This reverts commit d514f9334bc4f1097abfe5ecaf9ab091b8d0a18b as it
is not needed/used.

Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
---
drivers/block/xen-blkfront.c | 120 ++++++++++----------------------------
include/xen/interface/io/blkif.h | 12 ----
2 files changed, 32 insertions(+), 100 deletions(-)

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 43860d3..e4fb337 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -73,8 +73,7 @@ struct blk_shadow {
static DEFINE_MUTEX(blkfront_mutex);
static const struct block_device_operations xlvbd_block_fops;

-#define BLK_MAX_RING_AREA_SIZE (BLKIF_MAX_NUM_RING_PAGES * PAGE_SIZE)
-#define BLK_MAX_RING_SIZE __CONST_RING_SIZE(blkif, BLK_MAX_RING_AREA_SIZE)
+#define BLK_RING_SIZE __CONST_RING_SIZE(blkif, PAGE_SIZE)

/*
* We have one of these per vbd, whether ide, scsi or 'other'. They
@@ -90,15 +89,14 @@ struct blkfront_info
int vdevice;
blkif_vdev_t handle;
enum blkif_state connected;
- int num_ring_pages;
- int ring_ref[BLKIF_MAX_NUM_RING_PAGES];
+ int ring_ref;
struct blkif_front_ring ring;
struct scatterlist sg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
unsigned int evtchn, irq;
struct request_queue *rq;
struct work_struct work;
struct gnttab_free_callback callback;
- struct blk_shadow shadow[BLK_MAX_RING_SIZE];
+ struct blk_shadow shadow[BLK_RING_SIZE];
unsigned long shadow_free;
unsigned int feature_flush;
unsigned int flush_op;
@@ -137,8 +135,7 @@ static DEFINE_SPINLOCK(minor_lock);
static int get_id_from_freelist(struct blkfront_info *info)
{
unsigned long free = info->shadow_free;
- int ring_size = __RING_SIZE((struct blkif_sring *)0, info->num_ring_pages * PAGE_SIZE);
- BUG_ON(free >= ring_size);
+ BUG_ON(free >= BLK_RING_SIZE);
info->shadow_free = info->shadow[free].req.u.rw.id;
info->shadow[free].req.u.rw.id = 0x0fffffee; /* debug */
return free;
@@ -710,8 +707,6 @@ static void blkif_restart_queue(struct work_struct *work)

static void blkif_free(struct blkfront_info *info, int suspend)
{
- int i;
-
/* Prevent new requests being issued until we fix things up. */
spin_lock_irq(&info->io_lock);
info->connected = suspend ?
@@ -727,17 +722,10 @@ static void blkif_free(struct blkfront_info *info, int suspend)
flush_work_sync(&info->work);

/* Free resources associated with old device channel. */
- for (i = 0; i < info->num_ring_pages; i++) {
- /* Free resources associated with old device channel. */
- if (info->ring_ref[i] != GRANT_INVALID_REF) {
- gnttab_end_foreign_access(info->ring_ref[i], 0, 0L);
- info->ring_ref[i] = GRANT_INVALID_REF;
- }
- }
- if (info->ring.sring) {
- int ring_area_size = info->num_ring_pages * PAGE_SIZE;
- free_pages((unsigned long)info->ring.sring,
- get_order(ring_area_size));
+ 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;
}
if (info->irq)
@@ -874,32 +862,27 @@ static int setup_blkring(struct xenbus_device *dev,
struct blkfront_info *info)
{
struct blkif_sring *sring;
- int i, order, err;
- int ring_area_size = info->num_ring_pages * PAGE_SIZE;
+ int err;

- for (i = 0; i < info->num_ring_pages; i++) {
- info->ring_ref[i] = GRANT_INVALID_REF;
- }
+ info->ring_ref = GRANT_INVALID_REF;

- order = get_order(ring_area_size);
- sring = (struct blkif_sring *)__get_free_pages(GFP_KERNEL, order);
+ sring = (struct blkif_sring *)__get_free_page(GFP_NOIO | __GFP_HIGH);
if (!sring) {
xenbus_dev_fatal(dev, -ENOMEM, "allocating shared ring");
return -ENOMEM;
}
SHARED_RING_INIT(sring);
- FRONT_RING_INIT(&info->ring, sring, ring_area_size);
-
- for (i = 0; i < info->num_ring_pages; i++) {
- unsigned long addr = (unsigned long)info->ring.sring + i * PAGE_SIZE;
- err = xenbus_grant_ring(dev, virt_to_mfn(addr));
- if (err < 0) {
- free_pages((unsigned long)sring, order);
- info->ring.sring = NULL;
- goto fail;
- }
- info->ring_ref[i] = err;
+ FRONT_RING_INIT(&info->ring, sring, PAGE_SIZE);
+
+ sg_init_table(info->sg, BLKIF_MAX_SEGMENTS_PER_REQUEST);
+
+ err = xenbus_grant_ring(dev, virt_to_mfn(info->ring.sring));
+ if (err < 0) {
+ free_page((unsigned long)sring);
+ info->ring.sring = NULL;
+ goto fail;
}
+ info->ring_ref = err;

err = xenbus_alloc_evtchn(dev, &info->evtchn);
if (err)
@@ -928,13 +911,7 @@ static int talk_to_blkback(struct xenbus_device *dev,
{
const char *message = NULL;
struct xenbus_transaction xbt;
- int err, i;
-
- BUILD_BUG_ON(BLKIF_MAX_NUM_RING_PAGES != 1 &&
- BLKIF_MAX_NUM_RING_PAGES != 2 &&
- BLKIF_MAX_NUM_RING_PAGES != 4 &&
- BLKIF_MAX_NUM_RING_PAGES != 8 &&
- BLKIF_MAX_NUM_RING_PAGES != 16);
+ int err;

/* Create shared ring, alloc event channel. */
err = setup_blkring(dev, info);
@@ -948,30 +925,11 @@ again:
goto destroy_blkring;
}

- if (info->num_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, "num-ring-pages", "%u",
- info->num_ring_pages);
- if (err) {
- message = "writing num-ring-pages";
- goto abort_transaction;
- }
- for (i = 0; i < info->num_ring_pages; i++) {
- char buf[16];
- snprintf(buf, sizeof(buf), "ring-ref%d", i);
- err = xenbus_printf(xbt, dev->nodename, buf, "%u",
- info->ring_ref[i]);
- if (err) {
- message = "writing ring-refs";
- goto abort_transaction;
- }
- }
+ err = xenbus_printf(xbt, dev->nodename,
+ "ring-ref", "%u", info->ring_ref);
+ if (err) {
+ message = "writing ring-ref";
+ goto abort_transaction;
}
err = xenbus_printf(xbt, dev->nodename,
"event-channel", "%u", info->evtchn);
@@ -1019,7 +977,6 @@ static int blkfront_probe(struct xenbus_device *dev,
{
int err, vdevice, i;
struct blkfront_info *info;
- int ring_size, max_ring_pages;

/* FIXME: Use dynamic device id if this is not set. */
err = xenbus_scanf(XBT_NIL, dev->nodename,
@@ -1033,10 +990,6 @@ static int blkfront_probe(struct xenbus_device *dev,
return err;
}
}
- err = xenbus_scanf(XBT_NIL, dev->otherend,
- "max-ring-pages", "%u", &max_ring_pages);
- if (err != 1)
- max_ring_pages = 1;

if (xen_hvm_domain()) {
char *type;
@@ -1080,13 +1033,9 @@ static int blkfront_probe(struct xenbus_device *dev,
info->connected = BLKIF_STATE_DISCONNECTED;
INIT_WORK(&info->work, blkif_restart_queue);

- info->num_ring_pages = min(max_ring_pages, BLKIF_MAX_NUM_RING_PAGES);
-
- ring_size = __RING_SIZE((struct blkif_sring *)0,
- info->num_ring_pages * PAGE_SIZE);
- for (i = 0; i < ring_size; i++)
+ for (i = 0; i < BLK_RING_SIZE; i++)
info->shadow[i].req.u.rw.id = i+1;
- info->shadow[ring_size-1].req.u.rw.id = 0x0fffffff;
+ 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);
@@ -1099,9 +1048,6 @@ static int blkfront_probe(struct xenbus_device *dev,
return err;
}

- printk(KERN_INFO "blkfront %s num-ring-pages %d nr_ents %d.
",
- dev->nodename, info->num_ring_pages, ring_size);
-
return 0;
}

@@ -1112,7 +1058,6 @@ static int blkif_recover(struct blkfront_info *info)
struct blkif_request *req;
struct blk_shadow *copy;
int j;
- int ring_size = __RING_SIZE((struct blkif_sring *)0, info->num_ring_pages * PAGE_SIZE);

/* Stage 1: Make a safe copy of the shadow state. */
copy = kmalloc(sizeof(info->shadow),
@@ -1123,13 +1068,13 @@ static int blkif_recover(struct blkfront_info *info)

/* Stage 2: Set up free list. */
memset(&info->shadow, 0, sizeof(info->shadow));
- for (i = 0; i < ring_size; i++)
+ for (i = 0; i < BLK_RING_SIZE; i++)
info->shadow[i].req.u.rw.id = i+1;
info->shadow_free = info->ring.req_prod_pvt;
- info->shadow[ring_size-1].req.u.rw.id = 0x0fffffff;
+ info->shadow[BLK_RING_SIZE-1].req.u.rw.id = 0x0fffffff;

/* Stage 3: Find pending requests and requeue them. */
- for (i = 0; i < ring_size; i++) {
+ for (i = 0; i < BLK_RING_SIZE; i++) {
/* Not in use? */
if (!copy[i].request)
continue;
@@ -1600,4 +1545,3 @@ MODULE_LICENSE("GPL");
MODULE_ALIAS_BLOCKDEV_MAJOR(XENVBD_MAJOR);
MODULE_ALIAS("xen:vbd");
MODULE_ALIAS("xenblk");
-
diff --git a/include/xen/interface/io/blkif.h b/include/xen/interface/io/blkif.h
index 31063bd..ee338bf 100644
--- a/include/xen/interface/io/blkif.h
+++ b/include/xen/interface/io/blkif.h
@@ -168,18 +168,6 @@ struct blkif_response {

DEFINE_RING_TYPES(blkif, struct blkif_request, struct blkif_response);

-/*
- * Maximum number of pages used for a blkif ring
- * max-ring-pages advertised by blkback to blkfront may be lowered at blkback
- * mod load time. Load time param set to default.
- */
-#define BLKIF_MAX_NUM_RING_PAGES 16
-#define BLKIF_MAX_NUM_RING_PAGES_DFLT 4
-#if BLKIF_MAX_NUM_RING_PAGES < BLKIF_MAX_NUM_RING_PAGES_DFLT
-#undef BLKIF_MAX_NUM_RING_PAGES_DFLT
-#define BLKIF_MAX_NUM_RING_PAGES_DFLT BLKIF_MAX_NUM_RING_PAGES
-#endif
-
#define VDISK_CDROM 0x1
#define VDISK_REMOVABLE 0x2
#define VDISK_READONLY 0x4
--
1.7.9.5


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