// 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/bsg.h>#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;	struct bsg_device	*bd;	bsg_job_fn		*job_fn;	bsg_timeout_fn		*timeout_fn;}; static int bsg_transport_sg_io_fn(struct request_queue *q, struct sg_io_v4 *hdr,		bool open_for_write, unsigned int timeout){	struct bsg_job *job;	struct request *rq;	struct bio *bio;	void *reply;	int ret; 	if (hdr->protocol != BSG_PROTOCOL_SCSI  ||	    hdr->subprotocol != BSG_SUB_PROTOCOL_SCSI_TRANSPORT)		return -EINVAL;	if (!capable(CAP_SYS_RAWIO))		return -EPERM; 	rq = blk_mq_alloc_request(q, hdr->dout_xfer_len ?			     REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);	if (IS_ERR(rq))		return PTR_ERR(rq);	rq->timeout = timeout; 	job = blk_mq_rq_to_pdu(rq);	reply = job->reply;	memset(job, 0, sizeof(*job));	job->reply = reply;	job->reply_len = SCSI_SENSE_BUFFERSIZE;	job->dd_data = job + 1; 	job->request_len = hdr->request_len;	job->request = memdup_user(uptr64(hdr->request), hdr->request_len);	if (IS_ERR(job->request)) {		ret = PTR_ERR(job->request);		goto out_free_rq;	} 	if (hdr->dout_xfer_len && hdr->din_xfer_len) {		job->bidi_rq = blk_mq_alloc_request(rq->q, REQ_OP_DRV_IN, 0);		if (IS_ERR(job->bidi_rq)) {			ret = PTR_ERR(job->bidi_rq);			goto out_free_job_request;		} 		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;	} 	ret = 0;	if (hdr->dout_xfer_len) {		ret = blk_rq_map_user(rq->q, rq, NULL, uptr64(hdr->dout_xferp),				hdr->dout_xfer_len, GFP_KERNEL);	} else if (hdr->din_xfer_len) {		ret = blk_rq_map_user(rq->q, rq, NULL, uptr64(hdr->din_xferp),				hdr->din_xfer_len, GFP_KERNEL);	} 	if (ret)		goto out_unmap_bidi_rq; 	bio = rq->bio;	blk_execute_rq(rq, !(hdr->flags & BSG_FLAG_Q_AT_TAIL)); 	/*	 * 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 = 0;	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;	} 	blk_rq_unmap_user(bio);out_unmap_bidi_rq:	if (job->bidi_rq)		blk_rq_unmap_user(job->bidi_bio);out_free_bidi_rq:	if (job->bidi_rq)		blk_mq_free_request(job->bidi_rq);out_free_job_request:	kfree(job->request);out_free_rq:	blk_mq_free_request(rq);	return ret;} /** * 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, 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, 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;} 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(bset->bd);		blk_mq_destroy_queue(q);		blk_put_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){	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,	.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 * @lim: queue limits for the bsg queue * @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,		struct queue_limits *lim, 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_obj(*bset);	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_BLOCKING;	if (blk_mq_alloc_tag_set(set))		goto out_tag_set; 	q = blk_mq_alloc_queue(set, lim, dev);	if (IS_ERR(q)) {		ret = PTR_ERR(q);		goto out_queue;	} 	blk_queue_rq_timeout(q, BLK_DEFAULT_SG_TIMEOUT); 	bset->bd = bsg_register_queue(q, dev, name, bsg_transport_sg_io_fn, NULL);	if (IS_ERR(bset->bd)) {		ret = PTR_ERR(bset->bd);		goto out_cleanup_queue;	} 	return q;out_cleanup_queue:	blk_mq_destroy_queue(q);	blk_put_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);