path: root/drivers/usb/storage/uas.c

/*
 * USB Attached SCSI
 * Note that this is not the same as the USB Mass Storage driver
 *
 * Copyright Matthew Wilcox for Intel Corp, 2010
 * Copyright Sarah Sharp for Intel Corp, 2010
 *
 * Distributed under the terms of the GNU GPL, version two.
 */

#include <linux/blkdev.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/module.h>
#include <linux/usb.h>
#include <linux/usb/hcd.h>
#include <linux/usb/storage.h>
#include <linux/usb/uas.h>

#include <scsi/scsi.h>
#include <scsi/scsi_dbg.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_tcq.h>

/*
 * The r00-r01c specs define this version of the SENSE IU data structure.
 * It's still in use by several different firmware releases.
 */
struct sense_iu_old {
	__u8 iu_id;
	__u8 rsvd1;
	__be16 tag;
	__be16 len;
	__u8 status;
	__u8 service_response;
	__u8 sense[SCSI_SENSE_BUFFERSIZE];
};

struct uas_dev_info {
	struct usb_interface *intf;
	struct usb_device *udev;
	int qdepth;
	unsigned cmd_pipe, status_pipe, data_in_pipe, data_out_pipe;
	unsigned use_streams:1;
	unsigned uas_sense_old:1;
	struct scsi_cmnd *cmnd;
	struct urb *status_urb; /* used only if stream support is available */
};

enum {
	ALLOC_STATUS_URB	= (1 << 0),
	SUBMIT_STATUS_URB	= (1 << 1),
	ALLOC_DATA_IN_URB	= (1 << 2),
	SUBMIT_DATA_IN_URB	= (1 << 3),
	ALLOC_DATA_OUT_URB	= (1 << 4),
	SUBMIT_DATA_OUT_URB	= (1 << 5),
	ALLOC_CMD_URB		= (1 << 6),
	SUBMIT_CMD_URB		= (1 << 7),
	COMPLETED_DATA_IN	= (1 << 8),
	COMPLETED_DATA_OUT	= (1 << 9),
	DATA_COMPLETES_CMD	= (1 << 10),
};

/* Overrides scsi_pointer */
struct uas_cmd_info {
	unsigned int state;
	unsigned int stream;
	struct urb *cmd_urb;
	/* status_urb is used only if stream support isn't available */
	struct urb *status_urb;
	struct urb *data_in_urb;
	struct urb *data_out_urb;
	struct list_head list;
};

/* I hate forward declarations, but I actually have a loop */
static int uas_submit_urbs(struct scsi_cmnd *cmnd,
				struct uas_dev_info *devinfo, gfp_t gfp);
static void uas_do_work(struct work_struct *work);

static DECLARE_WORK(uas_work, uas_do_work);
static DEFINE_SPINLOCK(uas_work_lock);
static LIST_HEAD(uas_work_list);

static void uas_do_work(struct work_struct *work)
{
	struct uas_cmd_info *cmdinfo;
	struct uas_cmd_info *temp;
	struct list_head list;
	int err;

	spin_lock_irq(&uas_work_lock);
	list_replace_init(&uas_work_list, &list);
	spin_unlock_irq(&uas_work_lock);

	list_for_each_entry_safe(cmdinfo, temp, &list, list) {
		struct scsi_pointer *scp = (void *)cmdinfo;
		struct scsi_cmnd *cmnd = container_of(scp,
							struct scsi_cmnd, SCp);
		err = uas_submit_urbs(cmnd, cmnd->device->hostdata, GFP_NOIO);
		if (err) {
			list_del(&cmdinfo->list);
			spin_lock_irq(&uas_work_lock);
			list_add_tail(&cmdinfo->list, &uas_work_list);
			spin_unlock_irq(&uas_work_lock);
			schedule_work(&uas_work);
		}
	}
}

static void uas_sense(struct urb *urb, struct scsi_cmnd *cmnd)
{
	struct sense_iu *sense_iu = urb->transfer_buffer;
	struct scsi_device *sdev = cmnd->device;
	struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;

	if (urb->actual_length > 16) {
		unsigned len = be16_to_cpup(&sense_iu->len);
		if (len + 16 != urb->actual_length) {
			int newlen = min(len + 16, urb->actual_length) - 16;
			if (newlen < 0)
				newlen = 0;
			sdev_printk(KERN_INFO, sdev, "%s: urb length %d "
				"disagrees with IU sense data length %d, "
				"using %d bytes of sense data\n", __func__,
					urb->actual_length, len, newlen);
			len = newlen;
		}
		memcpy(cmnd->sense_buffer, sense_iu->sense, len);
	}

	cmnd->result = sense_iu->status;
	if (!(cmdinfo->state & DATA_COMPLETES_CMD))
		cmnd->scsi_done(cmnd);
}

static void uas_sense_old(struct urb *urb, struct scsi_cmnd *cmnd)
{
	struct sense_iu_old *sense_iu = urb->transfer_buffer;
	struct scsi_device *sdev = cmnd->device;
	struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;

	if (urb->actual_length > 8) {
		unsigned len = be16_to_cpup(&sense_iu->len) - 2;
		if (len + 8 != urb->actual_length) {
			int newlen = min(len + 8, urb->actual_length)