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Commit 2d073846 authored by David Vrabel's avatar David Vrabel Committed by Konrad Rzeszutek Wilk
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block: xen-blkback: use API provided by xenbus module to map rings 



The xenbus module provides xenbus_map_ring_valloc() and
xenbus_map_ring_vfree().  Use these to map the ring pages granted by
the frontend.

Acked-by: default avatarJens Axboe <jaxboe@fusionio.com>
Signed-off-by: default avatarDavid Vrabel <david.vrabel@citrix.com>
Signed-off-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
parent 4dcaebbf

drivers/block/xen-blkback/common.h

+1 −4
Original line number Diff line number Diff line
@@ -139,7 +139,7 @@ struct xen_blkif { 
	/* Comms information. */

	enum blkif_protocol	blk_protocol;

	union blkif_back_rings	blk_rings;

	struct vm_struct	*blk_ring_area;

	void			*blk_ring;

	/* The VBD attached to this interface. */

	struct xen_vbd		vbd;

	/* Back pointer to the backend_info. */
@@ -163,9 +163,6 @@ struct xen_blkif { 
	int			st_wr_sect;



	wait_queue_head_t	waiting_to_free;



	grant_handle_t		shmem_handle;

	grant_ref_t		shmem_ref;

};

drivers/block/xen-blkback/xenbus.c

+7 −47
Original line number Diff line number Diff line
@@ -120,38 +120,6 @@ static struct xen_blkif *xen_blkif_alloc(domid_t domid) 
	return blkif;

}



static int map_frontend_page(struct xen_blkif *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 xen_blkif *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();

}



static int xen_blkif_map(struct xen_blkif *blkif, unsigned long shared_page,

			 unsigned int evtchn)

{
@@ -161,35 +129,29 @@ static int xen_blkif_map(struct xen_blkif *blkif, unsigned long shared_page, 
	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);

	err = xenbus_map_ring_valloc(blkif->be->dev, shared_page, &blkif->blk_ring);

	if (err < 0)

		return err;

	}



	switch (blkif->blk_protocol) {

	case BLKIF_PROTOCOL_NATIVE:

	{

		struct blkif_sring *sring;

		sring = (struct blkif_sring *)blkif->blk_ring_area->addr;

		sring = (struct blkif_sring *)blkif->blk_ring;

		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;

		sring_x86_32 = (struct blkif_x86_32_sring *)blkif->blk_ring;

		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;

		sring_x86_64 = (struct blkif_x86_64_sring *)blkif->blk_ring;

		BACK_RING_INIT(&blkif->blk_rings.x86_64, sring_x86_64, PAGE_SIZE);

		break;

	}
@@ -201,8 +163,7 @@ static int xen_blkif_map(struct xen_blkif *blkif, unsigned long shared_page, 
						    xen_blkif_be_int, 0,

						    "blkif-backend", blkif);

	if (err < 0) {

		unmap_frontend_page(blkif);

		free_vm_area(blkif->blk_ring_area);

		xenbus_unmap_ring_vfree(blkif->be->dev, blkif->blk_ring);

		blkif->blk_rings.common.sring = NULL;

		return err;

	}
@@ -228,8 +189,7 @@ static void xen_blkif_disconnect(struct xen_blkif *blkif) 
	}



	if (blkif->blk_rings.common.sring) {

		unmap_frontend_page(blkif);

		free_vm_area(blkif->blk_ring_area);

		xenbus_unmap_ring_vfree(blkif->be->dev, blkif->blk_ring);

		blkif->blk_rings.common.sring = NULL;

	}

}