Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted

Pull I3C updates from Alexandre Belloni:
 "A new driver this cycle, for the AMD AXI I3C controller.

  There are also new features such as IBI wakeup support, SETAASA device
  discovery and ACPI support for the the DAA methods, meaning we can now
  communicate with the SPD devices on DDR5 modules.

  New driver:
   - AMD AXI I3C master controller

  Subsystem:
   - I3C Common Command Code (CCC) handling improvements, especially
     around GET CCCs
   - SETAASA device discovery support
   - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
     well as I2C devices on I3C bus
   - IBI-based wakeup support

  Drivers:
   - dw: SETAASA support
   - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
     controller support, PIO queue management support for HCI v1.2
   - renesas: improve suspend to RAM support, add runtime PM support"

* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
  i3c: dw: reduce do_daa time if there's no client
  i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
  i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
  i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
  i3c: dw: rename "pclk" to "apb" to match dt-binding
  i3c: dw: make struct dw_i3c_cmd smaller
  i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
  i3c: renesas: Don't register devices when ENTDAA times out
  i3c: master: dw-i3c-master: fix OD timing for first broadcast
  i3c: mipi-i3c-hci: Advertise IBI wakeup capability
  i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
  i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
  i3c: master: Reject IBI requests from non-IBI-capable devices
  i3c: master: Add helper to query bus wakeup requirements
  i3c: master: Report wakeup events for IBIs
  i3c: master: Support IBI-based wakeup capability
  i3c: master: Fix potential UAF in i3c_device_match()
  i3c: master: Fix potential UAF in i3c_device_uevent()
  i3c: Make dev->desc locking assumptions explicit
  i3c: master: Fix use-after-free of master->this
  ...

1 files changed, 697 insertions, 0 deletions

diff --git a/drivers/mtd/ubi/debug.c b/drivers/mtd/ubi/debug.c
new file mode 100644
index 000000000..d2a53961d
--- /dev/null
+++ b/drivers/mtd/ubi/debug.c
@@ -0,0 +1,697 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) International Business Machines Corp., 2006
+ *
+ * Author: Artem Bityutskiy (Битюцкий Артём)
+ */
+
+#include "ubi.h"
+#include <linux/debugfs.h>
+#include <linux/uaccess.h>
+#include <linux/module.h>
+#include <linux/seq_file.h>
+#include <linux/fault-inject.h>
+
+#ifdef CONFIG_MTD_UBI_FAULT_INJECTION
+static DECLARE_FAULT_ATTR(fault_eccerr_attr);
+static DECLARE_FAULT_ATTR(fault_bitflips_attr);
+static DECLARE_FAULT_ATTR(fault_read_failure_attr);
+static DECLARE_FAULT_ATTR(fault_write_failure_attr);
+static DECLARE_FAULT_ATTR(fault_erase_failure_attr);
+static DECLARE_FAULT_ATTR(fault_power_cut_attr);
+static DECLARE_FAULT_ATTR(fault_io_ff_attr);
+static DECLARE_FAULT_ATTR(fault_io_ff_bitflips_attr);
+static DECLARE_FAULT_ATTR(fault_bad_hdr_attr);
+static DECLARE_FAULT_ATTR(fault_bad_hdr_ebadmsg_attr);
+
+#define FAIL_ACTION(name, fault_attr)			\
+bool should_fail_##name(void)				\
+{							\
+	return should_fail(&fault_attr, 1);		\
+}
+
+FAIL_ACTION(eccerr,		fault_eccerr_attr)
+FAIL_ACTION(bitflips,		fault_bitflips_attr)
+FAIL_ACTION(read_failure,	fault_read_failure_attr)
+FAIL_ACTION(write_failure,	fault_write_failure_attr)
+FAIL_ACTION(erase_failure,	fault_erase_failure_attr)
+FAIL_ACTION(power_cut,		fault_power_cut_attr)
+FAIL_ACTION(io_ff,		fault_io_ff_attr)
+FAIL_ACTION(io_ff_bitflips,	fault_io_ff_bitflips_attr)
+FAIL_ACTION(bad_hdr,		fault_bad_hdr_attr)
+FAIL_ACTION(bad_hdr_ebadmsg,	fault_bad_hdr_ebadmsg_attr)
+#endif
+
+/**
+ * ubi_dump_flash - dump a region of flash.
+ * @ubi: UBI device description object
+ * @pnum: the physical eraseblock number to dump
+ * @offset: the starting offset within the physical eraseblock to dump
+ * @len: the length of the region to dump
+ */
+void ubi_dump_flash(struct ubi_device *ubi, int pnum, int offset, int len)
+{
+	int err;
+	size_t read;
+	void *buf;
+	loff_t addr = (loff_t)pnum * ubi->peb_size + offset;
+
+	buf = vmalloc(len);
+	if (!buf)
+		return;
+	err = mtd_read(ubi->mtd, addr, len, &read, buf);
+	if (err && err != -EUCLEAN) {
+		ubi_err(ubi, "err %d while reading %d bytes from PEB %d:%d, read %zd bytes",
+			err, len, pnum, offset, read);
+		goto out;
+	}
+
+	ubi_msg(ubi, "dumping %d bytes of data from PEB %d, offset %d",
+		len, pnum, offset);
+	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1, buf, len, 1);
+out:
+	vfree(buf);
+	return;
+}
+
+/**
+ * ubi_dump_ec_hdr - dump an erase counter header.
+ * @ec_hdr: the erase counter header to dump
+ */
+void ubi_dump_ec_hdr(const struct ubi_ec_hdr *ec_hdr)
+{
+	pr_err("Erase counter header dump:\n");
+	pr_err("\tmagic          %#08x\n", be32_to_cpu(ec_hdr->magic));
+	pr_err("\tversion        %d\n", (int)ec_hdr->version);
+	pr_err("\tec             %llu\n", (long long)be64_to_cpu(ec_hdr->ec));
+	pr_err("\tvid_hdr_offset %d\n", be32_to_cpu(ec_hdr->vid_hdr_offset));
+	pr_err("\tdata_offset    %d\n", be32_to_cpu(ec_hdr->data_offset));
+	pr_err("\timage_seq      %d\n", be32_to_cpu(ec_hdr->image_seq));
+	pr_err("\thdr_crc        %#08x\n", be32_to_cpu(ec_hdr->hdr_crc));
+	pr_err("erase counter header hexdump:\n");
+	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
+		       ec_hdr, UBI_EC_HDR_SIZE, 1);
+}
+
+/**
+ * ubi_dump_vid_hdr - dump a volume identifier header.
+ * @vid_hdr: the volume identifier header to dump
+ */
+void ubi_dump_vid_hdr(const struct ubi_vid_hdr *vid_hdr)
+{
+	pr_err("Volume identifier header dump:\n");
+	pr_err("\tmagic     %08x\n", be32_to_cpu(vid_hdr->magic));
+	pr_err("\tversion   %d\n",  (int)vid_hdr->version);
+	pr_err("\tvol_type  %d\n",  (int)vid_hdr->vol_type);
+	pr_err("\tcopy_flag %d\n",  (int)vid_hdr->copy_flag);
+	pr_err("\tcompat    %d\n",  (int)vid_hdr->compat);
+	pr_err("\tvol_id    %d\n",  be32_to_cpu(vid_hdr->vol_id));
+	pr_err("\tlnum      %d\n",  be32_to_cpu(vid_hdr->lnum));
+	pr_err("\tdata_size %d\n",  be32_to_cpu(vid_hdr->data_size));
+	pr_err("\tused_ebs  %d\n",  be32_to_cpu(vid_hdr->used_ebs));
+	pr_err("\tdata_pad  %d\n",  be32_to_cpu(vid_hdr->data_pad));
+	pr_err("\tsqnum     %llu\n",
+		(unsigned long long)be64_to_cpu(vid_hdr->sqnum));
+	pr_err("\thdr_crc   %08x\n", be32_to_cpu(vid_hdr->hdr_crc));
+	pr_err("Volume identifier header hexdump:\n");
+	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
+		       vid_hdr, UBI_VID_HDR_SIZE, 1);
+}
+
+/**
+ * ubi_dump_vol_info - dump volume information.
+ * @vol: UBI volume description object
+ */
+void ubi_dump_vol_info(const struct ubi_volume *vol)
+{
+	pr_err("Volume information dump:\n");
+	pr_err("\tvol_id          %d\n", vol->vol_id);
+	pr_err("\treserved_pebs   %d\n", vol->reserved_pebs);
+	pr_err("\talignment       %d\n", vol->alignment);
+	pr_err("\tdata_pad        %d\n", vol->data_pad);
+	pr_err("\tvol_type        %d\n", vol->vol_type);
+	pr_err("\tname_len        %d\n", vol->name_len);
+	pr_err("\tusable_leb_size %d\n", vol->usable_leb_size);
+	pr_err("\tused_ebs        %d\n", vol->used_ebs);
+	pr_err("\tused_bytes      %lld\n", vol->used_bytes);
+	pr_err("\tlast_eb_bytes   %d\n", vol->last_eb_bytes);
+	pr_err("\tcorrupted       %d\n", vol->corrupted);
+	pr_err("\tupd_marker      %d\n", vol->upd_marker);
+	pr_err("\tskip_check      %d\n", vol->skip_check);
+
+	if (vol->name_len <= UBI_VOL_NAME_MAX &&
+	    strnlen(vol->name, vol->name_len + 1) == vol->name_len) {
+		pr_err("\tname            %s\n", vol->name);
+	} else {
+		pr_err("\t1st 5 characters of name: %c%c%c%c%c\n",
+		       vol->name[0], vol->name[1], vol->name[2],
+		       vol->name[3], vol->name[4]);
+	}
+}
+
+/**
+ * ubi_dump_vtbl_record - dump a &struct ubi_vtbl_record object.
+ * @r: the object to dump
+ * @idx: volume table index
+ */
+void ubi_dump_vtbl_record(const struct ubi_vtbl_record *r, int idx)
+{
+	int name_len = be16_to_cpu(r->name_len);
+
+	pr_err("Volume table record %d dump:\n", idx);
+	pr_err("\treserved_pebs   %d\n", be32_to_cpu(r->reserved_pebs));
+	pr_err("\talignment       %d\n", be32_to_cpu(r->alignment));
+	pr_err("\tdata_pad        %d\n", be32_to_cpu(r->data_pad));
+	pr_err("\tvol_type        %d\n", (int)r->vol_type);
+	pr_err("\tupd_marker      %d\n", (int)r->upd_marker);
+	pr_err("\tname_len        %d\n", name_len);
+
+	if (r->name[0] == '\0') {
+		pr_err("\tname            NULL\n");
+		return;
+	}
+
+	if (name_len <= UBI_VOL_NAME_MAX &&
+	    strnlen(&r->name[0], name_len + 1) == name_len) {
+		pr_err("\tname            %s\n", &r->name[0]);
+	} else {
+		pr_err("\t1st 5 characters of name: %c%c%c%c%c\n",
+			r->name[0], r->name[1], r->name[2], r->name[3],
+			r->name[4]);
+	}
+	pr_err("\tcrc             %#08x\n", be32_to_cpu(r->crc));
+}
+
+/**
+ * ubi_dump_av - dump a &struct ubi_ainf_volume object.
+ * @av: the object to dump
+ */
+void ubi_dump_av(const struct ubi_ainf_volume *av)
+{
+	pr_err("Volume attaching information dump:\n");
+	pr_err("\tvol_id         %d\n", av->vol_id);
+	pr_err("\thighest_lnum   %d\n", av->highest_lnum);
+	pr_err("\tleb_count      %d\n", av->leb_count);
+	pr_err("\tcompat         %d\n", av->compat);
+	pr_err("\tvol_type       %d\n", av->vol_type);
+	pr_err("\tused_ebs       %d\n", av->used_ebs);
+	pr_err("\tlast_data_size %d\n", av->last_data_size);
+	pr_err("\tdata_pad       %d\n", av->data_pad);
+}
+
+/**
+ * ubi_dump_aeb - dump a &struct ubi_ainf_peb object.
+ * @aeb: the object to dump
+ * @type: object type: 0 - not corrupted, 1 - corrupted
+ */
+void ubi_dump_aeb(const struct ubi_ainf_peb *aeb, int type)
+{
+	pr_err("eraseblock attaching information dump:\n");
+	pr_err("\tec       %d\n", aeb->ec);
+	pr_err("\tpnum     %d\n", aeb->pnum);
+	if (type == 0) {
+		pr_err("\tlnum     %d\n", aeb->lnum);
+		pr_err("\tscrub    %d\n", aeb->scrub);
+		pr_err("\tsqnum    %llu\n", aeb->sqnum);
+	}
+}
+
+/**
+ * ubi_dump_mkvol_req - dump a &struct ubi_mkvol_req object.
+ * @req: the object to dump
+ */
+void ubi_dump_mkvol_req(const struct ubi_mkvol_req *req)
+{
+	char nm[17];
+
+	pr_err("Volume creation request dump:\n");
+	pr_err("\tvol_id    %d\n",   req->vol_id);
+	pr_err("\talignment %d\n",   req->alignment);
+	pr_err("\tbytes     %lld\n", (long long)req->bytes);
+	pr_err("\tvol_type  %d\n",   req->vol_type);
+	pr_err("\tname_len  %d\n",   req->name_len);
+
+	memcpy(nm, req->name, 16);
+	nm[16] = 0;
+	pr_err("\t1st 16 characters of name: %s\n", nm);
+}
+
+/*
+ * Root directory for UBI stuff in debugfs. Contains sub-directories which
+ * contain the stuff specific to particular UBI devices.
+ */
+static struct dentry *dfs_rootdir;
+
+#ifdef CONFIG_MTD_UBI_FAULT_INJECTION
+static void dfs_create_fault_entry(struct dentry *parent)
+{
+	struct dentry *dir;
+
+	dir = debugfs_create_dir("fault_inject", parent);
+	if (IS_ERR_OR_NULL(dir)) {
+		int err = dir ? PTR_ERR(dir) : -ENODEV;
+
+		pr_warn("UBI error: cannot create \"fault_inject\" debugfs directory, error %d\n",
+			 err);
+		return;
+	}
+
+	fault_create_debugfs_attr("emulate_eccerr", dir,
+				  &fault_eccerr_attr);
+
+	fault_create_debugfs_attr("emulate_read_failure", dir,
+				  &fault_read_failure_attr);
+
+	fault_create_debugfs_attr("emulate_bitflips", dir,
+				  &fault_bitflips_attr);
+
+	fault_create_debugfs_attr("emulate_write_failure", dir,
+				  &fault_write_failure_attr);
+
+	fault_create_debugfs_attr("emulate_erase_failure", dir,
+				  &fault_erase_failure_attr);
+
+	fault_create_debugfs_attr("emulate_power_cut", dir,
+				  &fault_power_cut_attr);
+
+	fault_create_debugfs_attr("emulate_io_ff", dir,
+				  &fault_io_ff_attr);
+
+	fault_create_debugfs_attr("emulate_io_ff_bitflips", dir,
+				  &fault_io_ff_bitflips_attr);
+
+	fault_create_debugfs_attr("emulate_bad_hdr", dir,
+				  &fault_bad_hdr_attr);
+
+	fault_create_debugfs_attr("emulate_bad_hdr_ebadmsg", dir,
+				  &fault_bad_hdr_ebadmsg_attr);
+}
+#endif
+
+/**
+ * ubi_debugfs_init - create UBI debugfs directory.
+ *
+ * Create UBI debugfs directory. Returns zero in case of success and a negative
+ * error code in case of failure.
+ */
+int ubi_debugfs_init(void)
+{
+	if (!IS_ENABLED(CONFIG_DEBUG_FS))
+		return 0;
+
+	dfs_rootdir = debugfs_create_dir("ubi", NULL);
+	if (IS_ERR_OR_NULL(dfs_rootdir)) {
+		int err = dfs_rootdir ? PTR_ERR(dfs_rootdir) : -ENODEV;
+
+		pr_err("UBI error: cannot create \"ubi\" debugfs directory, error %d\n",
+		       err);
+		return err;
+	}
+
+#ifdef CONFIG_MTD_UBI_FAULT_INJECTION
+	dfs_create_fault_entry(dfs_rootdir);
+#endif
+
+	return 0;
+}
+
+/**
+ * ubi_debugfs_exit - remove UBI debugfs directory.
+ */
+void ubi_debugfs_exit(void)
+{
+	if (IS_ENABLED(CONFIG_DEBUG_FS))
+		debugfs_remove(dfs_rootdir);
+}
+
+/* Read an UBI debugfs file */
+static ssize_t dfs_file_read(struct file *file, char __user *user_buf,
+			     size_t count, loff_t *ppos)
+{
+	unsigned long ubi_num = (unsigned long)file->private_data;
+	struct dentry *dent = file->f_path.dentry;
+	struct ubi_device *ubi;
+	struct ubi_debug_info *d;
+	char buf[16];
+	int val;
+
+	ubi = ubi_get_device(ubi_num);
+	if (!ubi)
+		return -ENODEV;
+	d = &ubi->dbg;
+
+	if (dent == d->dfs_chk_gen)
+		val = d->chk_gen;
+	else if (dent == d->dfs_chk_io)
+		val = d->chk_io;
+	else if (dent == d->dfs_chk_fastmap)
+		val = d->chk_fastmap;
+	else if (dent == d->dfs_disable_bgt)
+		val = d->disable_bgt;
+	else if (dent == d->dfs_emulate_bitflips)
+		val = d->emulate_bitflips;
+	else if (dent == d->dfs_emulate_io_failures)
+		val = d->emulate_io_failures;
+	else if (dent == d->dfs_emulate_failures) {
+		snprintf(buf, sizeof(buf), "0x%04x\n", d->emulate_failures);
+		count = simple_read_from_buffer(user_buf, count, ppos,
+						buf, strlen(buf));
+		goto out;
+	} else if (dent == d->dfs_emulate_power_cut) {
+		snprintf(buf, sizeof(buf), "%u\n", d->emulate_power_cut);
+		count = simple_read_from_buffer(user_buf, count, ppos,
+						buf, strlen(buf));
+		goto out;
+	} else if (dent == d->dfs_power_cut_min) {
+		snprintf(buf, sizeof(buf), "%u\n", d->power_cut_min);
+		count = simple_read_from_buffer(user_buf, count, ppos,
+						buf, strlen(buf));
+		goto out;
+	} else if (dent == d->dfs_power_cut_max) {
+		snprintf(buf, sizeof(buf), "%u\n", d->power_cut_max);
+		count = simple_read_from_buffer(user_buf, count, ppos,
+						buf, strlen(buf));
+		goto out;
+	} else {
+		count = -EINVAL;
+		goto out;
+	}
+
+	if (val)
+		buf[0] = '1';
+	else
+		buf[0] = '0';
+	buf[1] = '\n';
+	buf[2] = 0x00;
+
+	count = simple_read_from_buffer(user_buf, count, ppos, buf, 2);
+
+out:
+	ubi_put_device(ubi);
+	return count;
+}
+
+/* Write an UBI debugfs file */
+static ssize_t dfs_file_write(struct file *file, const char __user *user_buf,
+			      size_t count, loff_t *ppos)
+{
+	unsigned long ubi_num = (unsigned long)file->private_data;
+	struct dentry *dent = file->f_path.dentry;
+	struct ubi_device *ubi;
+	struct ubi_debug_info *d;
+	size_t buf_size;
+	char buf[16] = {0};
+	int val;
+
+	ubi = ubi_get_device(ubi_num);
+	if (!ubi)
+		return -ENODEV;
+	d = &ubi->dbg;
+
+	buf_size = min_t(size_t, count, (sizeof(buf) - 1));
+	if (copy_from_user(buf, user_buf, buf_size)) {
+		count = -EFAULT;
+		goto out;
+	}
+
+	if (dent == d->dfs_emulate_failures) {
+		if (kstrtouint(buf, 0, &d->emulate_failures) != 0)
+			count = -EINVAL;
+		goto out;
+	} else if (dent == d->dfs_power_cut_min) {
+		if (kstrtouint(buf, 0, &d->power_cut_min) != 0)
+			count = -EINVAL;
+		goto out;
+	} else if (dent == d->dfs_power_cut_max) {
+		if (kstrtouint(buf, 0, &d->power_cut_max) != 0)
+			count = -EINVAL;
+		goto out;
+	} else if (dent == d->dfs_emulate_power_cut) {
+		if (kstrtoint(buf, 0, &val) != 0)
+			count = -EINVAL;
+		else
+			d->emulate_power_cut = val;
+		goto out;
+	}
+
+	if (buf[0] == '1')
+		val = 1;
+	else if (buf[0] == '0')
+		val = 0;
+	else {
+		count = -EINVAL;
+		goto out;
+	}
+
+	if (dent == d->dfs_chk_gen)
+		d->chk_gen = val;
+	else if (dent == d->dfs_chk_io)
+		d->chk_io = val;
+	else if (dent == d->dfs_chk_fastmap)
+		d->chk_fastmap = val;
+	else if (dent == d->dfs_disable_bgt)
+		d->disable_bgt = val;
+	else if (dent == d->dfs_emulate_bitflips)
+		d->emulate_bitflips = val;
+	else if (dent == d->dfs_emulate_io_failures)
+		d->emulate_io_failures = val;
+	else
+		count = -EINVAL;
+
+out:
+	ubi_put_device(ubi);
+	return count;
+}
+
+/* File operations for all UBI debugfs files except
+ * detailed_erase_block_info
+ */
+static const struct file_operations dfs_fops = {
+	.read   = dfs_file_read,
+	.write  = dfs_file_write,
+	.open	= simple_open,
+	.owner  = THIS_MODULE,
+};
+
+/* As long as the position is less then that total number of erase blocks,
+ * we still have more to print.
+ */
+static void *eraseblk_count_seq_start(struct seq_file *s, loff_t *pos)
+{
+	struct ubi_device *ubi = s->private;
+
+	if (*pos < ubi->peb_count)
+		return pos;
+
+	return NULL;
+}
+
+/* Since we are using the position as the iterator, we just need to check if we
+ * are done and increment the position.
+ */
+static void *eraseblk_count_seq_next(struct seq_file *s, void *v, loff_t *pos)
+{
+	struct ubi_device *ubi = s->private;
+
+	(*pos)++;
+
+	if (*pos < ubi->peb_count)
+		return pos;
+
+	return NULL;
+}
+
+static void eraseblk_count_seq_stop(struct seq_file *s, void *v)
+{
+}
+
+static int eraseblk_count_seq_show(struct seq_file *s, void *iter)
+{
+	struct ubi_device *ubi = s->private;
+	struct ubi_wl_entry *wl;
+	int *block_number = iter;
+	int erase_count = -1;
+	int err;
+
+	/* If this is the start, print a header */
+	if (*block_number == 0)
+		seq_puts(s, "physical_block_number\terase_count\n");
+
+	err = ubi_io_is_bad(ubi, *block_number);
+	if (err)
+		return err;
+
+	spin_lock(&ubi->wl_lock);
+
+	wl = ubi->lookuptbl[*block_number];
+	if (wl)
+		erase_count = wl->ec;
+
+	spin_unlock(&ubi->wl_lock);
+
+	if (erase_count < 0)
+		return 0;
+
+	seq_printf(s, "%-22d\t%-11d\n", *block_number, erase_count);
+
+	return 0;
+}
+
+static const struct seq_operations eraseblk_count_seq_ops = {
+	.start = eraseblk_count_seq_start,
+	.next = eraseblk_count_seq_next,
+	.stop = eraseblk_count_seq_stop,
+	.show = eraseblk_count_seq_show
+};
+
+static int eraseblk_count_open(struct inode *inode, struct file *f)
+{
+	struct seq_file *s;
+	int err;
+
+	err = seq_open(f, &eraseblk_count_seq_ops);
+	if (err)
+		return err;
+
+	s = f->private_data;
+	s->private = ubi_get_device((unsigned long)inode->i_private);
+
+	if (!s->private)
+		return -ENODEV;
+	else
+		return 0;
+}
+
+static int eraseblk_count_release(struct inode *inode, struct file *f)
+{
+	struct seq_file *s = f->private_data;
+	struct ubi_device *ubi = s->private;
+
+	ubi_put_device(ubi);
+
+	return seq_release(inode, f);
+}
+
+static const struct file_operations eraseblk_count_fops = {
+	.owner = THIS_MODULE,
+	.open = eraseblk_count_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = eraseblk_count_release,
+};
+
+/**
+ * ubi_debugfs_init_dev - initialize debugfs for an UBI device.
+ * @ubi: UBI device description object
+ *
+ * This function creates all debugfs files for UBI device @ubi. Returns zero in
+ * case of success and a negative error code in case of failure.
+ */
+int ubi_debugfs_init_dev(struct ubi_device *ubi)
+{
+	unsigned long ubi_num = ubi->ubi_num;
+	struct ubi_debug_info *d = &ubi->dbg;
+	umode_t mode = S_IRUSR | S_IWUSR;
+	int n;
+
+	if (!IS_ENABLED(CONFIG_DEBUG_FS))
+		return 0;
+
+	n = snprintf(d->dfs_dir_name, UBI_DFS_DIR_LEN, UBI_DFS_DIR_NAME,
+		     ubi->ubi_num);
+	if (n >= UBI_DFS_DIR_LEN) {
+		/* The array size is too small */
+		return -EINVAL;
+	}
+
+	d->dfs_dir = debugfs_create_dir(d->dfs_dir_name, dfs_rootdir);
+
+	d->dfs_chk_gen = debugfs_create_file("chk_gen", mode, d->dfs_dir,
+					     (void *)ubi_num, &dfs_fops);
+
+	d->dfs_chk_io = debugfs_create_file("chk_io", mode, d->dfs_dir,
+					    (void *)ubi_num, &dfs_fops);
+
+	d->dfs_chk_fastmap = debugfs_create_file("chk_fastmap", mode,
+						 d->dfs_dir, (void *)ubi_num,
+						 &dfs_fops);
+
+	d->dfs_disable_bgt = debugfs_create_file("tst_disable_bgt", mode,
+						 d->dfs_dir, (void *)ubi_num,
+						 &dfs_fops);
+
+	d->dfs_emulate_bitflips = debugfs_create_file("tst_emulate_bitflips",
+						      mode, d->dfs_dir,
+						      (void *)ubi_num,
+						      &dfs_fops);
+
+	d->dfs_emulate_io_failures = debugfs_create_file("tst_emulate_io_failures",
+							 mode, d->dfs_dir,
+							 (void *)ubi_num,
+							 &dfs_fops);
+
+	d->dfs_emulate_power_cut = debugfs_create_file("tst_emulate_power_cut",
+						       mode, d->dfs_dir,
+						       (void *)ubi_num,
+						       &dfs_fops);
+
+	d->dfs_power_cut_min = debugfs_create_file("tst_emulate_power_cut_min",
+						   mode, d->dfs_dir,
+						   (void *)ubi_num, &dfs_fops);
+
+	d->dfs_power_cut_max = debugfs_create_file("tst_emulate_power_cut_max",
+						   mode, d->dfs_dir,
+						   (void *)ubi_num, &dfs_fops);
+
+	debugfs_create_file("detailed_erase_block_info", S_IRUSR, d->dfs_dir,
+			    (void *)ubi_num, &eraseblk_count_fops);
+
+#ifdef CONFIG_MTD_UBI_FAULT_INJECTION
+	d->dfs_emulate_failures = debugfs_create_file("emulate_failures",
+						       mode, d->dfs_dir,
+						       (void *)ubi_num,
+						       &dfs_fops);
+#endif
+	return 0;
+}
+
+/**
+ * ubi_debugfs_exit_dev - free all debugfs files corresponding to device @ubi
+ * @ubi: UBI device description object
+ */
+void ubi_debugfs_exit_dev(struct ubi_device *ubi)
+{
+	if (IS_ENABLED(CONFIG_DEBUG_FS))
+		debugfs_remove_recursive(ubi->dbg.dfs_dir);
+}
+
+/**
+ * ubi_dbg_power_cut - emulate a power cut if it is time to do so
+ * @ubi: UBI device description object
+ * @caller: Flags set to indicate from where the function is being called
+ *
+ * Returns non-zero if a power cut was emulated, zero if not.
+ */
+int ubi_dbg_power_cut(struct ubi_device *ubi, int caller)
+{
+	unsigned int range;
+
+	if ((ubi->dbg.emulate_power_cut & caller) == 0)
+		return 0;
+
+	if (ubi->dbg.power_cut_counter == 0) {
+		ubi->dbg.power_cut_counter = ubi->dbg.power_cut_min;
+
+		if (ubi->dbg.power_cut_max > ubi->dbg.power_cut_min) {
+			range = ubi->dbg.power_cut_max - ubi->dbg.power_cut_min;
+			ubi->dbg.power_cut_counter += get_random_u32_below(range);
+		}
+		return 0;
+	}
+
+	ubi->dbg.power_cut_counter--;
+	if (ubi->dbg.power_cut_counter)
+		return 0;
+
+	return 1;
+}