sd.c

Linux Kernel 2.6.9 for OMAP1710

	             (unsigned long __user *)&loc->start))
		return -EFAULT;
	return 0;
}

/**
 *	sd_ioctl - process an ioctl
 *	@inode: only i_rdev/i_bdev members may be used
 *	@filp: only f_mode and f_flags may be used
 *	@cmd: ioctl command number
 *	@arg: this is third argument given to ioctl(2) system call.
 *	Often contains a pointer.
 *
 *	Returns 0 if successful (some ioctls return postive numbers on
 *	success as well). Returns a negated errno value in case of error.
 *
 *	Note: most ioctls are forward onto the block subsystem or further
 *	down in the scsi subsytem.
 **/
static int sd_ioctl(struct inode * inode, struct file * filp, 
		    unsigned int cmd, unsigned long arg)
{
	struct block_device *bdev = inode->i_bdev;
	struct gendisk *disk = bdev->bd_disk;
	struct scsi_device *sdp = scsi_disk(disk)->device;
	void __user *p = (void __user *)arg;
	int error;
    
	SCSI_LOG_IOCTL(1, printk("sd_ioctl: disk=%s, cmd=0x%x\n",
						disk->disk_name, cmd));

	/*
	 * If we are in the middle of error recovery, don't let anyone
	 * else try and use this device.  Also, if error recovery fails, it
	 * may try and take the device offline, in which case all further
	 * access to the device is prohibited.
	 */
	if (!scsi_block_when_processing_errors(sdp))
		return -ENODEV;

	if (cmd == HDIO_GETGEO) {
		if (!arg)
			return -EINVAL;
		return sd_hdio_getgeo(bdev, p);
	}

	/*
	 * Send SCSI addressing ioctls directly to mid level, send other
	 * ioctls to block level and then onto mid level if they can't be
	 * resolved.
	 */
	switch (cmd) {
		case SCSI_IOCTL_GET_IDLUN:
		case SCSI_IOCTL_GET_BUS_NUMBER:
			return scsi_ioctl(sdp, cmd, p);
		default:
			error = scsi_cmd_ioctl(filp, disk, cmd, p);
			if (error != -ENOTTY)
				return error;
	}
	return scsi_ioctl(sdp, cmd, p);
}

static void set_media_not_present(struct scsi_disk *sdkp)
{
	sdkp->media_present = 0;
	sdkp->capacity = 0;
	sdkp->device->changed = 1;
}

/**
 *	sd_media_changed - check if our medium changed
 *	@disk: kernel device descriptor 
 *
 *	Returns 0 if not applicable or no change; 1 if change
 *
 *	Note: this function is invoked from the block subsystem.
 **/
static int sd_media_changed(struct gendisk *disk)
{
	struct scsi_disk *sdkp = scsi_disk(disk);
	struct scsi_device *sdp = sdkp->device;
	int retval;

	SCSI_LOG_HLQUEUE(3, printk("sd_media_changed: disk=%s\n",
						disk->disk_name));

	if (!sdp->removable)
		return 0;

	/*
	 * If the device is offline, don't send any commands - just pretend as
	 * if the command failed.  If the device ever comes back online, we
	 * can deal with it then.  It is only because of unrecoverable errors
	 * that we would ever take a device offline in the first place.
	 */
	if (!scsi_device_online(sdp))
		goto not_present;

	/*
	 * Using TEST_UNIT_READY enables differentiation between drive with
	 * no cartridge loaded - NOT READY, drive with changed cartridge -
	 * UNIT ATTENTION, or with same cartridge - GOOD STATUS.
	 *
	 * Drives that auto spin down. eg iomega jaz 1G, will be started
	 * by sd_spinup_disk() from sd_revalidate_disk(), which happens whenever
	 * sd_revalidate() is called.
	 */
	retval = -ENODEV;
	if (scsi_block_when_processing_errors(sdp))
		retval = scsi_test_unit_ready(sdp, SD_TIMEOUT, SD_MAX_RETRIES);

	/*
	 * Unable to test, unit probably not ready.   This usually
	 * means there is no disc in the drive.  Mark as changed,
	 * and we will figure it out later once the drive is
	 * available again.
	 */
	if (retval)
		 goto not_present;

	/*
	 * For removable scsi disk we have to recognise the presence
	 * of a disk in the drive. This is kept in the struct scsi_disk
	 * struct and tested at open !  Daniel Roche ([e-mail])
	 */
	sdkp->media_present = 1;

	retval = sdp->changed;
	sdp->changed = 0;

	return retval;

not_present:
	set_media_not_present(sdkp);
	return 1;
}

static int sd_sync_cache(struct scsi_device *sdp)
{
	struct scsi_request *sreq;
	int retries, res;

	if (!scsi_device_online(sdp))
		return -ENODEV;

	sreq = scsi_allocate_request(sdp, GFP_KERNEL);
	if (!sreq) {
		printk("FAILED\n  No memory for request\n");
		return -ENOMEM;
	}

	sreq->sr_data_direction = DMA_NONE;
	for (retries = 3; retries > 0; --retries) {
		unsigned char cmd[10] = { 0 };

		cmd[0] = SYNCHRONIZE_CACHE;
		/*
		 * Leave the rest of the command zero to indicate
		 * flush everything.
		 */
		scsi_wait_req(sreq, cmd, NULL, 0, SD_TIMEOUT, SD_MAX_RETRIES);
		if (sreq->sr_result == 0)
			break;
	}

	res = sreq->sr_result;
	if (res) {
		printk(KERN_WARNING "FAILED\n  status = %x, message = %02x, "
				    "host = %d, driver = %02x\n  ",
				    status_byte(res), msg_byte(res),
				    host_byte(res), driver_byte(res));
			if (driver_byte(res) & DRIVER_SENSE)
				scsi_print_req_sense("sd", sreq);
	}

	scsi_release_request(sreq);
	return res;
}

static int sd_issue_flush(struct device *dev, sector_t *error_sector)
{
	struct scsi_device *sdp = to_scsi_device(dev);
	struct scsi_disk *sdkp = dev_get_drvdata(dev);

	if (!sdkp)
               return -ENODEV;

	if (!sdkp->WCE)
		return 0;

	return sd_sync_cache(sdp);
}

static void sd_rescan(struct device *dev)
{
	struct scsi_disk *sdkp = dev_get_drvdata(dev);
	sd_revalidate_disk(sdkp->disk);
}

static struct block_device_operations sd_fops = {
	.owner			= THIS_MODULE,
	.open			= sd_open,
	.release		= sd_release,
	.ioctl			= sd_ioctl,
	.media_changed		= sd_media_changed,
	.revalidate_disk	= sd_revalidate_disk,
};

/**
 *	sd_rw_intr - bottom half handler: called when the lower level
 *	driver has completed (successfully or otherwise) a scsi command.
 *	@SCpnt: mid-level's per command structure.
 *
 *	Note: potentially run from within an ISR. Must not block.
 **/
static void sd_rw_intr(struct scsi_cmnd * SCpnt)
{
	int result = SCpnt->result;
	int this_count = SCpnt->bufflen;
	int good_bytes = (result == 0 ? this_count : 0);
	sector_t block_sectors = 1;
	sector_t error_sector;
#ifdef CONFIG_SCSI_LOGGING
	SCSI_LOG_HLCOMPLETE(1, printk("sd_rw_intr: %s: res=0x%x\n", 
				SCpnt->request->rq_disk->disk_name, result));
	if (0 != result) {
		SCSI_LOG_HLCOMPLETE(1, printk("sd_rw_intr: sb[0,2,asc,ascq]"
				"=%x,%x,%x,%x\n", SCpnt->sense_buffer[0],
			SCpnt->sense_buffer[2], SCpnt->sense_buffer[12],
			SCpnt->sense_buffer[13]));
	}
#endif
	/*
	   Handle MEDIUM ERRORs that indicate partial success.  Since this is a
	   relatively rare error condition, no care is taken to avoid
	   unnecessary additional work such as memcpy's that could be avoided.
	 */

	/* An error occurred */
	if (driver_byte(result) != 0 && 	/* An error occurred */
	    (SCpnt->sense_buffer[0] & 0x7f) == 0x70) { /* Sense current */
		switch (SCpnt->sense_buffer[2]) {
		case MEDIUM_ERROR:
			if (!(SCpnt->sense_buffer[0] & 0x80))
				break;
			if (!blk_fs_request(SCpnt->request))
				break;
			error_sector = (SCpnt->sense_buffer[3] << 24) |
			(SCpnt->sense_buffer[4] << 16) |
			(SCpnt->sense_buffer[5] << 8) |
			SCpnt->sense_buffer[6];
			if (SCpnt->request->bio != NULL)
				block_sectors = bio_sectors(SCpnt->request->bio);
			switch (SCpnt->device->sector_size) {
			case 1024:
				error_sector <<= 1;
				if (block_sectors < 2)
					block_sectors = 2;
				break;
			case 2048:
				error_sector <<= 2;
				if (block_sectors < 4)
					block_sectors = 4;
				break;
			case 4096:
				error_sector <<=3;
				if (block_sectors < 8)
					block_sectors = 8;
				break;
			case 256:
				error_sector >>= 1;
				break;
			default:
				break;
			}

			error_sector &= ~(block_sectors - 1);
			good_bytes = (error_sector - SCpnt->request->sector) << 9;
			if (good_bytes < 0 || good_bytes >= this_count)
				good_bytes = 0;
			break;

		case RECOVERED_ERROR: /* an error occurred, but it recovered */
		case NO_SENSE: /* LLDD got sense data */
			/*
			 * Inform the user, but make sure that it's not treated
			 * as a hard error.
			 */
			scsi_print_sense("sd", SCpnt);
			SCpnt->result = 0;
			SCpnt->sense_buffer[0] = 0x0;
			good_bytes = this_count;
			break;

		case ILLEGAL_REQUEST:
			if (SCpnt->device->use_10_for_rw &&
			    (SCpnt->cmnd[0] == READ_10 ||
			     SCpnt->cmnd[0] == WRITE_10))
				SCpnt->device->use_10_for_rw = 0;
			if (SCpnt->device->use_10_for_ms &&
			    (SCpnt->cmnd[0] == MODE_SENSE_10 ||
			     SCpnt->cmnd[0] == MODE_SELECT_10))
				SCpnt->device->use_10_for_ms = 0;
			break;

		default:
			break;
		}
	}
	/*
	 * This calls the generic completion function, now that we know
	 * how many actual sectors finished, and how many sectors we need
	 * to say have failed.
	 */
	scsi_io_completion(SCpnt, good_bytes, block_sectors << 9);
}

static int media_not_present(struct scsi_disk *sdkp, struct scsi_request *srp)
{
	if (!srp->sr_result)
		return 0;
	if (!(driver_byte(srp->sr_result) & DRIVER_SENSE))
		return 0;
	if (srp->sr_sense_buffer[2] != NOT_READY &&
	    srp->sr_sense_buffer[2] != UNIT_ATTENTION)
	    	return 0;
	if (srp->sr_sense_buffer[12] != 0x3A) /* medium not present */
		return 0;

	set_media_not_present(sdkp);
	return 1;
}

/*
 * spinup disk - called only in sd_revalidate_disk()
 */
static void
sd_spinup_disk(struct scsi_disk *sdkp, char *diskname,
	       struct scsi_request *SRpnt, unsigned char *buffer) {
	unsigned char cmd[10];
	unsigned long spintime_value = 0;
	int retries, spintime;
	unsigned int the_result;

	spintime = 0;

	/* Spin up drives, as required.  Only do this at boot time */
	/* Spinup needs to be done for module loads too. */
	do {
		retries = 0;

		do {
			cmd[0] = TEST_UNIT_READY;
			memset((void *) &cmd[1], 0, 9);

			SRpnt->sr_cmd_len = 0;
			SRpnt->sr_sense_buffer[0] = 0;
			SRpnt->sr_sense_buffer[2] = 0;
			SRpnt->sr_data_direction = DMA_NONE;

			scsi_wait_req (SRpnt, (void *) cmd, (void *) buffer,
				       0/*512*/, SD_TIMEOUT, SD_MAX_RETRIES);

			the_result = SRpnt->sr_result;
			retries++;
		} while (retries < 3 && 
			 (!scsi_status_is_good(the_result) ||
			  ((driver_byte(the_result) & DRIVER_SENSE) &&
			   SRpnt->sr_sense_buffer[2] == UNIT_ATTENTION)));

		/*
		 * If the drive has indicated to us that it doesn't have
		 * any media in it, don't bother with any of the rest of
		 * this crap.
		 */
		if (media_not_present(sdkp, SRpnt))
			return;

		if ((driver_byte(the_result) & DRIVER_SENSE) == 0) {
			/* no sense, TUR either succeeded or failed
			 * with a status error */
			if(!spintime && !scsi_status_is_good(the_result))
				printk(KERN_NOTICE "%s: Unit Not Ready, error = 0x%x\n", diskname, the_result);
			break;
		}
					
		/*
		 * The device does not want the automatic start to be issued.
		 */
		if (sdkp->device->no_start_on_add) {
			break;
		}

		/*
		 * If manual intervention is required, or this is an
		 * absent USB storage device, a spinup is meaningless.
		 */
		if (SRpnt->sr_sense_buffer[2] == NOT_READY &&
		    SRpnt->sr_sense_buffer[12] == 4 /* not ready */ &&
		    SRpnt->sr_sense_buffer[13] == 3) {
			break;		/* manual intervention required */

		/*
		 * Issue command to spin up drive when not ready
		 */
		} else if (SRpnt->sr_sense_buffer[2] == NOT_READY) {
			unsigned long time1;
			if (!spintime) {
				printk(KERN_NOTICE "%s: Spinning up disk...",
				       diskname);
				cmd[0] = START_STOP;
				cmd[1] = 1;	/* Return immediately */
				memset((void *) &cmd[2], 0, 8);
				cmd[4] = 1;	/* Start spin cycle */
				SRpnt->sr_cmd_len = 0;
				SRpnt->sr_sense_buffer[0] = 0;
				SRpnt->sr_sense_buffer[2] = 0;

				SRpnt->sr_data_direction = DMA_NONE;
				scsi_wait_req(SRpnt, (void *)cmd, 
					      (void *) buffer, 0/*512*/, 
					      SD_TIMEOUT, SD_MAX_RETRIES);
				spintime_value = jiffies;
			}
			spintime = 1;
			time1 = HZ;
			/* Wait 1 second for next try */
			do {
				current->state = TASK_UNINTERRUPTIBLE;
				time1 = schedule_timeout(time1);
			} while(time1);
			printk(".");
		} else {
			/* we don't understand the sense code, so it's
			 * probably pointless to loop */
			if(!spintime) {
				printk(KERN_NOTICE "%s: Unit Not Ready, sense:\n", diskname);
				scsi_print_req_sense("", SRpnt);
			}
			break;
		}
				
	} while (spintime &&
		 time_after(spintime_value + 100 * HZ, jiffies));

	if (spintime) {
		if (scsi_status_is_good(the_result))
			printk("ready\n");
		else
			printk("not responding...\n");
	}
}

/*
 * read disk capacity
 */
static void
sd_read_capacity(struct scsi_disk *sdkp, char *diskname,
		 struct scsi_request *SRpnt, unsigned char *buffer) {
	unsigned char cmd[16];
	struct scsi_device *sdp = sdkp->device;
	int the_result, retries;
	int sector_size = 0;
	int longrc = 0;

repeat:
	retries = 3;
	do {
		if (longrc) {
			memset((void *) cmd, 0, 16);
			cmd[0] = SERVICE_ACTION_IN;
			cmd[1] = SAI_READ_CAPACITY_16;
			cmd[13] = 12;
			memset((void *) buffer, 0, 12);
		} else {
			cmd[0] = READ_CAPACITY;
			memset((void *) &cmd[1], 0, 9);
			memset((void *) buffer, 0, 8);
		}
		
		SRpnt->sr_cmd_len = 0;
		SRpnt->sr_sense_buffer[0] = 0;
		SRpnt->sr_sense_buffer[2] = 0;
		SRpnt->sr_data_direction = DMA_FROM_DEVICE;

		scsi_wait_req(SRpnt, (void *) cmd, (void *) buffer,
			      longrc ? 12 : 8, SD_TIMEOUT, SD_MAX_RETRIES);

		if (media_not_present(sdkp, SRpnt))
			return;

		the_result = SRpnt->sr_result;
		retries--;

	} while (the_result && retries);

	if (the_result && !longrc) {
		printk(KERN_NOTICE "%s : READ CAPACITY failed.\n"
		       "%s : status=%x, message=%02x, host=%d, driver=%02x \n",
		       diskname, diskname,
		       status_byte(the_result),
		       msg_byte(the_result),
		       host_byte(the_result),
		       driver_byte(the_result));

		if (driver_byte(the_result) & DRIVER_SENSE)
			scsi_print_req_sense("sd", SRpnt);
		else
			printk("%s : sense not available. \n", diskname);

		/* Set dirty bit for removable devices if not ready -
		 * sometimes drives will not report this properly. */
		if (sdp->removable &&
		    SRpnt->sr_sense_buffer[2] == NOT_READY)
			sdp->changed = 1;

		/* Either no media are present but the drive didn't tell us,
		   or they are present but the read capacity command fails */
		/* sdkp->media_present = 0; -- not always correct */
		sdkp->capacity = 0x200000; /* 1 GB - random */

		return;
	} else if (the_result && longrc) {
		/* READ CAPACITY(16) has been failed */
		printk(KERN_NOTICE "%s : READ CAPACITY(16) failed.\n"
		       "%s : status=%x, message=%02x, host=%d, driver=%02x \n",
		       diskname, diskname,
		       status_byte(the_result),
		       msg_byte(the_result),
		       host_byte(the_result),
		       driver_byte(the_result));
		printk(KERN_NOTICE "%s : use 0xffffffff as device size\n",
		       diskname);
		
		sdkp->capacity = 1 + (sector_t) 0xffffffff;		
		goto got_data;
	}