scsi: cxlflash: Remove unnecessary DMA mapping

BugLink: http://bugs.launchpad.net/bugs/1702521
Devices supported by the cxlflash driver are fully coherent and do not require
a bus address mapping. Avoid unnecessary path length by using the virtual
address and length already present in the scatter-gather entry.

Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
(cherry picked from commit 50b787f7235efbd074bbdf4315e0cc261d85b4d7)
Signed-off-by: Victor Aoqui <victora@linux.vnet.ibm.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>

diff --git a/drivers/scsi/cxlflash/main.c b/drivers/scsi/cxlflash/main.c
index ebba3c90a2428353290b0c53797d142d9a8443ef..3c4a83307e6e534c230aaabf0ccc1d658d636b9d 100644 (file)
--- a/drivers/scsi/cxlflash/main.c
+++ b/drivers/scsi/cxlflash/main.c
@@ -176,7 +176,6 @@ static void cmd_complete(struct afu_cmd *cmd)
                dev_dbg_ratelimited(dev, "%s:scp=%p result=%08x ioasc=%08x\n",
                                    __func__, scp, scp->result, cmd->sa.ioasc);
 
-               scsi_dma_unmap(scp);
                scp->scsi_done(scp);
 
                if (cmd_is_tmf) {
@@ -445,7 +444,6 @@ static int cxlflash_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scp)
        struct scatterlist *sg = scsi_sglist(scp);
        u16 req_flags = SISL_REQ_FLAGS_SUP_UNDERRUN;
        ulong lock_flags;
-       int nseg = 0;
        int rc = 0;
 
        dev_dbg_ratelimited(dev, "%s: (scp=%p) %d/%d/%d/%llu "
@@ -487,15 +485,8 @@ static int cxlflash_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scp)
        }
 
        if (likely(sg)) {
-               nseg = scsi_dma_map(scp);
-               if (unlikely(nseg < 0)) {
-                       dev_err(dev, "%s: Fail DMA map\n", __func__);
-                       rc = SCSI_MLQUEUE_HOST_BUSY;
-                       goto out;
-               }
-
-               cmd->rcb.data_len = sg_dma_len(sg);
-               cmd->rcb.data_ea = sg_dma_address(sg);
+               cmd->rcb.data_len = sg->length;
+               cmd->rcb.data_ea = (uintptr_t)sg_virt(sg);
        }
 
        cmd->scp = scp;
@@ -513,8 +504,6 @@ static int cxlflash_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scp)
        memcpy(cmd->rcb.cdb, scp->cmnd, sizeof(cmd->rcb.cdb));
 
        rc = afu->send_cmd(afu, cmd);
-       if (unlikely(rc))
-               scsi_dma_unmap(scp);
 out:
        return rc;
 }