Hi Stephen and Co,
Attached is a quick patch to enable modern SCSI host_lock' less
operation for the HPSA SCSI LLD driver on >= .37 kernels. After an
initial LLD conversion and review, I would like to verify with you that
the following calls are currently protected by HPDA LLD internal locks
that disable interrupts from the newly renamed hpsa_scsi_queue_command()
dispatcher below..
*) For cmd_alloc(), struct ctlr_info *h->lock + spin_lock_irqsave() is
obtained and released.
*) For enqueue_cmd_and_start_io(), struct ctlr_info *h->lock +
spin_lock_irqsave() is obtained for addQ() + start_io() and released.
So the one new piece wrt to host_lock less mode that is *not* protected
in hpsa_scsi_queue_command() is the call to hpsa_scatter_gather(). This
should be OK to get called without h->lock held w/ spin_lock_irqsave(),
yes..?
So far this patch has been compile tested only. Please have a look and
comment.
Thanks!
--nab
diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
index 12deffc..e205f33 100644
--- a/drivers/scsi/hpsa.c
+++ b/drivers/scsi/hpsa.c
@@ -1906,9 +1906,11 @@ sglist_finished:
return 0;
}
-
-static int hpsa_scsi_queue_command_lck(struct scsi_cmnd *cmd,
- void (*done)(struct scsi_cmnd *))
+/*
+ * Running in struct Scsi_Host->host_lock less mode using LLD internal
+ * struct ctlr_info *h->lock w/ spin_lock_irqsave() protection.
+ */
+static int hpsa_scsi_queue_command(struct Scsi_Host *sh, struct scsi_cmnd *cmd)
{
struct ctlr_info *h;
struct hpsa_scsi_dev_t *dev;
@@ -1921,7 +1923,7 @@ static int hpsa_scsi_queue_command_lck(struct scsi_cmnd *cmd,
dev = cmd->device->hostdata;
if (!dev) {
cmd->result = DID_NO_CONNECT << 16;
- done(cmd);
+ cmd->scsi_done(cmd);
return 0;
}
memcpy(scsi3addr, dev->scsi3addr, sizeof(scsi3addr));
@@ -1936,9 +1938,6 @@ static int hpsa_scsi_queue_command_lck(struct scsi_cmnd *cmd,
}
/* Fill in the command list header */
-
- cmd->scsi_done = done; /* save this for use by completion code */
-
/* save c in case we have to abort it */
cmd->host_scribble = (unsigned char *) c;
@@ -2001,8 +2000,6 @@ static int hpsa_scsi_queue_command_lck(struct scsi_cmnd *cmd,
return 0;
}
-static DEF_SCSI_QCMD(hpsa_scsi_queue_command)
-
static void hpsa_scan_start(struct Scsi_Host *sh)
{
struct ctlr_info *h = shost_to_hba(sh);
--
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