From: Christoph Hellwig <hch@lst.de>
Date: Thu, 18 Oct 2018 15:05:36 +0200
Subject: scsi: pmcraid: don't allocate a dma coherent buffer for sense data
Patch-mainline: v5.0-rc1
Git-commit: a9b9e3adc9a98ce59a8544d31da597807a473bd1
References: bsc#1135990 jsc#SLE-4709

We can just dma map the sense buffer passed with the scsi command,
and that gets us out of the nasty business of doing dma coherent
allocations from irq context.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Daniel Wagner <dwagner@suse.de>
---
 drivers/scsi/pmcraid.c |   24 ++++++++----------------
 1 file changed, 8 insertions(+), 16 deletions(-)

--- a/drivers/scsi/pmcraid.c
+++ b/drivers/scsi/pmcraid.c
@@ -851,16 +851,9 @@ static void pmcraid_erp_done(struct pmcr
 			    cmd->ioa_cb->ioarcb.cdb[0], ioasc);
 	}
 
-	/* if we had allocated sense buffers for request sense, copy the sense
-	 * release the buffers
-	 */
-	if (cmd->sense_buffer != NULL) {
-		memcpy(scsi_cmd->sense_buffer,
-		       cmd->sense_buffer,
-		       SCSI_SENSE_BUFFERSIZE);
-		pci_free_consistent(pinstance->pdev,
-				    SCSI_SENSE_BUFFERSIZE,
-				    cmd->sense_buffer, cmd->sense_buffer_dma);
+	if (cmd->sense_buffer) {
+		dma_unmap_single(&pinstance->pdev->dev, cmd->sense_buffer_dma,
+				 SCSI_SENSE_BUFFERSIZE, DMA_FROM_DEVICE);
 		cmd->sense_buffer = NULL;
 		cmd->sense_buffer_dma = 0;
 	}
@@ -2451,13 +2444,12 @@ static void pmcraid_request_sense(struct
 {
 	struct pmcraid_ioarcb *ioarcb = &cmd->ioa_cb->ioarcb;
 	struct pmcraid_ioadl_desc *ioadl = ioarcb->add_data.u.ioadl;
+	struct device *dev = &cmd->drv_inst->pdev->dev;
 
-	/* allocate DMAable memory for sense buffers */
-	cmd->sense_buffer = pci_alloc_consistent(cmd->drv_inst->pdev,
-						 SCSI_SENSE_BUFFERSIZE,
-						 &cmd->sense_buffer_dma);
-
-	if (cmd->sense_buffer == NULL) {
+	cmd->sense_buffer = cmd->scsi_cmd->sense_buffer;
+	cmd->sense_buffer_dma = dma_map_single(dev, cmd->sense_buffer,
+			SCSI_SENSE_BUFFERSIZE, DMA_FROM_DEVICE);
+	if (dma_mapping_error(dev, cmd->sense_buffer_dma)) {
 		pmcraid_err
 			("couldn't allocate sense buffer for request sense\n");
 		pmcraid_erp_done(cmd);