[PATCH] scsi: mvumi: remove code handling zero scsi_sg_count(scmd) case

Alexey Khoroshilov
2017-04-23T23:02:38Z

As Christoph Hellwig noted, SCSI commands that transfer data
always have a SG entry. The patch removes dead code in
mvumi_make_sgl(), mvumi_complete_cmd() and mvumi_timed_out()
that handle zero scsi_sg_count(scmd) case.

Also the patch adds pci_unmap_sg() on failure path in mvumi_make_sgl().

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
---
drivers/scsi/mvumi.c | 85 ++++++++++++++++------------------------------------
1 file changed, 26 insertions(+), 59 deletions(-)

diff --git a/drivers/scsi/mvumi.c b/drivers/scsi/mvumi.c
index 247df5e79b71..fe97401ad192 100644
--- a/drivers/scsi/mvumi.c
+++ b/drivers/scsi/mvumi.c
@@ -210,39 +210,27 @@ static int mvumi_make_sgl(struct mvumi_hba *mhba, struct scsi_cmnd *scmd,
unsigned int sgnum = scsi_sg_count(scmd);
dma_addr_t busaddr;

- if (sgnum) {
- sg = scsi_sglist(scmd);
- *sg_count = pci_map_sg(mhba->pdev, sg, sgnum,
- (int) scmd->sc_data_direction);
- if (*sg_count > mhba->max_sge) {
- dev_err(&mhba->pdev->dev, "sg count[0x%x] is bigger "
- "than max sg[0x%x].\n",
- *sg_count, mhba->max_sge);
- return -1;
- }
- for (i = 0; i < *sg_count; i++) {
- busaddr = sg_dma_address(&sg[i]);
- m_sg->baseaddr_l = cpu_to_le32(lower_32_bits(busaddr));
- m_sg->baseaddr_h = cpu_to_le32(upper_32_bits(busaddr));
- m_sg->flags = 0;
- sgd_setsz(mhba, m_sg, cpu_to_le32(sg_dma_len(&sg[i])));
- if ((i + 1) == *sg_count)
- m_sg->flags |= 1U << mhba->eot_flag;
-
- sgd_inc(mhba, m_sg);
- }
- } else {
- scmd->SCp.dma_handle = scsi_bufflen(scmd) ?
- pci_map_single(mhba->pdev, scsi_sglist(scmd),
- scsi_bufflen(scmd),
- (int) scmd->sc_data_direction)
- : 0;
- busaddr = scmd->SCp.dma_handle;
+ sg = scsi_sglist(scmd);
+ *sg_count = pci_map_sg(mhba->pdev, sg, sgnum,
+ (int) scmd->sc_data_direction);
+ if (*sg_count > mhba->max_sge) {
+ dev_err(&mhba->pdev->dev,
+ "sg count[0x%x] is bigger than max sg[0x%x].\n",
+ *sg_count, mhba->max_sge);
+ pci_unmap_sg(mhba->pdev, sg, sgnum,
+ (int) scmd->sc_data_direction);
+ return -1;
+ }
+ for (i = 0; i < *sg_count; i++) {
+ busaddr = sg_dma_address(&sg[i]);
m_sg->baseaddr_l = cpu_to_le32(lower_32_bits(busaddr));
m_sg->baseaddr_h = cpu_to_le32(upper_32_bits(busaddr));
- m_sg->flags = 1U << mhba->eot_flag;
- sgd_setsz(mhba, m_sg, cpu_to_le32(scsi_bufflen(scmd)));
- *sg_count = 1;
+ m_sg->flags = 0;
+ sgd_setsz(mhba, m_sg, cpu_to_le32(sg_dma_len(&sg[i])));
+ if ((i + 1) == *sg_count)
+ m_sg->flags |= 1U << mhba->eot_flag;
+
+ sgd_inc(mhba, m_sg);
}

return 0;
@@ -1350,21 +1338,10 @@ static void mvumi_complete_cmd(struct mvumi_hba *mhba, struct mvumi_cmd *cmd,
break;
}

- if (scsi_bufflen(scmd)) {
- if (scsi_sg_count(scmd)) {
- pci_unmap_sg(mhba->pdev,
- scsi_sglist(scmd),
- scsi_sg_count(scmd),
- (int) scmd->sc_data_direction);
- } else {
- pci_unmap_single(mhba->pdev,
- scmd->SCp.dma_handle,
- scsi_bufflen(scmd),
- (int) scmd->sc_data_direction);
-
- scmd->SCp.dma_handle = 0;
- }
- }
+ if (scsi_bufflen(scmd))
+ pci_unmap_sg(mhba->pdev, scsi_sglist(scmd),
+ scsi_sg_count(scmd),
+ (int) scmd->sc_data_direction);
cmd->scmd->scsi_done(scmd);
mvumi_return_cmd(mhba, cmd);
}
@@ -2171,19 +2148,9 @@ static enum blk_eh_timer_return mvumi_timed_out(struct scsi_cmnd *scmd)
scmd->result = (DRIVER_INVALID << 24) | (DID_ABORT << 16);
scmd->SCp.ptr = NULL;
if (scsi_bufflen(scmd)) {
- if (scsi_sg_count(scmd)) {
- pci_unmap_sg(mhba->pdev,
- scsi_sglist(scmd),
- scsi_sg_count(scmd),
- (int)scmd->sc_data_direction);
- } else {
- pci_unmap_single(mhba->pdev,
- scmd->SCp.dma_handle,
- scsi_bufflen(scmd),
- (int)scmd->sc_data_direction);
-
- scmd->SCp.dma_handle = 0;
- }
+ pci_unmap_sg(mhba->pdev, scsi_sglist(scmd),
+ scsi_sg_count(scmd),
+ (int)scmd->sc_data_direction);
}
mvumi_return_cmd(mhba, cmd);
spin_unlock_irqrestore(mhba->shost->host_lock, flags);
--
2.7.4