linux/drivers/nvdimm/bus.c
Dan Williams 4d88a97aa9 libnvdimm, nvdimm: dimm driver and base libnvdimm device-driver infrastructure
* Implement the device-model infrastructure for loading modules and
  attaching drivers to nvdimm devices.  This is a simple association of a
  nd-device-type number with a driver that has a bitmask of supported
  device types.  To facilitate userspace bind/unbind operations 'modalias'
  and 'devtype', that also appear in the uevent, are added as generic
  sysfs attributes for all nvdimm devices.  The reason for the device-type
  number is to support sub-types within a given parent devtype, be it a
  vendor-specific sub-type or otherwise.

* The first consumer of this infrastructure is the driver
  for dimm devices.  It simply uses control messages to retrieve and
  store the configuration-data image (label set) from each dimm.

Note: nd_device_register() arranges for asynchronous registration of
      nvdimm bus devices by default.

Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Neil Brown <neilb@suse.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Tested-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-06-24 21:24:10 -04:00

578 lines
13 KiB
C

/*
* 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/sched.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/io.h>
#include <linux/mm.h>
#include <linux/nd.h>
#include "nd-core.h"
#include "nd.h"
int nvdimm_major;
static int nvdimm_bus_major;
static struct class *nd_class;
static int to_nd_device_type(struct device *dev)
{
if (is_nvdimm(dev))
return ND_DEVICE_DIMM;
return 0;
}
static int nvdimm_bus_uevent(struct device *dev, struct kobj_uevent_env *env)
{
return add_uevent_var(env, "MODALIAS=" ND_DEVICE_MODALIAS_FMT,
to_nd_device_type(dev));
}
static int nvdimm_bus_match(struct device *dev, struct device_driver *drv)
{
struct nd_device_driver *nd_drv = to_nd_device_driver(drv);
return test_bit(to_nd_device_type(dev), &nd_drv->type);
}
static int nvdimm_bus_probe(struct device *dev)
{
struct nd_device_driver *nd_drv = to_nd_device_driver(dev->driver);
struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
int rc;
rc = nd_drv->probe(dev);
dev_dbg(&nvdimm_bus->dev, "%s.probe(%s) = %d\n", dev->driver->name,
dev_name(dev), rc);
return rc;
}
static int nvdimm_bus_remove(struct device *dev)
{
struct nd_device_driver *nd_drv = to_nd_device_driver(dev->driver);
struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
int rc;
rc = nd_drv->remove(dev);
dev_dbg(&nvdimm_bus->dev, "%s.remove(%s) = %d\n", dev->driver->name,
dev_name(dev), rc);
return rc;
}
static struct bus_type nvdimm_bus_type = {
.name = "nd",
.uevent = nvdimm_bus_uevent,
.match = nvdimm_bus_match,
.probe = nvdimm_bus_probe,
.remove = nvdimm_bus_remove,
};
static ASYNC_DOMAIN_EXCLUSIVE(nd_async_domain);
void nd_synchronize(void)
{
async_synchronize_full_domain(&nd_async_domain);
}
EXPORT_SYMBOL_GPL(nd_synchronize);
static void nd_async_device_register(void *d, async_cookie_t cookie)
{
struct device *dev = d;
if (device_add(dev) != 0) {
dev_err(dev, "%s: failed\n", __func__);
put_device(dev);
}
put_device(dev);
}
static void nd_async_device_unregister(void *d, async_cookie_t cookie)
{
struct device *dev = d;
device_unregister(dev);
put_device(dev);
}
void nd_device_register(struct device *dev)
{
dev->bus = &nvdimm_bus_type;
device_initialize(dev);
get_device(dev);
async_schedule_domain(nd_async_device_register, dev,
&nd_async_domain);
}
EXPORT_SYMBOL(nd_device_register);
void nd_device_unregister(struct device *dev, enum nd_async_mode mode)
{
switch (mode) {
case ND_ASYNC:
get_device(dev);
async_schedule_domain(nd_async_device_unregister, dev,
&nd_async_domain);
break;
case ND_SYNC:
nd_synchronize();
device_unregister(dev);
break;
}
}
EXPORT_SYMBOL(nd_device_unregister);
/**
* __nd_driver_register() - register a region or a namespace driver
* @nd_drv: driver to register
* @owner: automatically set by nd_driver_register() macro
* @mod_name: automatically set by nd_driver_register() macro
*/
int __nd_driver_register(struct nd_device_driver *nd_drv, struct module *owner,
const char *mod_name)
{
struct device_driver *drv = &nd_drv->drv;
if (!nd_drv->type) {
pr_debug("driver type bitmask not set (%pf)\n",
__builtin_return_address(0));
return -EINVAL;
}
if (!nd_drv->probe || !nd_drv->remove) {
pr_debug("->probe() and ->remove() must be specified\n");
return -EINVAL;
}
drv->bus = &nvdimm_bus_type;
drv->owner = owner;
drv->mod_name = mod_name;
return driver_register(drv);
}
EXPORT_SYMBOL(__nd_driver_register);
static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
return sprintf(buf, ND_DEVICE_MODALIAS_FMT "\n",
to_nd_device_type(dev));
}
static DEVICE_ATTR_RO(modalias);
static ssize_t devtype_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
return sprintf(buf, "%s\n", dev->type->name);
}
static DEVICE_ATTR_RO(devtype);
static struct attribute *nd_device_attributes[] = {
&dev_attr_modalias.attr,
&dev_attr_devtype.attr,
NULL,
};
/**
* nd_device_attribute_group - generic attributes for all devices on an nd bus
*/
struct attribute_group nd_device_attribute_group = {
.attrs = nd_device_attributes,
};
EXPORT_SYMBOL_GPL(nd_device_attribute_group);
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 nvdimm_bus_exit(void)
{
class_destroy(nd_class);
unregister_chrdev(nvdimm_bus_major, "ndctl");
unregister_chrdev(nvdimm_major, "dimmctl");
bus_unregister(&nvdimm_bus_type);
}