diff --git a/drivers/mtd/Kconfig b/drivers/mtd/Kconfig index 796a2eccbef0..0421c6208de7 100644 --- a/drivers/mtd/Kconfig +++ b/drivers/mtd/Kconfig @@ -206,6 +206,15 @@ config MTD_PARTITIONED_MASTER the parent of the partition device be the master device, rather than what lies behind the master. +config MTD_VIRT_CONCAT + bool "Virtual concatenated MTD devices" + depends on MTD_PARTITIONED_MASTER + help + The driver enables the creation of virtual MTD device by + concatenating multiple physical MTD devices into a single + entity. This allows for the creation of partitions larger than + the individual physical chips, extending across chip boundaries. + source "drivers/mtd/chips/Kconfig" source "drivers/mtd/maps/Kconfig" diff --git a/drivers/mtd/Makefile b/drivers/mtd/Makefile index 593d0593a038..7b6dd53e8150 100644 --- a/drivers/mtd/Makefile +++ b/drivers/mtd/Makefile @@ -6,6 +6,7 @@ # Core functionality. obj-$(CONFIG_MTD) += mtd.o mtd-y := mtdcore.o mtdsuper.o mtdconcat.o mtdpart.o mtdchar.o +mtd-$(CONFIG_MTD_VIRT_CONCAT) += mtd_virt_concat.o obj-y += parsers/ diff --git a/drivers/mtd/mtd_virt_concat.c b/drivers/mtd/mtd_virt_concat.c new file mode 100644 index 000000000000..aea88d1c9bc5 --- /dev/null +++ b/drivers/mtd/mtd_virt_concat.c @@ -0,0 +1,363 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Virtual concat MTD device driver + * + * Copyright (C) 2018 Bernhard Frauendienst + * Author: Bernhard Frauendienst + */ + +#include +#include +#include "mtdcore.h" +#include +#include +#include +#include +#include + +#define CONCAT_PROP "part-concat-next" +#define CONCAT_POSTFIX "concat" +#define MIN_DEV_PER_CONCAT 1 + +static LIST_HEAD(concat_node_list); + +/** + * struct mtd_virt_concat_node - components of a concatenation + * @head: List handle + * @count: Number of nodes + * @nodes: Pointer to the nodes (partitions) to concatenate + * @concat: Concatenation container + */ +struct mtd_virt_concat_node { + struct list_head head; + unsigned int count; + struct device_node **nodes; + struct mtd_concat *concat; +}; + +/** + * mtd_is_part_concat - Check if the device is already part + * of a concatenated device + * @dev: pointer to 'device_node' + * + * Return: true if the device is already part of a concatenation, + * false otherwise. + */ +static bool mtd_is_part_concat(struct device_node *dev) +{ + struct mtd_virt_concat_node *item; + int idx; + + list_for_each_entry(item, &concat_node_list, head) { + for (idx = 0; idx < item->count; idx++) { + if (item->nodes[idx] == dev) + return true; + } + } + return false; +} + +static void mtd_virt_concat_put_mtd_devices(struct mtd_concat *concat) +{ + int i; + + for (i = 0; i < concat->num_subdev; i++) + put_mtd_device(concat->subdev[i]); +} + +void mtd_virt_concat_destroy_joins(void) +{ + struct mtd_virt_concat_node *item, *tmp; + struct mtd_info *mtd; + + list_for_each_entry_safe(item, tmp, &concat_node_list, head) { + mtd = &item->concat->mtd; + if (item->concat) { + mtd_device_unregister(mtd); + kfree(mtd->name); + mtd_concat_destroy(mtd); + mtd_virt_concat_put_mtd_devices(item->concat); + } + } +} + +/** + * mtd_virt_concat_destroy - Destroy the concat that includes the mtd object + * @mtd: pointer to 'mtd_info' + * + * Return: 0 on success, -error otherwise. + */ +int mtd_virt_concat_destroy(struct mtd_info *mtd) +{ + struct mtd_info *child, *master = mtd_get_master(mtd); + struct mtd_virt_concat_node *item, *tmp; + struct mtd_concat *concat; + int idx, ret = 0; + bool is_mtd_found; + + list_for_each_entry_safe(item, tmp, &concat_node_list, head) { + is_mtd_found = false; + + /* Find the concat item that hold the mtd device */ + for (idx = 0; idx < item->count; idx++) { + if (item->nodes[idx] == mtd->dev.of_node) { + is_mtd_found = true; + break; + } + } + if (!is_mtd_found) + continue; + concat = item->concat; + + /* + * Since this concatenated device is being removed, retrieve + * all MTD devices that are part of it and register them + * individually. + */ + for (idx = 0; idx < concat->num_subdev; idx++) { + child = concat->subdev[idx]; + if (child->dev.of_node != mtd->dev.of_node) { + ret = add_mtd_device(child); + if (ret) + goto out; + } + } + /* Destroy the concat */ + if (concat->mtd.name) { + del_mtd_device(&concat->mtd); + kfree(concat->mtd.name); + mtd_concat_destroy(&concat->mtd); + mtd_virt_concat_put_mtd_devices(item->concat); + } + + for (idx = 0; idx < item->count; idx++) + of_node_put(item->nodes[idx]); + + kfree(item->nodes); + kfree(item); + } + return 0; +out: + mutex_lock(&master->master.partitions_lock); + list_del(&child->part.node); + mutex_unlock(&master->master.partitions_lock); + kfree(mtd->name); + kfree(mtd); + + return ret; +} + +/** + * mtd_virt_concat_create_item - Create a concat item + * @parts: pointer to 'device_node' + * @count: number of mtd devices that make up + * the concatenated device. + * + * Return: 0 on success, -error otherwise. + */ +static int mtd_virt_concat_create_item(struct device_node *parts, + unsigned int count) +{ + struct mtd_virt_concat_node *item; + struct mtd_concat *concat; + int i; + + for (i = 0; i < (count - 1); i++) { + if (mtd_is_part_concat(of_parse_phandle(parts, CONCAT_PROP, i))) + return 0; + } + + item = kzalloc(sizeof(*item), GFP_KERNEL); + if (!item) + return -ENOMEM; + + item->count = count; + item->nodes = kcalloc(count, sizeof(*item->nodes), GFP_KERNEL); + if (!item->nodes) { + kfree(item); + return -ENOMEM; + } + + /* + * The partition in which "part-concat-next" property + * is defined is the first device in the list of concat + * devices. + */ + item->nodes[0] = parts; + + for (i = 1; i < count; i++) + item->nodes[i] = of_parse_phandle(parts, CONCAT_PROP, (i - 1)); + + concat = kzalloc(sizeof(*concat), GFP_KERNEL); + if (!concat) { + kfree(item); + return -ENOMEM; + } + + concat->subdev = kcalloc(count, sizeof(*concat->subdev), GFP_KERNEL); + if (!concat->subdev) { + kfree(item); + kfree(concat); + return -ENOMEM; + } + item->concat = concat; + + list_add_tail(&item->head, &concat_node_list); + + return 0; +} + +void mtd_virt_concat_destroy_items(void) +{ + struct mtd_virt_concat_node *item, *temp; + int i; + + list_for_each_entry_safe(item, temp, &concat_node_list, head) { + for (i = 0; i < item->count; i++) + of_node_put(item->nodes[i]); + + kfree(item->nodes); + kfree(item); + } +} + +/** + * mtd_virt_concat_create_add - Add a mtd device to the concat list + * @mtd: pointer to 'mtd_info' + * + * Return: true on success, false otherwise. + */ +bool mtd_virt_concat_add(struct mtd_info *mtd) +{ + struct mtd_virt_concat_node *item; + struct mtd_concat *concat; + int idx; + + list_for_each_entry(item, &concat_node_list, head) { + concat = item->concat; + for (idx = 0; idx < item->count; idx++) { + if (item->nodes[idx] == mtd->dev.of_node) { + concat->subdev[concat->num_subdev++] = mtd; + return true; + } + } + } + return false; +} + +/** + * mtd_virt_concat_node_create - List all the concatenations found in DT + * + * Return: 0 on success, -error otherwise. + */ +int mtd_virt_concat_node_create(void) +{ + struct device_node *parts = NULL; + int ret = 0, count = 0; + + /* List all the concatenations found in DT */ + do { + parts = of_find_node_with_property(parts, CONCAT_PROP); + if (!of_device_is_available(parts)) + continue; + + if (mtd_is_part_concat(parts)) + continue; + + count = of_count_phandle_with_args(parts, CONCAT_PROP, NULL); + if (count < MIN_DEV_PER_CONCAT) + continue; + + /* + * The partition in which "part-concat-next" property is defined + * is also part of the concat device, so increament count by 1. + */ + count++; + + ret = mtd_virt_concat_create_item(parts, count); + if (ret) { + of_node_put(parts); + goto destroy_items; + } + } while (parts); + + return ret; + +destroy_items: + mtd_virt_concat_destroy_items(); + + return ret; +} + +/** + * mtd_virt_concat_create_join - Create and register the concatenated + * MTD device. + * + * Return: 0 on success, -error otherwise. + */ +int mtd_virt_concat_create_join(void) +{ + struct mtd_virt_concat_node *item; + struct mtd_concat *concat; + struct mtd_info *mtd; + ssize_t name_sz; + int ret, idx; + char *name; + + list_for_each_entry(item, &concat_node_list, head) { + concat = item->concat; + /* + * Check if item->count != concat->num_subdev, it indicates + * that the MTD information for all devices included in the + * concatenation are not handy, concat MTD device can't be + * created hence switch to next concat device. + */ + if (item->count != concat->num_subdev) { + continue; + } else { + /* Calculate the legth of the name of the virtual device */ + for (idx = 0, name_sz = 0; idx < concat->num_subdev; idx++) + name_sz += (strlen(concat->subdev[idx]->name) + 1); + name_sz += strlen(CONCAT_POSTFIX); + name = kmalloc(name_sz + 1, GFP_KERNEL); + if (!name) { + mtd_virt_concat_put_mtd_devices(concat); + return -ENOMEM; + } + + ret = 0; + for (idx = 0; idx < concat->num_subdev; idx++) { + ret += sprintf((name + ret), "%s-", + concat->subdev[idx]->name); + } + sprintf((name + ret), CONCAT_POSTFIX); + + if (concat->mtd.name) { + ret = memcmp(concat->mtd.name, name, name_sz); + if (ret == 0) + continue; + } + mtd = mtd_concat_create(concat->subdev, concat->num_subdev, name); + if (!mtd) { + kfree(name); + return -ENXIO; + } + concat->mtd = *mtd; + /* Arbitrary set the first device as parent */ + concat->mtd.dev.parent = concat->subdev[0]->dev.parent; + concat->mtd.dev = concat->subdev[0]->dev; + + /* Add the mtd device */ + ret = add_mtd_device(&concat->mtd); + if (ret) + goto destroy_concat; + } + } + + return 0; + +destroy_concat: + mtd_concat_destroy(mtd); + + return ret; +} diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c index 64808493b4f5..576537774628 100644 --- a/drivers/mtd/mtdcore.c +++ b/drivers/mtd/mtdcore.c @@ -34,6 +34,7 @@ #include #include +#include #include "mtdcore.h" @@ -1120,6 +1121,12 @@ int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types, goto out; } + if (IS_REACHABLE(CONFIG_MTD_VIRT_CONCAT)) { + ret = mtd_virt_concat_node_create(); + if (ret < 0) + goto out; + } + /* Prefer parsed partitions over driver-provided fallback */ ret = parse_mtd_partitions(mtd, types, parser_data); if (ret == -EPROBE_DEFER) @@ -1137,6 +1144,11 @@ int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types, if (ret) goto out; + if (IS_REACHABLE(CONFIG_MTD_VIRT_CONCAT)) { + ret = mtd_virt_concat_create_join(); + if (ret < 0) + goto out; + } /* * FIXME: some drivers unfortunately call this function more than once. * So we have to check if we've already assigned the reboot notifier. @@ -1186,6 +1198,11 @@ int mtd_device_unregister(struct mtd_info *master) nvmem_unregister(master->otp_user_nvmem); nvmem_unregister(master->otp_factory_nvmem); + if (IS_REACHABLE(CONFIG_MTD_VIRT_CONCAT)) { + err = mtd_virt_concat_destroy(master); + if (err) + return err; + } err = del_mtd_partitions(master); if (err) return err; @@ -2621,6 +2638,10 @@ static int __init init_mtd(void) static void __exit cleanup_mtd(void) { + if (IS_REACHABLE(CONFIG_MTD_VIRT_CONCAT)) { + mtd_virt_concat_destroy_joins(); + mtd_virt_concat_destroy_items(); + } debugfs_remove_recursive(dfs_dir_mtd); cleanup_mtdchar(); if (proc_mtd) diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c index e016cfbc7224..795a94e6b482 100644 --- a/drivers/mtd/mtdpart.c +++ b/drivers/mtd/mtdpart.c @@ -18,6 +18,7 @@ #include #include #include +#include #include "mtdcore.h" @@ -409,6 +410,11 @@ int add_mtd_partitions(struct mtd_info *parent, goto err_del_partitions; } + if (IS_REACHABLE(CONFIG_MTD_VIRT_CONCAT)) { + if (mtd_virt_concat_add(child)) + continue; + } + mutex_lock(&master->master.partitions_lock); list_add_tail(&child->part.node, &parent->partitions); mutex_unlock(&master->master.partitions_lock); diff --git a/include/linux/mtd/concat.h b/include/linux/mtd/concat.h index b42d9af87c4e..2cd9d48958a8 100644 --- a/include/linux/mtd/concat.h +++ b/include/linux/mtd/concat.h @@ -28,5 +28,54 @@ struct mtd_info *mtd_concat_create( void mtd_concat_destroy(struct mtd_info *mtd); -#endif +/** + * mtd_virt_concat_node_create - Create a component for concatenation + * + * Returns a positive number representing the no. of devices found for + * concatenation, or a negative error code. + * + * List all the devices for concatenations found in DT and create a + * component for concatenation. + */ +int mtd_virt_concat_node_create(void); +/** + * mtd_virt_concat_add - add mtd_info object to the list of subdevices for concatenation + * @mtd: pointer to new MTD device info structure + * + * Returns true if the mtd_info object is added successfully else returns false. + * + * The mtd_info object is added to the list of subdevices for concatenation. + * It returns true if a match is found, and false if all subdevices have + * already been added or if the mtd_info object does not match any of the + * intended MTD devices. + */ +bool mtd_virt_concat_add(struct mtd_info *mtd); + +/** + * mtd_virt_concat_create_join - Create and register the concatenated MTD device + * + * Returns 0 on succes, or a negative error code. + * + * Creates and registers the concatenated MTD device + */ +int mtd_virt_concat_create_join(void); + +/** + * mtd_virt_concat_destroy - Remove the concat that includes a specific mtd device + * as one of its components. + * @mtd: pointer to MTD device info structure. + * + * Returns 0 on succes, or a negative error code. + * + * If the mtd_info object is part of a concatenated device, all other MTD devices + * within that concat are registered individually. The concatenated device is then + * removed, along with its concatenation component. + * + */ +int mtd_virt_concat_destroy(struct mtd_info *mtd); + +void mtd_virt_concat_destroy_joins(void); +void mtd_virt_concat_destroy_items(void); + +#endif