OK, -ve on error
+ */
+int fwu_gen_alt_info_from_mtd(char *buf, size_t len, struct mtd_info *mtd);
+
+/**
+ * fwu_mtd_get_alt_num() - Mapping of fwu_plat_get_alt_num for MTD device
+ * @image_guid: Image GUID for which DFU alt number needs to be retrieved
+ * @alt_num: Pointer to the alt_num
+ * @mtd_dev: Name of mtd device instance
+ *
+ * To map fwu_plat_get_alt_num onto mtd based metadata implementation.
+ *
+ * Return: 0 if OK, -ve on error
+ */
+int fwu_mtd_get_alt_num(efi_guid_t *image_guid, u8 *alt_num, const char *mtd_dev);
 
 #endif /* _FWU_H_ */

lib/fwu_updates/Makefile

···
 
 obj-$(CONFIG_FWU_MULTI_BANK_UPDATE) += fwu.o
 obj-$(CONFIG_FWU_MDATA_GPT_BLK) += fwu_gpt.o
+obj-$(CONFIG_FWU_MDATA_MTD) += fwu_mtd.o

lib/fwu_updates/fwu_mtd.c

···
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2023, Linaro Limited
+ */
+
+#include <dm.h>
+#include <dfu.h>
+#include <fwu.h>
+#include <fwu_mdata.h>
+#include <log.h>
+#include <malloc.h>
+#include <mtd.h>
+#include <uuid.h>
+#include <vsprintf.h>
+
+#include <dm/ofnode.h>
+
+struct fwu_mtd_image_info
+fwu_mtd_images[CONFIG_FWU_NUM_BANKS * CONFIG_FWU_NUM_IMAGES_PER_BANK];
+
+static struct fwu_mtd_image_info *mtd_img_by_uuid(const char *uuidbuf)
+{
+	int num_images = ARRAY_SIZE(fwu_mtd_images);
+
+	for (int i = 0; i < num_images; i++)
+		if (!strcmp(uuidbuf, fwu_mtd_images[i].uuidbuf))
+			return &fwu_mtd_images[i];
+
+	return NULL;
+}
+
+int fwu_mtd_get_alt_num(efi_guid_t *image_id, u8 *alt_num,
+			const char *mtd_dev)
+{
+	struct fwu_mtd_image_info *mtd_img_info;
+	char uuidbuf[UUID_STR_LEN + 1];
+	fdt_addr_t offset, size = 0;
+	struct dfu_entity *dfu;
+	int i, nalt, ret;
+
+	mtd_probe_devices();
+
+	uuid_bin_to_str(image_id->b, uuidbuf, UUID_STR_FORMAT_STD);
+
+	mtd_img_info = mtd_img_by_uuid(uuidbuf);
+	if (!mtd_img_info) {
+		log_err("%s: Not found partition for image %s\n", __func__, uuidbuf);
+		return -ENOENT;
+	}
+
+	offset = mtd_img_info->start;
+	size = mtd_img_info->size;
+
+	ret = dfu_init_env_entities(NULL, NULL);
+	if (ret)
+		return -ENOENT;
+
+	nalt = 0;
+	list_for_each_entry(dfu, &dfu_list, list)
+		nalt++;
+
+	if (!nalt) {
+		log_warning("No entities in dfu_alt_info\n");
+		dfu_free_entities();
+		return -ENOENT;
+	}
+
+	ret = -ENOENT;
+	for (i = 0; i < nalt; i++) {
+		dfu = dfu_get_entity(i);
+
+		/* Only MTD RAW access */
+		if (!dfu || dfu->dev_type != DFU_DEV_MTD ||
+		    dfu->layout != DFU_RAW_ADDR ||
+			dfu->data.mtd.start != offset ||
+			dfu->data.mtd.size != size)
+			continue;
+
+		*alt_num = dfu->alt;
+		ret = 0;
+		break;
+	}
+
+	dfu_free_entities();
+
+	log_debug("%s: %s -> %d\n", __func__, uuidbuf, *alt_num);
+	return ret;
+}
+
+/**
+ * fwu_plat_get_alt_num() - Get the DFU Alt Num for the image from the platform
+ * @dev: FWU device
+ * @image_id: Image GUID for which DFU alt number needs to be retrieved
+ * @alt_num: Pointer to the alt_num
+ *
+ * Get the DFU alt number from the platform for the image specified by the
+ * image GUID.
+ *
+ * Note: This is a weak function and platforms can override this with
+ * their own implementation for obtaining the alt number value.
+ *
+ * Return: 0 if OK, -ve on error
+ */
+__weak int fwu_plat_get_alt_num(struct udevice *dev, efi_guid_t *image_id,
+				u8 *alt_num)
+{
+	return fwu_mtd_get_alt_num(image_id, alt_num, "nor1");
+}
+
+static int gen_image_alt_info(char *buf, size_t len, int sidx,
+			      struct fwu_image_entry *img, struct mtd_info *mtd)
+{
+	char *p = buf, *end = buf + len;
+	int i;
+
+	p += snprintf(p, end - p, "mtd %s", mtd->name);
+	if (end < p) {
+		log_err("%s:%d Run out of buffer\n", __func__, __LINE__);
+		return -E2BIG;
+	}
+
+	/*
+	 * List the image banks in the FWU mdata and search the corresponding
+	 * partition based on partition's uuid.
+	 */
+	for (i = 0; i < CONFIG_FWU_NUM_BANKS; i++) {
+		struct fwu_mtd_image_info *mtd_img_info;
+		struct fwu_image_bank_info *bank;
+		char uuidbuf[UUID_STR_LEN + 1];
+		u32 offset, size;
+
+		/* Query a partition by image UUID */
+		bank = &img->img_bank_info[i];
+		uuid_bin_to_str(bank->image_uuid.b, uuidbuf, UUID_STR_FORMAT_STD);
+
+		mtd_img_info = mtd_img_by_uuid(uuidbuf);
+		if (!mtd_img_info) {
+			log_err("%s: Not found partition for image %s\n", __func__, uuidbuf);
+			break;
+		}
+
+		offset = mtd_img_info->start;
+		size = mtd_img_info->size;
+
+		p += snprintf(p, end - p, "%sbank%d raw %x %x",
+			      i == 0 ? "=" : ";", i, offset, size);
+		if (end < p) {
+			log_err("%s:%d Run out of buffer\n", __func__, __LINE__);
+			return -E2BIG;
+		}
+	}
+
+	if (i == CONFIG_FWU_NUM_BANKS)
+		return 0;
+
+	return -ENOENT;
+}
+
+int fwu_gen_alt_info_from_mtd(char *buf, size_t len, struct mtd_info *mtd)
+{
+	struct fwu_mdata mdata;
+	int i, l, ret;
+
+	ret = fwu_get_mdata(&mdata);
+	if (ret < 0) {
+		log_err("Failed to get the FWU mdata.\n");
+		return ret;
+	}
+
+	for (i = 0; i < CONFIG_FWU_NUM_IMAGES_PER_BANK; i++) {
+		ret = gen_image_alt_info(buf, len, i * CONFIG_FWU_NUM_BANKS,
+					 &mdata.img_entry[i], mtd);
+		if (ret)
+			break;
+
+		l = strlen(buf);
+		/* Replace the last ';' with '&' if there is another image. */
+		if (i != CONFIG_FWU_NUM_IMAGES_PER_BANK - 1 && l)
+			buf[l - 1] = '&';
+		len -= l;
+		buf += l;
+	}
+
+	return ret;
+}