[PATCH v11 03/15] FWU: Add FWU metadata access driver for GPT partitioned block devices

Sughosh Ganu
2022-09-28T09:31:00Z

In the FWU Multi Bank Update feature, the information about the
updatable images is stored as part of the metadata, on a separate
partition. Add a driver for reading from and writing to the metadata
when the updatable images and the metadata are stored on a block
device which is formatted with GPT based partition scheme.

Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Etienne Carriere <etienne.carriere@linaro.org>
---
Changes since V10:
* Use array for storing the metadata partition numbers as suggested by
Ilias
* Skip a couple of goto's in gpt_check_mdata_validity() as suggested
by Ilias
* Have the FWU_MDATA_GPT_BLK config symbol depend on FWU_MDATA and BLK
* Remove the comment in fwu_gpt_mdata_check() as it is already
mentioned in the corresponding API comment

drivers/fwu-mdata/Kconfig | 16 ++
drivers/fwu-mdata/Makefile | 8 +
drivers/fwu-mdata/gpt_blk.c | 356 ++++++++++++++++++++++++++++++++++++
include/fwu.h | 4 +
4 files changed, 384 insertions(+)
create mode 100644 drivers/fwu-mdata/Kconfig
create mode 100644 drivers/fwu-mdata/Makefile
create mode 100644 drivers/fwu-mdata/gpt_blk.c

diff --git a/drivers/fwu-mdata/Kconfig b/drivers/fwu-mdata/Kconfig
new file mode 100644
index 0000000000..36c4479a59
--- /dev/null
+++ b/drivers/fwu-mdata/Kconfig
@@ -0,0 +1,16 @@
+config FWU_MDATA
+ bool "Driver support for accessing FWU Metadata"
+ depends on DM
+ help
+ Enable support for accessing FWU Metadata partitions. The
+ FWU Metadata partitions reside on the same storage device
+ which contains the other FWU updatable firmware images.
+
+config FWU_MDATA_GPT_BLK
+ bool "FWU Metadata access for 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.
diff --git a/drivers/fwu-mdata/Makefile b/drivers/fwu-mdata/Makefile
new file mode 100644
index 0000000000..3fee64c10c
--- /dev/null
+++ b/drivers/fwu-mdata/Makefile
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# Copyright (c) 2022, Linaro Limited
+#
+
+
+obj-$(CONFIG_FWU_MDATA) += fwu-mdata-uclass.o
+obj-$(CONFIG_FWU_MDATA_GPT_BLK) += gpt_blk.o
diff --git a/drivers/fwu-mdata/gpt_blk.c b/drivers/fwu-mdata/gpt_blk.c
new file mode 100644
index 0000000000..d20bb19d52
--- /dev/null
+++ b/drivers/fwu-mdata/gpt_blk.c
@@ -0,0 +1,356 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2022, Linaro Limited
+ */
+
+#define LOG_CATEGORY UCLASS_FWU_MDATA
+
+#include <blk.h>
+#include <dm.h>
+#include <efi_loader.h>
+#include <fwu.h>
+#include <fwu_mdata.h>
+#include <log.h>
+#include <memalign.h>
+#include <part.h>
+#include <part_efi.h>
+
+#include <dm/device-internal.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+
+#define PRIMARY_PART BIT(0)
+#define SECONDARY_PART BIT(1)
+#define BOTH_PARTS (PRIMARY_PART | SECONDARY_PART)
+
+#define MDATA_READ BIT(0)
+#define MDATA_WRITE BIT(1)
+
+static int gpt_get_mdata_partitions(struct blk_desc *desc,
+ uint *mdata_parts)
+{
+ int i, ret;
+ u32 nparts;
+ efi_guid_t part_type_guid;
+ struct disk_partition info;
+ const efi_guid_t fwu_mdata_guid = FWU_MDATA_GUID;
+
+ nparts = 0;
+ for (i = 1; i < MAX_SEARCH_PARTITIONS; i++) {
+ if (part_get_info(desc, i, &info))
+ continue;
+ uuid_str_to_bin(info.type_guid, part_type_guid.b,
+ UUID_STR_FORMAT_GUID);
+
+ if (nparts < 2 && !guidcmp(&fwu_mdata_guid, &part_type_guid)) {
+ mdata_parts[nparts] = i;
+ ++nparts;
+ }
+ }
+
+ if (nparts != 2) {
+ log_debug("Expect two copies of the FWU metadata instead of %d\n",
+ nparts);
+ ret = -EINVAL;
+ } else {
+ ret = 0;
+ }
+
+ return ret;
+}
+
+static int gpt_get_mdata_disk_part(struct blk_desc *desc,
+ struct disk_partition *info,
+ u32 part_num)
+{
+ int ret;
+ char *mdata_guid_str = "8a7a84a0-8387-40f6-ab41-a8b9a5a60d23";
+
+ ret = part_get_info(desc, part_num, info);
+ if (ret < 0) {
+ log_debug("Unable to get the partition info for the FWU metadata part %d\n",
+ part_num);
+ return -ENOENT;
+ }
+
+ /* Check that it is indeed the FWU metadata partition */
+ if (!strncmp(info->type_guid, mdata_guid_str, UUID_STR_LEN)) {
+ /* Found the FWU metadata partition */
+ return 0;
+ }
+
+ return -ENOENT;
+}
+
+static int gpt_read_write_mdata(struct blk_desc *desc,
+ struct fwu_mdata *mdata,
+ u8 access, u32 part_num)
+{
+ int ret;
+ u32 len, blk_start, blkcnt;
+ struct disk_partition info;
+
+ ALLOC_CACHE_ALIGN_BUFFER_PAD(struct fwu_mdata, mdata_aligned, 1,
+ desc->blksz);
+
+ ret = gpt_get_mdata_disk_part(desc, &info, part_num);
+ if (ret < 0) {
+ printf("Unable to get the FWU metadata partition\n");
+ return -ENOENT;
+ }
+
+ len = sizeof(*mdata);
+ blkcnt = BLOCK_CNT(len, desc);
+ if (blkcnt > info.size) {
+ log_debug("Block count exceeds FWU metadata partition size\n");
+ return -ERANGE;
+ }
+
+ blk_start = info.start;
+ if (access == MDATA_READ) {
+ if (blk_dread(desc, blk_start, blkcnt, mdata_aligned) != blkcnt) {
+ log_debug("Error reading FWU metadata from the device\n");
+ return -EIO;
+ }
+ memcpy(mdata, mdata_aligned, sizeof(struct fwu_mdata));
+ } else {
+ if (blk_dwrite(desc, blk_start, blkcnt, mdata) != blkcnt) {
+ log_debug("Error writing FWU metadata to the device\n");
+ return -EIO;
+ }
+ }
+
+ return 0;
+}
+
+static int gpt_read_mdata(struct blk_desc *desc,
+ struct fwu_mdata *mdata, u32 part_num)
+{
+ return gpt_read_write_mdata(desc, mdata, MDATA_READ, part_num);
+}
+
+static int gpt_write_mdata_partition(struct blk_desc *desc,
+ struct fwu_mdata *mdata,
+ u32 part_num)
+{
+ return gpt_read_write_mdata(desc, mdata, MDATA_WRITE, part_num);
+}
+
+static int fwu_gpt_update_mdata(struct udevice *dev, struct fwu_mdata *mdata)
+{
+ int ret;
+ struct blk_desc *desc;
+ uint mdata_parts[2];
+ struct fwu_mdata_gpt_blk_priv *priv = dev_get_priv(dev);
+
+ desc = dev_get_uclass_plat(priv->blk_dev);
+
+ ret = gpt_get_mdata_partitions(desc, mdata_parts);
+ if (ret < 0) {
+ log_debug("Error getting the FWU metadata partitions\n");
+ return -ENOENT;
+ }
+
+ /* First write the primary partition */
+ ret = gpt_write_mdata_partition(desc, mdata, mdata_parts[0]);
+ if (ret < 0) {
+ log_debug("Updating primary FWU metadata partition failed\n");
+ return ret;
+ }
+
+ /* And now the replica */
+ ret = gpt_write_mdata_partition(desc, mdata, mdata_parts[1]);
+ if (ret < 0) {
+ log_debug("Updating secondary FWU metadata partition failed\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static int gpt_get_mdata(struct blk_desc *desc, struct fwu_mdata *mdata)
+{
+ int ret;
+ uint mdata_parts[2];
+
+ ret = gpt_get_mdata_partitions(desc, mdata_parts);
+
+ if (ret < 0) {
+ log_debug("Error getting the FWU metadata partitions\n");
+ return -ENOENT;
+ }
+
+ ret = gpt_read_mdata(desc, mdata, mdata_parts[0]);
+ if (ret < 0) {
+ log_debug("Failed to read the FWU metadata from the device\n");
+ return -EIO;
+ }
+
+ ret = fwu_verify_mdata(mdata, 1);
+ if (!ret)
+ return 0;
+
+ /*
+ * Verification of the primary FWU metadata copy failed.
+ * Try to read the replica.
+ */
+ memset(mdata, '\0', sizeof(struct fwu_mdata));
+ ret = gpt_read_mdata(desc, mdata, mdata_parts[1]);
+ if (ret < 0) {
+ log_debug("Failed to read the FWU metadata from the device\n");
+ return -EIO;
+ }
+
+ ret = fwu_verify_mdata(mdata, 0);
+ if (!ret)
+ return 0;
+
+ /* Both the FWU metadata copies are corrupted. */
+ return -EIO;
+}
+
+static int gpt_check_mdata_validity(struct udevice *dev)
+{
+ int ret;
+ struct blk_desc *desc;
+ struct fwu_mdata pri_mdata;
+ struct fwu_mdata secondary_mdata;
+ uint mdata_parts[2];
+ uint valid_partitions, invalid_partitions;
+ struct fwu_mdata_gpt_blk_priv *priv = dev_get_priv(dev);
+
+ desc = dev_get_uclass_plat(priv->blk_dev);
+
+ /*
+ * Two FWU metadata partitions are expected.
+ * If we don't have two, user needs to create
+ * them first
+ */
+ valid_partitions = 0;
+ ret = gpt_get_mdata_partitions(desc, mdata_parts);
+ if (ret < 0) {
+ log_debug("Error getting the FWU metadata partitions\n");
+ return -ENOENT;
+ }
+
+ ret = gpt_read_mdata(desc, &pri_mdata, mdata_parts[0]);
+ if (!ret) {
+ ret = fwu_verify_mdata(&pri_mdata, 1);
+ if (!ret)
+ valid_partitions |= PRIMARY_PART;
+ }
+
+ /* Now check the secondary partition */
+ ret = gpt_read_mdata(desc, &secondary_mdata, mdata_parts[1]);
+ if (!ret) {
+ ret = fwu_verify_mdata(&secondary_mdata, 0);
+ if (!ret)
+ valid_partitions |= SECONDARY_PART;
+ }
+
+ if (valid_partitions == (PRIMARY_PART | SECONDARY_PART)) {
+ ret = -1;
+ /*
+ * Before returning, check that both the
+ * FWU metadata copies are the same. If not,
+ * the FWU metadata copies need to be
+ * re-populated.
+ */
+ if (!memcmp(&pri_mdata, &secondary_mdata,
+ sizeof(struct fwu_mdata))) {
+ ret = 0;
+ } else {
+ log_debug("Both FWU metadata copies are valid but do not match. Please check!\n");
+ }
+ goto out;
+ }
+
+ ret = -1;
+ if (!(valid_partitions & BOTH_PARTS))
+ goto out;
+
+ invalid_partitions = valid_partitions ^ BOTH_PARTS;
+ ret = gpt_write_mdata_partition(desc,
+ (invalid_partitions == PRIMARY_PART) ?
+ &secondary_mdata : &pri_mdata,
+ (invalid_partitions == PRIMARY_PART) ?
+ mdata_parts[0] : mdata_parts[1]);
+
+ if (ret < 0)
+ log_debug("Restoring %s FWU metadata partition failed\n",
+ (invalid_partitions == PRIMARY_PART) ?
+ "primary" : "secondary");
+
+out:
+ return ret;
+}
+
+static int fwu_gpt_mdata_check(struct udevice *dev)
+{
+ return gpt_check_mdata_validity(dev);
+}
+
+static int fwu_gpt_get_mdata(struct udevice *dev, struct fwu_mdata *mdata)
+{
+ struct fwu_mdata_gpt_blk_priv *priv = dev_get_priv(dev);
+
+ return gpt_get_mdata(dev_get_uclass_plat(priv->blk_dev), mdata);
+}
+
+static int fwu_get_mdata_device(struct udevice *dev, struct udevice **mdata_dev)
+{
+ u32 phandle;
+ int ret, size;
+ struct udevice *parent;
+ const fdt32_t *phandle_p = NULL;
+
+ phandle_p = dev_read_prop(dev, "fwu-mdata-store", &size);
+ if (!phandle_p) {
+ log_debug("fwu-mdata-store property not found\n");
+ return -ENOENT;
+ }
+
+ phandle = fdt32_to_cpu(*phandle_p);
+
+ ret = device_get_global_by_ofnode(ofnode_get_by_phandle(phandle),
+ &parent);
+ if (ret)
+ return ret;
+
+ return blk_get_from_parent(parent, mdata_dev);
+}
+
+static int fwu_mdata_gpt_blk_probe(struct udevice *dev)
+{
+ int ret;
+ struct udevice *mdata_dev = NULL;
+ struct fwu_mdata_gpt_blk_priv *priv = dev_get_priv(dev);
+
+ ret = fwu_get_mdata_device(dev, &mdata_dev);
+ if (ret)
+ return ret;
+
+ priv->blk_dev = mdata_dev;
+
+ return 0;
+}
+
+static const struct fwu_mdata_ops fwu_gpt_blk_ops = {
+ .check_mdata = fwu_gpt_mdata_check,
+ .get_mdata = fwu_gpt_get_mdata,
+ .update_mdata = fwu_gpt_update_mdata,
+};
+
+static const struct udevice_id fwu_mdata_ids[] = {
+ { .compatible = "u-boot,fwu-mdata-gpt" },
+ { }
+};
+
+U_BOOT_DRIVER(fwu_mdata_gpt_blk) = {
+ .name = "fwu-mdata-gpt-blk",
+ .id = UCLASS_FWU_MDATA,
+ .of_match = fwu_mdata_ids,
+ .ops = &fwu_gpt_blk_ops,
+ .probe = fwu_mdata_gpt_blk_probe,
+ .priv_auto = sizeof(struct fwu_mdata_gpt_blk_priv),
+};
diff --git a/include/fwu.h b/include/fwu.h
index a4d2d35d9a..167f91388e 100644
--- a/include/fwu.h
+++ b/include/fwu.h
@@ -14,6 +14,10 @@
struct fwu_mdata;
struct udevice;

+struct fwu_mdata_gpt_blk_priv {
+ struct udevice *blk_dev;
+};
+
/**
* @mdata_check: check the validity of the FWU metadata partitions
* @get_mdata() - Get a FWU metadata copy
--
2.34.1