scsi_sysfs.c

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/*
 * scsi_sysfs.c
 *
 * SCSI sysfs interface routines.
 *
 * Created to pull SCSI mid layer sysfs routines into one file.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <linux/device.h>

#include <scsi/scsi.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_tcq.h>
#include <scsi/scsi_transport.h>
#include <scsi/scsi_driver.h>

#include "scsi_priv.h"
#include "scsi_logging.h"

static const struct {
	enum scsi_device_state	value;
	char			*name;
} sdev_states[] = {
	{ SDEV_CREATED, "created" },
	{ SDEV_RUNNING, "running" },
	{ SDEV_CANCEL, "cancel" },
	{ SDEV_DEL, "deleted" },
	{ SDEV_QUIESCE, "quiesce" },
	{ SDEV_OFFLINE,	"offline" },
	{ SDEV_BLOCK,	"blocked" },
};

const char *scsi_device_state_name(enum scsi_device_state state)
{
	int i;
	char *name = NULL;

	for (i = 0; i < ARRAY_SIZE(sdev_states); i++) {
		if (sdev_states[i].value == state) {
			name = sdev_states[i].name;
			break;
		}
	}
	return name;
}

static const struct {
	enum scsi_host_state	value;
	char			*name;
} shost_states[] = {
	{ SHOST_CREATED, "created" },
	{ SHOST_RUNNING, "running" },
	{ SHOST_CANCEL, "cancel" },
	{ SHOST_DEL, "deleted" },
	{ SHOST_RECOVERY, "recovery" },
	{ SHOST_CANCEL_RECOVERY, "cancel/recovery" },
	{ SHOST_DEL_RECOVERY, "deleted/recovery", },
};
const char *scsi_host_state_name(enum scsi_host_state state)
{
	int i;
	char *name = NULL;

	for (i = 0; i < ARRAY_SIZE(shost_states); i++) {
		if (shost_states[i].value == state) {
			name = shost_states[i].name;
			break;
		}
	}
	return name;
}

static int check_set(unsigned int *val, char *src)
{
	char *last;

	if (strncmp(src, "-", 20) == 0) {
		*val = SCAN_WILD_CARD;
	} else {
		/*
		 * Doesn't check for int overflow
		 */
		*val = simple_strtoul(src, &last, 0);
		if (*last != '\0')
			return 1;
	}
	return 0;
}

static int scsi_scan(struct Scsi_Host *shost, const char *str)
{
	char s1[15], s2[15], s3[15], junk;
	unsigned int channel, id, lun;
	int res;

	res = sscanf(str, "%10s %10s %10s %c", s1, s2, s3, &junk);
	if (res != 3)
		return -EINVAL;
	if (check_set(&channel, s1))
		return -EINVAL;
	if (check_set(&id, s2))
		return -EINVAL;
	if (check_set(&lun, s3))
		return -EINVAL;
	if (shost->transportt->user_scan)
		res = shost->transportt->user_scan(shost, channel, id, lun);
	else
		res = scsi_scan_host_selected(shost, channel, id, lun, 1);
	return res;
}

/*
 * shost_show_function: macro to create an attr function that can be used to
 * show a non-bit field.
 */
#define shost_show_function(name, field, format_string)			\
static ssize_t								\
show_##name (struct class_device *class_dev, char *buf)			\
{									\
	struct Scsi_Host *shost = class_to_shost(class_dev);		\
	return snprintf (buf, 20, format_string, shost->field);		\
}

/*
 * shost_rd_attr: macro to create a function and attribute variable for a
 * read only field.
 */
#define shost_rd_attr2(name, field, format_string)			\
	shost_show_function(name, field, format_string)			\
static CLASS_DEVICE_ATTR(name, S_IRUGO, show_##name, NULL);

#define shost_rd_attr(field, format_string) \
shost_rd_attr2(field, field, format_string)

/*
 * Create the actual show/store functions and data structures.
 */

static ssize_t store_scan(struct class_device *class_dev, const char *buf,
			  size_t count)
{
	struct Scsi_Host *shost = class_to_shost(class_dev);
	int res;

	res = scsi_scan(shost, buf);
	if (res == 0)
		res = count;
	return res;
};
static CLASS_DEVICE_ATTR(scan, S_IWUSR, NULL, store_scan);

static ssize_t
store_shost_state(struct class_device *class_dev, const char *buf, size_t count)
{
	int i;
	struct Scsi_Host *shost = class_to_shost(class_dev);
	enum scsi_host_state state = 0;

	for (i = 0; i < ARRAY_SIZE(shost_states); i++) {
		const int len = strlen(shost_states[i].name);
		if (strncmp(shost_states[i].name, buf, len) == 0 &&
		   buf[len] == '\n') {
			state = shost_states[i].value;
			break;
		}
	}
	if (!state)
		return -EINVAL;

	if (scsi_host_set_state(shost, state))
		return -EINVAL;
	return count;
}

static ssize_t
show_shost_state(struct class_device *class_dev, char *buf)
{
	struct Scsi_Host *shost = class_to_shost(class_dev);
	const char *name = scsi_host_state_name(shost->shost_state);

	if (!name)
		return -EINVAL;

	return snprintf(buf, 20, "%s\n", name);
}

static CLASS_DEVICE_ATTR(state, S_IRUGO | S_IWUSR, show_shost_state, store_shost_state);

static ssize_t
show_shost_mode(unsigned int mode, char *buf)
{
	ssize_t len = 0;

	if (mode & MODE_INITIATOR)
		len = sprintf(buf, "%s", "Initiator");

	if (mode & MODE_TARGET)
		len += sprintf(buf + len, "%s%s", len ? ", " : "", "Target");

	len += sprintf(buf + len, "\n");

	return len;
}

static ssize_t show_shost_supported_mode(struct class_device *class_dev, char *buf)
{
	struct Scsi_Host *shost = class_to_shost(class_dev);
	unsigned int supported_mode = shost->hostt->supported_mode;

	if (supported_mode == MODE_UNKNOWN)
		/* by default this should be initiator */
		supported_mode = MODE_INITIATOR;

	return show_shost_mode(supported_mode, buf);
}

static CLASS_DEVICE_ATTR(supported_mode, S_IRUGO | S_IWUSR, show_shost_supported_mode, NULL);

static ssize_t show_shost_active_mode(struct class_device *class_dev, char *buf)
{
	struct Scsi_Host *shost = class_to_shost(class_dev);

	if (shost->active_mode == MODE_UNKNOWN)
		return snprintf(buf, 20, "unknown\n");
	else
		return show_shost_mode(shost->active_mode, buf);
}

static CLASS_DEVICE_ATTR(active_mode, S_IRUGO | S_IWUSR, show_shost_active_mode, NULL);

shost_rd_attr(unique_id, "%u\n");
shost_rd_attr(host_busy, "%hu\n");
shost_rd_attr(cmd_per_lun, "%hd\n");
shost_rd_attr(can_queue, "%hd\n");
shost_rd_attr(sg_tablesize, "%hu\n");
shost_rd_attr(unchecked_isa_dma, "%d\n");
shost_rd_attr2(proc_name, hostt->proc_name, "%s\n");

static struct class_device_attribute *scsi_sysfs_shost_attrs[] = {
	&class_device_attr_unique_id,
	&class_device_attr_host_busy,
	&class_device_attr_cmd_per_lun,
	&class_device_attr_can_queue,
	&class_device_attr_sg_tablesize,
	&class_device_attr_unchecked_isa_dma,
	&class_device_attr_proc_name,
	&class_device_attr_scan,
	&class_device_attr_state,
	&class_device_attr_supported_mode,
	&class_device_attr_active_mode,
	NULL
};

static void scsi_device_cls_release(struct class_device *class_dev)
{
	struct scsi_device *sdev;

	sdev = class_to_sdev(class_dev);
	put_device(&sdev->sdev_gendev);
}

static void scsi_device_dev_release_usercontext(struct work_struct *work)
{
	struct scsi_device *sdev;
	struct device *parent;
	struct scsi_target *starget;
	struct list_head *this, *tmp;
	unsigned long flags;

	sdev = container_of(work, struct scsi_device, ew.work);

	parent = sdev->sdev_gendev.parent;
	starget = to_scsi_target(parent);

	spin_lock_irqsave(sdev->host->host_lock, flags);
	starget->reap_ref++;
	list_del(&sdev->siblings);
	list_del(&sdev->same_target_siblings);
	list_del(&sdev->starved_entry);
	spin_unlock_irqrestore(sdev->host->host_lock, flags);

	cancel_work_sync(&sdev->event_work);

	list_for_each_safe(this, tmp, &sdev->event_list) {
		struct scsi_event *evt;

		evt = list_entry(this, struct scsi_event, node);
		list_del(&evt->node);
		kfree(evt);
	}

	if (sdev->request_queue) {
		sdev->request_queue->queuedata = NULL;
		/* user context needed to free queue */
		scsi_free_queue(sdev->request_queue);
		/* temporary expedient, try to catch use of queue lock
		 * after free of sdev */
		sdev->request_queue = NULL;
	}

	scsi_target_reap(scsi_target(sdev));

	kfree(sdev->inquiry);
	kfree(sdev);

	if (parent)
		put_device(parent);
}

static void scsi_device_dev_release(struct device *dev)
{
	struct scsi_device *sdp = to_scsi_device(dev);
	execute_in_process_context(scsi_device_dev_release_usercontext,
				   &sdp->ew);
}

static struct class sdev_class = {
	.name		= "scsi_device",
	.release	= scsi_device_cls_release,
};

/* all probing is done in the individual ->probe routines */
static int scsi_bus_match(struct device *dev, struct device_driver *gendrv)
{
	struct scsi_device *sdp = to_scsi_device(dev);
	if (sdp->no_uld_attach)
		return 0;
	return (sdp->inq_periph_qual == SCSI_INQ_PQ_CON)? 1: 0;
}

static int scsi_bus_uevent(struct device *dev, struct kobj_uevent_env *env)
{
	struct scsi_device *sdev = to_scsi_device(dev);

	add_uevent_var(env, "MODALIAS=" SCSI_DEVICE_MODALIAS_FMT, sdev->type);
	return 0;
}

static int scsi_bus_suspend(struct device * dev, pm_message_t state)
{
	struct device_driver *drv = dev->driver;
	struct scsi_device *sdev = to_scsi_device(dev);
	int err;

	err = scsi_device_quiesce(sdev);
	if (err)
		return err;

	if (drv && drv->suspend) {
		err = drv->suspend(dev, state);
		if (err)
			return err;
	}

	return 0;
}

static int scsi_bus_resume(struct device * dev)
{
	struct device_driver *drv = dev->driver;
	struct scsi_device *sdev = to_scsi_device(dev);
	int err = 0;

	if (drv && drv->resume)
		err = drv->resume(dev);

	scsi_device_resume(sdev);

	return err;
}

static int scsi_bus_remove(struct device *dev)
{
	struct device_driver *drv = dev->driver;
	struct scsi_device *sdev = to_scsi_device(dev);
	int err = 0;

	/* reset the prep_fn back to the default since the
	 * driver may have altered it and it's being removed */
	blk_queue_prep_rq(sdev->request_queue, scsi_prep_fn);

	if (drv && drv->remove)
		err = drv->remove(dev);

	return 0;
}

struct bus_type scsi_bus_type = {
        .name		= "scsi",
        .match		= scsi_bus_match,
	.uevent		= scsi_bus_uevent,
	.suspend	= scsi_bus_suspend,
	.resume		= scsi_bus_resume,
	.remove		= scsi_bus_remove,
};

int scsi_sysfs_register(void)
{
	int error;

	error = bus_register(&scsi_bus_type);
	if (!error) {
		error = class_register(&sdev_class);
		if (error)
			bus_unregister(&scsi_bus_type);
	}

	return error;
}

void scsi_sysfs_unregister(void)
{
	class_unregister(&sdev_class);
	bus_unregister(&scsi_bus_type);
}

/*
 * sdev_show_function: macro to create an attr function that can be used to
 * show a non-bit field.
 */
#define sdev_show_function(field, format_string)				\
static ssize_t								\
sdev_show_##field (struct device *dev, struct device_attribute *attr, char *buf)				\
{									\
	struct scsi_device *sdev;					\
	sdev = to_scsi_device(dev);					\
	return snprintf (buf, 20, format_string, sdev->field);		\
}									\

/*
 * sdev_rd_attr: macro to create a function and attribute variable for a
 * read only field.
 */
#define sdev_rd_attr(field, format_string)				\
	sdev_show_function(field, format_string)			\
static DEVICE_ATTR(field, S_IRUGO, sdev_show_##field, NULL);


/*
 * sdev_rd_attr: create a function and attribute variable for a
 * read/write field.
 */
#define sdev_rw_attr(field, format_string)				\
	sdev_show_function(field, format_string)				\
									\
static ssize_t								\
sdev_store_##field (struct device *dev, struct device_attribute *attr, const char *buf, size_t count)	\
{									\
	struct scsi_device *sdev;					\
	sdev = to_scsi_device(dev);					\
	snscanf (buf, 20, format_string, &sdev->field);			\
	return count;							\
}									\
static DEVICE_ATTR(field, S_IRUGO | S_IWUSR, sdev_show_##field, sdev_store_##field);

/* Currently we don't export bit fields, but we might in future,
 * so leave this code in */
#if 0
/*
 * sdev_rd_attr: create a function and attribute variable for a
 * read/write bit field.
 */
#define sdev_rw_attr_bit(field)						\
	sdev_show_function(field, "%d\n")					\
									\
static ssize_t								\
sdev_store_##field (struct device *dev, struct device_attribute *attr, const char *buf, size_t count)	\
{									\
	int ret;							\
	struct scsi_device *sdev;					\
	ret = scsi_sdev_check_buf_bit(buf);				\
	if (ret >= 0)	{						\
		sdev = to_scsi_device(dev);				\
		sdev->field = ret;					\
		ret = count;						\
	}								\
	return ret;							\
}									\
static DEVICE_ATTR(field, S_IRUGO | S_IWUSR, sdev_show_##field, sdev_store_##field);

/*
 * scsi_sdev_check_buf_bit: return 0 if buf is "0", return 1 if buf is "1",
 * else return -EINVAL.
 */
static int scsi_sdev_check_buf_bit(const char *buf)
{
	if ((buf[1] == '\0') || ((buf[1] == '\n') && (buf[2] == '\0'))) {
		if (buf[0] == '1')
			return 1;
		else if (buf[0] == '0')
			return 0;
		else 
			return -EINVAL;
	} else
		return -EINVAL;
}
#endif
/*
 * Create the actual show/store functions and data structures.
 */
sdev_rd_attr (device_blocked, "%d\n");
sdev_rd_attr (queue_depth, "%d\n");
sdev_rd_attr (type, "%d\n");
sdev_rd_attr (scsi_level, "%d\n");
sdev_rd_attr (vendor, "%.8s\n");
sdev_rd_attr (model, "%.16s\n");
sdev_rd_attr (rev, "%.4s\n");

static ssize_t
sdev_show_timeout (struct device *dev, struct device_attribute *attr, char *buf)
{
	struct scsi_device *sdev;
	sdev = to_scsi_device(dev);
	return snprintf (buf, 20, "%d\n", sdev->timeout / HZ);
}

static ssize_t
sdev_store_timeout (struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
	struct scsi_device *sdev;
	int timeout;
	sdev = to_scsi_device(dev);
	sscanf (buf, "%d\n", &timeout);
	sdev->timeout = timeout * HZ;
	return count;
}
static DEVICE_ATTR(timeout, S_IRUGO | S_IWUSR, sdev_show_timeout, sdev_store_timeout);

static ssize_t