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author | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2011-04-20 10:57:29 -0400 |
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committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2011-04-20 11:57:59 -0400 |
commit | ee9ff8537eacb4383bf9146df6c21b9301c9baa2 (patch) | |
tree | 4899443b2ac14df1e4dec69c1c21e38181fe2c5e /drivers/block/xen-blkback/xenbus.c | |
parent | dfc07b13dcacefda6ebdea14584ed8724dc980ef (diff) | |
download | op-kernel-dev-ee9ff8537eacb4383bf9146df6c21b9301c9baa2.zip op-kernel-dev-ee9ff8537eacb4383bf9146df6c21b9301c9baa2.tar.gz |
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>
Diffstat (limited to 'drivers/block/xen-blkback/xenbus.c')
-rw-r--r-- | drivers/block/xen-blkback/xenbus.c | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c index b41ed65d..0c263a2 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 |