scsi: scsi_transport_sas: switch to bsg-lib for SMP passthrough

Simplify the SMP passthrough code by switching it to the generic bsg-lib
helpers that abstract away the details of the request code, and gets
drivers out of seeing struct scsi_request.

For the libsas host SMP code there is a small behavior difference in
that we now always clear the residual len for successful commands,
similar to the three other SMP handler implementations.  Given that
there is no partial command handling in the host SMP handler this should
not matter in practice.

[mkp: typos and checkpatch fixes]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/message/fusion/mptsas.c

@@ -2210,33 +2210,26 @@ mptsas_get_bay_identifier(struct sas_rphy *rphy)
 	return rc;
 }
 
-static int mptsas_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
-			      struct request *req)
+static void mptsas_smp_handler(struct bsg_job *job, struct Scsi_Host *shost,
+		struct sas_rphy *rphy)
 {
 	MPT_ADAPTER *ioc = ((MPT_SCSI_HOST *) shost->hostdata)->ioc;
 	MPT_FRAME_HDR *mf;
 	SmpPassthroughRequest_t *smpreq;
-	struct request *rsp = req->next_rq;
-	int ret;
 	int flagsLength;
 	unsigned long timeleft;
 	char *psge;
-	dma_addr_t dma_addr_in = 0;
-	dma_addr_t dma_addr_out = 0;
 	u64 sas_address = 0;
-
-	if (!rsp) {
-		printk(MYIOC_s_ERR_FMT "%s: the smp response space is missing\n",
-		    ioc->name, __func__);
-		return -EINVAL;
-	}
+	unsigned int reslen = 0;
+	int ret = -EINVAL;
 
 	/* do we need to support multiple segments? */
-	if (bio_multiple_segments(req->bio) ||
-	    bio_multiple_segments(rsp->bio)) {
+	if (job->request_payload.sg_cnt > 1 ||
+	    job->reply_payload.sg_cnt > 1) {
 		printk(MYIOC_s_ERR_FMT "%s: multiple segments req %u, rsp %u\n",
-		    ioc->name, __func__, blk_rq_bytes(req), blk_rq_bytes(rsp));
-		return -EINVAL;
+		    ioc->name, __func__, job->request_payload.payload_len,
+		    job->reply_payload.payload_len);
+		goto out;
 	}
 
 	ret = mutex_lock_interruptible(&ioc->sas_mgmt.mutex);
@@ -2252,7 +2245,8 @@ static int mptsas_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
 	smpreq = (SmpPassthroughRequest_t *)mf;
 	memset(smpreq, 0, sizeof(*smpreq));
 
-	smpreq->RequestDataLength = cpu_to_le16(blk_rq_bytes(req) - 4);
+	smpreq->RequestDataLength =
+		cpu_to_le16(job->request_payload.payload_len - 4);
 	smpreq->Function = MPI_FUNCTION_SMP_PASSTHROUGH;
 
 	if (rphy)
@@ -2278,13 +2272,14 @@ static int mptsas_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
 		       MPI_SGE_FLAGS_END_OF_BUFFER |
 		       MPI_SGE_FLAGS_DIRECTION)
 		       << MPI_SGE_FLAGS_SHIFT;
-	flagsLength |= (blk_rq_bytes(req) - 4);
 
-	dma_addr_out = pci_map_single(ioc->pcidev, bio_data(req->bio),
-				      blk_rq_bytes(req), PCI_DMA_BIDIRECTIONAL);
-	if (pci_dma_mapping_error(ioc->pcidev, dma_addr_out))
+	if (!dma_map_sg(&ioc->pcidev->dev, job->request_payload.sg_list,
+			1, PCI_DMA_BIDIRECTIONAL))
 		goto put_mf;
-	ioc->add_sge(psge, flagsLength, dma_addr_out);
+
+	flagsLength |= (sg_dma_len(job->request_payload.sg_list) - 4);
+	ioc->add_sge(psge, flagsLength,
+			sg_dma_address(job->request_payload.sg_list));
 	psge += ioc->SGE_size;
 
 	/* response */
@@ -2294,12 +2289,13 @@ static int mptsas_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
 		MPI_SGE_FLAGS_END_OF_BUFFER;
 
 	flagsLength = flagsLength << MPI_SGE_FLAGS_SHIFT;
-	flagsLength |= blk_rq_bytes(rsp) + 4;
-	dma_addr_in =  pci_map_single(ioc->pcidev, bio_data(rsp->bio),
-				      blk_rq_bytes(rsp), PCI_DMA_BIDIRECTIONAL);
-	if (pci_dma_mapping_error(ioc->pcidev, dma_addr_in))
-		goto unmap;
-	ioc->add_sge(psge, flagsLength, dma_addr_in);
+
+	if (!dma_map_sg(&ioc->pcidev->dev, job->reply_payload.sg_list,
+			1, PCI_DMA_BIDIRECTIONAL))
+		goto unmap_out;
+	flagsLength |= sg_dma_len(job->reply_payload.sg_list) + 4;
+	ioc->add_sge(psge, flagsLength,
+			sg_dma_address(job->reply_payload.sg_list));
 
 	INITIALIZE_MGMT_STATUS(ioc->sas_mgmt.status)
 	mpt_put_msg_frame(mptsasMgmtCtx, ioc, mf);
@@ -2310,10 +2306,10 @@ static int mptsas_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
 		mpt_free_msg_frame(ioc, mf);
 		mf = NULL;
 		if (ioc->sas_mgmt.status & MPT_MGMT_STATUS_DID_IOCRESET)
-			goto unmap;
+			goto unmap_in;
 		if (!timeleft)
 			mpt_Soft_Hard_ResetHandler(ioc, CAN_SLEEP);
-		goto unmap;
+		goto unmap_in;
 	}
 	mf = NULL;
 
@@ -2321,23 +2317,22 @@ static int mptsas_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
 		SmpPassthroughReply_t *smprep;
 
 		smprep = (SmpPassthroughReply_t *)ioc->sas_mgmt.reply;
-		memcpy(scsi_req(req)->sense, smprep, sizeof(*smprep));
-		scsi_req(req)->sense_len = sizeof(*smprep);
-		scsi_req(req)->resid_len = 0;
-		scsi_req(rsp)->resid_len -= smprep->ResponseDataLength;
+		memcpy(job->reply, smprep, sizeof(*smprep));
+		job->reply_len = sizeof(*smprep);
+		reslen = smprep->ResponseDataLength;
 	} else {
 		printk(MYIOC_s_ERR_FMT
 		    "%s: smp passthru reply failed to be returned\n",
 		    ioc->name, __func__);
 		ret = -ENXIO;
 	}
-unmap:
-	if (dma_addr_out)
-		pci_unmap_single(ioc->pcidev, dma_addr_out, blk_rq_bytes(req),
-				 PCI_DMA_BIDIRECTIONAL);
-	if (dma_addr_in)
-		pci_unmap_single(ioc->pcidev, dma_addr_in, blk_rq_bytes(rsp),
-				 PCI_DMA_BIDIRECTIONAL);
+
+unmap_in:
+	dma_unmap_sg(&ioc->pcidev->dev, job->reply_payload.sg_list, 1,
+			PCI_DMA_BIDIRECTIONAL);
+unmap_out:
+	dma_unmap_sg(&ioc->pcidev->dev, job->request_payload.sg_list, 1,
+			PCI_DMA_BIDIRECTIONAL);
 put_mf:
 	if (mf)
 		mpt_free_msg_frame(ioc, mf);
@@ -2345,7 +2340,7 @@ out_unlock:
 	CLEAR_MGMT_STATUS(ioc->sas_mgmt.status)
 	mutex_unlock(&ioc->sas_mgmt.mutex);
 out:
-	return ret;
+	bsg_job_done(job, ret, reslen);
 }
 
 static struct sas_function_template mptsas_transport_functions = {

drivers/scsi/libsas/Kconfig

@@ -26,6 +26,7 @@ config SCSI_SAS_LIBSAS
 	tristate "SAS Domain Transport Attributes"
 	depends on SCSI
 	select SCSI_SAS_ATTRS
+	select BLK_DEV_BSGLIB
 	help
 	  This provides transport specific helpers for SAS drivers which
 	  use the domain device construct (like the aic94xxx).

drivers/scsi/libsas/sas_expander.c

@@ -64,8 +64,8 @@ static void smp_task_done(struct sas_task *task)
 /* Give it some long enough timeout. In seconds. */
 #define SMP_TIMEOUT 10
 
-static int smp_execute_task(struct domain_device *dev, void *req, int req_size,
-			    void *resp, int resp_size)
+static int smp_execute_task_sg(struct domain_device *dev,
+		struct scatterlist *req, struct scatterlist *resp)
 {
 	int res, retry;
 	struct sas_task *task = NULL;
@@ -86,8 +86,8 @@ static int smp_execute_task(struct domain_device *dev, void *req, int req_size,
 		}
 		task->dev = dev;
 		task->task_proto = dev->tproto;
-		sg_init_one(&task->smp_task.smp_req, req, req_size);
-		sg_init_one(&task->smp_task.smp_resp, resp, resp_size);
+		task->smp_task.smp_req = *req;
+		task->smp_task.smp_resp = *resp;
 
 		task->task_done = smp_task_done;
 
@@ -151,6 +151,17 @@ static int smp_execute_task(struct domain_device *dev, void *req, int req_size,
 	return res;
 }
 
+static int smp_execute_task(struct domain_device *dev, void *req, int req_size,
+			    void *resp, int resp_size)
+{
+	struct scatterlist req_sg;
+	struct scatterlist resp_sg;
+
+	sg_init_one(&req_sg, req, req_size);
+	sg_init_one(&resp_sg, resp, resp_size);
+	return smp_execute_task_sg(dev, &req_sg, &resp_sg);
+}
+
 /* ---------- Allocations ---------- */
 
 static inline void *alloc_smp_req(int size)
@@ -2130,57 +2141,50 @@ int sas_ex_revalidate_domain(struct domain_device *port_dev)
 	return res;
 }
 
-int sas_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
-		    struct request *req)
+void sas_smp_handler(struct bsg_job *job, struct Scsi_Host *shost,
+		struct sas_rphy *rphy)
 {
 	struct domain_device *dev;
-	int ret, type;
-	struct request *rsp = req->next_rq;
-
-	if (!rsp) {
-		printk("%s: space for a smp response is missing\n",
-		       __func__);
-		return -EINVAL;
-	}
+	unsigned int reslen = 0;
+	int ret = -EINVAL;
 
 	/* no rphy means no smp target support (ie aic94xx host) */
 	if (!rphy)
-		return sas_smp_host_handler(shost, req, rsp);
-
-	type = rphy->identify.device_type;
+		return sas_smp_host_handler(job, shost);
 
-	if (type != SAS_EDGE_EXPANDER_DEVICE &&
-	    type != SAS_FANOUT_EXPANDER_DEVICE) {
+	switch (rphy->identify.device_type) {
+	case SAS_EDGE_EXPANDER_DEVICE:
+	case SAS_FANOUT_EXPANDER_DEVICE:
+		break;
+	default:
 		printk("%s: can we send a smp request to a device?\n",
 		       __func__);
-		return -EINVAL;
+		goto out;
 	}
 
 	dev = sas_find_dev_by_rphy(rphy);
 	if (!dev) {
 		printk("%s: fail to find a domain_device?\n", __func__);
-		return -EINVAL;
+		goto out;
 	}
 
 	/* do we need to support multiple segments? */
-	if (bio_multiple_segments(req->bio) ||
-	    bio_multiple_segments(rsp->bio)) {
+	if (job->request_payload.sg_cnt > 1 ||
+	    job->reply_payload.sg_cnt > 1) {
 		printk("%s: multiple segments req %u, rsp %u\n",
-		       __func__, blk_rq_bytes(req), blk_rq_bytes(rsp));
-		return -EINVAL;
+		       __func__, job->request_payload.payload_len,
+		       job->reply_payload.payload_len);
+		goto out;
 	}
 
-	ret = smp_execute_task(dev, bio_data(req->bio), blk_rq_bytes(req),
-			       bio_data(rsp->bio), blk_rq_bytes(rsp));
+	ret = smp_execute_task_sg(dev, job->request_payload.sg_list,
+			job->reply_payload.sg_list);
 	if (ret > 0) {
 		/* positive number is the untransferred residual */
-		scsi_req(rsp)->resid_len = ret;
-		scsi_req(req)->resid_len = 0;
+		reslen = ret;
 		ret = 0;
-	} else if (ret == 0) {
-		scsi_req(rsp)->resid_len = 0;
-		scsi_req(req)->resid_len = 0;
 	}
 
-	return ret;
+out:
+	bsg_job_done(job, ret, reslen);
 }

drivers/scsi/libsas/sas_host_smp.c

@@ -225,47 +225,36 @@ static void sas_phy_control(struct sas_ha_struct *sas_ha, u8 phy_id,
 		resp_data[2] = SMP_RESP_FUNC_ACC;
 }
 
-int sas_smp_host_handler(struct Scsi_Host *shost, struct request *req,
-			 struct request *rsp)
+void sas_smp_host_handler(struct bsg_job *job, struct Scsi_Host *shost)
 {
-	u8 *req_data = NULL, *resp_data = NULL, *buf;
 	struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
+	u8 *req_data, *resp_data;
+	unsigned int reslen = 0;
 	int error = -EINVAL;
 
 	/* eight is the minimum size for request and response frames */
-	if (blk_rq_bytes(req) < 8 || blk_rq_bytes(rsp) < 8)
+	if (job->request_payload.payload_len < 8 ||
+	    job->reply_payload.payload_len < 8)
 		goto out;
 
-	if (bio_offset(req->bio) + blk_rq_bytes(req) > PAGE_SIZE ||
-	    bio_offset(rsp->bio) + blk_rq_bytes(rsp) > PAGE_SIZE) {
-		shost_printk(KERN_ERR, shost,
-			"SMP request/response frame crosses page boundary");
+	error = -ENOMEM;
+	req_data = kzalloc(job->request_payload.payload_len, GFP_KERNEL);
+	if (!req_data)
 		goto out;
-	}
-
-	req_data = kzalloc(blk_rq_bytes(req), GFP_KERNEL);
+	sg_copy_to_buffer(job->request_payload.sg_list,
+			  job->request_payload.sg_cnt, req_data,
+			  job->request_payload.payload_len);
 
 	/* make sure frame can always be built ... we copy
 	 * back only the requested length */
-	resp_data = kzalloc(max(blk_rq_bytes(rsp), 128U), GFP_KERNEL);
-
-	if (!req_data || !resp_data) {
-		error = -ENOMEM;
-		goto out;
-	}
-
-	local_irq_disable();
-	buf = kmap_atomic(bio_page(req->bio));
-	memcpy(req_data, buf, blk_rq_bytes(req));
-	kunmap_atomic(buf - bio_offset(req->bio));
-	local_irq_enable();
+	resp_data = kzalloc(max(job->reply_payload.payload_len, 128U),
+			GFP_KERNEL);
+	if (!resp_data)
+		goto out_free_req;
 
+	error = -EINVAL;
 	if (req_data[0] != SMP_REQUEST)
-		goto out;
-
-	/* always succeeds ... even if we can't process the request
-	 * the result is in the response frame */
-	error = 0;
+		goto out_free_resp;
 
 	/* set up default don't know response */
 	resp_data[0] = SMP_RESPONSE;
@@ -274,20 +263,18 @@ int sas_smp_host_handler(struct Scsi_Host *shost, struct request *req,
 
 	switch (req_data[1]) {
 	case SMP_REPORT_GENERAL:
-		scsi_req(req)->resid_len -= 8;
-		scsi_req(rsp)->resid_len -= 32;
 		resp_data[2] = SMP_RESP_FUNC_ACC;
 		resp_data[9] = sas_ha->num_phys;
+		reslen = 32;
 		break;
 
 	case SMP_REPORT_MANUF_INFO:
-		scsi_req(req)->resid_len -= 8;
-		scsi_req(rsp)->resid_len -= 64;
 		resp_data[2] = SMP_RESP_FUNC_ACC;
 		memcpy(resp_data + 12, shost->hostt->name,
 		       SAS_EXPANDER_VENDOR_ID_LEN);
 		memcpy(resp_data + 20, "libsas virt phy",
 		       SAS_EXPANDER_PRODUCT_ID_LEN);
+		reslen = 64;
 		break;
 
 	case SMP_READ_GPIO_REG:
@@ -295,14 +282,10 @@ int sas_smp_host_handler(struct Scsi_Host *shost, struct request *req,
 		break;
 
 	case SMP_DISCOVER:
-		scsi_req(req)->resid_len -= 16;
-		if ((int)scsi_req(req)->resid_len < 0) {
-			scsi_req(req)->resid_len = 0;
-			error = -EINVAL;
-			goto out;
-		}
-		scsi_req(rsp)->resid_len -= 56;
+		if (job->request_payload.payload_len < 16)
+			goto out_free_resp;
 		sas_host_smp_discover(sas_ha, resp_data, req_data[9]);
+		reslen = 56;
 		break;
 
 	case SMP_REPORT_PHY_ERR_LOG:
@@ -311,14 +294,10 @@ int sas_smp_host_handler(struct Scsi_Host *shost, struct request *req,
 		break;
 
 	case SMP_REPORT_PHY_SATA:
-		scsi_req(req)->resid_len -= 16;
-		if ((int)scsi_req(req)->resid_len < 0) {
-			scsi_req(req)->resid_len = 0;
-			error = -EINVAL;
-			goto out;
-		}
-		scsi_req(rsp)->resid_len -= 60;
+		if (job->request_payload.payload_len < 16)
+			goto out_free_resp;
 		sas_report_phy_sata(sas_ha, resp_data, req_data[9]);
+		reslen = 60;
 		break;
 
 	case SMP_REPORT_ROUTE_INFO:
@@ -330,16 +309,15 @@ int sas_smp_host_handler(struct Scsi_Host *shost, struct request *req,
 		const int base_frame_size = 11;
 		int to_write = req_data[4];
 
-		if (blk_rq_bytes(req) < base_frame_size + to_write * 4 ||
-		    scsi_req(req)->resid_len < base_frame_size + to_write * 4) {
+		if (job->request_payload.payload_len <
+				base_frame_size + to_write * 4) {
 			resp_data[2] = SMP_RESP_INV_FRM_LEN;
 			break;
 		}
 
 		to_write = sas_host_smp_write_gpio(sas_ha, resp_data, req_data[2],
 						   req_data[3], to_write, &req_data[8]);
-		scsi_req(req)->resid_len -= base_frame_size + to_write * 4;
-		scsi_req(rsp)->resid_len -= 8;
+		reslen = 8;
 		break;
 	}
 
@@ -348,16 +326,12 @@ int sas_smp_host_handler(struct Scsi_Host *shost, struct request *req,
 		break;
 
 	case SMP_PHY_CONTROL:
-		scsi_req(req)->resid_len -= 44;
-		if ((int)scsi_req(req)->resid_len < 0) {
-			scsi_req(req)->resid_len = 0;
-			error = -EINVAL;
-			goto out;
-		}
-		scsi_req(rsp)->resid_len -= 8;
+		if (job->request_payload.payload_len < 44)
+			goto out_free_resp;
 		sas_phy_control(sas_ha, req_data[9], req_data[10],
 				req_data[32] >> 4, req_data[33] >> 4,
 				resp_data);
+		reslen = 8;
 		break;
 
 	case SMP_PHY_TEST_FUNCTION:
@@ -369,15 +343,15 @@ int sas_smp_host_handler(struct Scsi_Host *shost, struct request *req,
 		break;
 	}
 
-	local_irq_disable();
-	buf = kmap_atomic(bio_page(rsp->bio));
-	memcpy(buf, resp_data, blk_rq_bytes(rsp));
-	flush_kernel_dcache_page(bio_page(rsp->bio));
-	kunmap_atomic(buf - bio_offset(rsp->bio));
-	local_irq_enable();
+	sg_copy_from_buffer(job->reply_payload.sg_list,
+			    job->reply_payload.sg_cnt, resp_data,
+			    job->reply_payload.payload_len);
 
- out:
-	kfree(req_data);
+	error = 0;
+out_free_resp:
 	kfree(resp_data);
-	return error;
+out_free_req:
+	kfree(req_data);
+out:
+	bsg_job_done(job, error, reslen);
 }

drivers/scsi/libsas/sas_internal.h

@@ -81,6 +81,8 @@ int sas_queue_work(struct sas_ha_struct *ha, struct sas_work *sw);
 int sas_notify_lldd_dev_found(struct domain_device *);
 void sas_notify_lldd_dev_gone(struct domain_device *);
 
+void sas_smp_handler(struct bsg_job *job, struct Scsi_Host *shost,
+		struct sas_rphy *rphy);
 int sas_smp_phy_control(struct domain_device *dev, int phy_id,
 			enum phy_func phy_func, struct sas_phy_linkrates *);
 int sas_smp_get_phy_events(struct sas_phy *phy);
@@ -98,16 +100,14 @@ void sas_hae_reset(struct work_struct *work);
 void sas_free_device(struct kref *kref);
 
 #ifdef CONFIG_SCSI_SAS_HOST_SMP
-extern int sas_smp_host_handler(struct Scsi_Host *shost, struct request *req,
-				struct request *rsp);
+extern void sas_smp_host_handler(struct bsg_job *job, struct Scsi_Host *shost);
 #else
-static inline int sas_smp_host_handler(struct Scsi_Host *shost,
-				       struct request *req,
-				       struct request *rsp)
+static inline void sas_smp_host_handler(struct bsg_job *job,
+		struct Scsi_Host *shost)
 {
 	shost_printk(KERN_ERR, shost,
 		"Cannot send SMP to a sas host (not enabled in CONFIG)\n");
-	return -EINVAL;
+	bsg_job_done(job, -EINVAL, 0);
 }
 #endif
 

drivers/scsi/mpt3sas/mpt3sas_transport.c

@@ -1870,6 +1870,38 @@ _transport_phy_speed(struct sas_phy *phy, struct sas_phy_linkrates *rates)
 	return rc;
 }
 
+static int
+_transport_map_smp_buffer(struct device *dev, struct bsg_buffer *buf,
+		dma_addr_t *dma_addr, size_t *dma_len, void **p)
+{
+	/* Check if the request is split across multiple segments */
+	if (buf->sg_cnt > 1) {
+		*p = dma_alloc_coherent(dev, buf->payload_len, dma_addr,
+				GFP_KERNEL);
+		if (!*p)
+			return -ENOMEM;
+		*dma_len = buf->payload_len;
+	} else {
+		if (!dma_map_sg(dev, buf->sg_list, 1, DMA_BIDIRECTIONAL))
+			return -ENOMEM;
+		*dma_addr = sg_dma_address(buf->sg_list);
+		*dma_len = sg_dma_len(buf->sg_list);
+		*p = NULL;
+	}
+
+	return 0;
+}
+
+static void
+_transport_unmap_smp_buffer(struct device *dev, struct bsg_buffer *buf,
+		dma_addr_t dma_addr, void *p)
+{
+	if (p)
+		dma_free_coherent(dev, buf->payload_len, p, dma_addr);
+	else
+		dma_unmap_sg(dev, buf->sg_list, 1, DMA_BIDIRECTIONAL);
+}
+
 /**
  * _transport_smp_handler - transport portal for smp passthru
  * @shost: shost object
@@ -1880,9 +1912,9 @@ _transport_phy_speed(struct sas_phy *phy, struct sas_phy_linkrates *rates)
  * Example:
  *           smp_rep_general /sys/class/bsg/expander-5:0
  */
-static int
-_transport_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
-	struct request *req)
+static void
+_transport_smp_handler(struct bsg_job *job, struct Scsi_Host *shost,
+		struct sas_rphy *rphy)
 {
 	struct MPT3SAS_ADAPTER *ioc = shost_priv(shost);
 	Mpi2SmpPassthroughRequest_t *mpi_request;
@@ -1891,33 +1923,25 @@ _transport_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
 	u16 smid;
 	u32 ioc_state;
 	void *psge;
-	u8 issue_reset = 0;
-	dma_addr_t dma_addr_in = 0;
-	dma_addr_t dma_addr_out = 0;
-	dma_addr_t pci_dma_in = 0;
-	dma_addr_t pci_dma_out = 0;
-	void *pci_addr_in = NULL;
-	void *pci_addr_out = NULL;
+	dma_addr_t dma_addr_in;
+	dma_addr_t dma_addr_out;
+	void *addr_in = NULL;
+	void *addr_out = NULL;
+	size_t dma_len_in;
+	size_t dma_len_out;
 	u16 wait_state_count;
-	struct request *rsp = req->next_rq;
-	struct bio_vec bvec;
-	struct bvec_iter iter;
-
-	if (!rsp) {
-		pr_err(MPT3SAS_FMT "%s: the smp response space is missing\n",
-			ioc->name, __func__);
-		return -EINVAL;
-	}
+	unsigned int reslen = 0;
 
 	if (ioc->shost_recovery || ioc->pci_error_recovery) {
 		pr_info(MPT3SAS_FMT "%s: host reset in progress!\n",
 		    __func__, ioc->name);
-		return -EFAULT;
+		rc = -EFAULT;
+		goto out;
 	}
 
 	rc = mutex_lock_interruptible(&ioc->transport_cmds.mutex);
 	if (rc)
-		return rc;
+		goto out;
 
 	if (ioc->transport_cmds.status != MPT3_CMD_NOT_USED) {
 		pr_err(MPT3SAS_FMT "%s: transport_cmds in use\n", ioc->name,
@@ -1927,58 +1951,20 @@ _transport_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
 	}
 	ioc->transport_cmds.status = MPT3_CMD_PENDING;
 
-	/* Check if the request is split across multiple segments */
-	if (bio_multiple_segments(req->bio)) {
-		u32 offset = 0;
-
-		/* Allocate memory and copy the request */
-		pci_addr_out = pci_alloc_consistent(ioc->pdev,
-		    blk_rq_bytes(req), &pci_dma_out);
-		if (!pci_addr_out) {
-			pr_info(MPT3SAS_FMT "%s(): PCI Addr out = NULL\n",
-			    ioc->name, __func__);
-			rc = -ENOMEM;
-			goto out;
-		}
-
-		bio_for_each_segment(bvec, req->bio, iter) {
-			memcpy(pci_addr_out + offset,
-			    page_address(bvec.bv_page) + bvec.bv_offset,
-			    bvec.bv_len);
-			offset += bvec.bv_len;
-		}
-	} else {
-		dma_addr_out = pci_map_single(ioc->pdev, bio_data(req->bio),
-		    blk_rq_bytes(req), PCI_DMA_BIDIRECTIONAL);
-		if (pci_dma_mapping_error(ioc->pdev, dma_addr_out)) {
-			pr_info(MPT3SAS_FMT "%s(): DMA Addr out = NULL\n",
-			    ioc->name, __func__);
-			rc = -ENOMEM;
-			goto free_pci;
-		}
+	rc = _transport_map_smp_buffer(&ioc->pdev->dev, &job->request_payload,
+			&dma_addr_out, &dma_len_out, &addr_out);
+	if (rc)
+		goto out;
+	if (addr_out) {
+		sg_copy_to_buffer(job->request_payload.sg_list,
+				job->request_payload.sg_cnt, addr_out,
+				job->request_payload.payload_len);
 	}
 
-	/* Check if the response needs to be populated across
-	 * multiple segments */
-	if (bio_multiple_segments(rsp->bio)) {
-		pci_addr_in = pci_alloc_consistent(ioc->pdev, blk_rq_bytes(rsp),
-		    &pci_dma_in);
-		if (!pci_addr_in) {
-			pr_info(MPT3SAS_FMT "%s(): PCI Addr in = NULL\n",
-			    ioc->name, __func__);
-			rc = -ENOMEM;
-			goto unmap;
-		}
-	} else {
-		dma_addr_in =  pci_map_single(ioc->pdev, bio_data(rsp->bio),
-		    blk_rq_bytes(rsp), PCI_DMA_BIDIRECTIONAL);
-		if (pci_dma_mapping_error(ioc->pdev, dma_addr_in)) {
-			pr_info(MPT3SAS_FMT "%s(): DMA Addr in = NULL\n",
-			    ioc->name, __func__);
-			rc = -ENOMEM;
-			goto unmap;
-		}
-	}
+	rc = _transport_map_smp_buffer(&ioc->pdev->dev, &job->reply_payload,
+			&dma_addr_in, &dma_len_in, &addr_in);
+	if (rc)
+		goto unmap_out;
 
 	wait_state_count = 0;
 	ioc_state = mpt3sas_base_get_iocstate(ioc, 1);
@@ -1988,7 +1974,7 @@ _transport_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
 			    "%s: failed due to ioc not operational\n",
 			    ioc->name, __func__);
 			rc = -EFAULT;
-			goto unmap;
+			goto unmap_in;
 		}
 		ssleep(1);
 		ioc_state = mpt3sas_base_get_iocstate(ioc, 1);
@@ -2005,7 +1991,7 @@ _transport_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
 		pr_err(MPT3SAS_FMT "%s: failed obtaining a smid\n",
 		    ioc->name, __func__);
 		rc = -EAGAIN;
-		goto unmap;
+		goto unmap_in;
 	}
 
 	rc = 0;
@@ -2018,15 +2004,11 @@ _transport_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
 	mpi_request->SASAddress = (rphy) ?
 	    cpu_to_le64(rphy->identify.sas_address) :
 	    cpu_to_le64(ioc->sas_hba.sas_address);
-	mpi_request->RequestDataLength = cpu_to_le16(blk_rq_bytes(req) - 4);
+	mpi_request->RequestDataLength = cpu_to_le16(dma_len_out - 4);
 	psge = &mpi_request->SGL;
 
-	if (bio_multiple_segments(req->bio))
-		ioc->build_sg(ioc, psge, pci_dma_out, (blk_rq_bytes(req) - 4),
-		    pci_dma_in, (blk_rq_bytes(rsp) + 4));
-	else
-		ioc->build_sg(ioc, psge, dma_addr_out, (blk_rq_bytes(req) - 4),
-		    dma_addr_in, (blk_rq_bytes(rsp) + 4));
+	ioc->build_sg(ioc, psge, dma_addr_out, dma_len_out - 4, dma_addr_in,
+			dma_len_in - 4);
 
 	dtransportprintk(ioc, pr_info(MPT3SAS_FMT
 		"%s - sending smp request\n", ioc->name, __func__));
@@ -2040,83 +2022,51 @@ _transport_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
 		    __func__, ioc->name);
 		_debug_dump_mf(mpi_request,
 		    sizeof(Mpi2SmpPassthroughRequest_t)/4);
-		if (!(ioc->transport_cmds.status & MPT3_CMD_RESET))
-			issue_reset = 1;
-		goto issue_host_reset;
+		if (!(ioc->transport_cmds.status & MPT3_CMD_RESET)) {
+			mpt3sas_base_hard_reset_handler(ioc, FORCE_BIG_HAMMER);
+			rc = -ETIMEDOUT;
+			goto unmap_in;
+		}
 	}
 
 	dtransportprintk(ioc, pr_info(MPT3SAS_FMT
 		"%s - complete\n", ioc->name, __func__));
 
-	if (ioc->transport_cmds.status & MPT3_CMD_REPLY_VALID) {
-
-		mpi_reply = ioc->transport_cmds.reply;
-
-		dtransportprintk(ioc, pr_info(MPT3SAS_FMT
-		    "%s - reply data transfer size(%d)\n",
-		    ioc->name, __func__,
-		    le16_to_cpu(mpi_reply->ResponseDataLength)));
-
-		memcpy(scsi_req(req)->sense, mpi_reply, sizeof(*mpi_reply));
-		scsi_req(req)->sense_len = sizeof(*mpi_reply);
-		scsi_req(req)->resid_len = 0;
-		scsi_req(rsp)->resid_len -=
-		    le16_to_cpu(mpi_reply->ResponseDataLength);
-
-		/* check if the resp needs to be copied from the allocated
-		 * pci mem */
-		if (bio_multiple_segments(rsp->bio)) {
-			u32 offset = 0;
-			u32 bytes_to_copy =
-			    le16_to_cpu(mpi_reply->ResponseDataLength);
-			bio_for_each_segment(bvec, rsp->bio, iter) {
-				if (bytes_to_copy <= bvec.bv_len) {
-					memcpy(page_address(bvec.bv_page) +
-					    bvec.bv_offset, pci_addr_in +
-					    offset, bytes_to_copy);
-					break;
-				} else {
-					memcpy(page_address(bvec.bv_page) +
-					    bvec.bv_offset, pci_addr_in +
-					    offset, bvec.bv_len);
-					bytes_to_copy -= bvec.bv_len;
-				}
-				offset += bvec.bv_len;
-			}
-		}
-	} else {
+	if (!(ioc->transport_cmds.status & MPT3_CMD_REPLY_VALID)) {
 		dtransportprintk(ioc, pr_info(MPT3SAS_FMT
 		    "%s - no reply\n", ioc->name, __func__));
 		rc = -ENXIO;
+		goto unmap_in;
 	}
 
- issue_host_reset:
-	if (issue_reset) {
-		mpt3sas_base_hard_reset_handler(ioc, FORCE_BIG_HAMMER);
-		rc = -ETIMEDOUT;
-	}
+	mpi_reply = ioc->transport_cmds.reply;
 
- unmap:
-	if (dma_addr_out)
-		pci_unmap_single(ioc->pdev, dma_addr_out, blk_rq_bytes(req),
-		    PCI_DMA_BIDIRECTIONAL);
-	if (dma_addr_in)
-		pci_unmap_single(ioc->pdev, dma_addr_in, blk_rq_bytes(rsp),
-		    PCI_DMA_BIDIRECTIONAL);
+	dtransportprintk(ioc,
+		pr_info(MPT3SAS_FMT "%s - reply data transfer size(%d)\n",
+			ioc->name, __func__,
+			le16_to_cpu(mpi_reply->ResponseDataLength)));
 
- free_pci:
-	if (pci_addr_out)
-		pci_free_consistent(ioc->pdev, blk_rq_bytes(req), pci_addr_out,
-		    pci_dma_out);
+	memcpy(job->reply, mpi_reply, sizeof(*mpi_reply));
+	job->reply_len = sizeof(*mpi_reply);
+	reslen = le16_to_cpu(mpi_reply->ResponseDataLength);
 
-	if (pci_addr_in)
-		pci_free_consistent(ioc->pdev, blk_rq_bytes(rsp), pci_addr_in,
-		    pci_dma_in);
+	if (addr_in) {
+		sg_copy_to_buffer(job->reply_payload.sg_list,
+				job->reply_payload.sg_cnt, addr_in,
+				job->reply_payload.payload_len);
+	}
 
+	rc = 0;
+ unmap_in:
+	_transport_unmap_smp_buffer(&ioc->pdev->dev, &job->reply_payload,
+			dma_addr_in, addr_in);
+ unmap_out:
+	_transport_unmap_smp_buffer(&ioc->pdev->dev, &job->request_payload,
+			dma_addr_out, addr_out);
  out:
 	ioc->transport_cmds.status = MPT3_CMD_NOT_USED;
 	mutex_unlock(&ioc->transport_cmds.mutex);
-	return rc;
+	bsg_job_done(job, rc, reslen);
 }
 
 struct sas_function_template mpt3sas_transport_functions = {

drivers/scsi/scsi_transport_sas.c

@@ -169,39 +169,22 @@ static struct sas_end_device *sas_sdev_to_rdev(struct scsi_device *sdev)
 	return rdev;
 }
 
-static void sas_smp_request(struct request_queue *q, struct Scsi_Host *shost,
-			    struct sas_rphy *rphy)
+static int sas_smp_dispatch(struct bsg_job *job)
 {
-	struct request *req;
-	blk_status_t ret;
-	int (*handler)(struct Scsi_Host *, struct sas_rphy *, struct request *);
+	struct Scsi_Host *shost = dev_to_shost(job->dev);
+	struct sas_rphy *rphy = NULL;
 
-	while ((req = blk_fetch_request(q)) != NULL) {
-		spin_unlock_irq(q->queue_lock);
+	if (!scsi_is_host_device(job->dev))
+		rphy = dev_to_rphy(job->dev);
 
-		scsi_req(req)->resid_len = blk_rq_bytes(req);
-		if (req->next_rq)
-			scsi_req(req->next_rq)->resid_len =
-				blk_rq_bytes(req->next_rq);
-		handler = to_sas_internal(shost->transportt)->f->smp_handler;
-		ret = handler(shost, rphy, req);
-		scsi_req(req)->result = ret;
-
-		blk_end_request_all(req, 0);
-
-		spin_lock_irq(q->queue_lock);
+	if (!job->req->next_rq) {
+		dev_warn(job->dev, "space for a smp response is missing\n");
+		bsg_job_done(job, -EINVAL, 0);
+		return 0;
 	}
-}
 
-static void sas_host_smp_request(struct request_queue *q)
-{
-	sas_smp_request(q, (struct Scsi_Host *)q->queuedata, NULL);
-}
-
-static void sas_non_host_smp_request(struct request_queue *q)
-{
-	struct sas_rphy *rphy = q->queuedata;
-	sas_smp_request(q, rphy_to_shost(rphy), rphy);
+	to_sas_internal(shost->transportt)->f->smp_handler(job, shost, rphy);
+	return 0;
 }
 
 static void sas_host_release(struct device *dev)
@@ -217,81 +200,36 @@ static void sas_host_release(struct device *dev)
 static int sas_bsg_initialize(struct Scsi_Host *shost, struct sas_rphy *rphy)
 {
 	struct request_queue *q;
-	int error;
-	struct device *dev;
-	char namebuf[20];
-	const char *name;
-	void (*release)(struct device *);
 
 	if (!to_sas_internal(shost->transportt)->f->smp_handler) {
 		printk("%s can't handle SMP requests\n", shost->hostt->name);
 		return 0;
 	}
 
-	q = blk_alloc_queue(GFP_KERNEL);
-	if (!q)
-		return -ENOMEM;
-	q->initialize_rq_fn = scsi_initialize_rq;
-	q->cmd_size = sizeof(struct scsi_request);
-
 	if (rphy) {
-		q->request_fn = sas_non_host_smp_request;
-		dev = &rphy->dev;
-		name = dev_name(dev);
-		release = NULL;
+		q = bsg_setup_queue(&rphy->dev, dev_name(&rphy->dev),
+				sas_smp_dispatch, 0, NULL);
+		if (IS_ERR(q))
+			return PTR_ERR(q);
+		rphy->q = q;
 	} else {
-		q->request_fn = sas_host_smp_request;
-		dev = &shost->shost_gendev;
-		snprintf(namebuf, sizeof(namebuf),
-			 "sas_host%d", shost->host_no);
-		name = namebuf;
-		release = sas_host_release;
+		char name[20];
+
+		snprintf(name, sizeof(name), "sas_host%d", shost->host_no);
+		q = bsg_setup_queue(&shost->shost_gendev, name,
+				sas_smp_dispatch, 0, sas_host_release);
+		if (IS_ERR(q))
+			return PTR_ERR(q);
+		to_sas_host_attrs(shost)->q = q;
 	}
-	error = blk_init_allocated_queue(q);
-	if (error)
-		goto out_cleanup_queue;
 
 	/*
 	 * by default assume old behaviour and bounce for any highmem page
 	 */
 	blk_queue_bounce_limit(q, BLK_BOUNCE_HIGH);
-
-	error = bsg_register_queue(q, dev, name, release);
-	if (error)
-		goto out_cleanup_queue;
-
-	if (rphy)
-		rphy->q = q;
-	else
-		to_sas_host_attrs(shost)->q = q;
-
-	if (rphy)
-		q->queuedata = rphy;
-	else
-		q->queuedata = shost;
-
 	queue_flag_set_unlocked(QUEUE_FLAG_BIDI, q);
 	queue_flag_set_unlocked(QUEUE_FLAG_SCSI_PASSTHROUGH, q);
 	return 0;
-
-out_cleanup_queue:
-	blk_cleanup_queue(q);
-	return error;
-}
-
-static void sas_bsg_remove(struct Scsi_Host *shost, struct sas_rphy *rphy)
-{
-	struct request_queue *q;
-
-	if (rphy)
-		q = rphy->q;
-	else
-		q = to_sas_host_attrs(shost)->q;
-
-	if (!q)
-		return;
-
-	bsg_unregister_queue(q);
 }
 
 /*
@@ -321,9 +259,10 @@ static int sas_host_remove(struct transport_container *tc, struct device *dev,
 			   struct device *cdev)
 {
 	struct Scsi_Host *shost = dev_to_shost(dev);
+	struct request_queue *q = to_sas_host_attrs(shost)->q;
 
-	sas_bsg_remove(shost, NULL);
-
+	if (q)
+		bsg_unregister_queue(q);
 	return 0;
 }
 
@@ -1713,7 +1652,8 @@ sas_rphy_remove(struct sas_rphy *rphy)
 	}
 
 	sas_rphy_unlink(rphy);
-	sas_bsg_remove(NULL, rphy);
+	if (rphy->q)
+		bsg_unregister_queue(rphy->q);
 	transport_remove_device(dev);
 	device_del(dev);
 }

include/scsi/libsas.h

@@ -721,9 +721,6 @@ extern int sas_slave_alloc(struct scsi_device *);
 extern int sas_ioctl(struct scsi_device *sdev, int cmd, void __user *arg);
 extern int sas_drain_work(struct sas_ha_struct *ha);
 
-extern int sas_smp_handler(struct Scsi_Host *shost, struct sas_rphy *rphy,
-			   struct request *req);
-
 extern void sas_ssp_task_response(struct device *dev, struct sas_task *task,
 				  struct ssp_response_iu *iu);
 struct sas_phy *sas_get_local_phy(struct domain_device *dev);

include/scsi/scsi_transport_sas.h

@@ -5,6 +5,7 @@
 #include <linux/types.h>
 #include <linux/mutex.h>
 #include <scsi/sas.h>
+#include <linux/bsg-lib.h>
 
 struct scsi_transport_template;
 struct sas_rphy;
@@ -176,7 +177,8 @@ struct sas_function_template {
 	int (*phy_setup)(struct sas_phy *);
 	void (*phy_release)(struct sas_phy *);
 	int (*set_phy_speed)(struct sas_phy *, struct sas_phy_linkrates *);
-	int (*smp_handler)(struct Scsi_Host *, struct sas_rphy *, struct request *);
+	void (*smp_handler)(struct bsg_job *, struct Scsi_Host *,
+			struct sas_rphy *);
 };