[PATCH 02/15] ib_srp: Introduce srp_handle_qp_err()

Bart Van Assche
2012-03-25T14:48:17Z

Move the IB completion handler error handling code into the new
function srp_handle_qp_err(). Convert srp_target_port.qp_in_error
from int to bool. Move the initialization of that variable into
srp_connect_target(). Help the CPU branch predictor by making it
clear that IB_WC_SUCCESS is the most likely case.

Signed-off-by: Bart Van Assche <bvanassche-HInyCGIudOg@public.gmane.org>
Cc: David Dillow <dillowda-1Heg1YXhbW8@public.gmane.org>
Cc: Roland Dreier <roland-BHEL68pLQRGGvPXPguhicg@public.gmane.org>
---
drivers/infiniband/ulp/srp/ib_srp.c | 37 ++++++++++++++++++----------------
drivers/infiniband/ulp/srp/ib_srp.h | 2 +-
2 files changed, 21 insertions(+), 18 deletions(-)

diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index 5543c2b..6279343 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -515,6 +515,8 @@ static int srp_connect_target(struct srp_target_port *target)
int retries = 3;
int ret;

+ target->qp_in_error = false;
+
ret = srp_lookup_path(target);
if (ret)
return ret;
@@ -648,7 +650,6 @@ static int srp_reconnect_target(struct srp_target_port *target)
for (i = 0; i < SRP_SQ_SIZE; ++i)
list_add(&target->tx_ring[i]->list, &target->free_tx);

- target->qp_in_error = 0;
ret = srp_connect_target(target);
if (ret)
goto err;
@@ -1215,6 +1216,15 @@ static void srp_handle_recv(struct srp_target_port *target, struct ib_wc *wc)
PFX "Recv failed with error code %d\n", res);
}

+static void srp_handle_qp_err(enum ib_wc_status wc_status,
+ enum ib_wc_opcode wc_opcode,
+ struct srp_target_port *target)
+{
+ shost_printk(KERN_ERR, target->scsi_host, PFX "failed %s status %d\n",
+ wc_opcode & IB_WC_RECV ? "receive" : "send", wc_status);
+ target->qp_in_error = true;
+}
+
static void srp_recv_completion(struct ib_cq *cq, void *target_ptr)
{
struct srp_target_port *target = target_ptr;
@@ -1222,15 +1232,12 @@ static void srp_recv_completion(struct ib_cq *cq, void *target_ptr)

ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
while (ib_poll_cq(cq, 1, &wc) > 0) {
- if (wc.status) {
- shost_printk(KERN_ERR, target->scsi_host,
- PFX "failed receive status %d\n",
- wc.status);
- target->qp_in_error = 1;
+ if (likely(wc.status == IB_WC_SUCCESS)) {
+ srp_handle_recv(target, &wc);
+ } else {
+ srp_handle_qp_err(wc.status, wc.opcode, target);
break;
}
-
- srp_handle_recv(target, &wc);
}
}

@@ -1241,16 +1248,13 @@ static void srp_send_completion(struct ib_cq *cq, void *target_ptr)
struct srp_iu *iu;

while (ib_poll_cq(cq, 1, &wc) > 0) {
- if (wc.status) {
- shost_printk(KERN_ERR, target->scsi_host,
- PFX "failed send status %d\n",
- wc.status);
- target->qp_in_error = 1;
+ if (likely(wc.status == IB_WC_SUCCESS)) {
+ iu = (struct srp_iu *) (uintptr_t) wc.wr_id;
+ list_add(&iu->list, &target->free_tx);
+ } else {
+ srp_handle_qp_err(wc.status, wc.opcode, target);
break;
}
-
- iu = (struct srp_iu *) (uintptr_t) wc.wr_id;
- list_add(&iu->list, &target->free_tx);
}
}

@@ -2237,7 +2241,6 @@ static ssize_t srp_create_target(struct device *dev,
if (ret)
goto err_free_ib;

- target->qp_in_error = 0;
ret = srp_connect_target(target);
if (ret) {
shost_printk(KERN_ERR, target->scsi_host,
diff --git a/drivers/infiniband/ulp/srp/ib_srp.h b/drivers/infiniband/ulp/srp/ib_srp.h
index e3a6304..f0daeb3 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.h
+++ b/drivers/infiniband/ulp/srp/ib_srp.h
@@ -180,7 +180,7 @@ struct srp_target_port {
struct list_head list;
struct completion done;
int status;
- int qp_in_error;
+ bool qp_in_error;

struct completion tsk_mgmt_done;
u8 tsk_mgmt_status;