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path: root/drivers/block/xen-blkfront.c
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Diffstat (limited to 'drivers/block/xen-blkfront.c')
-rw-r--r--drivers/block/xen-blkfront.c120
1 files changed, 88 insertions, 32 deletions
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 60eed4bdd2e4..31b3541f8096 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -73,7 +73,8 @@ struct blk_shadow {
static DEFINE_MUTEX(blkfront_mutex);
static const struct block_device_operations xlvbd_block_fops;
-#define BLK_RING_SIZE __CONST_RING_SIZE(blkif, PAGE_SIZE)
+#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)
/*
* We have one of these per vbd, whether ide, scsi or 'other'. They
@@ -89,14 +90,15 @@ struct blkfront_info
int vdevice;
blkif_vdev_t handle;
enum blkif_state connected;
- int ring_ref;
+ int num_ring_pages;
+ int ring_ref[BLKIF_MAX_NUM_RING_PAGES];
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_RING_SIZE];
+ struct blk_shadow shadow[BLK_MAX_RING_SIZE];
unsigned long shadow_free;
unsigned int feature_flush;
unsigned int flush_op;
@@ -135,7 +137,8 @@ static DEFINE_SPINLOCK(minor_lock);
static int get_id_from_freelist(struct blkfront_info *info)
{
unsigned long free = info->shadow_free;
- BUG_ON(free >= BLK_RING_SIZE);
+ int ring_size = __RING_SIZE((struct blkif_sring *)0, info->num_ring_pages * PAGE_SIZE);
+ BUG_ON(free >= ring_size);
info->shadow_free = info->shadow[free].req.u.rw.id;
info->shadow[free].req.u.rw.id = 0x0fffffee; /* debug */
return free;
@@ -685,6 +688,8 @@ 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 ?
@@ -700,10 +705,17 @@ static void blkif_free(struct blkfront_info *info, int suspend)
flush_work_sync(&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;
+ 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));
info->ring.sring = NULL;
}
if (info->irq)
@@ -828,27 +840,32 @@ static int setup_blkring(struct xenbus_device *dev,
struct blkfront_info *info)
{
struct blkif_sring *sring;
- int err;
+ int i, order, err;
+ int ring_area_size = info->num_ring_pages * PAGE_SIZE;
- info->ring_ref = GRANT_INVALID_REF;
+ for (i = 0; i < info->num_ring_pages; i++) {
+ info->ring_ref[i] = GRANT_INVALID_REF;
+ }
- sring = (struct blkif_sring *)__get_free_page(GFP_NOIO | __GFP_HIGH);
+ order = get_order(ring_area_size);
+ sring = (struct blkif_sring *)__get_free_pages(GFP_KERNEL, order);
if (!sring) {
xenbus_dev_fatal(dev, -ENOMEM, "allocating shared ring");
return -ENOMEM;
}
SHARED_RING_INIT(sring);
- 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;
+ 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;
}
- info->ring_ref = err;
err = xenbus_alloc_evtchn(dev, &info->evtchn);
if (err)
@@ -877,7 +894,13 @@ static int talk_to_blkback(struct xenbus_device *dev,
{
const char *message = NULL;
struct xenbus_transaction xbt;
- int err;
+ 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);
/* Create shared ring, alloc event channel. */
err = setup_blkring(dev, info);
@@ -891,11 +914,30 @@ again:
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->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,
"event-channel", "%u", info->evtchn);
@@ -943,6 +985,7 @@ 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,
@@ -956,6 +999,10 @@ 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;
@@ -999,9 +1046,13 @@ static int blkfront_probe(struct xenbus_device *dev,
info->connected = BLKIF_STATE_DISCONNECTED;
INIT_WORK(&info->work, blkif_restart_queue);
- for (i = 0; i < BLK_RING_SIZE; i++)
+ 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++)
info->shadow[i].req.u.rw.id = i+1;
- info->shadow[BLK_RING_SIZE-1].req.u.rw.id = 0x0fffffff;
+ info->shadow[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);
@@ -1014,6 +1065,9 @@ static int blkfront_probe(struct xenbus_device *dev,
return err;
}
+ printk(KERN_INFO "blkfront %s num-ring-pages %d nr_ents %d.\n",
+ dev->nodename, info->num_ring_pages, ring_size);
+
return 0;
}
@@ -1024,6 +1078,7 @@ 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),
@@ -1034,13 +1089,13 @@ 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 < BLK_RING_SIZE; i++)
+ for (i = 0; i < ring_size; 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[ring_size-1].req.u.rw.id = 0x0fffffff;
/* Stage 3: Find pending requests and requeue them. */
- for (i = 0; i < BLK_RING_SIZE; i++) {
+ for (i = 0; i < ring_size; i++) {
/* Not in use? */
if (!copy[i].request)
continue;
@@ -1511,3 +1566,4 @@ MODULE_LICENSE("GPL");
MODULE_ALIAS_BLOCKDEV_MAJOR(XENVBD_MAJOR);
MODULE_ALIAS("xen:vbd");
MODULE_ALIAS("xenblk");
+
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-14 05:19:59 +0000