From 471a17d8d1b838092d1a76e48cdce8b5b67ff809 Mon Sep 17 00:00:00 2001 From: Daniel Golle Date: Mon, 27 Nov 2023 01:54:28 +0000 Subject: [PATCH 04/15] mtd: ubi: attach from device tree Introduce device tree compatible 'linux,ubi' and attach compatible MTD devices using the MTD add notifier. This is needed for a UBI device to be available early at boot (and not only after late_initcall), so volumes on them can be used eg. as NVMEM providers for other drivers. Signed-off-by: Daniel Golle --- drivers/mtd/ubi/build.c | 146 ++++++++++++++++++++++++++++------------ drivers/mtd/ubi/cdev.c | 2 +- drivers/mtd/ubi/ubi.h | 2 +- 3 files changed, 106 insertions(+), 44 deletions(-) --- a/drivers/mtd/ubi/build.c +++ b/drivers/mtd/ubi/build.c @@ -27,6 +27,7 @@ #include #include #include +#include #include #include #include "ubi.h" @@ -1071,6 +1072,7 @@ out_free: * ubi_detach_mtd_dev - detach an MTD device. * @ubi_num: UBI device number to detach from * @anyway: detach MTD even if device reference count is not zero + * @have_lock: called by MTD notifier holding mtd_table_mutex * * This function destroys an UBI device number @ubi_num and detaches the * underlying MTD device. Returns zero in case of success and %-EBUSY if the @@ -1080,7 +1082,7 @@ out_free: * Note, the invocations of this function has to be serialized by the * @ubi_devices_mutex. */ -int ubi_detach_mtd_dev(int ubi_num, int anyway) +int ubi_detach_mtd_dev(int ubi_num, int anyway, bool have_lock) { struct ubi_device *ubi; @@ -1136,7 +1138,11 @@ int ubi_detach_mtd_dev(int ubi_num, int vfree(ubi->peb_buf); vfree(ubi->fm_buf); ubi_msg(ubi, "mtd%d is detached", ubi->mtd->index); - put_mtd_device(ubi->mtd); + if (have_lock) + __put_mtd_device(ubi->mtd); + else + put_mtd_device(ubi->mtd); + put_device(&ubi->dev); return 0; } @@ -1213,43 +1219,43 @@ static struct mtd_info * __init open_mtd return mtd; } -static int __init ubi_init(void) +static void ubi_notify_add(struct mtd_info *mtd) { - int err, i, k; + struct device_node *np = mtd_get_of_node(mtd); + int err; - /* Ensure that EC and VID headers have correct size */ - BUILD_BUG_ON(sizeof(struct ubi_ec_hdr) != 64); - BUILD_BUG_ON(sizeof(struct ubi_vid_hdr) != 64); + if (!of_device_is_compatible(np, "linux,ubi")) + return; - if (mtd_devs > UBI_MAX_DEVICES) { - pr_err("UBI error: too many MTD devices, maximum is %d\n", - UBI_MAX_DEVICES); - return -EINVAL; - } + /* + * we are already holding &mtd_table_mutex, but still need + * to bump refcount + */ + err = __get_mtd_device(mtd); + if (err) + return; - /* Create base sysfs directory and sysfs files */ - err = class_register(&ubi_class); + /* called while holding mtd_table_mutex */ + mutex_lock_nested(&ubi_devices_mutex, SINGLE_DEPTH_NESTING); + err = ubi_attach_mtd_dev(mtd, UBI_DEV_NUM_AUTO, 0, 0, false); + mutex_unlock(&ubi_devices_mutex); if (err < 0) - return err; - - err = misc_register(&ubi_ctrl_cdev); - if (err) { - pr_err("UBI error: cannot register device\n"); - goto out; - } + __put_mtd_device(mtd); +} - ubi_wl_entry_slab = kmem_cache_create("ubi_wl_entry_slab", - sizeof(struct ubi_wl_entry), - 0, 0, NULL); - if (!ubi_wl_entry_slab) { - err = -ENOMEM; - goto out_dev_unreg; - } +static void ubi_notify_remove(struct mtd_info *mtd) +{ + WARN(1, "mtd%d removed despite UBI still being attached", mtd->index); +} - err = ubi_debugfs_init(); - if (err) - goto out_slab; +static struct mtd_notifier ubi_mtd_notifier = { + .add = ubi_notify_add, + .remove = ubi_notify_remove, +}; +static int __init ubi_init_attach(void) +{ + int err, i, k; /* Attach MTD devices */ for (i = 0; i < mtd_devs; i++) { @@ -1297,25 +1303,79 @@ static int __init ubi_init(void) } } + return 0; + +out_detach: + for (k = 0; k < i; k++) + if (ubi_devices[k]) { + mutex_lock(&ubi_devices_mutex); + ubi_detach_mtd_dev(ubi_devices[k]->ubi_num, 1, false); + mutex_unlock(&ubi_devices_mutex); + } + return err; +} +#ifndef CONFIG_MTD_UBI_MODULE +late_initcall(ubi_init_attach); +#endif + +static int __init ubi_init(void) +{ + int err; + + /* Ensure that EC and VID headers have correct size */ + BUILD_BUG_ON(sizeof(struct ubi_ec_hdr) != 64); + BUILD_BUG_ON(sizeof(struct ubi_vid_hdr) != 64); + + if (mtd_devs > UBI_MAX_DEVICES) { + pr_err("UBI error: too many MTD devices, maximum is %d\n", + UBI_MAX_DEVICES); + return -EINVAL; + } + + /* Create base sysfs directory and sysfs files */ + err = class_register(&ubi_class); + if (err < 0) + return err; + + err = misc_register(&ubi_ctrl_cdev); + if (err) { + pr_err("UBI error: cannot register device\n"); + goto out; + } + + ubi_wl_entry_slab = kmem_cache_create("ubi_wl_entry_slab", + sizeof(struct ubi_wl_entry), + 0, 0, NULL); + if (!ubi_wl_entry_slab) { + err = -ENOMEM; + goto out_dev_unreg; + } + + err = ubi_debugfs_init(); + if (err) + goto out_slab; + err = ubiblock_init(); if (err) { pr_err("UBI error: block: cannot initialize, error %d\n", err); /* See comment above re-ubi_is_module(). */ if (ubi_is_module()) - goto out_detach; + goto out_slab; + } + + register_mtd_user(&ubi_mtd_notifier); + + if (ubi_is_module()) { + err = ubi_init_attach(); + if (err) + goto out_mtd_notifier; } return 0; -out_detach: - for (k = 0; k < i; k++) - if (ubi_devices[k]) { - mutex_lock(&ubi_devices_mutex); - ubi_detach_mtd_dev(ubi_devices[k]->ubi_num, 1); - mutex_unlock(&ubi_devices_mutex); - } - ubi_debugfs_exit(); +out_mtd_notifier: + unregister_mtd_user(&ubi_mtd_notifier); out_slab: kmem_cache_destroy(ubi_wl_entry_slab); out_dev_unreg: @@ -1325,18 +1385,20 @@ out: pr_err("UBI error: cannot initialize UBI, error %d\n", err); return err; } -late_initcall(ubi_init); +device_initcall(ubi_init); + static void __exit ubi_exit(void) { int i; ubiblock_exit(); + unregister_mtd_user(&ubi_mtd_notifier); for (i = 0; i < UBI_MAX_DEVICES; i++) if (ubi_devices[i]) { mutex_lock(&ubi_devices_mutex); - ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1); + ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1, false); mutex_unlock(&ubi_devices_mutex); } ubi_debugfs_exit(); --- a/drivers/mtd/ubi/cdev.c +++ b/drivers/mtd/ubi/cdev.c @@ -1065,7 +1065,7 @@ static long ctrl_cdev_ioctl(struct file } mutex_lock(&ubi_devices_mutex); - err = ubi_detach_mtd_dev(ubi_num, 0); + err = ubi_detach_mtd_dev(ubi_num, 0, false); mutex_unlock(&ubi_devices_mutex); break; } --- a/drivers/mtd/ubi/ubi.h +++ b/drivers/mtd/ubi/ubi.h @@ -939,7 +939,7 @@ int ubi_io_write_vid_hdr(struct ubi_devi int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset, int max_beb_per1024, bool disable_fm); -int ubi_detach_mtd_dev(int ubi_num, int anyway); +int ubi_detach_mtd_dev(int ubi_num, int anyway, bool have_lock); struct ubi_device *ubi_get_device(int ubi_num); void ubi_put_device(struct ubi_device *ubi); struct ubi_device *ubi_get_by_major(int major);