marvell/linux/drivers/mtd/parsers/ofpart_asrsdtim.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) ASR Microelectronics 2023
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/of.h>
#include <linux/mtd/mtd.h>
#include <linux/slab.h>
#include <linux/mtd/partitions.h>

#include "../mtdsplit/mtdsplit.h"

#define ASR_SDTIM_PARTS		1
#define ASR_TIMH_OFFSET 	0x4
#define ASR_SDTIM_OFFSET	0x38
#define ASR_IMGID_OFFSET	0x98
#define ASR_TIMH_MAGIC		0x54494D48 // TIMH
#define ASR_SDTIM_MAGIC		0x5354494D // STIM

static int check_asr_fs_with_sdtim(struct mtd_info *master,
				 const struct mtd_partition *part)
{
	void *buf;
	size_t retlen;
	int err;
	u32 magic_tim, magic_sdtim;

#ifdef CONFIG_ASR_SDTIM
	/*
	 * For filesystem partition with sdtim header, force to create
	 * "-sdtim" and "-mount" to make sure A/B fs mount succeed even
	 * one of sdtim header and fs area destroied, by adding property
	 * "sdtim-fs" to correspond partition node.
	 */
	if (of_get_property(part->of_node, "sdtim-fs", NULL))
		return ASR_SDTIM_PARTS;
#endif

	buf = kzalloc(master->writesize, GFP_KERNEL);
	if (!buf)
		return -ENOMEM;

	err = mtd_read(master, part->offset, master->writesize, &retlen, buf);
	if (err && err != -EUCLEAN)
		goto free_buf;

	if (retlen != master->writesize) {
		err = -EIO;
		goto free_buf;
	}

	magic_tim = *((u32 *)(buf + ASR_TIMH_OFFSET));
	magic_sdtim = *((u32 *)(buf + ASR_SDTIM_OFFSET));
	if (magic_tim != ASR_TIMH_MAGIC || magic_sdtim != ASR_SDTIM_MAGIC) {
		err = 0;
		goto free_buf;
	}

	if (part->size <= master->erasesize) {
		err = 0;
		goto free_buf;
	}

	/* check if this part may exist filesystem, read from next block */
	err = mtd_check_rootfs_magic(master, part->offset + master->erasesize, NULL);
	if (err) {
		err = 0;
		goto free_buf;
	}

	kfree(buf);
	return ASR_SDTIM_PARTS;

free_buf:
	kfree(buf);
	return err;
}

int asr_sdtim_partitions_post_parse(struct mtd_info *mtd,
				struct mtd_partition **pparts, int nr_parts)
{
	struct mtd_partition *parts = *pparts;
	struct mtd_partition *nparts;
	int new_nr = 0;
	int i;

	nparts = kcalloc(nr_parts * 2 + 1, sizeof(*parts), GFP_KERNEL);
	if (!nparts)
		return -ENOMEM;

	for (i = 0; i < nr_parts; i++) {
#ifdef CONFIG_AB_SYSTEM
		/* add "-sdtim" and "-mount" for sdtim img with filesystem */
		if (check_asr_fs_with_sdtim(mtd, parts + i) > 0) {
			/* add -sdtim partition */
			nparts[new_nr].name = kstrdup(parts[i].name, GFP_KERNEL);
			strcat((char *)nparts[new_nr].name, "-sdtim");
			nparts[new_nr].offset = parts[i].offset;
			nparts[new_nr].size = mtd->erasesize;
			nparts[new_nr].mask_flags = parts[i].mask_flags;
			nparts[new_nr].types = parts[i].types;
			nparts[new_nr].of_node = parts[i].of_node;
			new_nr++;

			/* add -mount partition */
			nparts[new_nr].name = kmemdup(parts[i].name, 128, GFP_KERNEL);
			strcat((char *)nparts[new_nr].name, "-mount");
			nparts[new_nr].offset = parts[i].offset + mtd->erasesize;
			nparts[new_nr].size = parts[i].size - mtd->erasesize;
			nparts[new_nr].mask_flags = parts[i].mask_flags;
			nparts[new_nr].types = parts[i].types;
			nparts[new_nr].of_node = parts[i].of_node;
			new_nr++;
		}

		/* copy original partition */
		nparts[new_nr].name = kstrdup(parts[i].name, GFP_KERNEL);
		nparts[new_nr].offset = parts[i].offset;
		nparts[new_nr].size = parts[i].size;
		nparts[new_nr].mask_flags = parts[i].mask_flags;
		nparts[new_nr].types = parts[i].types;
		nparts[new_nr].of_node = parts[i].of_node;
		new_nr++;
#else
		if (check_asr_fs_with_sdtim(mtd, parts + i) > 0) {
			/* add -sdtim partition */
			nparts[new_nr].name = kstrdup(parts[i].name, GFP_KERNEL);
			strcat((char *)nparts[new_nr].name, "-sdtim");
			nparts[new_nr].offset = parts[i].offset;
			nparts[new_nr].size = mtd->erasesize;
			nparts[new_nr].mask_flags = parts[i].mask_flags;
			nparts[new_nr].types = parts[i].types;
			nparts[new_nr].of_node = parts[i].of_node;
			new_nr++;

			nparts[new_nr].name = kstrdup(parts[i].name, GFP_KERNEL);
			nparts[new_nr].offset = parts[i].offset + mtd->erasesize;
			nparts[new_nr].size = parts[i].size - mtd->erasesize;
			nparts[new_nr].mask_flags = parts[i].mask_flags;
			nparts[new_nr].types = parts[i].types;
			nparts[new_nr].of_node = parts[i].of_node;
			new_nr++;
		} else {
			/* copy original partition */
			nparts[new_nr].name = kstrdup(parts[i].name, GFP_KERNEL);
			nparts[new_nr].offset = parts[i].offset;
			nparts[new_nr].size = parts[i].size;
			nparts[new_nr].mask_flags = parts[i].mask_flags;
			nparts[new_nr].types = parts[i].types;
			nparts[new_nr].of_node = parts[i].of_node;
			new_nr++;
		}
#endif
	}

	kfree(parts);
	*pparts = nparts;
	return new_nr;
}