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 <[email protected]> Reviewed-by: Johannes Thumshirn <[email protected]> Signed-off-by: Martin K. Petersen <[email protected]>
sirdarckcat · Aug 30, 2017 · 651a013 · 651a013
1 parent eaa79a6
commit 651a013
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Showing 9 changed files with 243 additions and 380 deletions.
diff --git a/drivers/message/fusion/mptsas.c b/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);
@@ -2310,42 +2306,41 @@ 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;
 
 	if (ioc->sas_mgmt.status & MPT_MGMT_STATUS_RF_VALID) {
 		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);
 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 = {

diff --git a/drivers/scsi/libsas/Kconfig b/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).

diff --git a/drivers/scsi/libsas/sas_expander.c b/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);
 }