/* *  BSG helper library * *  Copyright (C) 2008   James Smart, Emulex Corporation *  Copyright (C) 2011   Red Hat, Inc.  All rights reserved. *  Copyright (C) 2011   Mike Christie * *  This program is free software; you can redistribute it and/or modify *  it under the terms of the GNU General Public License as published by *  the Free Software Foundation; either version 2 of the License, or *  (at your option) any later version. * *  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. * *  You should have received a copy of the GNU General Public License *  along with this program; if not, write to the Free Software *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA * */#include <linux/slab.h>#include <linux/blkdev.h>#include <linux/delay.h>#include <linux/scatterlist.h>#include <linux/bsg-lib.h>#include <linux/export.h>#include <scsi/scsi_cmnd.h> /** * bsg_destroy_job - routine to teardown/delete a bsg job * @job: bsg_job that is to be torn down */static void bsg_destroy_job(struct bsg_job *job){	put_device(job->dev);	/* release reference for the request */ 	kfree(job->request_payload.sg_list);	kfree(job->reply_payload.sg_list);	kfree(job);} /** * bsg_job_done - completion routine for bsg requests * @job: bsg_job that is complete * @result: job reply result * @reply_payload_rcv_len: length of payload recvd * * The LLD should call this when the bsg job has completed. */void bsg_job_done(struct bsg_job *job, int result,		  unsigned int reply_payload_rcv_len){	struct request *req = job->req;	struct request *rsp = req->next_rq;	int err; 	err = job->req->errors = result;	if (err < 0)		/* we're only returning the result field in the reply */		job->req->sense_len = sizeof(u32);	else		job->req->sense_len = job->reply_len;	/* we assume all request payload was transferred, residual == 0 */	req->resid_len = 0; 	if (rsp) {		WARN_ON(reply_payload_rcv_len > rsp->resid_len); 		/* set reply (bidi) residual */		rsp->resid_len -= min(reply_payload_rcv_len, rsp->resid_len);	}	blk_complete_request(req);}EXPORT_SYMBOL_GPL(bsg_job_done); /** * bsg_softirq_done - softirq done routine for destroying the bsg requests * @rq: BSG request that holds the job to be destroyed */static void bsg_softirq_done(struct request *rq){	struct bsg_job *job = rq->special; 	blk_end_request_all(rq, rq->errors);	bsg_destroy_job(job);} static int bsg_map_buffer(struct bsg_buffer *buf, struct request *req){	size_t sz = (sizeof(struct scatterlist) * req->nr_phys_segments); 	BUG_ON(!req->nr_phys_segments); 	buf->sg_list = kzalloc(sz, GFP_KERNEL);	if (!buf->sg_list)		return -ENOMEM;	sg_init_table(buf->sg_list, req->nr_phys_segments);	buf->sg_cnt = blk_rq_map_sg(req->q, req, buf->sg_list);	buf->payload_len = blk_rq_bytes(req);	return 0;} /** * bsg_create_job - create the bsg_job structure for the bsg request * @dev: device that is being sent the bsg request * @req: BSG request that needs a job structure */static int bsg_create_job(struct device *dev, struct request *req){	struct request *rsp = req->next_rq;	struct request_queue *q = req->q;	struct bsg_job *job;	int ret; 	BUG_ON(req->special); 	job = kzalloc(sizeof(struct bsg_job) + q->bsg_job_size, GFP_KERNEL);	if (!job)		return -ENOMEM; 	req->special = job;	job->req = req;	if (q->bsg_job_size)		job->dd_data = (void *)&job[1];	job->request = req->cmd;	job->request_len = req->cmd_len;	job->reply = req->sense;	job->reply_len = SCSI_SENSE_BUFFERSIZE;	/* Size of sense buffer						 * allocated */	if (req->bio) {		ret = bsg_map_buffer(&job->request_payload, req);		if (ret)			goto failjob_rls_job;	}	if (rsp && rsp->bio) {		ret = bsg_map_buffer(&job->reply_payload, rsp);		if (ret)			goto failjob_rls_rqst_payload;	}	job->dev = dev;	/* take a reference for the request */	get_device(job->dev);	return 0; failjob_rls_rqst_payload:	kfree(job->request_payload.sg_list);failjob_rls_job:	kfree(job);	return -ENOMEM;} /** * bsg_request_fn - generic handler for bsg requests * @q: request queue to manage * * On error the create_bsg_job function should return a -Exyz error value * that will be set to the req->errors. * * Drivers/subsys should pass this to the queue init function. */void bsg_request_fn(struct request_queue *q){	struct device *dev = q->queuedata;	struct request *req;	struct bsg_job *job;	int ret; 	if (!get_device(dev))		return; 	while (1) {		req = blk_fetch_request(q);		if (!req)			break;		spin_unlock_irq(q->queue_lock); 		ret = bsg_create_job(dev, req);		if (ret) {			req->errors = ret;			blk_end_request_all(req, ret);			spin_lock_irq(q->queue_lock);			continue;		} 		job = req->special;		ret = q->bsg_job_fn(job);		spin_lock_irq(q->queue_lock);		if (ret)			break;	} 	spin_unlock_irq(q->queue_lock);	put_device(dev);	spin_lock_irq(q->queue_lock);}EXPORT_SYMBOL_GPL(bsg_request_fn); /** * bsg_setup_queue - Create and add the bsg hooks so we can receive requests * @dev: device to attach bsg device to * @q: request queue setup by caller * @name: device to give bsg device * @job_fn: bsg job handler * @dd_job_size: size of LLD data needed for each job * * The caller should have setup the reuqest queue with bsg_request_fn * as the request_fn. */int bsg_setup_queue(struct device *dev, struct request_queue *q,		    char *name, bsg_job_fn *job_fn, int dd_job_size){	int ret; 	q->queuedata = dev;	q->bsg_job_size = dd_job_size;	q->bsg_job_fn = job_fn;	queue_flag_set_unlocked(QUEUE_FLAG_BIDI, q);	blk_queue_softirq_done(q, bsg_softirq_done);	blk_queue_rq_timeout(q, BLK_DEFAULT_SG_TIMEOUT); 	ret = bsg_register_queue(q, dev, name, NULL);	if (ret) {		printk(KERN_ERR "%s: bsg interface failed to "		       "initialize - register queue\n", dev->kobj.name);		return ret;	} 	return 0;}EXPORT_SYMBOL_GPL(bsg_setup_queue);