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

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  BSG helper library
 *
 *  Copyright (C) 2008   James Smart, Emulex Corporation
 *  Copyright (C) 2011   Red Hat, Inc.  All rights reserved.
 *  Copyright (C) 2011   Mike Christie
 */
#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)
{
	struct request *rq = blk_mq_rq_from_pdu(job);

	job->result = result;
	job->reply_payload_rcv_len = reply_payload_rcv_len;
	if (likely(!blk_should_fake_timeout(rq->q)))
		blk_mq_complete_request(rq);
}
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 = kmalloc(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);
	blk_status_t sts = BLK_STS_IOERR;
	int ret;

	blk_mq_start_request(req);

	if (!get_device(dev))
		return BLK_STS_IOERR;

	if (!bsg_prepare_job(dev, req))
		goto out;

	ret = bset->job_fn(blk_mq_rq_to_pdu(req));
	if (!ret)
		sts = BLK_STS_OK;

out:
	put_device(dev);
	return sts;
}

/* 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
 * @timeout: timeout handler function pointer
 * @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
a497ee34	1	// SPDX-License-Identifier: GPL-2.0-or-later
aa387cc8 MC	2	/*
	3	* BSG helper library
	4	*
	5	* Copyright (C) 2008 James Smart, Emulex Corporation
	6	* Copyright (C) 2011 Red Hat, Inc. All rights reserved.
	7	* Copyright (C) 2011 Mike Christie
aa387cc8 MC	8	*/
aa387cc8 MC	9	#include <linux/slab.h>
cd2f076f	10	#include <linux/blk-mq.h>
aa387cc8 MC	11	#include <linux/delay.h>
	12	#include <linux/scatterlist.h>
	13	#include <linux/bsg-lib.h>
6adb1236	14	#include <linux/export.h>
aa387cc8	15	#include <scsi/scsi_cmnd.h>
17cb960f CH	16	#include <scsi/sg.h>
	17
	18	#define uptr64(val) ((void __user *)(uintptr_t)(val))
	19
1028e4b3 JA	20	struct bsg_set {
	21	struct blk_mq_tag_set tag_set;
	22	bsg_job_fn *job_fn;
	23	bsg_timeout_fn *timeout_fn;
	24	};
	25
17cb960f CH	26	static int bsg_transport_check_proto(struct sg_io_v4 *hdr)
	27	{
	28	if (hdr->protocol != BSG_PROTOCOL_SCSI \|\|
	29	hdr->subprotocol != BSG_SUB_PROTOCOL_SCSI_TRANSPORT)
	30	return -EINVAL;
	31	if (!capable(CAP_SYS_RAWIO))
	32	return -EPERM;
	33	return 0;
	34	}
	35
	36	static int bsg_transport_fill_hdr(struct request rq, struct sg_io_v4 hdr,
	37	fmode_t mode)
	38	{
	39	struct bsg_job *job = blk_mq_rq_to_pdu(rq);
972248e9	40	int ret;
17cb960f CH	41
	42	job->request_len = hdr->request_len;
	43	job->request = memdup_user(uptr64(hdr->request), hdr->request_len);
972248e9 CH	44	if (IS_ERR(job->request))
	45	return PTR_ERR(job->request);
	46
	47	if (hdr->dout_xfer_len && hdr->din_xfer_len) {
	48	job->bidi_rq = blk_get_request(rq->q, REQ_OP_SCSI_IN, 0);
	49	if (IS_ERR(job->bidi_rq)) {
	50	ret = PTR_ERR(job->bidi_rq);
	51	goto out;
	52	}
	53
	54	ret = blk_rq_map_user(rq->q, job->bidi_rq, NULL,
	55	uptr64(hdr->din_xferp), hdr->din_xfer_len,
	56	GFP_KERNEL);
	57	if (ret)
	58	goto out_free_bidi_rq;
	59
	60	job->bidi_bio = job->bidi_rq->bio;
	61	} else {
	62	job->bidi_rq = NULL;
	63	job->bidi_bio = NULL;
	64	}
47255491	65
972248e9 CH	66	return 0;
	67
	68	out_free_bidi_rq:
	69	if (job->bidi_rq)
	70	blk_put_request(job->bidi_rq);
	71	out:
	72	kfree(job->request);
	73	return ret;
17cb960f CH	74	}
	75
	76	static int bsg_transport_complete_rq(struct request rq, struct sg_io_v4 hdr)
	77	{
	78	struct bsg_job *job = blk_mq_rq_to_pdu(rq);
	79	int ret = 0;
	80
	81	/*
	82	* The assignments below don't make much sense, but are kept for
	83	* bug by bug backwards compatibility:
	84	*/
	85	hdr->device_status = job->result & 0xff;
	86	hdr->transport_status = host_byte(job->result);
	87	hdr->driver_status = driver_byte(job->result);
	88	hdr->info = 0;
	89	if (hdr->device_status \|\| hdr->transport_status \|\| hdr->driver_status)
	90	hdr->info \|= SG_INFO_CHECK;
	91	hdr->response_len = 0;
	92
	93	if (job->result < 0) {
	94	/* we're only returning the result field in the reply */
	95	job->reply_len = sizeof(u32);
	96	ret = job->result;
	97	}
	98
	99	if (job->reply_len && hdr->response) {
	100	int len = min(hdr->max_response_len, job->reply_len);
	101
	102	if (copy_to_user(uptr64(hdr->response), job->reply, len))
	103	ret = -EFAULT;
	104	else
	105	hdr->response_len = len;
	106	}
	107
	108	/* we assume all request payload was transferred, residual == 0 */
	109	hdr->dout_resid = 0;
	110
972248e9	111	if (job->bidi_rq) {
17cb960f CH	112	unsigned int rsp_len = job->reply_payload.payload_len;
	113
	114	if (WARN_ON(job->reply_payload_rcv_len > rsp_len))
	115	hdr->din_resid = 0;
	116	else
	117	hdr->din_resid = rsp_len - job->reply_payload_rcv_len;
	118	} else {
	119	hdr->din_resid = 0;
	120	}
	121
	122	return ret;
	123	}
	124
	125	static void bsg_transport_free_rq(struct request *rq)
	126	{
	127	struct bsg_job *job = blk_mq_rq_to_pdu(rq);
	128
972248e9 CH	129	if (job->bidi_rq) {
	130	blk_rq_unmap_user(job->bidi_bio);
	131	blk_put_request(job->bidi_rq);
	132	}
	133
17cb960f CH	134	kfree(job->request);
	135	}
	136
	137	static const struct bsg_ops bsg_transport_ops = {
	138	.check_proto = bsg_transport_check_proto,
	139	.fill_hdr = bsg_transport_fill_hdr,
	140	.complete_rq = bsg_transport_complete_rq,
	141	.free_rq = bsg_transport_free_rq,
	142	};
aa387cc8 MC	143
aa387cc8 MC	144	/**
50b4d485	145	* bsg_teardown_job - routine to teardown a bsg job
aa98192d	146	* @kref: kref inside bsg_job that is to be torn down
aa387cc8	147	*/
50b4d485	148	static void bsg_teardown_job(struct kref *kref)
aa387cc8	149	{
bf0f2d38	150	struct bsg_job *job = container_of(kref, struct bsg_job, kref);
ef6fa64f	151	struct request *rq = blk_mq_rq_from_pdu(job);
c00da4c9	152
aa387cc8 MC	153	put_device(job->dev); /* release reference for the request */
	154
	155	kfree(job->request_payload.sg_list);
	156	kfree(job->reply_payload.sg_list);
50b4d485	157
cd2f076f	158	blk_mq_end_request(rq, BLK_STS_OK);
aa387cc8 MC	159	}
aa387cc8 MC	160
fb6f7c8d JT	161	void bsg_job_put(struct bsg_job *job)
fb6f7c8d JT	162	{
50b4d485	163	kref_put(&job->kref, bsg_teardown_job);
fb6f7c8d JT	164	}
	165	EXPORT_SYMBOL_GPL(bsg_job_put);
	166
	167	int bsg_job_get(struct bsg_job *job)
	168	{
	169	return kref_get_unless_zero(&job->kref);
	170	}
	171	EXPORT_SYMBOL_GPL(bsg_job_get);
aa387cc8 MC	172
	173	/**
	174	* bsg_job_done - completion routine for bsg requests
	175	* @job: bsg_job that is complete
	176	* @result: job reply result
	177	* @reply_payload_rcv_len: length of payload recvd
	178	*
	179	* The LLD should call this when the bsg job has completed.
	180	*/
	181	void bsg_job_done(struct bsg_job *job, int result,
	182	unsigned int reply_payload_rcv_len)
	183	{
15f73f5b CH	184	struct request *rq = blk_mq_rq_from_pdu(job);
15f73f5b CH	185
17cb960f CH	186	job->result = result;
17cb960f CH	187	job->reply_payload_rcv_len = reply_payload_rcv_len;
15f73f5b CH	188	if (likely(!blk_should_fake_timeout(rq->q)))
15f73f5b CH	189	blk_mq_complete_request(rq);
aa387cc8 MC	190	}
	191	EXPORT_SYMBOL_GPL(bsg_job_done);
	192
	193	/**
cd2f076f	194	* bsg_complete - softirq done routine for destroying the bsg requests
aa387cc8 MC	195	* @rq: BSG request that holds the job to be destroyed
aa387cc8 MC	196	*/
cd2f076f	197	static void bsg_complete(struct request *rq)
aa387cc8	198	{
50b4d485	199	struct bsg_job *job = blk_mq_rq_to_pdu(rq);
aa387cc8	200
fb6f7c8d	201	bsg_job_put(job);
aa387cc8 MC	202	}
	203
	204	static int bsg_map_buffer(struct bsg_buffer buf, struct request req)
	205	{
	206	size_t sz = (sizeof(struct scatterlist) * req->nr_phys_segments);
	207
	208	BUG_ON(!req->nr_phys_segments);
	209
f952eefe	210	buf->sg_list = kmalloc(sz, GFP_KERNEL);
aa387cc8 MC	211	if (!buf->sg_list)
	212	return -ENOMEM;
	213	sg_init_table(buf->sg_list, req->nr_phys_segments);
	214	buf->sg_cnt = blk_rq_map_sg(req->q, req, buf->sg_list);
	215	buf->payload_len = blk_rq_bytes(req);
	216	return 0;
	217	}
	218
	219	/**
50b4d485	220	* bsg_prepare_job - create the bsg_job structure for the bsg request
aa387cc8 MC	221	* @dev: device that is being sent the bsg request
	222	* @req: BSG request that needs a job structure
	223	*/
17cb960f	224	static bool bsg_prepare_job(struct device dev, struct request req)
aa387cc8	225	{
50b4d485	226	struct bsg_job *job = blk_mq_rq_to_pdu(req);
aa387cc8 MC	227	int ret;
aa387cc8 MC	228
31156ec3	229	job->timeout = req->timeout;
50b4d485	230
aa387cc8 MC	231	if (req->bio) {
	232	ret = bsg_map_buffer(&job->request_payload, req);
	233	if (ret)
	234	goto failjob_rls_job;
	235	}
972248e9 CH	236	if (job->bidi_rq) {
972248e9 CH	237	ret = bsg_map_buffer(&job->reply_payload, job->bidi_rq);
aa387cc8 MC	238	if (ret)
	239	goto failjob_rls_rqst_payload;
	240	}
	241	job->dev = dev;
	242	/* take a reference for the request */
	243	get_device(job->dev);
bf0f2d38	244	kref_init(&job->kref);
17cb960f	245	return true;
aa387cc8 MC	246
	247	failjob_rls_rqst_payload:
	248	kfree(job->request_payload.sg_list);
	249	failjob_rls_job:
17cb960f CH	250	job->result = -ENOMEM;
17cb960f CH	251	return false;
aa387cc8 MC	252	}
aa387cc8 MC	253
aa387cc8	254	/**
cd2f076f JA	255	* bsg_queue_rq - generic handler for bsg requests
	256	* @hctx: hardware queue
	257	* @bd: queue data
aa387cc8 MC	258	*
aa387cc8 MC	259	* On error the create_bsg_job function should return a -Exyz error value
17d5363b	260	* that will be set to ->result.
aa387cc8 MC	261	*
	262	* Drivers/subsys should pass this to the queue init function.
	263	*/
cd2f076f JA	264	static blk_status_t bsg_queue_rq(struct blk_mq_hw_ctx *hctx,
cd2f076f JA	265	const struct blk_mq_queue_data *bd)
aa387cc8	266	{
cd2f076f	267	struct request_queue *q = hctx->queue;
aa387cc8	268	struct device *dev = q->queuedata;
cd2f076f	269	struct request *req = bd->rq;
1028e4b3 JA	270	struct bsg_set *bset =
1028e4b3 JA	271	container_of(q->tag_set, struct bsg_set, tag_set);
c44a4edb	272	blk_status_t sts = BLK_STS_IOERR;
aa387cc8 MC	273	int ret;
aa387cc8 MC	274
cd2f076f JA	275	blk_mq_start_request(req);
cd2f076f JA	276
aa387cc8	277	if (!get_device(dev))
cd2f076f JA	278	return BLK_STS_IOERR;
	279
	280	if (!bsg_prepare_job(dev, req))
d46fe2cb	281	goto out;
cd2f076f	282
1028e4b3	283	ret = bset->job_fn(blk_mq_rq_to_pdu(req));
d46fe2cb MW	284	if (!ret)
d46fe2cb MW	285	sts = BLK_STS_OK;
aa387cc8	286
d46fe2cb	287	out:
aa387cc8	288	put_device(dev);
d46fe2cb	289	return sts;
aa387cc8	290	}
aa387cc8	291
17cb960f	292	/* called right after the request is allocated for the request_queue */
cd2f076f JA	293	static int bsg_init_rq(struct blk_mq_tag_set set, struct request req,
cd2f076f JA	294	unsigned int hctx_idx, unsigned int numa_node)
50b4d485 BB	295	{
50b4d485 BB	296	struct bsg_job *job = blk_mq_rq_to_pdu(req);
eab40cf3	297
cd2f076f	298	job->reply = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_KERNEL);
17cb960f	299	if (!job->reply)
eab40cf3	300	return -ENOMEM;
eab40cf3 BB	301	return 0;
	302	}
	303
17cb960f	304	/* called right before the request is given to the request_queue user */
eab40cf3 BB	305	static void bsg_initialize_rq(struct request *req)
	306	{
	307	struct bsg_job *job = blk_mq_rq_to_pdu(req);
17cb960f	308	void *reply = job->reply;
eab40cf3	309
50b4d485	310	memset(job, 0, sizeof(*job));
17cb960f CH	311	job->reply = reply;
17cb960f CH	312	job->reply_len = SCSI_SENSE_BUFFERSIZE;
50b4d485	313	job->dd_data = job + 1;
50b4d485 BB	314	}
50b4d485 BB	315
cd2f076f JA	316	static void bsg_exit_rq(struct blk_mq_tag_set set, struct request req,
cd2f076f JA	317	unsigned int hctx_idx)
50b4d485 BB	318	{
50b4d485 BB	319	struct bsg_job *job = blk_mq_rq_to_pdu(req);
50b4d485	320
17cb960f	321	kfree(job->reply);
50b4d485 BB	322	}
50b4d485 BB	323
5e28b8d8 JA	324	void bsg_remove_queue(struct request_queue *q)
	325	{
	326	if (q) {
1028e4b3 JA	327	struct bsg_set *bset =
1028e4b3 JA	328	container_of(q->tag_set, struct bsg_set, tag_set);
cd2f076f	329
5e28b8d8 JA	330	bsg_unregister_queue(q);
5e28b8d8 JA	331	blk_cleanup_queue(q);
1028e4b3 JA	332	blk_mq_free_tag_set(&bset->tag_set);
1028e4b3 JA	333	kfree(bset);
5e28b8d8 JA	334	}
	335	}
	336	EXPORT_SYMBOL_GPL(bsg_remove_queue);
	337
cd2f076f JA	338	static enum blk_eh_timer_return bsg_timeout(struct request *rq, bool reserved)
cd2f076f JA	339	{
1028e4b3 JA	340	struct bsg_set *bset =
1028e4b3 JA	341	container_of(rq->q->tag_set, struct bsg_set, tag_set);
cd2f076f	342
1028e4b3 JA	343	if (!bset->timeout_fn)
	344	return BLK_EH_DONE;
	345	return bset->timeout_fn(rq);
cd2f076f JA	346	}
	347
	348	static const struct blk_mq_ops bsg_mq_ops = {
	349	.queue_rq = bsg_queue_rq,
	350	.init_request = bsg_init_rq,
	351	.exit_request = bsg_exit_rq,
	352	.initialize_rq_fn = bsg_initialize_rq,
	353	.complete = bsg_complete,
	354	.timeout = bsg_timeout,
	355	};
	356
aa387cc8 MC	357	/**
	358	* bsg_setup_queue - Create and add the bsg hooks so we can receive requests
	359	* @dev: device to attach bsg device to
aa387cc8 MC	360	* @name: device to give bsg device
aa387cc8 MC	361	* @job_fn: bsg job handler
a0b77e36	362	* @timeout: timeout handler function pointer
aa387cc8	363	* @dd_job_size: size of LLD data needed for each job
aa387cc8	364	*/
c1225f01	365	struct request_queue bsg_setup_queue(struct device dev, const char *name,
1028e4b3	366	bsg_job_fn job_fn, bsg_timeout_fn timeout, int dd_job_size)
aa387cc8	367	{
1028e4b3	368	struct bsg_set *bset;
cd2f076f	369	struct blk_mq_tag_set *set;
8ae94eb6	370	struct request_queue *q;
cd2f076f	371	int ret = -ENOMEM;
aa387cc8	372
1028e4b3 JA	373	bset = kzalloc(sizeof(*bset), GFP_KERNEL);
1028e4b3 JA	374	if (!bset)
8ae94eb6	375	return ERR_PTR(-ENOMEM);
82ed4db4	376
1028e4b3 JA	377	bset->job_fn = job_fn;
	378	bset->timeout_fn = timeout;
	379
	380	set = &bset->tag_set;
03ef5941	381	set->ops = &bsg_mq_ops;
cd2f076f JA	382	set->nr_hw_queues = 1;
	383	set->queue_depth = 128;
	384	set->numa_node = NUMA_NO_NODE;
	385	set->cmd_size = sizeof(struct bsg_job) + dd_job_size;
	386	set->flags = BLK_MQ_F_NO_SCHED \| BLK_MQ_F_BLOCKING;
	387	if (blk_mq_alloc_tag_set(set))
	388	goto out_tag_set;
	389
	390	q = blk_mq_init_queue(set);
	391	if (IS_ERR(q)) {
	392	ret = PTR_ERR(q);
	393	goto out_queue;
	394	}
8ae94eb6	395
aa387cc8	396	q->queuedata = dev;
aa387cc8 MC	397	blk_queue_rq_timeout(q, BLK_DEFAULT_SG_TIMEOUT);
aa387cc8 MC	398
5de815a7	399	ret = bsg_register_queue(q, dev, name, &bsg_transport_ops);
aa387cc8 MC	400	if (ret) {
	401	printk(KERN_ERR "%s: bsg interface failed to "
	402	"initialize - register queue\n", dev->kobj.name);
82ed4db4	403	goto out_cleanup_queue;
aa387cc8 MC	404	}
aa387cc8 MC	405
8ae94eb6	406	return q;
82ed4db4 CH	407	out_cleanup_queue:
82ed4db4 CH	408	blk_cleanup_queue(q);
cd2f076f JA	409	out_queue:
	410	blk_mq_free_tag_set(set);
	411	out_tag_set:
1028e4b3	412	kfree(bset);
82ed4db4	413	return ERR_PTR(ret);
aa387cc8 MC	414	}
aa387cc8 MC	415	EXPORT_SYMBOL_GPL(bsg_setup_queue);