xen/blkback: Squash vbd.c,interface.c in blkback.c and xenbus.c respectivly.

Daniel Stodden suggested to eliminate vbd.c and interface.c, inlining the
critical bits where they belong, respectively.

Leaving only blkback.c for the data- and xenbus.c for the control path.

Suggested-by:  Daniel Stodden <daniel.stodden@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

1 files changed, 151 insertions, 0 deletions

diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c
index b41ed65db2d3..0c263a248007 100644
--- a/drivers/block/xen-blkback/xenbus.c
+++ b/drivers/block/xen-blkback/xenbus.c
@@ -20,6 +20,8 @@
 #include <stdarg.h>
 #include <linux/module.h>
 #include <linux/kthread.h>
+#include <xen/events.h>
+#include <xen/grant_table.h>
 #include "common.h"
 
 #undef DPRINTK
@@ -36,6 +38,7 @@ struct backend_info {
 	char *mode;
 };
 
+static struct kmem_cache *blkif_cachep;
 static void connect(struct backend_info *);
 static int connect_ring(struct backend_info *);
 static void backend_changed(struct xenbus_watch *, const char **,
@@ -106,6 +109,154 @@ static void update_blkif_status(struct blkif_st *blkif)
 	}
 }
 
+struct blkif_st *blkif_alloc(domid_t domid)
+{
+	struct blkif_st *blkif;
+
+	blkif = kmem_cache_alloc(blkif_cachep, GFP_KERNEL);
+	if (!blkif)
+		return ERR_PTR(-ENOMEM);
+
+	memset(blkif, 0, sizeof(*blkif));
+	blkif->domid = domid;
+	spin_lock_init(&blkif->blk_ring_lock);
+	atomic_set(&blkif->refcnt, 1);
+	init_waitqueue_head(&blkif->wq);
+	blkif->st_print = jiffies;
+	init_waitqueue_head(&blkif->waiting_to_free);
+
+	return blkif;
+}
+
+static int map_frontend_page(struct blkif_st *blkif, unsigned long shared_page)
+{
+	struct gnttab_map_grant_ref op;
+
+	gnttab_set_map_op(&op, (unsigned long)blkif->blk_ring_area->addr,
+			  GNTMAP_host_map, shared_page, blkif->domid);
+
+	if (HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, &op, 1))
+		BUG();
+
+	if (op.status) {
+		DPRINTK(" Grant table operation failure !\n");
+		return op.status;
+	}
+
+	blkif->shmem_ref = shared_page;
+	blkif->shmem_handle = op.handle;
+
+	return 0;
+}
+
+static void unmap_frontend_page(struct blkif_st *blkif)
+{
+	struct gnttab_unmap_grant_ref op;
+
+	gnttab_set_unmap_op(&op, (unsigned long)blkif->blk_ring_area->addr,
+			    GNTMAP_host_map, blkif->shmem_handle);
+
+	if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, &op, 1))
+		BUG();
+}
+
+int blkif_map(struct blkif_st *blkif, unsigned long shared_page,
+	      unsigned int evtchn)
+{
+	int err;
+
+	/* Already connected through? */
+	if (blkif->irq)
+		return 0;
+
+	blkif->blk_ring_area = alloc_vm_area(PAGE_SIZE);
+	if (!blkif->blk_ring_area)
+		return -ENOMEM;
+
+	err = map_frontend_page(blkif, shared_page);
+	if (err) {
+		free_vm_area(blkif->blk_ring_area);
+		return err;
+	}
+
+	switch (blkif->blk_protocol) {
+	case BLKIF_PROTOCOL_NATIVE:
+	{
+		struct blkif_sring *sring;
+		sring = (struct blkif_sring *)blkif->blk_ring_area->addr;
+		BACK_RING_INIT(&blkif->blk_rings.native, sring, PAGE_SIZE);
+		break;
+	}
+	case BLKIF_PROTOCOL_X86_32:
+	{
+		struct blkif_x86_32_sring *sring_x86_32;
+		sring_x86_32 = (struct blkif_x86_32_sring *)blkif->blk_ring_area->addr;
+		BACK_RING_INIT(&blkif->blk_rings.x86_32, sring_x86_32, PAGE_SIZE);
+		break;
+	}
+	case BLKIF_PROTOCOL_X86_64:
+	{
+		struct blkif_x86_64_sring *sring_x86_64;
+		sring_x86_64 = (struct blkif_x86_64_sring *)blkif->blk_ring_area->addr;
+		BACK_RING_INIT(&blkif->blk_rings.x86_64, sring_x86_64, PAGE_SIZE);
+		break;
+	}
+	default:
+		BUG();
+	}
+
+	err = bind_interdomain_evtchn_to_irqhandler(
+		blkif->domid, evtchn, blkif_be_int, 0, "blkif-backend", blkif);
+	if (err < 0) {
+		unmap_frontend_page(blkif);
+		free_vm_area(blkif->blk_ring_area);
+		blkif->blk_rings.common.sring = NULL;
+		return err;
+	}
+	blkif->irq = err;
+
+	return 0;
+}
+
+void blkif_disconnect(struct blkif_st *blkif)
+{
+	if (blkif->xenblkd) {
+		kthread_stop(blkif->xenblkd);
+		blkif->xenblkd = NULL;
+	}
+
+	atomic_dec(&blkif->refcnt);
+	wait_event(blkif->waiting_to_free, atomic_read(&blkif->refcnt) == 0);
+	atomic_inc(&blkif->refcnt);
+
+	if (blkif->irq) {
+		unbind_from_irqhandler(blkif->irq, blkif);
+		blkif->irq = 0;
+	}
+
+	if (blkif->blk_rings.common.sring) {
+		unmap_frontend_page(blkif);
+		free_vm_area(blkif->blk_ring_area);
+		blkif->blk_rings.common.sring = NULL;
+	}
+}
+
+void blkif_free(struct blkif_st *blkif)
+{
+	if (!atomic_dec_and_test(&blkif->refcnt))
+		BUG();
+	kmem_cache_free(blkif_cachep, blkif);
+}
+
+int __init blkif_interface_init(void)
+{
+	blkif_cachep = kmem_cache_create("blkif_cache", sizeof(struct blkif_st),
+					 0, 0, NULL);
+	if (!blkif_cachep)
+		return -ENOMEM;
+
+	return 0;
+}
 
 /*
  *  sysfs interface for VBD I/O requests