summaryrefslogtreecommitdiff
path: root/drivers/s390/scsi/zfcp_qdio.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/s390/scsi/zfcp_qdio.c')
-rw-r--r--drivers/s390/scsi/zfcp_qdio.c108
1 files changed, 61 insertions, 47 deletions
diff --git a/drivers/s390/scsi/zfcp_qdio.c b/drivers/s390/scsi/zfcp_qdio.c
index dbfa312a7f50..28117e130e2c 100644
--- a/drivers/s390/scsi/zfcp_qdio.c
+++ b/drivers/s390/scsi/zfcp_qdio.c
@@ -3,7 +3,7 @@
*
* Setup and helper functions to access QDIO.
*
- * Copyright IBM Corporation 2002, 2009
+ * Copyright IBM Corporation 2002, 2010
*/
#define KMSG_COMPONENT "zfcp"
@@ -151,8 +151,7 @@ static void zfcp_qdio_sbal_limit(struct zfcp_qdio *qdio,
}
static struct qdio_buffer_element *
-zfcp_qdio_sbal_chain(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
- unsigned long sbtype)
+zfcp_qdio_sbal_chain(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
{
struct qdio_buffer_element *sbale;
@@ -180,17 +179,16 @@ zfcp_qdio_sbal_chain(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
/* set storage-block type for new SBAL */
sbale = zfcp_qdio_sbale_curr(qdio, q_req);
- sbale->flags |= sbtype;
+ sbale->flags |= q_req->sbtype;
return sbale;
}
static struct qdio_buffer_element *
-zfcp_qdio_sbale_next(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
- unsigned int sbtype)
+zfcp_qdio_sbale_next(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
{
- if (q_req->sbale_curr == ZFCP_LAST_SBALE_PER_SBAL)
- return zfcp_qdio_sbal_chain(qdio, q_req, sbtype);
+ if (q_req->sbale_curr == ZFCP_QDIO_LAST_SBALE_PER_SBAL)
+ return zfcp_qdio_sbal_chain(qdio, q_req);
q_req->sbale_curr++;
return zfcp_qdio_sbale_curr(qdio, q_req);
}
@@ -206,62 +204,38 @@ static void zfcp_qdio_undo_sbals(struct zfcp_qdio *qdio,
zfcp_qdio_zero_sbals(sbal, first, count);
}
-static int zfcp_qdio_fill_sbals(struct zfcp_qdio *qdio,
- struct zfcp_qdio_req *q_req,
- unsigned int sbtype, void *start_addr,
- unsigned int total_length)
-{
- struct qdio_buffer_element *sbale;
- unsigned long remaining, length;
- void *addr;
-
- /* split segment up */
- for (addr = start_addr, remaining = total_length; remaining > 0;
- addr += length, remaining -= length) {
- sbale = zfcp_qdio_sbale_next(qdio, q_req, sbtype);
- if (!sbale) {
- atomic_inc(&qdio->req_q_full);
- zfcp_qdio_undo_sbals(qdio, q_req);
- return -EINVAL;
- }
-
- /* new piece must not exceed next page boundary */
- length = min(remaining,
- (PAGE_SIZE - ((unsigned long)addr &
- (PAGE_SIZE - 1))));
- sbale->addr = addr;
- sbale->length = length;
- }
- return 0;
-}
-
/**
* zfcp_qdio_sbals_from_sg - fill SBALs from scatter-gather list
- * @fsf_req: request to be processed
- * @sbtype: SBALE flags
+ * @qdio: pointer to struct zfcp_qdio
+ * @q_req: pointer to struct zfcp_qdio_req
* @sg: scatter-gather list
* @max_sbals: upper bound for number of SBALs to be used
* Returns: number of bytes, or error (negativ)
*/
int zfcp_qdio_sbals_from_sg(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
- unsigned long sbtype, struct scatterlist *sg,
- int max_sbals)
+ struct scatterlist *sg, int max_sbals)
{
struct qdio_buffer_element *sbale;
- int retval, bytes = 0;
+ int bytes = 0;
/* figure out last allowed SBAL */
zfcp_qdio_sbal_limit(qdio, q_req, max_sbals);
/* set storage-block type for this request */
sbale = zfcp_qdio_sbale_req(qdio, q_req);
- sbale->flags |= sbtype;
+ sbale->flags |= q_req->sbtype;
for (; sg; sg = sg_next(sg)) {
- retval = zfcp_qdio_fill_sbals(qdio, q_req, sbtype,
- sg_virt(sg), sg->length);
- if (retval < 0)
- return retval;
+ sbale = zfcp_qdio_sbale_next(qdio, q_req);
+ if (!sbale) {
+ atomic_inc(&qdio->req_q_full);
+ zfcp_qdio_undo_sbals(qdio, q_req);
+ return -EINVAL;
+ }
+
+ sbale->addr = sg_virt(sg);
+ sbale->length = sg->length;
+
bytes += sg->length;
}
@@ -272,6 +246,46 @@ int zfcp_qdio_sbals_from_sg(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
return bytes;
}
+static int zfcp_qdio_sbal_check(struct zfcp_qdio *qdio)
+{
+ struct zfcp_qdio_queue *req_q = &qdio->req_q;
+
+ spin_lock_bh(&qdio->req_q_lock);
+ if (atomic_read(&req_q->count))
+ return 1;
+ spin_unlock_bh(&qdio->req_q_lock);
+ return 0;
+}
+
+/**
+ * zfcp_qdio_sbal_get - get free sbal in request queue, wait if necessary
+ * @qdio: pointer to struct zfcp_qdio
+ *
+ * The req_q_lock must be held by the caller of this function, and
+ * this function may only be called from process context; it will
+ * sleep when waiting for a free sbal.
+ *
+ * Returns: 0 on success, -EIO if there is no free sbal after waiting.
+ */
+int zfcp_qdio_sbal_get(struct zfcp_qdio *qdio)
+{
+ long ret;
+
+ spin_unlock_bh(&qdio->req_q_lock);
+ ret = wait_event_interruptible_timeout(qdio->req_q_wq,
+ zfcp_qdio_sbal_check(qdio), 5 * HZ);
+ if (ret > 0)
+ return 0;
+ if (!ret) {
+ atomic_inc(&qdio->req_q_full);
+ /* assume hanging outbound queue, try queue recovery */
+ zfcp_erp_adapter_reopen(qdio->adapter, 0, "qdsbg_1", NULL);
+ }
+
+ spin_lock_bh(&qdio->req_q_lock);
+ return -EIO;
+}
+
/**
* zfcp_qdio_send - set PCI flag in first SBALE and send req to QDIO
* @qdio: pointer to struct zfcp_qdio