* Block-device interface management.
*
* Copyright (c) 2004, Keir Fraser
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation; or, when distributed
+ * separately from the Linux kernel or incorporated into other
+ * software packages, subject to the following license:
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this source file (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy, modify,
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
*/
#include "common.h"
-
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-#define VMALLOC_VMADDR(x) ((unsigned long)(x))
-#endif
-
-#define BLKIF_HASHSZ 1024
-#define BLKIF_HASH(_d,_h) (((int)(_d)^(int)(_h))&(BLKIF_HASHSZ-1))
+#include <xen/evtchn.h>
+#include <linux/kthread.h>
static kmem_cache_t *blkif_cachep;
-static blkif_t *blkif_hash[BLKIF_HASHSZ];
-blkif_t *blkif_find_by_handle(domid_t domid, unsigned int handle)
+blkif_t *blkif_alloc(domid_t domid)
{
- blkif_t *blkif = blkif_hash[BLKIF_HASH(domid, handle)];
- while ( (blkif != NULL) &&
- ((blkif->domid != domid) || (blkif->handle != handle)) )
- blkif = blkif->hash_next;
- return blkif;
-}
+ blkif_t *blkif;
-static void __blkif_disconnect_complete(void *arg)
-{
- blkif_t *blkif = (blkif_t *)arg;
- ctrl_msg_t cmsg;
- blkif_be_disconnect_t disc;
-
- /*
- * These can't be done in blkif_disconnect() because at that point there
- * may be outstanding requests at the disc whose asynchronous responses
- * must still be notified to the remote driver.
- */
- unbind_evtchn_from_irq(blkif->evtchn);
- vfree(blkif->blk_ring.sring);
-
- /* Construct the deferred response message. */
- cmsg.type = CMSG_BLKIF_BE;
- cmsg.subtype = CMSG_BLKIF_BE_DISCONNECT;
- cmsg.id = blkif->disconnect_rspid;
- cmsg.length = sizeof(blkif_be_disconnect_t);
- disc.domid = blkif->domid;
- disc.blkif_handle = blkif->handle;
- disc.status = BLKIF_BE_STATUS_OKAY;
- memcpy(cmsg.msg, &disc, sizeof(disc));
-
- /*
- * Make sure message is constructed /before/ status change, because
- * after the status change the 'blkif' structure could be deallocated at
- * any time. Also make sure we send the response /after/ status change,
- * as otherwise a subsequent CONNECT request could spuriously fail if
- * another CPU doesn't see the status change yet.
- */
- mb();
- if ( blkif->status != DISCONNECTING )
- BUG();
- blkif->status = DISCONNECTED;
- mb();
-
- /* Send the successful response. */
- ctrl_if_send_response(&cmsg);
+ 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;
}
-void blkif_disconnect_complete(blkif_t *blkif)
+static int map_frontend_page(blkif_t *blkif, unsigned long shared_page)
{
- INIT_WORK(&blkif->work, __blkif_disconnect_complete, (void *)blkif);
- schedule_work(&blkif->work);
+ struct gnttab_map_grant_ref op;
+ int ret;
+
+ gnttab_set_map_op(&op, (unsigned long)blkif->blk_ring_area->addr,
+ GNTMAP_host_map, shared_page, blkif->domid);
+
+ lock_vm_area(blkif->blk_ring_area);
+ ret = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, &op, 1);
+ unlock_vm_area(blkif->blk_ring_area);
+ BUG_ON(ret);
+
+ if (op.status) {
+ DPRINTK(" Grant table operation failure !\n");
+ return op.status;
+ }
+
+ blkif->shmem_ref = shared_page;
+ blkif->shmem_handle = op.handle;
+
+ return 0;
}
-void blkif_create(blkif_be_create_t *create)
+static void unmap_frontend_page(blkif_t *blkif)
{
- domid_t domid = create->domid;
- unsigned int handle = create->blkif_handle;
- blkif_t **pblkif, *blkif;
-
- if ( (blkif = kmem_cache_alloc(blkif_cachep, GFP_KERNEL)) == NULL )
- {
- DPRINTK("Could not create blkif: out of memory\n");
- create->status = BLKIF_BE_STATUS_OUT_OF_MEMORY;
- return;
- }
-
- memset(blkif, 0, sizeof(*blkif));
- blkif->domid = domid;
- blkif->handle = handle;
- blkif->status = DISCONNECTED;
- spin_lock_init(&blkif->vbd_lock);
- spin_lock_init(&blkif->blk_ring_lock);
- atomic_set(&blkif->refcnt, 0);
-
- pblkif = &blkif_hash[BLKIF_HASH(domid, handle)];
- while ( *pblkif != NULL )
- {
- if ( ((*pblkif)->domid == domid) && ((*pblkif)->handle == handle) )
- {
- DPRINTK("Could not create blkif: already exists\n");
- create->status = BLKIF_BE_STATUS_INTERFACE_EXISTS;
- kmem_cache_free(blkif_cachep, blkif);
- return;
- }
- pblkif = &(*pblkif)->hash_next;
- }
-
- blkif->hash_next = *pblkif;
- *pblkif = blkif;
-
- DPRINTK("Successfully created blkif\n");
- create->status = BLKIF_BE_STATUS_OKAY;
+ struct gnttab_unmap_grant_ref op;
+ int ret;
+
+ gnttab_set_unmap_op(&op, (unsigned long)blkif->blk_ring_area->addr,
+ GNTMAP_host_map, blkif->shmem_handle);
+
+ lock_vm_area(blkif->blk_ring_area);
+ ret = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, &op, 1);
+ unlock_vm_area(blkif->blk_ring_area);
+ BUG_ON(ret);
}
-void blkif_destroy(blkif_be_destroy_t *destroy)
+int blkif_map(blkif_t *blkif, unsigned long shared_page, unsigned int evtchn)
{
- 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) )
- {
- if ( blkif->status != DISCONNECTED )
- goto still_connected;
- goto destroy;
- }
- pblkif = &blkif->hash_next;
- }
-
- destroy->status = BLKIF_BE_STATUS_INTERFACE_NOT_FOUND;
- return;
-
- still_connected:
- destroy->status = BLKIF_BE_STATUS_INTERFACE_CONNECTED;
- return;
-
- destroy:
- *pblkif = blkif->hash_next;
- destroy_all_vbds(blkif);
- kmem_cache_free(blkif_cachep, blkif);
- destroy->status = BLKIF_BE_STATUS_OKAY;
+ blkif_sring_t *sring;
+ int err;
+ struct evtchn_bind_interdomain bind_interdomain;
+
+ /* Already connected through? */
+ if (blkif->irq)
+ return 0;
+
+ if ( (blkif->blk_ring_area = alloc_vm_area(PAGE_SIZE)) == NULL )
+ return -ENOMEM;
+
+ err = map_frontend_page(blkif, shared_page);
+ if (err) {
+ free_vm_area(blkif->blk_ring_area);
+ return err;
+ }
+
+ bind_interdomain.remote_dom = blkif->domid;
+ bind_interdomain.remote_port = evtchn;
+
+ err = HYPERVISOR_event_channel_op(EVTCHNOP_bind_interdomain,
+ &bind_interdomain);
+ if (err) {
+ unmap_frontend_page(blkif);
+ free_vm_area(blkif->blk_ring_area);
+ return err;
+ }
+
+ blkif->evtchn = bind_interdomain.local_port;
+
+ sring = (blkif_sring_t *)blkif->blk_ring_area->addr;
+ BACK_RING_INIT(&blkif->blk_ring, sring, PAGE_SIZE);
+
+ blkif->irq = bind_evtchn_to_irqhandler(
+ blkif->evtchn, blkif_be_int, 0, "blkif-backend", blkif);
+
+ return 0;
}
-void blkif_connect(blkif_be_connect_t *connect)
+void blkif_disconnect(blkif_t *blkif)
{
- domid_t domid = connect->domid;
- unsigned int handle = connect->blkif_handle;
- unsigned int evtchn = connect->evtchn;
- unsigned long shmem_frame = connect->shmem_frame;
- struct vm_struct *vma;
- pgprot_t prot;
- int error;
- blkif_t *blkif;
- blkif_sring_t *sring;
-
- blkif = blkif_find_by_handle(domid, handle);
- if ( unlikely(blkif == NULL) )
- {
- DPRINTK("blkif_connect attempted for non-existent blkif (%u,%u)\n",
- connect->domid, connect->blkif_handle);
- connect->status = BLKIF_BE_STATUS_INTERFACE_NOT_FOUND;
- return;
- }
-
- if ( (vma = get_vm_area(PAGE_SIZE, VM_IOREMAP)) == NULL )
- {
- connect->status = BLKIF_BE_STATUS_OUT_OF_MEMORY;
- return;
- }
-
- prot = __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED);
- error = direct_remap_area_pages(&init_mm, VMALLOC_VMADDR(vma->addr),
- shmem_frame<<PAGE_SHIFT, PAGE_SIZE,
- prot, domid);
- if ( error != 0 )
- {
- if ( error == -ENOMEM )
- connect->status = BLKIF_BE_STATUS_OUT_OF_MEMORY;
- else if ( error == -EFAULT )
- connect->status = BLKIF_BE_STATUS_MAPPING_ERROR;
- else
- connect->status = BLKIF_BE_STATUS_ERROR;
- vfree(vma->addr);
- return;
- }
-
- if ( blkif->status != DISCONNECTED )
- {
- connect->status = BLKIF_BE_STATUS_INTERFACE_CONNECTED;
- vfree(vma->addr);
- return;
- }
- sring = (blkif_sring_t *)vma->addr;
- SHARED_RING_INIT(sring);
- BACK_RING_INIT(&blkif->blk_ring, sring, PAGE_SIZE);
-
- blkif->evtchn = evtchn;
- blkif->irq = bind_evtchn_to_irq(evtchn);
- blkif->shmem_frame = shmem_frame;
- blkif->status = CONNECTED;
- blkif_get(blkif);
-
- request_irq(blkif->irq, blkif_be_int, 0, "blkif-backend", blkif);
-
- connect->status = BLKIF_BE_STATUS_OKAY;
+ 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_ring.sring) {
+ unmap_frontend_page(blkif);
+ free_vm_area(blkif->blk_ring_area);
+ blkif->blk_ring.sring = NULL;
+ }
}
-int blkif_disconnect(blkif_be_disconnect_t *disconnect, u8 rsp_id)
+void blkif_free(blkif_t *blkif)
{
- domid_t domid = disconnect->domid;
- unsigned int handle = disconnect->blkif_handle;
- blkif_t *blkif;
-
- blkif = blkif_find_by_handle(domid, handle);
- if ( unlikely(blkif == NULL) )
- {
- DPRINTK("blkif_disconnect attempted for non-existent blkif"
- " (%u,%u)\n", disconnect->domid, disconnect->blkif_handle);
- disconnect->status = BLKIF_BE_STATUS_INTERFACE_NOT_FOUND;
- return 1; /* Caller will send response error message. */
- }
-
- if ( blkif->status == CONNECTED )
- {
- blkif->status = DISCONNECTING;
- blkif->disconnect_rspid = rsp_id;
- wmb(); /* Let other CPUs see the status change. */
- free_irq(blkif->irq, blkif);
- blkif_deschedule(blkif);
- blkif_put(blkif);
- return 0; /* Caller should not send response message. */
- }
-
- disconnect->status = BLKIF_BE_STATUS_OKAY;
- return 1;
+ if (!atomic_dec_and_test(&blkif->refcnt))
+ BUG();
+ kmem_cache_free(blkif_cachep, blkif);
}
void __init blkif_interface_init(void)
{
- blkif_cachep = kmem_cache_create("blkif_cache", sizeof(blkif_t),
- 0, 0, NULL, NULL);
- memset(blkif_hash, 0, sizeof(blkif_hash));
+ blkif_cachep = kmem_cache_create("blkif_cache", sizeof(blkif_t),
+ 0, 0, NULL, NULL);
}
git://git.onelab.eu / linux-2.6.git / blobdiff