"the gntalloc device");
static LIST_HEAD(gref_list);
-static DEFINE_SPINLOCK(gref_lock);
+static DEFINE_MUTEX(gref_mutex);
static int gref_size;
struct notify_info {
uint64_t index;
};
+struct gntalloc_vma_private_data {
+ struct gntalloc_gref *gref;
+ int users;
+ int count;
+};
+
static void __del_gref(struct gntalloc_gref *gref);
static void do_cleanup(void)
}
/* Add to gref lists. */
- spin_lock(&gref_lock);
+ mutex_lock(&gref_mutex);
list_splice_tail(&queue_gref, &gref_list);
list_splice_tail(&queue_file, &priv->list);
- spin_unlock(&gref_lock);
+ mutex_unlock(&gref_mutex);
return 0;
undo:
- spin_lock(&gref_lock);
+ mutex_lock(&gref_mutex);
gref_size -= (op->count - i);
list_for_each_entry(gref, &queue_file, next_file) {
*/
if (unlikely(!list_empty(&queue_gref)))
list_splice_tail(&queue_gref, &gref_list);
- spin_unlock(&gref_lock);
+ mutex_unlock(&gref_mutex);
return rc;
}
tmp[gref->notify.pgoff] = 0;
kunmap(gref->page);
}
- if (gref->notify.flags & UNMAP_NOTIFY_SEND_EVENT)
+ if (gref->notify.flags & UNMAP_NOTIFY_SEND_EVENT) {
notify_remote_via_evtchn(gref->notify.event);
+ evtchn_put(gref->notify.event);
+ }
gref->notify.flags = 0;
if (!gnttab_end_foreign_access_ref(gref->gref_id, 0))
return;
+
+ gnttab_free_grant_reference(gref->gref_id);
}
gref_size--;
pr_debug("%s: priv %p\n", __func__, priv);
- spin_lock(&gref_lock);
+ mutex_lock(&gref_mutex);
while (!list_empty(&priv->list)) {
gref = list_entry(priv->list.next,
struct gntalloc_gref, next_file);
__del_gref(gref);
}
kfree(priv);
- spin_unlock(&gref_lock);
+ mutex_unlock(&gref_mutex);
return 0;
}
goto out;
}
- spin_lock(&gref_lock);
+ mutex_lock(&gref_mutex);
/* Clean up pages that were at zero (local) users but were still mapped
* by remote domains. Since those pages count towards the limit that we
* are about to enforce, removing them here is a good idea.
*/
do_cleanup();
if (gref_size + op.count > limit) {
- spin_unlock(&gref_lock);
+ mutex_unlock(&gref_mutex);
rc = -ENOSPC;
goto out_free;
}
gref_size += op.count;
op.index = priv->index;
priv->index += op.count * PAGE_SIZE;
- spin_unlock(&gref_lock);
+ mutex_unlock(&gref_mutex);
rc = add_grefs(&op, gref_ids, priv);
if (rc < 0)
goto dealloc_grant_out;
}
- spin_lock(&gref_lock);
+ mutex_lock(&gref_mutex);
gref = find_grefs(priv, op.index, op.count);
if (gref) {
/* Remove from the file list only, and decrease reference count.
do_cleanup();
- spin_unlock(&gref_lock);
+ mutex_unlock(&gref_mutex);
dealloc_grant_out:
return rc;
}
index = op.index & ~(PAGE_SIZE - 1);
pgoff = op.index & (PAGE_SIZE - 1);
- spin_lock(&gref_lock);
+ mutex_lock(&gref_mutex);
gref = find_grefs(priv, index, 1);
if (!gref) {
goto unlock_out;
}
+ /* We need to grab a reference to the event channel we are going to use
+ * to send the notify before releasing the reference we may already have
+ * (if someone has called this ioctl twice). This is required so that
+ * it is possible to change the clear_byte part of the notification
+ * without disturbing the event channel part, which may now be the last
+ * reference to that event channel.
+ */
+ if (op.action & UNMAP_NOTIFY_SEND_EVENT) {
+ if (evtchn_get(op.event_channel_port)) {
+ rc = -EINVAL;
+ goto unlock_out;
+ }
+ }
+
+ if (gref->notify.flags & UNMAP_NOTIFY_SEND_EVENT)
+ evtchn_put(gref->notify.event);
+
gref->notify.flags = op.action;
gref->notify.pgoff = pgoff;
gref->notify.event = op.event_channel_port;
rc = 0;
+
unlock_out:
- spin_unlock(&gref_lock);
+ mutex_unlock(&gref_mutex);
return rc;
}
static void gntalloc_vma_open(struct vm_area_struct *vma)
{
- struct gntalloc_gref *gref = vma->vm_private_data;
- if (!gref)
+ struct gntalloc_vma_private_data *priv = vma->vm_private_data;
+
+ if (!priv)
return;
- spin_lock(&gref_lock);
- gref->users++;
- spin_unlock(&gref_lock);
+ mutex_lock(&gref_mutex);
+ priv->users++;
+ mutex_unlock(&gref_mutex);
}
static void gntalloc_vma_close(struct vm_area_struct *vma)
{
- struct gntalloc_gref *gref = vma->vm_private_data;
- if (!gref)
+ struct gntalloc_vma_private_data *priv = vma->vm_private_data;
+ struct gntalloc_gref *gref, *next;
+ int i;
+
+ if (!priv)
return;
- spin_lock(&gref_lock);
- gref->users--;
- if (gref->users == 0)
- __del_gref(gref);
- spin_unlock(&gref_lock);
+ mutex_lock(&gref_mutex);
+ priv->users--;
+ if (priv->users == 0) {
+ gref = priv->gref;
+ for (i = 0; i < priv->count; i++) {
+ gref->users--;
+ next = list_entry(gref->next_gref.next,
+ struct gntalloc_gref, next_gref);
+ if (gref->users == 0)
+ __del_gref(gref);
+ gref = next;
+ }
+ kfree(priv);
+ }
+ mutex_unlock(&gref_mutex);
}
static struct vm_operations_struct gntalloc_vmops = {
static int gntalloc_mmap(struct file *filp, struct vm_area_struct *vma)
{
struct gntalloc_file_private_data *priv = filp->private_data;
+ struct gntalloc_vma_private_data *vm_priv;
struct gntalloc_gref *gref;
int count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
int rv, i;
- pr_debug("%s: priv %p, page %lu+%d\n", __func__,
- priv, vma->vm_pgoff, count);
-
if (!(vma->vm_flags & VM_SHARED)) {
printk(KERN_ERR "%s: Mapping must be shared.\n", __func__);
return -EINVAL;
}
- spin_lock(&gref_lock);
+ vm_priv = kmalloc(sizeof(*vm_priv), GFP_KERNEL);
+ if (!vm_priv)
+ return -ENOMEM;
+
+ mutex_lock(&gref_mutex);
+
+ pr_debug("%s: priv %p,%p, page %lu+%d\n", __func__,
+ priv, vm_priv, vma->vm_pgoff, count);
+
gref = find_grefs(priv, vma->vm_pgoff << PAGE_SHIFT, count);
if (gref == NULL) {
rv = -ENOENT;
pr_debug("%s: Could not find grant reference",
__func__);
+ kfree(vm_priv);
goto out_unlock;
}
- vma->vm_private_data = gref;
+ vm_priv->gref = gref;
+ vm_priv->users = 1;
+ vm_priv->count = count;
+
+ vma->vm_private_data = vm_priv;
- vma->vm_flags |= VM_RESERVED;
+ vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
vma->vm_ops = &gntalloc_vmops;
rv = 0;
out_unlock:
- spin_unlock(&gref_lock);
+ mutex_unlock(&gref_mutex);
return rv;
}
projects / ~andy / linux / blobdiff