[thirdparty/kernel/linux.git] / block / bsg-lib.c

/*
 *  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/blk-mq.h>
#include <linux/delay.h>
#include <linux/scatterlist.h>
#include <linux/bsg-lib.h>
#include <linux/export.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/sg.h>

#define uptr64(val) ((void __user *)(uintptr_t)(val))

struct bsg_set {
	struct blk_mq_tag_set	tag_set;
	bsg_job_fn		*job_fn;
	bsg_timeout_fn		*timeout_fn;
};

static int bsg_transport_check_proto(struct sg_io_v4 *hdr)
{
	if (hdr->protocol != BSG_PROTOCOL_SCSI  ||
	    hdr->subprotocol != BSG_SUB_PROTOCOL_SCSI_TRANSPORT)
		return -EINVAL;
	if (!capable(CAP_SYS_RAWIO))
		return -EPERM;
	return 0;
}

static int bsg_transport_fill_hdr(struct request *rq, struct sg_io_v4 *hdr,
		fmode_t mode)
{
	struct bsg_job *job = blk_mq_rq_to_pdu(rq);
	int ret;

	job->request_len = hdr->request_len;
	job->request = memdup_user(uptr64(hdr->request), hdr->request_len);
	if (IS_ERR(job->request))
		return PTR_ERR(job->request);

	if (hdr->dout_xfer_len && hdr->din_xfer_len) {
		job->bidi_rq = blk_get_request(rq->q, REQ_OP_SCSI_IN, 0);
		if (IS_ERR(job->bidi_rq)) {
			ret = PTR_ERR(job->bidi_rq);
			goto out;
		}

		ret = blk_rq_map_user(rq->q, job->bidi_rq, NULL,
				uptr64(hdr->din_xferp), hdr->din_xfer_len,
				GFP_KERNEL);
		if (ret)
			goto out_free_bidi_rq;

		job->bidi_bio = job->bidi_rq->bio;
	} else {
		job->bidi_rq = NULL;
		job->bidi_bio = NULL;
	}

	return 0;

out_free_bidi_rq:
	if (job->bidi_rq)
		blk_put_request(job->bidi_rq);
out:
	kfree(job->request);
	return ret;
}

static int bsg_transport_complete_rq(struct request *rq, struct sg_io_v4 *hdr)
{
	struct bsg_job *job = blk_mq_rq_to_pdu(rq);
	int ret = 0;

	/*
	 * The assignments below don't make much sense, but are kept for
	 * bug by bug backwards compatibility:
	 */
	hdr->device_status = job->result & 0xff;
	hdr->transport_status = host_byte(job->result);
	hdr->driver_status = driver_byte(job->result);
	hdr->info = 0;
	if (hdr->device_status || hdr->transport_status || hdr->driver_status)
		hdr->info |= SG_INFO_CHECK;
	hdr->response_len = 0;

	if (job->result < 0) {
		/* we're only returning the result field in the reply */
		job->reply_len = sizeof(u32);
		ret = job->result;
	}

	if (job->reply_len && hdr->response) {
		int len = min(hdr->max_response_len, job->reply_len);

		if (copy_to_user(uptr64(hdr->response), job->reply, len))
			ret = -EFAULT;
		else
			hdr->response_len = len;
	}

	/* we assume all request payload was transferred, residual == 0 */
	hdr->dout_resid = 0;

	if (job->bidi_rq) {
		unsigned int rsp_len = job->reply_payload.payload_len;

		if (WARN_ON(job->reply_payload_rcv_len > rsp_len))
			hdr->din_resid = 0;
		else
			hdr->din_resid = rsp_len - job->reply_payload_rcv_len;
	} else {
		hdr->din_resid = 0;
	}

	return ret;
}

static void bsg_transport_free_rq(struct request *rq)
{
	struct bsg_job *job = blk_mq_rq_to_pdu(rq);

	if (job->bidi_rq) {
		blk_rq_unmap_user(job->bidi_bio);
		blk_put_request(job->bidi_rq);
	}

	kfree(job->request);
}

static const struct bsg_ops bsg_transport_ops = {
	.check_proto		= bsg_transport_check_proto,
	.fill_hdr		= bsg_transport_fill_hdr,
	.complete_rq		= bsg_transport_complete_rq,
	.free_rq		= bsg_transport_free_rq,
};

/**
 * bsg_teardown_job - routine to teardown a bsg job
 * @kref: kref inside bsg_job that is to be torn down
 */
static void bsg_teardown_job(struct kref *kref)
{
	struct bsg_job *job = container_of(kref, struct bsg_job, kref);
	struct request *rq = blk_mq_rq_from_pdu(job);

	put_device(job->dev);	/* release reference for the request */

	kfree(job->request_payload.sg_list);
	kfree(job->reply_payload.sg_list);

	blk_mq_end_request(rq, BLK_STS_OK);
}

void bsg_job_put(struct bsg_job *job)
{
	kref_put(&job->kref, bsg_teardown_job);
}
EXPORT_SYMBOL_GPL(bsg_job_put);

int bsg_job_get(struct bsg_job *job)
{
	return kref_get_unless_zero(&job->kref);
}
EXPORT_SYMBOL_GPL(bsg_job_get);

/**
 * 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)
{
	job->result = result;
	job->reply_payload_rcv_len = reply_payload_rcv_len;
	blk_mq_complete_request(blk_mq_rq_from_pdu(job));
}
EXPORT_SYMBOL_GPL(bsg_job_done);

/**
 * bsg_complete - softirq done routine for destroying the bsg requests
 * @rq: BSG request that holds the job to be destroyed
 */
static void bsg_complete(struct request *rq)
{
	struct bsg_job *job = blk_mq_rq_to_pdu(rq);

	bsg_job_put(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_prepare_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 bool bsg_prepare_job(struct device *dev, struct request *req)
{
	struct bsg_job *job = blk_mq_rq_to_pdu(req);
	int ret;

	job->timeout = req->timeout;

	if (req->bio) {
		ret = bsg_map_buffer(&job->request_payload, req);
		if (ret)
			goto failjob_rls_job;
	}
	if (job->bidi_rq) {
		ret = bsg_map_buffer(&job->reply_payload, job->bidi_rq);
		if (ret)
			goto failjob_rls_rqst_payload;
	}
	job->dev = dev;
	/* take a reference for the request */
	get_device(job->dev);
	kref_init(&job->kref);
	return true;

failjob_rls_rqst_payload:
	kfree(job->request_payload.sg_list);
failjob_rls_job:
	job->result = -ENOMEM;
	return false;
}

/**
 * bsg_queue_rq - generic handler for bsg requests
 * @hctx: hardware queue
 * @bd: queue data
 *
 * On error the create_bsg_job function should return a -Exyz error value
 * that will be set to ->result.
 *
 * Drivers/subsys should pass this to the queue init function.
 */
static blk_status_t bsg_queue_rq(struct blk_mq_hw_ctx *hctx,
				 const struct blk_mq_queue_data *bd)
{
	struct request_queue *q = hctx->queue;
	struct device *dev = q->queuedata;
	struct request *req = bd->rq;
	struct bsg_set *bset =
		container_of(q->tag_set, struct bsg_set, tag_set);
	int ret;

	blk_mq_start_request(req);

	if (!get_device(dev))
		return BLK_STS_IOERR;

	if (!bsg_prepare_job(dev, req))
		return BLK_STS_IOERR;

	ret = bset->job_fn(blk_mq_rq_to_pdu(req));
	if (ret)
		return BLK_STS_IOERR;

	put_device(dev);
	return BLK_STS_OK;
}

/* called right after the request is allocated for the request_queue */
static int bsg_init_rq(struct blk_mq_tag_set *set, struct request *req,
		       unsigned int hctx_idx, unsigned int numa_node)
{
	struct bsg_job *job = blk_mq_rq_to_pdu(req);

	job->reply = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_KERNEL);
	if (!job->reply)
		return -ENOMEM;
	return 0;
}

/* called right before the request is given to the request_queue user */
static void bsg_initialize_rq(struct request *req)
{
	struct bsg_job *job = blk_mq_rq_to_pdu(req);
	void *reply = job->reply;

	memset(job, 0, sizeof(*job));
	job->reply = reply;
	job->reply_len = SCSI_SENSE_BUFFERSIZE;
	job->dd_data = job + 1;
}

static void bsg_exit_rq(struct blk_mq_tag_set *set, struct request *req,
		       unsigned int hctx_idx)
{
	struct bsg_job *job = blk_mq_rq_to_pdu(req);

	kfree(job->reply);
}

void bsg_remove_queue(struct request_queue *q)
{
	if (q) {
		struct bsg_set *bset =
			container_of(q->tag_set, struct bsg_set, tag_set);

		bsg_unregister_queue(q);
		blk_cleanup_queue(q);
		blk_mq_free_tag_set(&bset->tag_set);
		kfree(bset);
	}
}
EXPORT_SYMBOL_GPL(bsg_remove_queue);

static enum blk_eh_timer_return bsg_timeout(struct request *rq, bool reserved)
{
	struct bsg_set *bset =
		container_of(rq->q->tag_set, struct bsg_set, tag_set);

	if (!bset->timeout_fn)
		return BLK_EH_DONE;
	return bset->timeout_fn(rq);
}

static const struct blk_mq_ops bsg_mq_ops = {
	.queue_rq		= bsg_queue_rq,
	.init_request		= bsg_init_rq,
	.exit_request		= bsg_exit_rq,
	.initialize_rq_fn	= bsg_initialize_rq,
	.complete		= bsg_complete,
	.timeout		= bsg_timeout,
};

/**
 * bsg_setup_queue - Create and add the bsg hooks so we can receive requests
 * @dev: device to attach bsg device to
 * @name: device to give bsg device
 * @job_fn: bsg job handler
 * @dd_job_size: size of LLD data needed for each job
 */
struct request_queue *bsg_setup_queue(struct device *dev, const char *name,
		bsg_job_fn *job_fn, bsg_timeout_fn *timeout, int dd_job_size)
{
	struct bsg_set *bset;
	struct blk_mq_tag_set *set;
	struct request_queue *q;
	int ret = -ENOMEM;

	bset = kzalloc(sizeof(*bset), GFP_KERNEL);
	if (!bset)
		return ERR_PTR(-ENOMEM);

	bset->job_fn = job_fn;
	bset->timeout_fn = timeout;

	set = &bset->tag_set;
	set->ops = &bsg_mq_ops,
	set->nr_hw_queues = 1;
	set->queue_depth = 128;
	set->numa_node = NUMA_NO_NODE;
	set->cmd_size = sizeof(struct bsg_job) + dd_job_size;
	set->flags = BLK_MQ_F_NO_SCHED | BLK_MQ_F_BLOCKING;
	if (blk_mq_alloc_tag_set(set))
		goto out_tag_set;

	q = blk_mq_init_queue(set);
	if (IS_ERR(q)) {
		ret = PTR_ERR(q);
		goto out_queue;
	}

	q->queuedata = dev;
	blk_queue_rq_timeout(q, BLK_DEFAULT_SG_TIMEOUT);

	ret = bsg_register_queue(q, dev, name, &bsg_transport_ops);
	if (ret) {
		printk(KERN_ERR "%s: bsg interface failed to "
		       "initialize - register queue\n", dev->kobj.name);
		goto out_cleanup_queue;
	}

	return q;
out_cleanup_queue:
	blk_cleanup_queue(q);
out_queue:
	blk_mq_free_tag_set(set);
out_tag_set:
	kfree(bset);
	return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(bsg_setup_queue);
Commit	Line	Data
aa387cc8 MC	1	/*
	2	* BSG helper library
	3	*
	4	* Copyright (C) 2008 James Smart, Emulex Corporation
	5	* Copyright (C) 2011 Red Hat, Inc. All rights reserved.
	6	* Copyright (C) 2011 Mike Christie
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License as published by
	10	* the Free Software Foundation; either version 2 of the License, or
	11	* (at your option) any later version.
	12	*
	13	* This program is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	* GNU General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU General Public License
	19	* along with this program; if not, write to the Free Software
	20	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	21	*
	22	*/
	23	#include <linux/slab.h>
cd2f076f	24	#include <linux/blk-mq.h>
aa387cc8 MC	25	#include <linux/delay.h>
	26	#include <linux/scatterlist.h>
	27	#include <linux/bsg-lib.h>
6adb1236	28	#include <linux/export.h>
aa387cc8	29	#include <scsi/scsi_cmnd.h>
17cb960f CH	30	#include <scsi/sg.h>
	31
	32	#define uptr64(val) ((void __user *)(uintptr_t)(val))
	33
1028e4b3 JA	34	struct bsg_set {
	35	struct blk_mq_tag_set tag_set;
	36	bsg_job_fn *job_fn;
	37	bsg_timeout_fn *timeout_fn;
	38	};
	39
17cb960f CH	40	static int bsg_transport_check_proto(struct sg_io_v4 *hdr)
	41	{
	42	if (hdr->protocol != BSG_PROTOCOL_SCSI \|\|
	43	hdr->subprotocol != BSG_SUB_PROTOCOL_SCSI_TRANSPORT)
	44	return -EINVAL;
	45	if (!capable(CAP_SYS_RAWIO))
	46	return -EPERM;
	47	return 0;
	48	}
	49
	50	static int bsg_transport_fill_hdr(struct request rq, struct sg_io_v4 hdr,
	51	fmode_t mode)
	52	{
	53	struct bsg_job *job = blk_mq_rq_to_pdu(rq);
972248e9	54	int ret;
17cb960f CH	55
	56	job->request_len = hdr->request_len;
	57	job->request = memdup_user(uptr64(hdr->request), hdr->request_len);
972248e9 CH	58	if (IS_ERR(job->request))
	59	return PTR_ERR(job->request);
	60
	61	if (hdr->dout_xfer_len && hdr->din_xfer_len) {
	62	job->bidi_rq = blk_get_request(rq->q, REQ_OP_SCSI_IN, 0);
	63	if (IS_ERR(job->bidi_rq)) {
	64	ret = PTR_ERR(job->bidi_rq);
	65	goto out;
	66	}
	67
	68	ret = blk_rq_map_user(rq->q, job->bidi_rq, NULL,
	69	uptr64(hdr->din_xferp), hdr->din_xfer_len,
	70	GFP_KERNEL);
	71	if (ret)
	72	goto out_free_bidi_rq;
	73
	74	job->bidi_bio = job->bidi_rq->bio;
	75	} else {
	76	job->bidi_rq = NULL;
	77	job->bidi_bio = NULL;
	78	}
47255491	79
972248e9 CH	80	return 0;
	81
	82	out_free_bidi_rq:
	83	if (job->bidi_rq)
	84	blk_put_request(job->bidi_rq);
	85	out:
	86	kfree(job->request);
	87	return ret;
17cb960f CH	88	}
	89
	90	static int bsg_transport_complete_rq(struct request rq, struct sg_io_v4 hdr)
	91	{
	92	struct bsg_job *job = blk_mq_rq_to_pdu(rq);
	93	int ret = 0;
	94
	95	/*
	96	* The assignments below don't make much sense, but are kept for
	97	* bug by bug backwards compatibility:
	98	*/
	99	hdr->device_status = job->result & 0xff;
	100	hdr->transport_status = host_byte(job->result);
	101	hdr->driver_status = driver_byte(job->result);
	102	hdr->info = 0;
	103	if (hdr->device_status \|\| hdr->transport_status \|\| hdr->driver_status)
	104	hdr->info \|= SG_INFO_CHECK;
	105	hdr->response_len = 0;
	106
	107	if (job->result < 0) {
	108	/* we're only returning the result field in the reply */
	109	job->reply_len = sizeof(u32);
	110	ret = job->result;
	111	}
	112
	113	if (job->reply_len && hdr->response) {
	114	int len = min(hdr->max_response_len, job->reply_len);
	115
	116	if (copy_to_user(uptr64(hdr->response), job->reply, len))
	117	ret = -EFAULT;
	118	else
	119	hdr->response_len = len;
	120	}
	121
	122	/* we assume all request payload was transferred, residual == 0 */
	123	hdr->dout_resid = 0;
	124
972248e9	125	if (job->bidi_rq) {
17cb960f CH	126	unsigned int rsp_len = job->reply_payload.payload_len;
	127
	128	if (WARN_ON(job->reply_payload_rcv_len > rsp_len))
	129	hdr->din_resid = 0;
	130	else
	131	hdr->din_resid = rsp_len - job->reply_payload_rcv_len;
	132	} else {
	133	hdr->din_resid = 0;
	134	}
	135
	136	return ret;
	137	}
	138
	139	static void bsg_transport_free_rq(struct request *rq)
	140	{
	141	struct bsg_job *job = blk_mq_rq_to_pdu(rq);
	142
972248e9 CH	143	if (job->bidi_rq) {
	144	blk_rq_unmap_user(job->bidi_bio);
	145	blk_put_request(job->bidi_rq);
	146	}
	147
17cb960f CH	148	kfree(job->request);
	149	}
	150
	151	static const struct bsg_ops bsg_transport_ops = {
	152	.check_proto = bsg_transport_check_proto,
	153	.fill_hdr = bsg_transport_fill_hdr,
	154	.complete_rq = bsg_transport_complete_rq,
	155	.free_rq = bsg_transport_free_rq,
	156	};
aa387cc8 MC	157
aa387cc8 MC	158	/**
50b4d485	159	* bsg_teardown_job - routine to teardown a bsg job
aa98192d	160	* @kref: kref inside bsg_job that is to be torn down
aa387cc8	161	*/
50b4d485	162	static void bsg_teardown_job(struct kref *kref)
aa387cc8	163	{
bf0f2d38	164	struct bsg_job *job = container_of(kref, struct bsg_job, kref);
ef6fa64f	165	struct request *rq = blk_mq_rq_from_pdu(job);
c00da4c9	166
aa387cc8 MC	167	put_device(job->dev); /* release reference for the request */
	168
	169	kfree(job->request_payload.sg_list);
	170	kfree(job->reply_payload.sg_list);
50b4d485	171
cd2f076f	172	blk_mq_end_request(rq, BLK_STS_OK);
aa387cc8 MC	173	}
aa387cc8 MC	174
fb6f7c8d JT	175	void bsg_job_put(struct bsg_job *job)
fb6f7c8d JT	176	{
50b4d485	177	kref_put(&job->kref, bsg_teardown_job);
fb6f7c8d JT	178	}
	179	EXPORT_SYMBOL_GPL(bsg_job_put);
	180
	181	int bsg_job_get(struct bsg_job *job)
	182	{
	183	return kref_get_unless_zero(&job->kref);
	184	}
	185	EXPORT_SYMBOL_GPL(bsg_job_get);
aa387cc8 MC	186
	187	/**
	188	* bsg_job_done - completion routine for bsg requests
	189	* @job: bsg_job that is complete
	190	* @result: job reply result
	191	* @reply_payload_rcv_len: length of payload recvd
	192	*
	193	* The LLD should call this when the bsg job has completed.
	194	*/
	195	void bsg_job_done(struct bsg_job *job, int result,
	196	unsigned int reply_payload_rcv_len)
	197	{
17cb960f CH	198	job->result = result;
17cb960f CH	199	job->reply_payload_rcv_len = reply_payload_rcv_len;
cd2f076f	200	blk_mq_complete_request(blk_mq_rq_from_pdu(job));
aa387cc8 MC	201	}
	202	EXPORT_SYMBOL_GPL(bsg_job_done);
	203
	204	/**
cd2f076f	205	* bsg_complete - softirq done routine for destroying the bsg requests
aa387cc8 MC	206	* @rq: BSG request that holds the job to be destroyed
aa387cc8 MC	207	*/
cd2f076f	208	static void bsg_complete(struct request *rq)
aa387cc8	209	{
50b4d485	210	struct bsg_job *job = blk_mq_rq_to_pdu(rq);
aa387cc8	211
fb6f7c8d	212	bsg_job_put(job);
aa387cc8 MC	213	}
	214
	215	static int bsg_map_buffer(struct bsg_buffer buf, struct request req)
	216	{
	217	size_t sz = (sizeof(struct scatterlist) * req->nr_phys_segments);
	218
	219	BUG_ON(!req->nr_phys_segments);
	220
	221	buf->sg_list = kzalloc(sz, GFP_KERNEL);
	222	if (!buf->sg_list)
	223	return -ENOMEM;
	224	sg_init_table(buf->sg_list, req->nr_phys_segments);
	225	buf->sg_cnt = blk_rq_map_sg(req->q, req, buf->sg_list);
	226	buf->payload_len = blk_rq_bytes(req);
	227	return 0;
	228	}
	229
	230	/**
50b4d485	231	* bsg_prepare_job - create the bsg_job structure for the bsg request
aa387cc8 MC	232	* @dev: device that is being sent the bsg request
	233	* @req: BSG request that needs a job structure
	234	*/
17cb960f	235	static bool bsg_prepare_job(struct device dev, struct request req)
aa387cc8	236	{
50b4d485	237	struct bsg_job *job = blk_mq_rq_to_pdu(req);
aa387cc8 MC	238	int ret;
aa387cc8 MC	239
31156ec3	240	job->timeout = req->timeout;
50b4d485	241
aa387cc8 MC	242	if (req->bio) {
	243	ret = bsg_map_buffer(&job->request_payload, req);
	244	if (ret)
	245	goto failjob_rls_job;
	246	}
972248e9 CH	247	if (job->bidi_rq) {
972248e9 CH	248	ret = bsg_map_buffer(&job->reply_payload, job->bidi_rq);
aa387cc8 MC	249	if (ret)
	250	goto failjob_rls_rqst_payload;
	251	}
	252	job->dev = dev;
	253	/* take a reference for the request */
	254	get_device(job->dev);
bf0f2d38	255	kref_init(&job->kref);
17cb960f	256	return true;
aa387cc8 MC	257
	258	failjob_rls_rqst_payload:
	259	kfree(job->request_payload.sg_list);
	260	failjob_rls_job:
17cb960f CH	261	job->result = -ENOMEM;
17cb960f CH	262	return false;
aa387cc8 MC	263	}
aa387cc8 MC	264
aa387cc8	265	/**
cd2f076f JA	266	* bsg_queue_rq - generic handler for bsg requests
	267	* @hctx: hardware queue
	268	* @bd: queue data
aa387cc8 MC	269	*
aa387cc8 MC	270	* On error the create_bsg_job function should return a -Exyz error value
17d5363b	271	* that will be set to ->result.
aa387cc8 MC	272	*
	273	* Drivers/subsys should pass this to the queue init function.
	274	*/
cd2f076f JA	275	static blk_status_t bsg_queue_rq(struct blk_mq_hw_ctx *hctx,
cd2f076f JA	276	const struct blk_mq_queue_data *bd)
aa387cc8	277	{
cd2f076f	278	struct request_queue *q = hctx->queue;
aa387cc8	279	struct device *dev = q->queuedata;
cd2f076f	280	struct request *req = bd->rq;
1028e4b3 JA	281	struct bsg_set *bset =
1028e4b3 JA	282	container_of(q->tag_set, struct bsg_set, tag_set);
aa387cc8 MC	283	int ret;
aa387cc8 MC	284
cd2f076f JA	285	blk_mq_start_request(req);
cd2f076f JA	286
aa387cc8	287	if (!get_device(dev))
cd2f076f JA	288	return BLK_STS_IOERR;
	289
	290	if (!bsg_prepare_job(dev, req))
	291	return BLK_STS_IOERR;
	292
1028e4b3	293	ret = bset->job_fn(blk_mq_rq_to_pdu(req));
cd2f076f JA	294	if (ret)
cd2f076f JA	295	return BLK_STS_IOERR;
aa387cc8	296
aa387cc8	297	put_device(dev);
cd2f076f	298	return BLK_STS_OK;
aa387cc8	299	}
aa387cc8	300
17cb960f	301	/* called right after the request is allocated for the request_queue */
cd2f076f JA	302	static int bsg_init_rq(struct blk_mq_tag_set set, struct request req,
cd2f076f JA	303	unsigned int hctx_idx, unsigned int numa_node)
50b4d485 BB	304	{
50b4d485 BB	305	struct bsg_job *job = blk_mq_rq_to_pdu(req);
eab40cf3	306
cd2f076f	307	job->reply = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_KERNEL);
17cb960f	308	if (!job->reply)
eab40cf3	309	return -ENOMEM;
eab40cf3 BB	310	return 0;
	311	}
	312
17cb960f	313	/* called right before the request is given to the request_queue user */
eab40cf3 BB	314	static void bsg_initialize_rq(struct request *req)
	315	{
	316	struct bsg_job *job = blk_mq_rq_to_pdu(req);
17cb960f	317	void *reply = job->reply;
eab40cf3	318
50b4d485	319	memset(job, 0, sizeof(*job));
17cb960f CH	320	job->reply = reply;
17cb960f CH	321	job->reply_len = SCSI_SENSE_BUFFERSIZE;
50b4d485	322	job->dd_data = job + 1;
50b4d485 BB	323	}
50b4d485 BB	324
cd2f076f JA	325	static void bsg_exit_rq(struct blk_mq_tag_set set, struct request req,
cd2f076f JA	326	unsigned int hctx_idx)
50b4d485 BB	327	{
50b4d485 BB	328	struct bsg_job *job = blk_mq_rq_to_pdu(req);
50b4d485	329
17cb960f	330	kfree(job->reply);
50b4d485 BB	331	}
50b4d485 BB	332
5e28b8d8 JA	333	void bsg_remove_queue(struct request_queue *q)
	334	{
	335	if (q) {
1028e4b3 JA	336	struct bsg_set *bset =
1028e4b3 JA	337	container_of(q->tag_set, struct bsg_set, tag_set);
cd2f076f	338
5e28b8d8 JA	339	bsg_unregister_queue(q);
5e28b8d8 JA	340	blk_cleanup_queue(q);
1028e4b3 JA	341	blk_mq_free_tag_set(&bset->tag_set);
1028e4b3 JA	342	kfree(bset);
5e28b8d8 JA	343	}
	344	}
	345	EXPORT_SYMBOL_GPL(bsg_remove_queue);
	346
cd2f076f JA	347	static enum blk_eh_timer_return bsg_timeout(struct request *rq, bool reserved)
cd2f076f JA	348	{
1028e4b3 JA	349	struct bsg_set *bset =
1028e4b3 JA	350	container_of(rq->q->tag_set, struct bsg_set, tag_set);
cd2f076f	351
1028e4b3 JA	352	if (!bset->timeout_fn)
	353	return BLK_EH_DONE;
	354	return bset->timeout_fn(rq);
cd2f076f JA	355	}
	356
	357	static const struct blk_mq_ops bsg_mq_ops = {
	358	.queue_rq = bsg_queue_rq,
	359	.init_request = bsg_init_rq,
	360	.exit_request = bsg_exit_rq,
	361	.initialize_rq_fn = bsg_initialize_rq,
	362	.complete = bsg_complete,
	363	.timeout = bsg_timeout,
	364	};
	365
aa387cc8 MC	366	/**
	367	* bsg_setup_queue - Create and add the bsg hooks so we can receive requests
	368	* @dev: device to attach bsg device to
aa387cc8 MC	369	* @name: device to give bsg device
	370	* @job_fn: bsg job handler
	371	* @dd_job_size: size of LLD data needed for each job
aa387cc8	372	*/
c1225f01	373	struct request_queue bsg_setup_queue(struct device dev, const char *name,
1028e4b3	374	bsg_job_fn job_fn, bsg_timeout_fn timeout, int dd_job_size)
aa387cc8	375	{
1028e4b3	376	struct bsg_set *bset;
cd2f076f	377	struct blk_mq_tag_set *set;
8ae94eb6	378	struct request_queue *q;
cd2f076f	379	int ret = -ENOMEM;
aa387cc8	380
1028e4b3 JA	381	bset = kzalloc(sizeof(*bset), GFP_KERNEL);
1028e4b3 JA	382	if (!bset)
8ae94eb6	383	return ERR_PTR(-ENOMEM);
82ed4db4	384
1028e4b3 JA	385	bset->job_fn = job_fn;
	386	bset->timeout_fn = timeout;
	387
	388	set = &bset->tag_set;
cd2f076f JA	389	set->ops = &bsg_mq_ops,
	390	set->nr_hw_queues = 1;
	391	set->queue_depth = 128;
	392	set->numa_node = NUMA_NO_NODE;
	393	set->cmd_size = sizeof(struct bsg_job) + dd_job_size;
	394	set->flags = BLK_MQ_F_NO_SCHED \| BLK_MQ_F_BLOCKING;
	395	if (blk_mq_alloc_tag_set(set))
	396	goto out_tag_set;
	397
	398	q = blk_mq_init_queue(set);
	399	if (IS_ERR(q)) {
	400	ret = PTR_ERR(q);
	401	goto out_queue;
	402	}
8ae94eb6	403
aa387cc8	404	q->queuedata = dev;
aa387cc8 MC	405	blk_queue_rq_timeout(q, BLK_DEFAULT_SG_TIMEOUT);
aa387cc8 MC	406
5de815a7	407	ret = bsg_register_queue(q, dev, name, &bsg_transport_ops);
aa387cc8 MC	408	if (ret) {
	409	printk(KERN_ERR "%s: bsg interface failed to "
	410	"initialize - register queue\n", dev->kobj.name);
82ed4db4	411	goto out_cleanup_queue;
aa387cc8 MC	412	}
aa387cc8 MC	413
8ae94eb6	414	return q;
82ed4db4 CH	415	out_cleanup_queue:
82ed4db4 CH	416	blk_cleanup_queue(q);
cd2f076f JA	417	out_queue:
	418	blk_mq_free_tag_set(set);
	419	out_tag_set:
1028e4b3	420	kfree(bset);
82ed4db4	421	return ERR_PTR(ret);
aa387cc8 MC	422	}
aa387cc8 MC	423	EXPORT_SYMBOL_GPL(bsg_setup_queue);