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authorDaniel De Graaf <dgdegra@tycho.nsa.gov>2011-02-03 12:19:04 -0500
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2011-02-14 14:16:17 -0500
commitbdc612dc6903c4ea06e40d02f84ad5e25d93459d (patch)
treef7f3e3272b21ae3c6015e86f9c1f7be31534704d /drivers/xen/gntdev.c
parentdd3140588d9551235ebc2a0dacdca098e7677573 (diff)
downloadop-kernel-dev-bdc612dc6903c4ea06e40d02f84ad5e25d93459d.zip
op-kernel-dev-bdc612dc6903c4ea06e40d02f84ad5e25d93459d.tar.gz
xen/gntalloc,gntdev: Add unmap notify ioctl
This ioctl allows the users of a shared page to be notified when the other end exits abnormally. [v2: updated description in structs] Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'drivers/xen/gntdev.c')
-rw-r--r--drivers/xen/gntdev.c61
1 files changed, 60 insertions, 1 deletions
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index bcaf797..9694a1a 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -37,6 +37,7 @@
#include <xen/xen.h>
#include <xen/grant_table.h>
#include <xen/gntdev.h>
+#include <xen/events.h>
#include <asm/xen/hypervisor.h>
#include <asm/xen/hypercall.h>
#include <asm/xen/page.h>
@@ -63,6 +64,13 @@ struct gntdev_priv {
struct mmu_notifier mn;
};
+struct unmap_notify {
+ int flags;
+ /* Address relative to the start of the grant_map */
+ int addr;
+ int event;
+};
+
struct grant_map {
struct list_head next;
struct vm_area_struct *vma;
@@ -71,6 +79,7 @@ struct grant_map {
int flags;
int is_mapped;
atomic_t users;
+ struct unmap_notify notify;
struct ioctl_gntdev_grant_ref *grants;
struct gnttab_map_grant_ref *map_ops;
struct gnttab_unmap_grant_ref *unmap_ops;
@@ -165,7 +174,7 @@ static struct grant_map *gntdev_find_map_index(struct gntdev_priv *priv,
list_for_each_entry(map, &priv->maps, next) {
if (map->index != index)
continue;
- if (map->count != count)
+ if (count && map->count != count)
continue;
return map;
}
@@ -184,6 +193,10 @@ static void gntdev_put_map(struct grant_map *map)
atomic_sub(map->count, &pages_mapped);
+ if (map->notify.flags & UNMAP_NOTIFY_SEND_EVENT) {
+ notify_remote_via_evtchn(map->notify.event);
+ }
+
if (map->pages) {
if (!use_ptemod)
unmap_grant_pages(map, 0, map->count);
@@ -274,6 +287,16 @@ static int unmap_grant_pages(struct grant_map *map, int offset, int pages)
{
int i, err = 0;
+ if (map->notify.flags & UNMAP_NOTIFY_CLEAR_BYTE) {
+ int pgno = (map->notify.addr >> PAGE_SHIFT);
+ if (pgno >= offset && pgno < offset + pages) {
+ uint8_t *tmp = kmap(map->pages[pgno]);
+ tmp[map->notify.addr & (PAGE_SIZE-1)] = 0;
+ kunmap(map->pages[pgno]);
+ map->notify.flags &= ~UNMAP_NOTIFY_CLEAR_BYTE;
+ }
+ }
+
pr_debug("map %d+%d [%d+%d]\n", map->index, map->count, offset, pages);
err = gnttab_unmap_refs(map->unmap_ops + offset, map->pages, pages);
if (err)
@@ -519,6 +542,39 @@ static long gntdev_ioctl_get_offset_for_vaddr(struct gntdev_priv *priv,
return 0;
}
+static long gntdev_ioctl_notify(struct gntdev_priv *priv, void __user *u)
+{
+ struct ioctl_gntdev_unmap_notify op;
+ struct grant_map *map;
+ int rc;
+
+ if (copy_from_user(&op, u, sizeof(op)))
+ return -EFAULT;
+
+ if (op.action & ~(UNMAP_NOTIFY_CLEAR_BYTE|UNMAP_NOTIFY_SEND_EVENT))
+ return -EINVAL;
+
+ spin_lock(&priv->lock);
+
+ list_for_each_entry(map, &priv->maps, next) {
+ uint64_t begin = map->index << PAGE_SHIFT;
+ uint64_t end = (map->index + map->count) << PAGE_SHIFT;
+ if (op.index >= begin && op.index < end)
+ goto found;
+ }
+ rc = -ENOENT;
+ goto unlock_out;
+
+ found:
+ map->notify.flags = op.action;
+ map->notify.addr = op.index - (map->index << PAGE_SHIFT);
+ map->notify.event = op.event_channel_port;
+ rc = 0;
+ unlock_out:
+ spin_unlock(&priv->lock);
+ return rc;
+}
+
static long gntdev_ioctl(struct file *flip,
unsigned int cmd, unsigned long arg)
{
@@ -535,6 +591,9 @@ static long gntdev_ioctl(struct file *flip,
case IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR:
return gntdev_ioctl_get_offset_for_vaddr(priv, ptr);
+ case IOCTL_GNTDEV_SET_UNMAP_NOTIFY:
+ return gntdev_ioctl_notify(priv, ptr);
+
default:
pr_debug("priv %p, unknown cmd %x\n", priv, cmd);
return -ENOIOCTLCMD;
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