drivers/nvdimm/bus.c - kernel/msm-5.4 - Gitiles

 /*
  * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of version 2 of the GNU General Public License as
  * published by the Free Software Foundation.
  *
  * This program is distributed in the hope that it will be useful, but
  * WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * General Public License for more details.
  */
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 #include <linux/vmalloc.h>
 #include <linux/uaccess.h>
 #include <linux/fcntl.h>
 #include <linux/async.h>
 #include <linux/ndctl.h>
 #include <linux/slab.h>
 #include <linux/fs.h>
 #include <linux/io.h>
 #include <linux/mm.h>
 #include "nd-core.h"

 int nvdimm_major;
 static int nvdimm_bus_major;
 static struct class *nd_class;

 struct bus_type nvdimm_bus_type = {
 	.name = "nd",
 };

 int nvdimm_bus_create_ndctl(struct nvdimm_bus *nvdimm_bus)
 {
 	dev_t devt = MKDEV(nvdimm_bus_major, nvdimm_bus->id);
 	struct device *dev;

 	dev = device_create(nd_class, &nvdimm_bus->dev, devt, nvdimm_bus,
 			"ndctl%d", nvdimm_bus->id);

 	if (IS_ERR(dev)) {
 		dev_dbg(&nvdimm_bus->dev, "failed to register ndctl%d: %ld\n",
 				nvdimm_bus->id, PTR_ERR(dev));
 		return PTR_ERR(dev);
 	}
 	return 0;
 }

 void nvdimm_bus_destroy_ndctl(struct nvdimm_bus *nvdimm_bus)
 {
 	device_destroy(nd_class, MKDEV(nvdimm_bus_major, nvdimm_bus->id));
 }

 static const struct nd_cmd_desc __nd_cmd_dimm_descs[] = {
 	[ND_CMD_IMPLEMENTED] = { },
 	[ND_CMD_SMART] = {
 		.out_num = 2,
 		.out_sizes = { 4, 8, },
 	},
 	[ND_CMD_SMART_THRESHOLD] = {
 		.out_num = 2,
 		.out_sizes = { 4, 8, },
 	},
 	[ND_CMD_DIMM_FLAGS] = {
 		.out_num = 2,
 		.out_sizes = { 4, 4 },
 	},
 	[ND_CMD_GET_CONFIG_SIZE] = {
 		.out_num = 3,
 		.out_sizes = { 4, 4, 4, },
 	},
 	[ND_CMD_GET_CONFIG_DATA] = {
 		.in_num = 2,
 		.in_sizes = { 4, 4, },
 		.out_num = 2,
 		.out_sizes = { 4, UINT_MAX, },
 	},
 	[ND_CMD_SET_CONFIG_DATA] = {
 		.in_num = 3,
 		.in_sizes = { 4, 4, UINT_MAX, },
 		.out_num = 1,
 		.out_sizes = { 4, },
 	},
 	[ND_CMD_VENDOR] = {
 		.in_num = 3,
 		.in_sizes = { 4, 4, UINT_MAX, },
 		.out_num = 3,
 		.out_sizes = { 4, 4, UINT_MAX, },
 	},
 };

 const struct nd_cmd_desc *nd_cmd_dimm_desc(int cmd)
 {
 	if (cmd < ARRAY_SIZE(__nd_cmd_dimm_descs))
 		return &__nd_cmd_dimm_descs[cmd];
 	return NULL;
 }
 EXPORT_SYMBOL_GPL(nd_cmd_dimm_desc);

 static const struct nd_cmd_desc __nd_cmd_bus_descs[] = {
 	[ND_CMD_IMPLEMENTED] = { },
 	[ND_CMD_ARS_CAP] = {
 		.in_num = 2,
 		.in_sizes = { 8, 8, },
 		.out_num = 2,
 		.out_sizes = { 4, 4, },
 	},
 	[ND_CMD_ARS_START] = {
 		.in_num = 4,
 		.in_sizes = { 8, 8, 2, 6, },
 		.out_num = 1,
 		.out_sizes = { 4, },
 	},
 	[ND_CMD_ARS_STATUS] = {
 		.out_num = 2,
 		.out_sizes = { 4, UINT_MAX, },
 	},
 };

 const struct nd_cmd_desc *nd_cmd_bus_desc(int cmd)
 {
 	if (cmd < ARRAY_SIZE(__nd_cmd_bus_descs))
 		return &__nd_cmd_bus_descs[cmd];
 	return NULL;
 }
 EXPORT_SYMBOL_GPL(nd_cmd_bus_desc);

 u32 nd_cmd_in_size(struct nvdimm *nvdimm, int cmd,
 		const struct nd_cmd_desc *desc, int idx, void *buf)
 {
 	if (idx >= desc->in_num)
 		return UINT_MAX;

 	if (desc->in_sizes[idx] < UINT_MAX)
 		return desc->in_sizes[idx];

 	if (nvdimm && cmd == ND_CMD_SET_CONFIG_DATA && idx == 2) {
 		struct nd_cmd_set_config_hdr *hdr = buf;

 		return hdr->in_length;
 	} else if (nvdimm && cmd == ND_CMD_VENDOR && idx == 2) {
 		struct nd_cmd_vendor_hdr *hdr = buf;

 		return hdr->in_length;
 	}

 	return UINT_MAX;
 }
 EXPORT_SYMBOL_GPL(nd_cmd_in_size);

 u32 nd_cmd_out_size(struct nvdimm *nvdimm, int cmd,
 		const struct nd_cmd_desc *desc, int idx, const u32 *in_field,
 		const u32 *out_field)
 {
 	if (idx >= desc->out_num)
 		return UINT_MAX;

 	if (desc->out_sizes[idx] < UINT_MAX)
 		return desc->out_sizes[idx];

 	if (nvdimm && cmd == ND_CMD_GET_CONFIG_DATA && idx == 1)
 		return in_field[1];
 	else if (nvdimm && cmd == ND_CMD_VENDOR && idx == 2)
 		return out_field[1];
 	else if (!nvdimm && cmd == ND_CMD_ARS_STATUS && idx == 1)
 		return ND_CMD_ARS_STATUS_MAX;

 	return UINT_MAX;
 }
 EXPORT_SYMBOL_GPL(nd_cmd_out_size);

 static int __nd_ioctl(struct nvdimm_bus *nvdimm_bus, struct nvdimm *nvdimm,
 		int read_only, unsigned int ioctl_cmd, unsigned long arg)
 {
 	struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
 	size_t buf_len = 0, in_len = 0, out_len = 0;
 	static char out_env[ND_CMD_MAX_ENVELOPE];
 	static char in_env[ND_CMD_MAX_ENVELOPE];
 	const struct nd_cmd_desc *desc = NULL;
 	unsigned int cmd = _IOC_NR(ioctl_cmd);
 	void __user *p = (void __user *) arg;
 	struct device *dev = &nvdimm_bus->dev;
 	const char *cmd_name, *dimm_name;
 	unsigned long dsm_mask;
 	void *buf;
 	int rc, i;

 	if (nvdimm) {
 		desc = nd_cmd_dimm_desc(cmd);
 		cmd_name = nvdimm_cmd_name(cmd);
 		dsm_mask = nvdimm->dsm_mask ? *(nvdimm->dsm_mask) : 0;
 		dimm_name = dev_name(&nvdimm->dev);
 	} else {
 		desc = nd_cmd_bus_desc(cmd);
 		cmd_name = nvdimm_bus_cmd_name(cmd);
 		dsm_mask = nd_desc->dsm_mask;
 		dimm_name = "bus";
 	}

 	if (!desc || (desc->out_num + desc->in_num == 0) ||
 			!test_bit(cmd, &dsm_mask))
 		return -ENOTTY;

 	/* fail write commands (when read-only) */
 	if (read_only)
 		switch (ioctl_cmd) {
 		case ND_IOCTL_VENDOR:
 		case ND_IOCTL_SET_CONFIG_DATA:
 		case ND_IOCTL_ARS_START:
 			dev_dbg(&nvdimm_bus->dev, "'%s' command while read-only.\n",
 					nvdimm ? nvdimm_cmd_name(cmd)
 					: nvdimm_bus_cmd_name(cmd));
 			return -EPERM;
 		default:
 			break;
 		}

 	/* process an input envelope */
 	for (i = 0; i < desc->in_num; i++) {
 		u32 in_size, copy;

 		in_size = nd_cmd_in_size(nvdimm, cmd, desc, i, in_env);
 		if (in_size == UINT_MAX) {
 			dev_err(dev, "%s:%s unknown input size cmd: %s field: %d\n",
 					__func__, dimm_name, cmd_name, i);
 			return -ENXIO;
 		}
 		if (!access_ok(VERIFY_READ, p + in_len, in_size))
 			return -EFAULT;
 		if (in_len < sizeof(in_env))
 			copy = min_t(u32, sizeof(in_env) - in_len, in_size);
 		else
 			copy = 0;
 		if (copy && copy_from_user(&in_env[in_len], p + in_len, copy))
 			return -EFAULT;
 		in_len += in_size;
 	}

 	/* process an output envelope */
 	for (i = 0; i < desc->out_num; i++) {
 		u32 out_size = nd_cmd_out_size(nvdimm, cmd, desc, i,
 				(u32 *) in_env, (u32 *) out_env);
 		u32 copy;

 		if (out_size == UINT_MAX) {
 			dev_dbg(dev, "%s:%s unknown output size cmd: %s field: %d\n",
 					__func__, dimm_name, cmd_name, i);
 			return -EFAULT;
 		}
 		if (!access_ok(VERIFY_WRITE, p + in_len + out_len, out_size))
 			return -EFAULT;
 		if (out_len < sizeof(out_env))
 			copy = min_t(u32, sizeof(out_env) - out_len, out_size);
 		else
 			copy = 0;
 		if (copy && copy_from_user(&out_env[out_len],
 					p + in_len + out_len, copy))
 			return -EFAULT;
 		out_len += out_size;
 	}

 	buf_len = out_len + in_len;
 	if (!access_ok(VERIFY_WRITE, p, sizeof(buf_len)))
 		return -EFAULT;

 	if (buf_len > ND_IOCTL_MAX_BUFLEN) {
 		dev_dbg(dev, "%s:%s cmd: %s buf_len: %zu > %d\n", __func__,
 				dimm_name, cmd_name, buf_len,
 				ND_IOCTL_MAX_BUFLEN);
 		return -EINVAL;
 	}

 	buf = vmalloc(buf_len);
 	if (!buf)
 		return -ENOMEM;

 	if (copy_from_user(buf, p, buf_len)) {
 		rc = -EFAULT;
 		goto out;
 	}

 	rc = nd_desc->ndctl(nd_desc, nvdimm, cmd, buf, buf_len);
 	if (rc < 0)
 		goto out;
 	if (copy_to_user(p, buf, buf_len))
 		rc = -EFAULT;
  out:
 	vfree(buf);
 	return rc;
 }

 static long nd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
 	long id = (long) file->private_data;
 	int rc = -ENXIO, read_only;
 	struct nvdimm_bus *nvdimm_bus;

 	read_only = (O_RDWR != (file->f_flags & O_ACCMODE));
 	mutex_lock(&nvdimm_bus_list_mutex);
 	list_for_each_entry(nvdimm_bus, &nvdimm_bus_list, list) {
 		if (nvdimm_bus->id == id) {
 			rc = __nd_ioctl(nvdimm_bus, NULL, read_only, cmd, arg);
 			break;
 		}
 	}
 	mutex_unlock(&nvdimm_bus_list_mutex);

 	return rc;
 }

 static int match_dimm(struct device *dev, void *data)
 {
 	long id = (long) data;

 	if (is_nvdimm(dev)) {
 		struct nvdimm *nvdimm = to_nvdimm(dev);

 		return nvdimm->id == id;
 	}

 	return 0;
 }

 static long nvdimm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
 	int rc = -ENXIO, read_only;
 	struct nvdimm_bus *nvdimm_bus;

 	read_only = (O_RDWR != (file->f_flags & O_ACCMODE));
 	mutex_lock(&nvdimm_bus_list_mutex);
 	list_for_each_entry(nvdimm_bus, &nvdimm_bus_list, list) {
 		struct device *dev = device_find_child(&nvdimm_bus->dev,
 				file->private_data, match_dimm);
 		struct nvdimm *nvdimm;

 		if (!dev)
 			continue;

 		nvdimm = to_nvdimm(dev);
 		rc = __nd_ioctl(nvdimm_bus, nvdimm, read_only, cmd, arg);
 		put_device(dev);
 		break;
 	}
 	mutex_unlock(&nvdimm_bus_list_mutex);

 	return rc;
 }

 static int nd_open(struct inode *inode, struct file *file)
 {
 	long minor = iminor(inode);

 	file->private_data = (void *) minor;
 	return 0;
 }

 static const struct file_operations nvdimm_bus_fops = {
 	.owner = THIS_MODULE,
 	.open = nd_open,
 	.unlocked_ioctl = nd_ioctl,
 	.compat_ioctl = nd_ioctl,
 	.llseek = noop_llseek,
 };

 static const struct file_operations nvdimm_fops = {
 	.owner = THIS_MODULE,
 	.open = nd_open,
 	.unlocked_ioctl = nvdimm_ioctl,
 	.compat_ioctl = nvdimm_ioctl,
 	.llseek = noop_llseek,
 };

 int __init nvdimm_bus_init(void)
 {
 	int rc;

 	rc = bus_register(&nvdimm_bus_type);
 	if (rc)
 		return rc;

 	rc = register_chrdev(0, "ndctl", &nvdimm_bus_fops);
 	if (rc < 0)
 		goto err_bus_chrdev;
 	nvdimm_bus_major = rc;

 	rc = register_chrdev(0, "dimmctl", &nvdimm_fops);
 	if (rc < 0)
 		goto err_dimm_chrdev;
 	nvdimm_major = rc;

 	nd_class = class_create(THIS_MODULE, "nd");
 	if (IS_ERR(nd_class))
 		goto err_class;

 	return 0;

  err_class:
 	unregister_chrdev(nvdimm_major, "dimmctl");
  err_dimm_chrdev:
 	unregister_chrdev(nvdimm_bus_major, "ndctl");
  err_bus_chrdev:
 	bus_unregister(&nvdimm_bus_type);

 	return rc;
 }

 void __exit nvdimm_bus_exit(void)
 {
 	class_destroy(nd_class);
 	unregister_chrdev(nvdimm_bus_major, "ndctl");
 	unregister_chrdev(nvdimm_major, "dimmctl");
 	bus_unregister(&nvdimm_bus_type);
 }
	/*
	* Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of version 2 of the GNU General Public License as
	* published by the Free Software Foundation.
	*
	* This program is distributed in the hope that it will be useful, but
	* WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* General Public License for more details.
	*/
	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
	#include <linux/vmalloc.h>
	#include <linux/uaccess.h>
	#include <linux/fcntl.h>
	#include <linux/async.h>
	#include <linux/ndctl.h>
	#include <linux/slab.h>
	#include <linux/fs.h>
	#include <linux/io.h>
	#include <linux/mm.h>
	#include "nd-core.h"

	int nvdimm_major;
	static int nvdimm_bus_major;
	static struct class *nd_class;

	struct bus_type nvdimm_bus_type = {
	.name = "nd",
	};

	int nvdimm_bus_create_ndctl(struct nvdimm_bus *nvdimm_bus)
	{
	dev_t devt = MKDEV(nvdimm_bus_major, nvdimm_bus->id);
	struct device *dev;

	dev = device_create(nd_class, &nvdimm_bus->dev, devt, nvdimm_bus,
	"ndctl%d", nvdimm_bus->id);

	if (IS_ERR(dev)) {
	dev_dbg(&nvdimm_bus->dev, "failed to register ndctl%d: %ld\n",
	nvdimm_bus->id, PTR_ERR(dev));
	return PTR_ERR(dev);
	}
	return 0;
	}

	void nvdimm_bus_destroy_ndctl(struct nvdimm_bus *nvdimm_bus)
	{
	device_destroy(nd_class, MKDEV(nvdimm_bus_major, nvdimm_bus->id));
	}

	static const struct nd_cmd_desc __nd_cmd_dimm_descs[] = {
	[ND_CMD_IMPLEMENTED] = { },
	[ND_CMD_SMART] = {
	.out_num = 2,
	.out_sizes = { 4, 8, },
	},
	[ND_CMD_SMART_THRESHOLD] = {
	.out_num = 2,
	.out_sizes = { 4, 8, },
	},
	[ND_CMD_DIMM_FLAGS] = {
	.out_num = 2,
	.out_sizes = { 4, 4 },
	},
	[ND_CMD_GET_CONFIG_SIZE] = {
	.out_num = 3,
	.out_sizes = { 4, 4, 4, },
	},
	[ND_CMD_GET_CONFIG_DATA] = {
	.in_num = 2,
	.in_sizes = { 4, 4, },
	.out_num = 2,
	.out_sizes = { 4, UINT_MAX, },
	},
	[ND_CMD_SET_CONFIG_DATA] = {
	.in_num = 3,
	.in_sizes = { 4, 4, UINT_MAX, },
	.out_num = 1,
	.out_sizes = { 4, },
	},
	[ND_CMD_VENDOR] = {
	.in_num = 3,
	.in_sizes = { 4, 4, UINT_MAX, },
	.out_num = 3,
	.out_sizes = { 4, 4, UINT_MAX, },
	},
	};

	const struct nd_cmd_desc *nd_cmd_dimm_desc(int cmd)
	{
	if (cmd < ARRAY_SIZE(__nd_cmd_dimm_descs))
	return &__nd_cmd_dimm_descs[cmd];
	return NULL;
	}
	EXPORT_SYMBOL_GPL(nd_cmd_dimm_desc);

	static const struct nd_cmd_desc __nd_cmd_bus_descs[] = {
	[ND_CMD_IMPLEMENTED] = { },
	[ND_CMD_ARS_CAP] = {
	.in_num = 2,
	.in_sizes = { 8, 8, },
	.out_num = 2,
	.out_sizes = { 4, 4, },
	},
	[ND_CMD_ARS_START] = {
	.in_num = 4,
	.in_sizes = { 8, 8, 2, 6, },
	.out_num = 1,
	.out_sizes = { 4, },
	},
	[ND_CMD_ARS_STATUS] = {
	.out_num = 2,
	.out_sizes = { 4, UINT_MAX, },
	},
	};

	const struct nd_cmd_desc *nd_cmd_bus_desc(int cmd)
	{
	if (cmd < ARRAY_SIZE(__nd_cmd_bus_descs))
	return &__nd_cmd_bus_descs[cmd];
	return NULL;
	}
	EXPORT_SYMBOL_GPL(nd_cmd_bus_desc);

	u32 nd_cmd_in_size(struct nvdimm *nvdimm, int cmd,
	const struct nd_cmd_desc desc, int idx, void buf)
	{
	if (idx >= desc->in_num)
	return UINT_MAX;

	if (desc->in_sizes[idx] < UINT_MAX)
	return desc->in_sizes[idx];

	if (nvdimm && cmd == ND_CMD_SET_CONFIG_DATA && idx == 2) {
	struct nd_cmd_set_config_hdr *hdr = buf;

	return hdr->in_length;
	} else if (nvdimm && cmd == ND_CMD_VENDOR && idx == 2) {
	struct nd_cmd_vendor_hdr *hdr = buf;

	return hdr->in_length;
	}

	return UINT_MAX;
	}
	EXPORT_SYMBOL_GPL(nd_cmd_in_size);

	u32 nd_cmd_out_size(struct nvdimm *nvdimm, int cmd,
	const struct nd_cmd_desc desc, int idx, const u32 in_field,
	const u32 *out_field)
	{
	if (idx >= desc->out_num)
	return UINT_MAX;

	if (desc->out_sizes[idx] < UINT_MAX)
	return desc->out_sizes[idx];

	if (nvdimm && cmd == ND_CMD_GET_CONFIG_DATA && idx == 1)
	return in_field[1];
	else if (nvdimm && cmd == ND_CMD_VENDOR && idx == 2)
	return out_field[1];
	else if (!nvdimm && cmd == ND_CMD_ARS_STATUS && idx == 1)
	return ND_CMD_ARS_STATUS_MAX;

	return UINT_MAX;
	}
	EXPORT_SYMBOL_GPL(nd_cmd_out_size);

	static int __nd_ioctl(struct nvdimm_bus nvdimm_bus, struct nvdimm nvdimm,
	int read_only, unsigned int ioctl_cmd, unsigned long arg)
	{
	struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
	size_t buf_len = 0, in_len = 0, out_len = 0;
	static char out_env[ND_CMD_MAX_ENVELOPE];
	static char in_env[ND_CMD_MAX_ENVELOPE];
	const struct nd_cmd_desc *desc = NULL;
	unsigned int cmd = _IOC_NR(ioctl_cmd);
	void __user p = (void __user ) arg;
	struct device *dev = &nvdimm_bus->dev;
	const char cmd_name, dimm_name;
	unsigned long dsm_mask;
	void *buf;
	int rc, i;

	if (nvdimm) {
	desc = nd_cmd_dimm_desc(cmd);
	cmd_name = nvdimm_cmd_name(cmd);
	dsm_mask = nvdimm->dsm_mask ? *(nvdimm->dsm_mask) : 0;
	dimm_name = dev_name(&nvdimm->dev);
	} else {
	desc = nd_cmd_bus_desc(cmd);
	cmd_name = nvdimm_bus_cmd_name(cmd);
	dsm_mask = nd_desc->dsm_mask;
	dimm_name = "bus";
	}

	if (!desc \|\| (desc->out_num + desc->in_num == 0) \|\|
	!test_bit(cmd, &dsm_mask))
	return -ENOTTY;

	/* fail write commands (when read-only) */
	if (read_only)
	switch (ioctl_cmd) {
	case ND_IOCTL_VENDOR:
	case ND_IOCTL_SET_CONFIG_DATA:
	case ND_IOCTL_ARS_START:
	dev_dbg(&nvdimm_bus->dev, "'%s' command while read-only.\n",
	nvdimm ? nvdimm_cmd_name(cmd)
	: nvdimm_bus_cmd_name(cmd));
	return -EPERM;
	default:
	break;
	}

	/* process an input envelope */
	for (i = 0; i < desc->in_num; i++) {
	u32 in_size, copy;

	in_size = nd_cmd_in_size(nvdimm, cmd, desc, i, in_env);
	if (in_size == UINT_MAX) {
	dev_err(dev, "%s:%s unknown input size cmd: %s field: %d\n",
	__func__, dimm_name, cmd_name, i);
	return -ENXIO;
	}
	if (!access_ok(VERIFY_READ, p + in_len, in_size))
	return -EFAULT;
	if (in_len < sizeof(in_env))
	copy = min_t(u32, sizeof(in_env) - in_len, in_size);
	else
	copy = 0;
	if (copy && copy_from_user(&in_env[in_len], p + in_len, copy))
	return -EFAULT;
	in_len += in_size;
	}

	/* process an output envelope */
	for (i = 0; i < desc->out_num; i++) {
	u32 out_size = nd_cmd_out_size(nvdimm, cmd, desc, i,
	(u32 ) in_env, (u32 ) out_env);
	u32 copy;

	if (out_size == UINT_MAX) {
	dev_dbg(dev, "%s:%s unknown output size cmd: %s field: %d\n",
	__func__, dimm_name, cmd_name, i);
	return -EFAULT;
	}
	if (!access_ok(VERIFY_WRITE, p + in_len + out_len, out_size))
	return -EFAULT;
	if (out_len < sizeof(out_env))
	copy = min_t(u32, sizeof(out_env) - out_len, out_size);
	else
	copy = 0;
	if (copy && copy_from_user(&out_env[out_len],
	p + in_len + out_len, copy))
	return -EFAULT;
	out_len += out_size;
	}

	buf_len = out_len + in_len;
	if (!access_ok(VERIFY_WRITE, p, sizeof(buf_len)))
	return -EFAULT;

	if (buf_len > ND_IOCTL_MAX_BUFLEN) {
	dev_dbg(dev, "%s:%s cmd: %s buf_len: %zu > %d\n", __func__,
	dimm_name, cmd_name, buf_len,
	ND_IOCTL_MAX_BUFLEN);
	return -EINVAL;
	}

	buf = vmalloc(buf_len);
	if (!buf)
	return -ENOMEM;

	if (copy_from_user(buf, p, buf_len)) {
	rc = -EFAULT;
	goto out;
	}

	rc = nd_desc->ndctl(nd_desc, nvdimm, cmd, buf, buf_len);
	if (rc < 0)
	goto out;
	if (copy_to_user(p, buf, buf_len))
	rc = -EFAULT;
	out:
	vfree(buf);
	return rc;
	}

	static long nd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
	{
	long id = (long) file->private_data;
	int rc = -ENXIO, read_only;
	struct nvdimm_bus *nvdimm_bus;

	read_only = (O_RDWR != (file->f_flags & O_ACCMODE));
	mutex_lock(&nvdimm_bus_list_mutex);
	list_for_each_entry(nvdimm_bus, &nvdimm_bus_list, list) {
	if (nvdimm_bus->id == id) {
	rc = __nd_ioctl(nvdimm_bus, NULL, read_only, cmd, arg);
	break;
	}
	}
	mutex_unlock(&nvdimm_bus_list_mutex);

	return rc;
	}

	static int match_dimm(struct device dev, void data)
	{
	long id = (long) data;

	if (is_nvdimm(dev)) {
	struct nvdimm *nvdimm = to_nvdimm(dev);

	return nvdimm->id == id;
	}

	return 0;
	}

	static long nvdimm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
	{
	int rc = -ENXIO, read_only;
	struct nvdimm_bus *nvdimm_bus;

	read_only = (O_RDWR != (file->f_flags & O_ACCMODE));
	mutex_lock(&nvdimm_bus_list_mutex);
	list_for_each_entry(nvdimm_bus, &nvdimm_bus_list, list) {
	struct device *dev = device_find_child(&nvdimm_bus->dev,
	file->private_data, match_dimm);
	struct nvdimm *nvdimm;

	if (!dev)
	continue;

	nvdimm = to_nvdimm(dev);
	rc = __nd_ioctl(nvdimm_bus, nvdimm, read_only, cmd, arg);
	put_device(dev);
	break;
	}
	mutex_unlock(&nvdimm_bus_list_mutex);

	return rc;
	}

	static int nd_open(struct inode inode, struct file file)
	{
	long minor = iminor(inode);

	file->private_data = (void *) minor;
	return 0;
	}

	static const struct file_operations nvdimm_bus_fops = {
	.owner = THIS_MODULE,
	.open = nd_open,
	.unlocked_ioctl = nd_ioctl,
	.compat_ioctl = nd_ioctl,
	.llseek = noop_llseek,
	};

	static const struct file_operations nvdimm_fops = {
	.owner = THIS_MODULE,
	.open = nd_open,
	.unlocked_ioctl = nvdimm_ioctl,
	.compat_ioctl = nvdimm_ioctl,
	.llseek = noop_llseek,
	};

	int __init nvdimm_bus_init(void)
	{
	int rc;

	rc = bus_register(&nvdimm_bus_type);
	if (rc)
	return rc;

	rc = register_chrdev(0, "ndctl", &nvdimm_bus_fops);
	if (rc < 0)
	goto err_bus_chrdev;
	nvdimm_bus_major = rc;

	rc = register_chrdev(0, "dimmctl", &nvdimm_fops);
	if (rc < 0)
	goto err_dimm_chrdev;
	nvdimm_major = rc;

	nd_class = class_create(THIS_MODULE, "nd");
	if (IS_ERR(nd_class))
	goto err_class;

	return 0;

	err_class:
	unregister_chrdev(nvdimm_major, "dimmctl");
	err_dimm_chrdev:
	unregister_chrdev(nvdimm_bus_major, "ndctl");
	err_bus_chrdev:
	bus_unregister(&nvdimm_bus_type);

	return rc;
	}

	void __exit nvdimm_bus_exit(void)
	{
	class_destroy(nd_class);
	unregister_chrdev(nvdimm_bus_major, "ndctl");
	unregister_chrdev(nvdimm_major, "dimmctl");
	bus_unregister(&nvdimm_bus_type);
	}