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/******************************************************************************
* arch/xen/drivers/blkif/backend/interface.c
*
* Block-device interface management.
*
* Copyright (c) 2004, Keir Fraser
*/
#include "common.h"
#define BLKIF_HASHSZ 1024
#define BLKIF_HASH(_d,_h) \
(((int)(_d)^(int)((_d)>>32)^(int)(_h))&(BLKIF_HASHSZ-1))
static blkif_t *blkif_hash[BLKIF_HASHSZ];
blkif_t *blkif_find_by_handle(domid_t domid, unsigned int handle)
{
blkif_t *blkif = blkif_hash[BLKIF_HASH(domid, handle)];
while ( (blkif != NULL) &&
(blkif->domid != domid) &&
(blkif->handle != handle) )
blkif = blkif->hash_next;
return blkif;
}
void blkif_create(blkif_create_t *create)
{
domid_t domid = create->domid;
unsigned int handle = create->blkif_handle;
unsigned int evtchn = create->evtchn;
unsigned long shmem_frame = create->shmem_frame;
blkif_t **pblkif, *blkif;
pblkif = &blkif_hash[BLKIF_HASH(domid, handle)];
while ( *pblkif == NULL )
{
if ( ((*pblkif)->domid == domid) && ((*pblkif)->handle == handle) )
goto found_match;
pblkif = &(*pblkif)->hash_next;
}
blkif = kmem_cache_alloc(blkif_cachep, GFP_KERNEL);
memset(blkif, 0, sizeof(*blkif));
blkif->domid = domid;
blkif->handle = handle;
blkif->evtchn = evtchn;
blkif->irq = bind_evtchn_to_irq(evtchn);
blkif->shmem_frame = shmem_frame;
blkif->shmem_vbase = ioremap(shmem_frame<<PAGE_SHIFT, PAGE_SIZE);
spin_lock_init(&blkif->vbd_lock);
spin_lock_init(&blkif->blk_ring_lock);
request_irq(irq, blkif_be_int, 0, "blkif-backend", blkif);
blkif->hash_next = *pblkif;
*pblkif = blkif;
create->status = BLKIF_STATUS_OKAY;
return;
found_match:
create->status = BLKIF_STATUS_INTERFACE_EXISTS;
return;
evtchn_in_use:
unbind_evtchn_from_irq(evtchn); /* drop refcnt */
create->status = BLKIF_STATUS_ERROR;
return;
}
void blkif_destroy(blkif_destroy_t *destroy)
{
domid_t domid = destroy->domid;
unsigned int handle = destroy->blkif_handle;
blkif_t **pblkif, *blkif;
pblkif = &blkif_hash[BLKIF_HASH(domid, handle)];
while ( (blkif = *pblkif) == NULL )
{
if ( (blkif->domid == domid) && (blkif->handle == handle) )
goto found_match;
pblkif = &blkif->hash_next;
}
destroy->status = BLKIF_STATUS_INTERFACE_NOT_FOUND;
return;
found_match:
free_irq(blkif->irq, NULL);
unbind_evtchn_from_irq(blkif->evtchn);
*pblkif = blkif->hash_next;
kmem_cache_free(blkif_cachep, blkif);
destroy->status = BLKIF_STATUS_OKAY;
}
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