csk_udisk_mgr.c

linux 2.6.13 USB2.0开发补丁,[e-mail]

		}

		scsi_unlock(host);

		/* reject the command if the direction indicator 
		* is UNKNOWN
		*/
		if (us->srb->sc_data_direction == DMA_BIDIRECTIONAL) {
			us->srb->result = DID_ERROR << 16;
		}

		/* reject if target != 0 or if LUN is higher than
		* the maximum known LUN
		*/
		else if (us->srb->device->id && 
			!(us->flags & US_FL_SCM_MULT_TARG)) {
				us->srb->result = DID_BAD_TARGET << 16;
		}

		else if (us->srb->device->lun > us->max_lun) {
			us->srb->result = DID_BAD_TARGET << 16;
		}

		/* Handle those devices which need us to fake 
		* their inquiry data */
		else  if ((us->srb->cmnd[0] == INQUIRY) &&
			(us->flags & US_FL_FIX_INQUIRY)) {
		}

		/* we've got a command, let's do it! */
		else {
	/* Pad the ATAPI command with zeros 
	*
	* NOTE: This only works because a scsi_cmnd struct field contains
	* a unsigned char cmnd[16], so we know we have storage available
	*/
	/* Pad the ATAPI command with zeros */

			for (; us->srb->cmd_len<12; us->srb->cmd_len++)
				us->srb->cmnd[us->srb->cmd_len] = 0;


			/* set command length to 12 bytes */
			us->srb->cmd_len = 12;

			/* send the command to the transport layer */
			usb_stor_invoke_transport(us->srb, us);
		}

		/* lock access to the state */
		scsi_lock(host);

		if (!us->srb)
			;		/* nothing to do */
		/* indicate that the command is done */
		else if (us->srb->result != DID_ABORT << 16) {
			us->srb->scsi_done(us->srb);
		} else {
		}

SkipForAbort:
		/* If an abort request was received we need to signal that
		* the abort has finished.  The proper test for this is
		* the TIMED_OUT flag, not srb->result == DID_ABORT, because
		* the timeout might have occurred after the command had
		* already completed with a different result code. */
		if (test_bit(US_FLIDX_TIMED_OUT, &us->flags)) {
			complete(&(us->notify));

			/* Allow USB transfers to resume */
			clear_bit(US_FLIDX_ABORTING, &us->flags);
			clear_bit(US_FLIDX_TIMED_OUT, &us->flags);
		}

		/* finished working on this command */
		us->srb = NULL;
		scsi_unlock(host);

		/* unlock the device pointers */
		mutex_unlock(&us->dev_mutex);
	} /* for (;;) */

	scsi_host_put(host);

	/* notify the exit routine that we're actually exiting now 
	*
	* complete()/wait_for_completion() is similar to up()/down(),
	* except that complete() is safe in the case where the structure
	* is getting deleted in a parallel mode of execution (i.e. just
	* after the down() -- that's necessary for the thread-shutdown
	* case.
	*
	*(struct bulk_cs_wrap *)bcb complete_and_exit() goes even further than this -- it is safe in
	* the case that the thread of the caller is going away (not just
	* the structure) -- this is necessary for the module-remove case.
	* This is important in preemption kernels, which transfer the flow
	* of execution immediately upon a complete().
	*/
	//complete_and_exit(&threads_gone, 0);
}	



static int usb_stor_clear_halt(struct us_data *us, unsigned int pipe)
{
	int result;
	int endp = usb_pipeendpoint(pipe);

	if (usb_pipein (pipe))
		endp |= USB_DIR_IN;

	result = usb_stor_control_msg(us, us->send_ctrl_pipe,
		USB_REQ_CLEAR_FEATURE, USB_RECIP_ENDPOINT,
		USB_ENDPOINT_HALT, endp,
		NULL, 0, 3*HZ);

	/* reset the endpoint toggle */
	if (result >= 0)
		usb_settoggle(us->pusb_dev, usb_pipeendpoint(pipe),
		usb_pipeout(pipe), 0);


	return result;
}


static int usb_stor_Bulk_transport(struct scsi_cmnd *srb, struct us_data *us)
{
	struct bulk_cb_wrap *bcb = (struct bulk_cb_wrap *) us->iobuf;
	struct bulk_cs_wrap *bcs = (struct bulk_cs_wrap *) us->iobuf;
	unsigned int transfer_length = srb->request_bufflen;
	unsigned int residue;
	int result;
	int fake_sense = 0;
	unsigned int cswlen;
	unsigned int cbwlen = US_BULK_CB_WRAP_LEN;


	/* set up the command wrapper */
	bcb->Signature = cpu_to_le32(US_BULK_CB_SIGN);
	bcb->DataTransferLength = cpu_to_le32(transfer_length);
	bcb->Flags = srb->sc_data_direction == DMA_FROM_DEVICE ? 1 << 7 : 0;
	bcb->Tag = ++us->tag;
	bcb->Lun = srb->device->lun;
	if (us->flags & US_FL_SCM_MULT_TARG)
		bcb->Lun |= srb->device->id << 4;
	bcb->Length = srb->cmd_len;

	/* copy the command payload */
	memset(bcb->CDB, 0, sizeof(bcb->CDB));
	memcpy(bcb->CDB, srb->cmnd, bcb->Length);

	/* send it to out endpoint */
	
	result = usb_stor_bulk_transfer_buf(us, us->send_bulk_pipe,
				bcb, cbwlen, NULL);

	if (result != USB_STOR_XFER_GOOD)
		return USB_STOR_TRANSPORT_ERROR;

	/* DATA STAGE */
	/* send/receive data payload, if there is any */

	/* Some USB-IDE converter chips need a 100us delay between the
	 * command phase and the data phase.  Some devices need a little
	 * more than that, probably because of clock rate inaccuracies. */
	if (unlikely(us->flags & US_FL_GO_SLOW))
		udelay(125);

	if (transfer_length) {
		unsigned int pipe = srb->sc_data_direction == DMA_FROM_DEVICE ? 
				us->recv_bulk_pipe : us->send_bulk_pipe;
		result = usb_stor_bulk_transfer_sg(us, pipe,
					srb->request_buffer, transfer_length,
					srb->use_sg, &srb->resid);

		if (result == USB_STOR_XFER_ERROR)
			return USB_STOR_TRANSPORT_ERROR;

		/* If the device tried to send back more data than the
		 * amount requested, the spec requires us to transfer
		 * the CSW anyway.  Since there's no point retrying the
		 * the command, we'll return fake sense data indicating
		 * Illegal Request, Invalid Field in CDB.
		 */
		if (result == USB_STOR_XFER_LONG)
			fake_sense = 1;
	}

	/* See flow chart on pg 15 of the Bulk Only Transport spec for
	 * an explanation of how this code works.
	 */

	/* get CSW for device status */
	
	result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
				bcs, US_BULK_CS_WRAP_LEN, &cswlen);

	/* Some broken devices add unnecessary zero-length packets to the
	 * end of their data transfers.  Such packets show up as 0-length
	 * CSWs.  If we encounter such a thing, try to read the CSW again.
	 */
	if (result == USB_STOR_XFER_SHORT && cswlen == 0) {
		
		result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
				bcs, US_BULK_CS_WRAP_LEN, &cswlen);
	}

	/* did the attempt to read the CSW fail? */
	if (result == USB_STOR_XFER_STALLED) {

		/* get the status again */
		
		result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
				bcs, US_BULK_CS_WRAP_LEN, NULL);
	}

	/* if we still have a failure at this point, we're in trouble */

	if (result != USB_STOR_XFER_GOOD)
		return USB_STOR_TRANSPORT_ERROR;

	/* check bulk status */
	residue = le32_to_cpu(bcs->Residue);
	
	if (bcs->Tag != us->tag || bcs->Status > US_BULK_STAT_PHASE) {
		
		return USB_STOR_TRANSPORT_ERROR;
	}

	/* Some broken devices report odd signatures, so we do not check them
	 * for validity against the spec. We store the first one we see,
	 * and check subsequent transfers for validity against this signature.
	 */
	if (!us->bcs_signature) {
		us->bcs_signature = bcs->Signature;

	} else if (bcs->Signature != us->bcs_signature) {
	
		return USB_STOR_TRANSPORT_ERROR;
	}

	/* try to compute the actual residue, based on how much data
	 * was really transferred and what the device tells us */
	if (residue) {
		if (!(us->flags & US_FL_IGNORE_RESIDUE)) {
			residue = min(residue, transfer_length);
			srb->resid = max(srb->resid, (int) residue);
		}
	}

	/* based on the status code, we report good or bad */
	switch (bcs->Status) {
		case US_BULK_STAT_OK:
			/* device babbled -- return fake sense data */
			if (fake_sense) {
				memcpy(srb->sense_buffer, 
				       usb_stor_sense_invalidCDB, 
				       sizeof(usb_stor_sense_invalidCDB));
				return USB_STOR_TRANSPORT_NO_SENSE;
			}

			/* command good -- note that data could be short */
			return USB_STOR_TRANSPORT_GOOD;

		case US_BULK_STAT_FAIL:
			/* command failed */
			return USB_STOR_TRANSPORT_FAILED;

		case US_BULK_STAT_PHASE:
			/* phase error -- note that a transport reset will be
			 * invoked by the invoke_transport() function
			 */
			return USB_STOR_TRANSPORT_ERROR;
	}

	/* we should never get here, but if we do, we're in trouble */
	return USB_STOR_TRANSPORT_ERROR;
}



/* Issue a USB port reset to the device.  The caller must not hold
 * us->dev_mutex.
 */
static int usb_stor_port_reset(struct us_data *us)
{
	int result, rc_lock;

	result = rc_lock =
		usb_lock_device_for_reset(us->pusb_dev, us->pusb_intf);
	if (result < 0)
		{}
	else {
		/* Were we disconnected while waiting for the lock? */
		if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) {
			result = -EIO;
		
		} else {
			result = usb_reset_composite_device(
					us->pusb_dev, us->pusb_intf);
			
		}
		if (rc_lock)
			usb_unlock_device(us->pusb_dev);
	}
	return result;
}

static void usb_stor_report_device_reset(struct us_data *us)
{
	int i;
	struct Scsi_Host *host = us_to_host(us);

	scsi_report_device_reset(host, 0, 0);
	if (us->flags & US_FL_SCM_MULT_TARG) {
		for (i = 1; i < host->max_id; ++i)
			scsi_report_device_reset(host, 0, i);
	}
}


/* This issues a Bulk-only Reset to the device in question, including
 * clearing the subsequent endpoint halts that may occur.
 */
static int usb_stor_Bulk_reset(struct us_data *us)
{
	
	int result;
	int result2;

	if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) {
		
		return -EIO;
	}

	result = usb_stor_control_msg(us, us->send_ctrl_pipe,
			US_BULK_RESET_REQUEST, USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0,  us->ifnum, 0, 0,
			5*HZ);
	if (result < 0) {
		
		return result;
	}

 	/* Give the device some time to recover from the reset,
 	 * but don't delay disconnect processing. */
 	wait_event_interruptible_timeout(us->delay_wait,
 			test_bit(US_FLIDX_DISCONNECTING, &us->flags),
 			HZ*6);
	if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) {
		
		return -EIO;
	}

	
	result = usb_stor_clear_halt(us, us->recv_bulk_pipe);

	
	result2 = usb_stor_clear_halt(us, us->send_bulk_pipe);

	/* return a result code based on the result of the clear-halts */
	if (result >= 0)
		result = result2;
	
	return result;
}


/*
 * Transfer one buffer via bulk pipe, without timeouts, but allowing early
 * termination.  Return codes are USB_STOR_XFER_xxx.  If the bulk pipe
 * stalls during the transfer, the halt is automatically cleared.
 */
static int usb_stor_bulk_transfer_buf(struct us_data *us, unsigned int pipe,
	void *buf, unsigned int length, unsigned int *act_len)
{
	int result;

	/* fill and submit the URB */
	usb_fill_bulk_urb(us->current_urb, us->pusb_dev, pipe, buf, length,
		      usb_stor_blocking_completion, NULL);
	result = usb_stor_msg_common(us, 0);

	/* store the actual length of the data transferred */
	if (act_len)
		*act_len = us->current_urb->actual_length;
	return interpret_urb_result(us, pipe, length, result, 
			us->current_urb->actual_length);
}


/*
 * Transfer an entire SCSI command's worth of data payload over the bulk
 * pipe.
 *
 * Note that this uses usb_stor_bulk_transfer_buf() and
 * usb_stor_bulk_transfer_sglist() to achieve its goals --
 * this function simply determines whether we're going to use
 * scatter-gather or not, and acts appropriately.
 */
static int usb_stor_bulk_transfer_sg(struct us_data* us, unsigned int pipe,
		void *buf, unsigned int length_left, int use_sg, int *residual)
{
	int result;
	unsigned int partial;

	/* are we scatter-gathering? */
	if (use_sg) {
		/* use the usb core scatter-gather primitives */
		result = usb_stor_bulk_transfer_sglist(us, pipe,
				(struct scatterlist *) buf, use_sg,
				length_left, &partial);
		length_left -= partial;
	} else {
		/* no scatter-gather, just make the request */
		result = usb_stor_bulk_transfer_buf(us, pipe, buf, 
				length_left, &partial);
		length_left -= partial;
	}

	/* store the residual and return the error code */
	if (residual)
		*residual = length_left;
	return result;
}



/*
 * Transfer one control message, with timeouts, and allowing early
 * termination.  Return codes are usual -Exxx, *not* USB_STOR_XFER_xxx.
 */
static int usb_stor_control_msg(struct us_data *us, unsigned int pipe,
		 u8 request, u8 requesttype, u16 value, u16 index, 
		 void *data, u16 size, int timeout)
{
	int status;


	/* fill in the devrequest structure */
	us->cr->bRequestType = requesttype;
	us->cr->bRequest = request;
	us->cr->wValue = cpu_to_le16(value);
	us->cr->wIndex = cpu_to_le16(index);
	us->cr->wLength = cpu_to_le16(size);