diff --git a/drivers/scsi/xen-scsifront.c b/drivers/scsi/xen-scsifront.c
index c01316c6c7b131b56057940566c0d4ac72ba06c8..9aa1fe1fc93967109256690be004d31fa04b52e7 100644
--- a/drivers/scsi/xen-scsifront.c
+++ b/drivers/scsi/xen-scsifront.c
@@ -79,10 +79,13 @@
struct vscsifrnt_shadow {
/* command between backend and frontend */
unsigned char act;
+ uint8_t nr_segments;
uint16_t rqid;
+ uint16_t ref_rqid;
unsigned int nr_grants; /* number of grants in gref[] */
struct scsiif_request_segment *sg; /* scatter/gather elements */
+ struct scsiif_request_segment seg[VSCSIIF_SG_TABLESIZE];
/* Do reset or abort function. */
wait_queue_head_t wq_reset; /* reset work queue */
@@ -172,68 +175,90 @@ static void scsifront_put_rqid(struct vscsifrnt_info *info, uint32_t id)
scsifront_wake_up(info);
}
-static struct vscsiif_request *scsifront_pre_req(struct vscsifrnt_info *info)
+static int scsifront_do_request(struct vscsifrnt_info *info,
+ struct vscsifrnt_shadow *shadow)
{
struct vscsiif_front_ring *ring = &(info->ring);
struct vscsiif_request *ring_req;
+ struct scsi_cmnd *sc = shadow->sc;
uint32_t id;
+ int i, notify;
+
+ if (RING_FULL(&info->ring))
+ return -EBUSY;
id = scsifront_get_rqid(info); /* use id in response */
if (id >= VSCSIIF_MAX_REQS)
- return NULL;
+ return -EBUSY;
- ring_req = RING_GET_REQUEST(&(info->ring), ring->req_prod_pvt);
+ info->shadow[id] = shadow;
+ shadow->rqid = id;
+ ring_req = RING_GET_REQUEST(&(info->ring), ring->req_prod_pvt);
ring->req_prod_pvt++;
- ring_req->rqid = (uint16_t)id;
+ ring_req->rqid = id;
+ ring_req->act = shadow->act;
+ ring_req->ref_rqid = shadow->ref_rqid;
+ ring_req->nr_segments = shadow->nr_segments;
- return ring_req;
-}
+ ring_req->id = sc->device->id;
+ ring_req->lun = sc->device->lun;
+ ring_req->channel = sc->device->channel;
+ ring_req->cmd_len = sc->cmd_len;
-static void scsifront_do_request(struct vscsifrnt_info *info)
-{
- struct vscsiif_front_ring *ring = &(info->ring);
- int notify;
+ BUG_ON(sc->cmd_len > VSCSIIF_MAX_COMMAND_SIZE);
+
+ memcpy(ring_req->cmnd, sc->cmnd, sc->cmd_len);
+
+ ring_req->sc_data_direction = (uint8_t)sc->sc_data_direction;
+ ring_req->timeout_per_command = sc->request->timeout / HZ;
+
+ for (i = 0; i < (shadow->nr_segments & ~VSCSIIF_SG_GRANT); i++)
+ ring_req->seg[i] = shadow->seg[i];
RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(ring, notify);
if (notify)
notify_remote_via_irq(info->irq);
+
+ return 0;
}
-static void scsifront_gnttab_done(struct vscsifrnt_info *info, uint32_t id)
+static void scsifront_gnttab_done(struct vscsifrnt_info *info,
+ struct vscsifrnt_shadow *shadow)
{
- struct vscsifrnt_shadow *s = info->shadow[id];
int i;
- if (s->sc->sc_data_direction == DMA_NONE)
+ if (shadow->sc->sc_data_direction == DMA_NONE)
return;
- for (i = 0; i < s->nr_grants; i++) {
- if (unlikely(gnttab_query_foreign_access(s->gref[i]) != 0)) {
+ for (i = 0; i < shadow->nr_grants; i++) {
+ if (unlikely(gnttab_query_foreign_access(shadow->gref[i]))) {
shost_printk(KERN_ALERT, info->host, KBUILD_MODNAME
"grant still in use by backend\n");
BUG();
}
- gnttab_end_foreign_access(s->gref[i], 0, 0UL);
+ gnttab_end_foreign_access(shadow->gref[i], 0, 0UL);
}
- kfree(s->sg);
+ kfree(shadow->sg);
}
static void scsifront_cdb_cmd_done(struct vscsifrnt_info *info,
struct vscsiif_response *ring_rsp)
{
+ struct vscsifrnt_shadow *shadow;
struct scsi_cmnd *sc;
uint32_t id;
uint8_t sense_len;
id = ring_rsp->rqid;
- sc = info->shadow[id]->sc;
+ shadow = info->shadow[id];
+ sc = shadow->sc;
BUG_ON(sc == NULL);
- scsifront_gnttab_done(info, id);
+ scsifront_gnttab_done(info, shadow);
scsifront_put_rqid(info, id);
sc->result = ring_rsp->rslt;
@@ -366,7 +391,6 @@ static void scsifront_finish_all(struct vscsifrnt_info *info)
static int map_data_for_request(struct vscsifrnt_info *info,
struct scsi_cmnd *sc,
- struct vscsiif_request *ring_req,
struct vscsifrnt_shadow *shadow)
{
grant_ref_t gref_head;
@@ -379,7 +403,6 @@ static int map_data_for_request(struct vscsifrnt_info *info,
struct scatterlist *sg;
struct scsiif_request_segment *seg;
- ring_req->nr_segments = 0;
if (sc->sc_data_direction == DMA_NONE || !data_len)
return 0;
@@ -398,7 +421,7 @@ static int map_data_for_request(struct vscsifrnt_info *info,
if (!shadow->sg)
return -ENOMEM;
}
- seg = shadow->sg ? : ring_req->seg;
+ seg = shadow->sg ? : shadow->seg;
err = gnttab_alloc_grant_references(seg_grants + data_grants,
&gref_head);
@@ -423,9 +446,9 @@ static int map_data_for_request(struct vscsifrnt_info *info,
info->dev->otherend_id,
xen_page_to_gfn(page), 1);
shadow->gref[ref_cnt] = ref;
- ring_req->seg[ref_cnt].gref = ref;
- ring_req->seg[ref_cnt].offset = (uint16_t)off;
- ring_req->seg[ref_cnt].length = (uint16_t)bytes;
+ shadow->seg[ref_cnt].gref = ref;
+ shadow->seg[ref_cnt].offset = (uint16_t)off;
+ shadow->seg[ref_cnt].length = (uint16_t)bytes;
page++;
len -= bytes;
@@ -473,44 +496,14 @@ static int map_data_for_request(struct vscsifrnt_info *info,
}
if (seg_grants)
- ring_req->nr_segments = VSCSIIF_SG_GRANT | seg_grants;
+ shadow->nr_segments = VSCSIIF_SG_GRANT | seg_grants;
else
- ring_req->nr_segments = (uint8_t)ref_cnt;
+ shadow->nr_segments = (uint8_t)ref_cnt;
shadow->nr_grants = ref_cnt;
return 0;
}
-static struct vscsiif_request *scsifront_command2ring(
- struct vscsifrnt_info *info, struct scsi_cmnd *sc,
- struct vscsifrnt_shadow *shadow)
-{
- struct vscsiif_request *ring_req;
-
- memset(shadow, 0, sizeof(*shadow));
-
- ring_req = scsifront_pre_req(info);
- if (!ring_req)
- return NULL;
-
- info->shadow[ring_req->rqid] = shadow;
- shadow->rqid = ring_req->rqid;
-
- ring_req->id = sc->device->id;
- ring_req->lun = sc->device->lun;
- ring_req->channel = sc->device->channel;
- ring_req->cmd_len = sc->cmd_len;
-
- BUG_ON(sc->cmd_len > VSCSIIF_MAX_COMMAND_SIZE);
-
- memcpy(ring_req->cmnd, sc->cmnd, sc->cmd_len);
-
- ring_req->sc_data_direction = (uint8_t)sc->sc_data_direction;
- ring_req->timeout_per_command = sc->request->timeout / HZ;
-
- return ring_req;
-}
-
static int scsifront_enter(struct vscsifrnt_info *info)
{
if (info->pause)
@@ -536,36 +529,25 @@ static int scsifront_queuecommand(struct Scsi_Host *shost,
struct scsi_cmnd *sc)
{
struct vscsifrnt_info *info = shost_priv(shost);
- struct vscsiif_request *ring_req;
struct vscsifrnt_shadow *shadow = scsi_cmd_priv(sc);
unsigned long flags;
int err;
- uint16_t rqid;
+
+ sc->result = 0;
+ memset(shadow, 0, sizeof(*shadow));
+
+ shadow->sc = sc;
+ shadow->act = VSCSIIF_ACT_SCSI_CDB;
spin_lock_irqsave(shost->host_lock, flags);
if (scsifront_enter(info)) {
spin_unlock_irqrestore(shost->host_lock, flags);
return SCSI_MLQUEUE_HOST_BUSY;
}
- if (RING_FULL(&info->ring))
- goto busy;
- ring_req = scsifront_command2ring(info, sc, shadow);
- if (!ring_req)
- goto busy;
-
- sc->result = 0;
-
- rqid = ring_req->rqid;
- ring_req->act = VSCSIIF_ACT_SCSI_CDB;
-
- shadow->sc = sc;
- shadow->act = VSCSIIF_ACT_SCSI_CDB;
-
- err = map_data_for_request(info, sc, ring_req, shadow);
+ err = map_data_for_request(info, sc, shadow);
if (err < 0) {
pr_debug("%s: err %d\n", __func__, err);
- scsifront_put_rqid(info, rqid);
scsifront_return(info);
spin_unlock_irqrestore(shost->host_lock, flags);
if (err == -ENOMEM)
@@ -575,7 +557,11 @@ static int scsifront_queuecommand(struct Scsi_Host *shost,
return 0;
}
- scsifront_do_request(info);
+ if (scsifront_do_request(info, shadow)) {
+ scsifront_gnttab_done(info, shadow);
+ goto busy;
+ }
+
scsifront_return(info);
spin_unlock_irqrestore(shost->host_lock, flags);
@@ -598,26 +584,30 @@ static int scsifront_action_handler(struct scsi_cmnd *sc, uint8_t act)
struct Scsi_Host *host = sc->device->host;
struct vscsifrnt_info *info = shost_priv(host);
struct vscsifrnt_shadow *shadow, *s = scsi_cmd_priv(sc);
- struct vscsiif_request *ring_req;
int err = 0;
- shadow = kmalloc(sizeof(*shadow), GFP_NOIO);
+ shadow = kzalloc(sizeof(*shadow), GFP_NOIO);
if (!shadow)
return FAILED;
+ shadow->act = act;
+ shadow->rslt_reset = RSLT_RESET_WAITING;
+ shadow->sc = sc;
+ shadow->ref_rqid = s->rqid;
+ init_waitqueue_head(&shadow->wq_reset);
+
spin_lock_irq(host->host_lock);
for (;;) {
- if (!RING_FULL(&info->ring)) {
- ring_req = scsifront_command2ring(info, sc, shadow);
- if (ring_req)
- break;
- }
- if (err || info->pause) {
- spin_unlock_irq(host->host_lock);
- kfree(shadow);
- return FAILED;
- }
+ if (scsifront_enter(info))
+ goto fail;
+
+ if (!scsifront_do_request(info, shadow))
+ break;
+
+ scsifront_return(info);
+ if (err)
+ goto fail;
info->wait_ring_available = 1;
spin_unlock_irq(host->host_lock);
err = wait_event_interruptible(info->wq_sync,
@@ -625,23 +615,6 @@ static int scsifront_action_handler(struct scsi_cmnd *sc, uint8_t act)
spin_lock_irq(host->host_lock);
}
- if (scsifront_enter(info)) {
- spin_unlock_irq(host->host_lock);
- kfree(shadow);
- return FAILED;
- }
-
- ring_req->act = act;
- ring_req->ref_rqid = s->rqid;
-
- shadow->act = act;
- shadow->rslt_reset = RSLT_RESET_WAITING;
- init_waitqueue_head(&shadow->wq_reset);
-
- ring_req->nr_segments = 0;
-
- scsifront_do_request(info);
-
spin_unlock_irq(host->host_lock);
err = wait_event_interruptible(shadow->wq_reset, shadow->wait_reset);
spin_lock_irq(host->host_lock);
@@ -660,6 +633,11 @@ static int scsifront_action_handler(struct scsi_cmnd *sc, uint8_t act)
scsifront_return(info);
spin_unlock_irq(host->host_lock);
return err;
+
+fail:
+ spin_unlock_irq(host->host_lock);
+ kfree(shadow);
+ return FAILED;
}
static int scsifront_eh_abort_handler(struct scsi_cmnd *sc)