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 <masami.hiramatsu@linaro.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

2 files changed, 186 insertions, 0 deletions

diff --git a/lib/fwu_updates/Makefile b/lib/fwu_updates/Makefile
index 1993088e5b..c9e3c06b48 100644
--- a/lib/fwu_updates/Makefile
+++ b/lib/fwu_updates/Makefile
@@ -5,3 +5,4 @@
 
 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
diff --git a/lib/fwu_updates/fwu_mtd.c b/lib/fwu_updates/fwu_mtd.c
new file mode 100644
index 0000000000..b73111ae24
--- /dev/null
+++ b/lib/fwu_updates/fwu_mtd.c
@@ -0,0 +1,185 @@
+// 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;
+}