mtd: bcm63xxpart: move imagetag parsing to its own parser

Move the bcm963xx Image Tag parsing into its own partition parser. This
Allows reusing the parser with different full flash parsers.

While moving it, rename it to bcm963* to better reflect it isn't chip,
but reference implementation specific.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

3 files changed, 226 insertions, 0 deletions

diff --git a/drivers/mtd/parsers/Kconfig b/drivers/mtd/parsers/Kconfig
index fccf1950e92d..c8be3f1507ca 100644
--- a/drivers/mtd/parsers/Kconfig
+++ b/drivers/mtd/parsers/Kconfig
@@ -1,3 +1,14 @@
+config MTD_PARSER_IMAGETAG
+	tristate "Parser for BCM963XX Image Tag format partitions"
+	depends on BCM63XX || BMIPS_GENERIC || COMPILE_TEST
+	select CRC32
+	help
+	  Image Tag is the firmware header used by broadcom on their xDSL line
+	  of devices. It is used to describe the offsets and lengths of kernel
+	  and rootfs partitions.
+	  This driver adds support for parsing a partition with an Image Tag
+	  header and creates up to two partitions, kernel and rootfs.
+
 config MTD_PARSER_TRX
 	tristate "Parser for TRX format partitions"
 	depends on MTD && (BCM47XX || ARCH_BCM_5301X || COMPILE_TEST)
diff --git a/drivers/mtd/parsers/Makefile b/drivers/mtd/parsers/Makefile
index d8418bf6804a..3860c4464c63 100644
--- a/drivers/mtd/parsers/Makefile
+++ b/drivers/mtd/parsers/Makefile
@@ -1,3 +1,4 @@
+obj-$(CONFIG_MTD_PARSER_IMAGETAG)	+= parser_imagetag.o
 obj-$(CONFIG_MTD_PARSER_TRX)		+= parser_trx.o
 obj-$(CONFIG_MTD_SHARPSL_PARTS)		+= sharpslpart.o
 obj-$(CONFIG_MTD_REDBOOT_PARTS)		+= redboot.o
diff --git a/drivers/mtd/parsers/parser_imagetag.c b/drivers/mtd/parsers/parser_imagetag.c
new file mode 100644
index 000000000000..74b66d009b5c
--- /dev/null
+++ b/drivers/mtd/parsers/parser_imagetag.c
@@ -0,0 +1,214 @@
+/*
+ * BCM63XX CFE image tag parser
+ *
+ * Copyright © 2006-2008  Florian Fainelli <florian@openwrt.org>
+ *			  Mike Albon <malbon@openwrt.org>
+ * Copyright © 2009-2010  Daniel Dickinson <openwrt@cshore.neomailbox.net>
+ * Copyright © 2011-2013  Jonas Gorski <jonas.gorski@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/bcm963xx_tag.h>
+#include <linux/crc32.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+
+/* Ensure strings read from flash structs are null terminated */
+#define STR_NULL_TERMINATE(x) \
+	do { char *_str = (x); _str[sizeof(x) - 1] = 0; } while (0)
+
+static int bcm963xx_read_imagetag(struct mtd_info *master, const char *name,
+	loff_t tag_offset, struct bcm_tag *buf)
+{
+	int ret;
+	size_t retlen;
+	u32 computed_crc;
+
+	ret = mtd_read(master, tag_offset, sizeof(*buf), &retlen, (void *)buf);
+	if (ret)
+		return ret;
+
+	if (retlen != sizeof(*buf))
+		return -EIO;
+
+	computed_crc = crc32_le(IMAGETAG_CRC_START, (u8 *)buf,
+				offsetof(struct bcm_tag, header_crc));
+	if (computed_crc == buf->header_crc) {
+		STR_NULL_TERMINATE(buf->board_id);
+		STR_NULL_TERMINATE(buf->tag_version);
+
+		pr_info("%s: CFE image tag found at 0x%llx with version %s, board type %s\n",
+			name, tag_offset, buf->tag_version, buf->board_id);
+
+		return 0;
+	}
+
+	pr_warn("%s: CFE image tag at 0x%llx CRC invalid (expected %08x, actual %08x)\n",
+		name, tag_offset, buf->header_crc, computed_crc);
+	return -EINVAL;
+}
+
+static int bcm963xx_parse_imagetag_partitions(struct mtd_info *master,
+					const struct mtd_partition **pparts,
+					struct mtd_part_parser_data *data)
+{
+	/* CFE, NVRAM and global Linux are always present */
+	int nrparts = 0, curpart = 0;
+	struct bcm_tag *buf = NULL;
+	struct mtd_partition *parts;
+	int ret;
+	unsigned int rootfsaddr, kerneladdr, spareaddr, offset;
+	unsigned int rootfslen, kernellen, sparelen, totallen;
+	int i;
+	bool rootfs_first = false;
+
+	buf = vmalloc(sizeof(struct bcm_tag));
+	if (!buf)
+		return -ENOMEM;
+
+	/* Get the tag */
+	ret = bcm963xx_read_imagetag(master, "rootfs", 0, buf);
+	if (!ret) {
+		STR_NULL_TERMINATE(buf->flash_image_start);
+		if (kstrtouint(buf->flash_image_start, 10, &rootfsaddr) ||
+				rootfsaddr < BCM963XX_EXTENDED_SIZE) {
+			pr_err("invalid rootfs address: %*ph\n",
+				(int)sizeof(buf->flash_image_start),
+				buf->flash_image_start);
+			goto out;
+		}
+
+		STR_NULL_TERMINATE(buf->kernel_address);
+		if (kstrtouint(buf->kernel_address, 10, &kerneladdr) ||
+				kerneladdr < BCM963XX_EXTENDED_SIZE) {
+			pr_err("invalid kernel address: %*ph\n",
+				(int)sizeof(buf->kernel_address),
+				buf->kernel_address);
+			goto out;
+		}
+
+		STR_NULL_TERMINATE(buf->kernel_length);
+		if (kstrtouint(buf->kernel_length, 10, &kernellen)) {
+			pr_err("invalid kernel length: %*ph\n",
+				(int)sizeof(buf->kernel_length),
+				buf->kernel_length);
+			goto out;
+		}
+
+		STR_NULL_TERMINATE(buf->total_length);
+		if (kstrtouint(buf->total_length, 10, &totallen)) {
+			pr_err("invalid total length: %*ph\n",
+				(int)sizeof(buf->total_length),
+				buf->total_length);
+			goto out;
+		}
+
+		/*
+		 * Addresses are flash absolute, so convert to partition
+		 * relative addresses. Assume either kernel or rootfs will
+		 * directly follow the image tag.
+		 */
+		if (rootfsaddr < kerneladdr)
+			offset = rootfsaddr - sizeof(struct bcm_tag);
+		else
+			offset = kerneladdr - sizeof(struct bcm_tag);
+
+		kerneladdr = kerneladdr - offset;
+		rootfsaddr = rootfsaddr - offset;
+		spareaddr = roundup(totallen, master->erasesize);
+
+		if (rootfsaddr < kerneladdr) {
+			/* default Broadcom layout */
+			rootfslen = kerneladdr - rootfsaddr;
+			rootfs_first = true;
+		} else {
+			/* OpenWrt layout */
+			rootfsaddr = kerneladdr + kernellen;
+			rootfslen = spareaddr - rootfsaddr;
+		}
+	} else {
+		goto out;
+	}
+	sparelen = master->size - spareaddr;
+
+	/* Determine number of partitions */
+	if (rootfslen > 0)
+		nrparts++;
+
+	if (kernellen > 0)
+		nrparts++;
+
+	parts = kzalloc(sizeof(*parts) * nrparts + 10 * nrparts, GFP_KERNEL);
+	if (!parts) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	/* Start building partition list */
+	if (kernellen > 0) {
+		int kernelpart = curpart;
+
+		if (rootfslen > 0 && rootfs_first)
+			kernelpart++;
+		parts[kernelpart].name = "kernel";
+		parts[kernelpart].offset = kerneladdr;
+		parts[kernelpart].size = kernellen;
+		curpart++;
+	}
+
+	if (rootfslen > 0) {
+		int rootfspart = curpart;
+
+		if (kernellen > 0 && rootfs_first)
+			rootfspart--;
+		parts[rootfspart].name = "rootfs";
+		parts[rootfspart].offset = rootfsaddr;
+		parts[rootfspart].size = rootfslen;
+		if (sparelen > 0  && !rootfs_first)
+			parts[rootfspart].size += sparelen;
+		curpart++;
+	}
+
+	for (i = 0; i < nrparts; i++)
+		pr_info("Partition %d is %s offset %llx and length %llx\n", i,
+			parts[i].name, parts[i].offset,	parts[i].size);
+
+	pr_info("Spare partition is offset %x and length %x\n",	spareaddr,
+		sparelen);
+
+	*pparts = parts;
+	ret = 0;
+
+out:
+	vfree(buf);
+
+	if (ret)
+		return ret;
+
+	return nrparts;
+}
+
+static struct mtd_part_parser bcm963xx_imagetag_parser = {
+	.parse_fn = bcm963xx_parse_imagetag_partitions,
+	.name = "bcm963xx-imagetag",
+};
+module_mtd_part_parser(bcm963xx_imagetag_parser);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Daniel Dickinson <openwrt@cshore.neomailbox.net>");
+MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
+MODULE_AUTHOR("Mike Albon <malbon@openwrt.org>");
+MODULE_AUTHOR("Jonas Gorski <jonas.gorski@gmail.com>");
+MODULE_DESCRIPTION("MTD parser for BCM963XX CFE Image Tag partitions");