@@ -212,6 +212,17 @@ static const struct file_operations twa_fops = {
.llseek = noop_llseek,
};
+/*
+ * The controllers use an inline buffer instead of a mapped SGL for small,
+ * single entry buffers. Note that we treat a zero-length transfer like
+ * a mapped SGL.
+ */
+static bool twa_command_mapped(struct scsi_cmnd *cmd)
+{
+ return scsi_sg_count(cmd) != 1 ||
+ scsi_bufflen(cmd) >= TW_MIN_SGL_LENGTH;
+}
+
/* This function will complete an aen request from the isr */
static int twa_aen_complete(TW_Device_Extension *tw_dev, int request_id)
{
@@ -1338,7 +1349,8 @@ static irqreturn_t twa_interrupt(int irq, void *dev_instance)
}
/* Now complete the io */
- scsi_dma_unmap(cmd);
+ if (twa_command_mapped(cmd))
+ scsi_dma_unmap(cmd);
cmd->scsi_done(cmd);
tw_dev->state[request_id] = TW_S_COMPLETED;
twa_free_request_id(tw_dev, request_id);
@@ -1581,7 +1593,8 @@ static int twa_reset_device_extension(TW_Device_Extension *tw_dev)
struct scsi_cmnd *cmd = tw_dev->srb[i];
cmd->result = (DID_RESET << 16);
- scsi_dma_unmap(cmd);
+ if (twa_command_mapped(cmd))
+ scsi_dma_unmap(cmd);
cmd->scsi_done(cmd);
}
}
@@ -1764,12 +1777,14 @@ static int twa_scsi_queue_lck(struct scsi_cmnd *SCpnt, void (*done)(struct scsi_
retval = twa_scsiop_execute_scsi(tw_dev, request_id, NULL, 0, NULL);
switch (retval) {
case SCSI_MLQUEUE_HOST_BUSY:
- scsi_dma_unmap(SCpnt);
+ if (twa_command_mapped(SCpnt))
+ scsi_dma_unmap(SCpnt);
twa_free_request_id(tw_dev, request_id);
break;
case 1:
SCpnt->result = (DID_ERROR << 16);
- scsi_dma_unmap(SCpnt);
+ if (twa_command_mapped(SCpnt))
+ scsi_dma_unmap(SCpnt);
done(SCpnt);
tw_dev->state[request_id] = TW_S_COMPLETED;
twa_free_request_id(tw_dev, request_id);
@@ -1830,8 +1845,7 @@ static int twa_scsiop_execute_scsi(TW_Device_Extension *tw_dev, int request_id,
/* Map sglist from scsi layer to cmd packet */
if (scsi_sg_count(srb)) {
- if ((scsi_sg_count(srb) == 1) &&
- (scsi_bufflen(srb) < TW_MIN_SGL_LENGTH)) {
+ if (!twa_command_mapped(srb)) {
if (srb->sc_data_direction == DMA_TO_DEVICE ||
srb->sc_data_direction == DMA_BIDIRECTIONAL)
scsi_sg_copy_to_buffer(srb,
@@ -1904,7 +1918,7 @@ static void twa_scsiop_execute_scsi_complete(TW_Device_Extension *tw_dev, int re
{
struct scsi_cmnd *cmd = tw_dev->srb[request_id];
- if (scsi_bufflen(cmd) < TW_MIN_SGL_LENGTH &&
+ if (!twa_command_mapped(cmd) &&
(cmd->sc_data_direction == DMA_FROM_DEVICE ||
cmd->sc_data_direction == DMA_BIDIRECTIONAL)) {
if (scsi_sg_count(cmd) == 1) {
This is a note to let you know that I have just added a patch titled 3w-9xxx: don't unmap bounce buffered commands to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue This patch is scheduled to be released in version 3.19.8-ckt10. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.19.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ------ From e2e061ca7d07c3d2cd116cdaf8902ffaa41cefd3 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig <hch@lst.de> Date: Sat, 3 Oct 2015 19:16:07 +0200 Subject: [PATCH 031/120] 3w-9xxx: don't unmap bounce buffered commands MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit commit 15e3d5a285ab9283136dba34bbf72886d9146706 upstream. 3w controller don't dma map small single SGL entry commands but instead bounce buffer them. Add a helper to identify these commands and don't call scsi_dma_unmap for them. Based on an earlier patch from James Bottomley. Fixes: 118c85 ("3w-9xxx: fix command completion race") Reported-by: Tóth Attila <atoth@atoth.sote.hu> Tested-by: Tóth Attila <atoth@atoth.sote.hu> Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Adam Radford <aradford@gmail.com> Signed-off-by: James Bottomley <JBottomley@Odin.com> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- drivers/scsi/3w-9xxx.c | 28 +++++++++++++++++++++------- 1 file changed, 21 insertions(+), 7 deletions(-) -- 1.9.1