module_param_named(max, xen_blkif_max_segments, int, S_IRUGO);
MODULE_PARM_DESC(max, "Maximum amount of segments in indirect requests (default is 32)");
-#define BLK_RING_SIZE __CONST_RING_SIZE(blkif, PAGE_SIZE)
+/*
+ * Maximum order of pages to be used for the shared ring between front and
+ * backend, 4KB page granularity is used.
+ */
+static unsigned int xen_blkif_max_ring_order;
+module_param_named(max_ring_page_order, xen_blkif_max_ring_order, int, S_IRUGO);
+MODULE_PARM_DESC(max_ring_page_order, "Maximum order of pages to be used for the shared ring");
+
+#define BLK_RING_SIZE(info) __CONST_RING_SIZE(blkif, PAGE_SIZE * (info)->nr_ring_pages)
+#define BLK_MAX_RING_SIZE __CONST_RING_SIZE(blkif, PAGE_SIZE * XENBUS_MAX_RING_PAGES)
+/*
+ * ring-ref%i i=(-1UL) would take 11 characters + 'ring-ref' is 8, so 19
+ * characters are enough. Define to 20 to keep consist with backend.
+ */
+#define RINGREF_NAME_LEN (20)
/*
* We have one of these per vbd, whether ide, scsi or 'other'. They
int vdevice;
blkif_vdev_t handle;
enum blkif_state connected;
- int ring_ref;
+ int ring_ref[XENBUS_MAX_RING_PAGES];
+ unsigned int nr_ring_pages;
struct blkif_front_ring ring;
unsigned int evtchn, irq;
struct request_queue *rq;
struct work_struct work;
struct gnttab_free_callback callback;
- struct blk_shadow shadow[BLK_RING_SIZE];
+ struct blk_shadow shadow[BLK_MAX_RING_SIZE];
struct list_head grants;
struct list_head indirect_pages;
unsigned int persistent_gnts_c;
static unsigned long *minors;
static DEFINE_SPINLOCK(minor_lock);
-#define MAXIMUM_OUTSTANDING_BLOCK_REQS \
- (BLKIF_MAX_SEGMENTS_PER_REQUEST * BLK_RING_SIZE)
#define GRANT_INVALID_REF 0
#define PARTS_PER_DISK 16
static int get_id_from_freelist(struct blkfront_info *info)
{
unsigned long free = info->shadow_free;
- BUG_ON(free >= BLK_RING_SIZE);
+ BUG_ON(free >= BLK_RING_SIZE(info));
info->shadow_free = info->shadow[free].req.u.rw.id;
info->shadow[free].req.u.rw.id = 0x0fffffee; /* debug */
return free;
}
}
- for (i = 0; i < BLK_RING_SIZE; i++) {
+ for (i = 0; i < BLK_RING_SIZE(info); i++) {
/*
* Clear persistent grants present in requests already
* on the shared ring
flush_work(&info->work);
/* Free resources associated with old device channel. */
- if (info->ring_ref != GRANT_INVALID_REF) {
- gnttab_end_foreign_access(info->ring_ref, 0,
- (unsigned long)info->ring.sring);
- info->ring_ref = GRANT_INVALID_REF;
- info->ring.sring = NULL;
+ for (i = 0; i < info->nr_ring_pages; i++) {
+ if (info->ring_ref[i] != GRANT_INVALID_REF) {
+ gnttab_end_foreign_access(info->ring_ref[i], 0, 0);
+ info->ring_ref[i] = GRANT_INVALID_REF;
+ }
}
+ free_pages((unsigned long)info->ring.sring, get_order(info->nr_ring_pages * PAGE_SIZE));
+ info->ring.sring = NULL;
+
if (info->irq)
unbind_from_irqhandler(info->irq, info);
info->evtchn = info->irq = 0;
s->req.u.indirect.nr_segments : s->req.u.rw.nr_segments;
if (bret->operation == BLKIF_OP_READ && info->feature_persistent) {
- /*
- * Copy the data received from the backend into the bvec.
- * Since bv_offset can be different than 0, and bv_len different
- * than PAGE_SIZE, we have to keep track of the current offset,
- * to be sure we are copying the data from the right shared page.
- */
for_each_sg(s->sg, sg, nseg, i) {
BUG_ON(sg->offset + sg->length > PAGE_SIZE);
shared_data = kmap_atomic(
* never have given to it (we stamp it up to BLK_RING_SIZE -
* look in get_id_from_freelist.
*/
- if (id >= BLK_RING_SIZE) {
+ if (id >= BLK_RING_SIZE(info)) {
WARN(1, "%s: response to %s has incorrect id (%ld)\n",
info->gd->disk_name, op_name(bret->operation), id);
/* We can't safely get the 'struct request' as
struct blkfront_info *info)
{
struct blkif_sring *sring;
- grant_ref_t gref;
- int err;
+ int err, i;
+ unsigned long ring_size = info->nr_ring_pages * PAGE_SIZE;
+ grant_ref_t gref[XENBUS_MAX_RING_PAGES];
- info->ring_ref = GRANT_INVALID_REF;
+ for (i = 0; i < info->nr_ring_pages; i++)
+ info->ring_ref[i] = GRANT_INVALID_REF;
- sring = (struct blkif_sring *)__get_free_page(GFP_NOIO | __GFP_HIGH);
+ sring = (struct blkif_sring *)__get_free_pages(GFP_NOIO | __GFP_HIGH,
+ get_order(ring_size));
if (!sring) {
xenbus_dev_fatal(dev, -ENOMEM, "allocating shared ring");
return -ENOMEM;
}
SHARED_RING_INIT(sring);
- FRONT_RING_INIT(&info->ring, sring, PAGE_SIZE);
+ FRONT_RING_INIT(&info->ring, sring, ring_size);
- err = xenbus_grant_ring(dev, info->ring.sring, 1, &gref);
+ err = xenbus_grant_ring(dev, info->ring.sring, info->nr_ring_pages, gref);
if (err < 0) {
- free_page((unsigned long)sring);
+ free_pages((unsigned long)sring, get_order(ring_size));
info->ring.sring = NULL;
goto fail;
}
- info->ring_ref = gref;
+ for (i = 0; i < info->nr_ring_pages; i++)
+ info->ring_ref[i] = gref[i];
err = xenbus_alloc_evtchn(dev, &info->evtchn);
if (err)
{
const char *message = NULL;
struct xenbus_transaction xbt;
- int err;
+ int err, i;
+ unsigned int max_page_order = 0;
+ unsigned int ring_page_order = 0;
+
+ err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
+ "max-ring-page-order", "%u", &max_page_order);
+ if (err != 1)
+ info->nr_ring_pages = 1;
+ else {
+ ring_page_order = min(xen_blkif_max_ring_order, max_page_order);
+ info->nr_ring_pages = 1 << ring_page_order;
+ }
/* Create shared ring, alloc event channel. */
err = setup_blkring(dev, info);
goto destroy_blkring;
}
- err = xenbus_printf(xbt, dev->nodename,
- "ring-ref", "%u", info->ring_ref);
- if (err) {
- message = "writing ring-ref";
- goto abort_transaction;
+ if (info->nr_ring_pages == 1) {
+ err = xenbus_printf(xbt, dev->nodename,
+ "ring-ref", "%u", info->ring_ref[0]);
+ if (err) {
+ message = "writing ring-ref";
+ goto abort_transaction;
+ }
+ } else {
+ err = xenbus_printf(xbt, dev->nodename,
+ "ring-page-order", "%u", ring_page_order);
+ if (err) {
+ message = "writing ring-page-order";
+ goto abort_transaction;
+ }
+
+ for (i = 0; i < info->nr_ring_pages; i++) {
+ char ring_ref_name[RINGREF_NAME_LEN];
+
+ snprintf(ring_ref_name, RINGREF_NAME_LEN, "ring-ref%u", i);
+ err = xenbus_printf(xbt, dev->nodename, ring_ref_name,
+ "%u", info->ring_ref[i]);
+ if (err) {
+ message = "writing ring-ref";
+ goto abort_transaction;
+ }
+ }
}
err = xenbus_printf(xbt, dev->nodename,
"event-channel", "%u", info->evtchn);
goto destroy_blkring;
}
+ for (i = 0; i < BLK_RING_SIZE(info); i++)
+ info->shadow[i].req.u.rw.id = i+1;
+ info->shadow[BLK_RING_SIZE(info)-1].req.u.rw.id = 0x0fffffff;
xenbus_switch_state(dev, XenbusStateInitialised);
return 0;
static int blkfront_probe(struct xenbus_device *dev,
const struct xenbus_device_id *id)
{
- int err, vdevice, i;
+ int err, vdevice;
struct blkfront_info *info;
/* FIXME: Use dynamic device id if this is not set. */
info->connected = BLKIF_STATE_DISCONNECTED;
INIT_WORK(&info->work, blkif_restart_queue);
- for (i = 0; i < BLK_RING_SIZE; i++)
- info->shadow[i].req.u.rw.id = i+1;
- info->shadow[BLK_RING_SIZE-1].req.u.rw.id = 0x0fffffff;
-
/* Front end dir is a number, which is used as the id. */
info->handle = simple_strtoul(strrchr(dev->nodename, '/')+1, NULL, 0);
dev_set_drvdata(&dev->dev, info);
- err = talk_to_blkback(dev, info);
- if (err) {
- kfree(info);
- dev_set_drvdata(&dev->dev, NULL);
- return err;
- }
-
return 0;
}
/* Stage 2: Set up free list. */
memset(&info->shadow, 0, sizeof(info->shadow));
- for (i = 0; i < BLK_RING_SIZE; i++)
+ for (i = 0; i < BLK_RING_SIZE(info); i++)
info->shadow[i].req.u.rw.id = i+1;
info->shadow_free = info->ring.req_prod_pvt;
- info->shadow[BLK_RING_SIZE-1].req.u.rw.id = 0x0fffffff;
+ info->shadow[BLK_RING_SIZE(info)-1].req.u.rw.id = 0x0fffffff;
rc = blkfront_setup_indirect(info);
if (rc) {
blk_queue_max_segments(info->rq, segs);
bio_list_init(&bio_list);
INIT_LIST_HEAD(&requests);
- for (i = 0; i < BLK_RING_SIZE; i++) {
+ for (i = 0; i < BLK_RING_SIZE(info); i++) {
/* Not in use? */
if (!copy[i].request)
continue;
segs = info->max_indirect_segments;
}
- err = fill_grant_buffer(info, (segs + INDIRECT_GREFS(segs)) * BLK_RING_SIZE);
+ err = fill_grant_buffer(info, (segs + INDIRECT_GREFS(segs)) * BLK_RING_SIZE(info));
if (err)
goto out_of_memory;
* grants, we need to allocate a set of pages that can be
* used for mapping indirect grefs
*/
- int num = INDIRECT_GREFS(segs) * BLK_RING_SIZE;
+ int num = INDIRECT_GREFS(segs) * BLK_RING_SIZE(info);
BUG_ON(!list_empty(&info->indirect_pages));
for (i = 0; i < num; i++) {
}
}
- for (i = 0; i < BLK_RING_SIZE; i++) {
+ for (i = 0; i < BLK_RING_SIZE(info); i++) {
info->shadow[i].grants_used = kzalloc(
sizeof(info->shadow[i].grants_used[0]) * segs,
GFP_NOIO);
return 0;
out_of_memory:
- for (i = 0; i < BLK_RING_SIZE; i++) {
+ for (i = 0; i < BLK_RING_SIZE(info); i++) {
kfree(info->shadow[i].grants_used);
info->shadow[i].grants_used = NULL;
kfree(info->shadow[i].sg);
dev_dbg(&dev->dev, "blkfront:blkback_changed to state %d.\n", backend_state);
switch (backend_state) {
- case XenbusStateInitialising:
case XenbusStateInitWait:
+ if (dev->state != XenbusStateInitialising)
+ break;
+ if (talk_to_blkback(dev, info)) {
+ kfree(info);
+ dev_set_drvdata(&dev->dev, NULL);
+ break;
+ }
+ case XenbusStateInitialising:
case XenbusStateInitialised:
case XenbusStateReconfiguring:
case XenbusStateReconfigured:
break;
/* Missed the backend's Closing state -- fallthrough */
case XenbusStateClosing:
- blkfront_closing(info);
+ if (info)
+ blkfront_closing(info);
break;
}
}
if (!xen_domain())
return -ENODEV;
+ if (xen_blkif_max_ring_order > XENBUS_MAX_RING_PAGE_ORDER) {
+ pr_info("Invalid max_ring_order (%d), will use default max: %d.\n",
+ xen_blkif_max_ring_order, XENBUS_MAX_RING_PAGE_ORDER);
+ xen_blkif_max_ring_order = 0;
+ }
+
if (!xen_has_pv_disk_devices())
return -ENODEV;
projects / linux-2.6-block.git / blobdiff