drivers/mtd/parsers/ofpart_core.c - third_party/kernel - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Flash partitions described by the OF (or flattened) device tree
  *
  * Copyright © 2006 MontaVista Software Inc.
  * Author: Vitaly Wool <vwool@ru.mvista.com>
  *
  * Revised to handle newer style flash binding by:
  *   Copyright © 2007 David Gibson, IBM Corporation.
  */

 #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 "ofpart_bcm4908.h"
 #include "ofpart_linksys_ns.h"

 struct fixed_partitions_quirks {
 	int (*post_parse)(struct mtd_info *mtd, struct mtd_partition *parts, int nr_parts);
 };

 static struct fixed_partitions_quirks bcm4908_partitions_quirks = {
 	.post_parse = bcm4908_partitions_post_parse,
 };

 static struct fixed_partitions_quirks linksys_ns_partitions_quirks = {
 	.post_parse = linksys_ns_partitions_post_parse,
 };

 static const struct of_device_id parse_ofpart_match_table[];

 static bool node_has_compatible(struct device_node *pp)
 {
 	return of_get_property(pp, "compatible", NULL);
 }

 static int parse_fixed_partitions(struct mtd_info *master,
 				  const struct mtd_partition **pparts,
 				  struct mtd_part_parser_data *data)
 {
 	const struct fixed_partitions_quirks *quirks;
 	const struct of_device_id *of_id;
 	struct mtd_partition *parts;
 	struct device_node *mtd_node;
 	struct device_node *ofpart_node;
 	const char *partname;
 	struct device_node *pp;
 	int nr_parts, i, ret = 0;
 	bool dedicated = true;

 	/* Pull of_node from the master device node */
 	mtd_node = mtd_get_of_node(master);
 	if (!mtd_node)
 		return 0;

 	if (!master->parent) { /* Master */
 		ofpart_node = of_get_child_by_name(mtd_node, "partitions");
 		if (!ofpart_node) {
 			/*
 			 * We might get here even when ofpart isn't used at all (e.g.,
 			 * when using another parser), so don't be louder than
 			 * KERN_DEBUG
 			 */
 			pr_debug("%s: 'partitions' subnode not found on %pOF. Trying to parse direct subnodes as partitions.\n",
 				master->name, mtd_node);
 			ofpart_node = mtd_node;
 			dedicated = false;
 		}
 	} else { /* Partition */
 		ofpart_node = mtd_node;
 	}

 	of_id = of_match_node(parse_ofpart_match_table, ofpart_node);
 	if (dedicated && !of_id) {
 		/* The 'partitions' subnode might be used by another parser */
 		return 0;
 	}

 	quirks = of_id ? of_id->data : NULL;

 	/* First count the subnodes */
 	nr_parts = 0;
 	for_each_child_of_node(ofpart_node,  pp) {
 		if (!dedicated && node_has_compatible(pp))
 			continue;

 		nr_parts++;
 	}

 	if (nr_parts == 0)
 		return 0;

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

 	i = 0;
 	for_each_child_of_node(ofpart_node,  pp) {
 		const __be32 *reg;
 		int len;
 		int a_cells, s_cells;

 		if (!dedicated && node_has_compatible(pp))
 			continue;

 		reg = of_get_property(pp, "reg", &len);
 		if (!reg) {
 			if (dedicated) {
 				pr_debug("%s: ofpart partition %pOF (%pOF) missing reg property.\n",
 					 master->name, pp,
 					 mtd_node);
 				goto ofpart_fail;
 			} else {
 				nr_parts--;
 				continue;
 			}
 		}

 		a_cells = of_n_addr_cells(pp);
 		s_cells = of_n_size_cells(pp);
 		if (!dedicated && s_cells == 0) {
 			/*
 			 * This is a ugly workaround to not create
 			 * regression on devices that are still creating
 			 * partitions as direct children of the nand controller.
 			 * This can happen in case the nand controller node has
 			 * #size-cells equal to 0 and the firmware (e.g.
 			 * U-Boot) just add the partitions there assuming
 			 * 32-bit addressing.
 			 *
 			 * If you get this warning your firmware and/or DTS
 			 * should be really fixed.
 			 *
 			 * This is working only for devices smaller than 4GiB.
 			 */
 			pr_warn("%s: ofpart partition %pOF (%pOF) #size-cells is wrongly set to <0>, assuming <1> for parsing partitions.\n",
 				master->name, pp, mtd_node);
 			s_cells = 1;
 		}
 		if (len / 4 != a_cells + s_cells) {
 			pr_debug("%s: ofpart partition %pOF (%pOF) error parsing reg property.\n",
 				 master->name, pp,
 				 mtd_node);
 			goto ofpart_fail;
 		}

 		parts[i].offset = of_read_number(reg, a_cells);
 		parts[i].size = of_read_number(reg + a_cells, s_cells);
 		parts[i].of_node = pp;

 		partname = of_get_property(pp, "label", &len);
 		if (!partname)
 			partname = of_get_property(pp, "name", &len);
 		parts[i].name = partname;

 		if (of_get_property(pp, "read-only", &len))
 			parts[i].mask_flags |= MTD_WRITEABLE;

 		if (of_get_property(pp, "lock", &len))
 			parts[i].mask_flags |= MTD_POWERUP_LOCK;

 		if (of_property_read_bool(pp, "slc-mode"))
 			parts[i].add_flags |= MTD_SLC_ON_MLC_EMULATION;

 		i++;
 	}

 	if (!nr_parts)
 		goto ofpart_none;

 	if (quirks && quirks->post_parse)
 		quirks->post_parse(master, parts, nr_parts);

 	*pparts = parts;
 	return nr_parts;

 ofpart_fail:
 	pr_err("%s: error parsing ofpart partition %pOF (%pOF)\n",
 	       master->name, pp, mtd_node);
 	ret = -EINVAL;
 ofpart_none:
 	of_node_put(pp);
 	kfree(parts);
 	return ret;
 }

 static const struct of_device_id parse_ofpart_match_table[] = {
 	/* Generic */
 	{ .compatible = "fixed-partitions" },
 	/* Customized */
 	{ .compatible = "brcm,bcm4908-partitions", .data = &bcm4908_partitions_quirks, },
 	{ .compatible = "linksys,ns-partitions", .data = &linksys_ns_partitions_quirks, },
 	{},
 };
 MODULE_DEVICE_TABLE(of, parse_ofpart_match_table);

 static struct mtd_part_parser ofpart_parser = {
 	.parse_fn = parse_fixed_partitions,
 	.name = "fixed-partitions",
 	.of_match_table = parse_ofpart_match_table,
 };

 static int parse_ofoldpart_partitions(struct mtd_info *master,
 				      const struct mtd_partition **pparts,
 				      struct mtd_part_parser_data *data)
 {
 	struct mtd_partition *parts;
 	struct device_node *dp;
 	int i, plen, nr_parts;
 	const struct {
 		__be32 offset, len;
 	} *part;
 	const char *names;

 	/* Pull of_node from the master device node */
 	dp = mtd_get_of_node(master);
 	if (!dp)
 		return 0;

 	part = of_get_property(dp, "partitions", &plen);
 	if (!part)
 		return 0; /* No partitions found */

 	pr_warn("Device tree uses obsolete partition map binding: %pOF\n", dp);

 	nr_parts = plen / sizeof(part[0]);

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

 	names = of_get_property(dp, "partition-names", &plen);

 	for (i = 0; i < nr_parts; i++) {
 		parts[i].offset = be32_to_cpu(part->offset);
 		parts[i].size   = be32_to_cpu(part->len) & ~1;
 		/* bit 0 set signifies read only partition */
 		if (be32_to_cpu(part->len) & 1)
 			parts[i].mask_flags = MTD_WRITEABLE;

 		if (names && (plen > 0)) {
 			int len = strlen(names) + 1;

 			parts[i].name = names;
 			plen -= len;
 			names += len;
 		} else {
 			parts[i].name = "unnamed";
 		}

 		part++;
 	}

 	*pparts = parts;
 	return nr_parts;
 }

 static struct mtd_part_parser ofoldpart_parser = {
 	.parse_fn = parse_ofoldpart_partitions,
 	.name = "ofoldpart",
 };

 static int __init ofpart_parser_init(void)
 {
 	register_mtd_parser(&ofpart_parser);
 	register_mtd_parser(&ofoldpart_parser);
 	return 0;
 }

 static void __exit ofpart_parser_exit(void)
 {
 	deregister_mtd_parser(&ofpart_parser);
 	deregister_mtd_parser(&ofoldpart_parser);
 }

 module_init(ofpart_parser_init);
 module_exit(ofpart_parser_exit);

 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("Parser for MTD partitioning information in device tree");
 MODULE_AUTHOR("Vitaly Wool, David Gibson");
 /*
  * When MTD core cannot find the requested parser, it tries to load the module
  * with the same name. Since we provide the ofoldpart parser, we should have
  * the corresponding alias.
  */
 MODULE_ALIAS("fixed-partitions");
 MODULE_ALIAS("ofoldpart");
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* Flash partitions described by the OF (or flattened) device tree
	*
	* Copyright © 2006 MontaVista Software Inc.
	* Author: Vitaly Wool <vwool@ru.mvista.com>
	*
	* Revised to handle newer style flash binding by:
	* Copyright © 2007 David Gibson, IBM Corporation.
	*/

	#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 "ofpart_bcm4908.h"
	#include "ofpart_linksys_ns.h"

	struct fixed_partitions_quirks {
	int (post_parse)(struct mtd_info mtd, struct mtd_partition *parts, int nr_parts);
	};

	static struct fixed_partitions_quirks bcm4908_partitions_quirks = {
	.post_parse = bcm4908_partitions_post_parse,
	};

	static struct fixed_partitions_quirks linksys_ns_partitions_quirks = {
	.post_parse = linksys_ns_partitions_post_parse,
	};

	static const struct of_device_id parse_ofpart_match_table[];

	static bool node_has_compatible(struct device_node *pp)
	{
	return of_get_property(pp, "compatible", NULL);
	}

	static int parse_fixed_partitions(struct mtd_info *master,
	const struct mtd_partition **pparts,
	struct mtd_part_parser_data *data)
	{
	const struct fixed_partitions_quirks *quirks;
	const struct of_device_id *of_id;
	struct mtd_partition *parts;
	struct device_node *mtd_node;
	struct device_node *ofpart_node;
	const char *partname;
	struct device_node *pp;
	int nr_parts, i, ret = 0;
	bool dedicated = true;

	/* Pull of_node from the master device node */
	mtd_node = mtd_get_of_node(master);
	if (!mtd_node)
	return 0;

	if (!master->parent) { /* Master */
	ofpart_node = of_get_child_by_name(mtd_node, "partitions");
	if (!ofpart_node) {
	/*
	* We might get here even when ofpart isn't used at all (e.g.,
	* when using another parser), so don't be louder than
	* KERN_DEBUG
	*/
	pr_debug("%s: 'partitions' subnode not found on %pOF. Trying to parse direct subnodes as partitions.\n",
	master->name, mtd_node);
	ofpart_node = mtd_node;
	dedicated = false;
	}
	} else { /* Partition */
	ofpart_node = mtd_node;
	}

	of_id = of_match_node(parse_ofpart_match_table, ofpart_node);
	if (dedicated && !of_id) {
	/* The 'partitions' subnode might be used by another parser */
	return 0;
	}

	quirks = of_id ? of_id->data : NULL;

	/* First count the subnodes */
	nr_parts = 0;
	for_each_child_of_node(ofpart_node, pp) {
	if (!dedicated && node_has_compatible(pp))
	continue;

	nr_parts++;
	}

	if (nr_parts == 0)
	return 0;

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

	i = 0;
	for_each_child_of_node(ofpart_node, pp) {
	const __be32 *reg;
	int len;
	int a_cells, s_cells;

	if (!dedicated && node_has_compatible(pp))
	continue;

	reg = of_get_property(pp, "reg", &len);
	if (!reg) {
	if (dedicated) {
	pr_debug("%s: ofpart partition %pOF (%pOF) missing reg property.\n",
	master->name, pp,
	mtd_node);
	goto ofpart_fail;
	} else {
	nr_parts--;
	continue;
	}
	}

	a_cells = of_n_addr_cells(pp);
	s_cells = of_n_size_cells(pp);
	if (!dedicated && s_cells == 0) {
	/*
	* This is a ugly workaround to not create
	* regression on devices that are still creating
	* partitions as direct children of the nand controller.
	* This can happen in case the nand controller node has
	* #size-cells equal to 0 and the firmware (e.g.
	* U-Boot) just add the partitions there assuming
	* 32-bit addressing.
	*
	* If you get this warning your firmware and/or DTS
	* should be really fixed.
	*
	* This is working only for devices smaller than 4GiB.
	*/
	pr_warn("%s: ofpart partition %pOF (%pOF) #size-cells is wrongly set to <0>, assuming <1> for parsing partitions.\n",
	master->name, pp, mtd_node);
	s_cells = 1;
	}
	if (len / 4 != a_cells + s_cells) {
	pr_debug("%s: ofpart partition %pOF (%pOF) error parsing reg property.\n",
	master->name, pp,
	mtd_node);
	goto ofpart_fail;
	}

	parts[i].offset = of_read_number(reg, a_cells);
	parts[i].size = of_read_number(reg + a_cells, s_cells);
	parts[i].of_node = pp;

	partname = of_get_property(pp, "label", &len);
	if (!partname)
	partname = of_get_property(pp, "name", &len);
	parts[i].name = partname;

	if (of_get_property(pp, "read-only", &len))
	parts[i].mask_flags \|= MTD_WRITEABLE;

	if (of_get_property(pp, "lock", &len))
	parts[i].mask_flags \|= MTD_POWERUP_LOCK;

	if (of_property_read_bool(pp, "slc-mode"))
	parts[i].add_flags \|= MTD_SLC_ON_MLC_EMULATION;

	i++;
	}

	if (!nr_parts)
	goto ofpart_none;

	if (quirks && quirks->post_parse)
	quirks->post_parse(master, parts, nr_parts);

	*pparts = parts;
	return nr_parts;

	ofpart_fail:
	pr_err("%s: error parsing ofpart partition %pOF (%pOF)\n",
	master->name, pp, mtd_node);
	ret = -EINVAL;
	ofpart_none:
	of_node_put(pp);
	kfree(parts);
	return ret;
	}

	static const struct of_device_id parse_ofpart_match_table[] = {
	/* Generic */
	{ .compatible = "fixed-partitions" },
	/* Customized */
	{ .compatible = "brcm,bcm4908-partitions", .data = &bcm4908_partitions_quirks, },
	{ .compatible = "linksys,ns-partitions", .data = &linksys_ns_partitions_quirks, },
	{},
	};
	MODULE_DEVICE_TABLE(of, parse_ofpart_match_table);

	static struct mtd_part_parser ofpart_parser = {
	.parse_fn = parse_fixed_partitions,
	.name = "fixed-partitions",
	.of_match_table = parse_ofpart_match_table,
	};

	static int parse_ofoldpart_partitions(struct mtd_info *master,
	const struct mtd_partition **pparts,
	struct mtd_part_parser_data *data)
	{
	struct mtd_partition *parts;
	struct device_node *dp;
	int i, plen, nr_parts;
	const struct {
	__be32 offset, len;
	} *part;
	const char *names;

	/* Pull of_node from the master device node */
	dp = mtd_get_of_node(master);
	if (!dp)
	return 0;

	part = of_get_property(dp, "partitions", &plen);
	if (!part)
	return 0; /* No partitions found */

	pr_warn("Device tree uses obsolete partition map binding: %pOF\n", dp);

	nr_parts = plen / sizeof(part[0]);

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

	names = of_get_property(dp, "partition-names", &plen);

	for (i = 0; i < nr_parts; i++) {
	parts[i].offset = be32_to_cpu(part->offset);
	parts[i].size = be32_to_cpu(part->len) & ~1;
	/* bit 0 set signifies read only partition */
	if (be32_to_cpu(part->len) & 1)
	parts[i].mask_flags = MTD_WRITEABLE;

	if (names && (plen > 0)) {
	int len = strlen(names) + 1;

	parts[i].name = names;
	plen -= len;
	names += len;
	} else {
	parts[i].name = "unnamed";
	}

	part++;
	}

	*pparts = parts;
	return nr_parts;
	}

	static struct mtd_part_parser ofoldpart_parser = {
	.parse_fn = parse_ofoldpart_partitions,
	.name = "ofoldpart",
	};

	static int __init ofpart_parser_init(void)
	{
	register_mtd_parser(&ofpart_parser);
	register_mtd_parser(&ofoldpart_parser);
	return 0;
	}

	static void __exit ofpart_parser_exit(void)
	{
	deregister_mtd_parser(&ofpart_parser);
	deregister_mtd_parser(&ofoldpart_parser);
	}

	module_init(ofpart_parser_init);
	module_exit(ofpart_parser_exit);

	MODULE_LICENSE("GPL");
	MODULE_DESCRIPTION("Parser for MTD partitioning information in device tree");
	MODULE_AUTHOR("Vitaly Wool, David Gibson");
	/*
	* When MTD core cannot find the requested parser, it tries to load the module
	* with the same name. Since we provide the ofoldpart parser, we should have
	* the corresponding alias.
	*/
	MODULE_ALIAS("fixed-partitions");
	MODULE_ALIAS("ofoldpart");