diff options
Diffstat (limited to 'drivers/xen/gntdev.c')
| -rw-r--r-- | drivers/xen/gntdev.c | 92 |
1 files changed, 63 insertions, 29 deletions
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c index cca62cc8549b..9be3e5e46d1f 100644 --- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -56,10 +56,15 @@ MODULE_PARM_DESC(limit, "Maximum number of grants that may be mapped by " static atomic_t pages_mapped = ATOMIC_INIT(0); static int use_ptemod; +#define populate_freeable_maps use_ptemod struct gntdev_priv { + /* maps with visible offsets in the file descriptor */ struct list_head maps; - /* lock protects maps from concurrent changes */ + /* maps that are not visible; will be freed on munmap. + * Only populated if populate_freeable_maps == 1 */ + struct list_head freeable_maps; + /* lock protects maps and freeable_maps */ spinlock_t lock; struct mm_struct *mm; struct mmu_notifier mn; @@ -193,7 +198,7 @@ static struct grant_map *gntdev_find_map_index(struct gntdev_priv *priv, return NULL; } -static void gntdev_put_map(struct grant_map *map) +static void gntdev_put_map(struct gntdev_priv *priv, struct grant_map *map) { if (!map) return; @@ -208,6 +213,12 @@ static void gntdev_put_map(struct grant_map *map) evtchn_put(map->notify.event); } + if (populate_freeable_maps && priv) { + spin_lock(&priv->lock); + list_del(&map->next); + spin_unlock(&priv->lock); + } + if (map->pages && !use_ptemod) unmap_grant_pages(map, 0, map->count); gntdev_free_map(map); @@ -376,11 +387,11 @@ static void gntdev_vma_open(struct vm_area_struct *vma) static void gntdev_vma_close(struct vm_area_struct *vma) { struct grant_map *map = vma->vm_private_data; + struct file *file = vma->vm_file; + struct gntdev_priv *priv = file->private_data; pr_debug("gntdev_vma_close %p\n", vma); if (use_ptemod) { - struct file *file = vma->vm_file; - struct gntdev_priv *priv = file->private_data; /* It is possible that an mmu notifier could be running * concurrently, so take priv->lock to ensure that the vma won't * vanishing during the unmap_grant_pages call, since we will @@ -393,7 +404,7 @@ static void gntdev_vma_close(struct vm_area_struct *vma) spin_unlock(&priv->lock); } vma->vm_private_data = NULL; - gntdev_put_map(map); + gntdev_put_map(priv, map); } static struct vm_operations_struct gntdev_vmops = { @@ -403,33 +414,43 @@ static struct vm_operations_struct gntdev_vmops = { /* ------------------------------------------------------------------ */ +static void unmap_if_in_range(struct grant_map *map, + unsigned long start, unsigned long end) +{ + unsigned long mstart, mend; + int err; + + if (!map->vma) + return; + if (map->vma->vm_start >= end) + return; + if (map->vma->vm_end <= start) + return; + mstart = max(start, map->vma->vm_start); + mend = min(end, map->vma->vm_end); + pr_debug("map %d+%d (%lx %lx), range %lx %lx, mrange %lx %lx\n", + map->index, map->count, + map->vma->vm_start, map->vma->vm_end, + start, end, mstart, mend); + err = unmap_grant_pages(map, + (mstart - map->vma->vm_start) >> PAGE_SHIFT, + (mend - mstart) >> PAGE_SHIFT); + WARN_ON(err); +} + static void mn_invl_range_start(struct mmu_notifier *mn, struct mm_struct *mm, unsigned long start, unsigned long end) { struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn); struct grant_map *map; - unsigned long mstart, mend; - int err; spin_lock(&priv->lock); list_for_each_entry(map, &priv->maps, next) { - if (!map->vma) - continue; - if (map->vma->vm_start >= end) - continue; - if (map->vma->vm_end <= start) - continue; - mstart = max(start, map->vma->vm_start); - mend = min(end, map->vma->vm_end); - pr_debug("map %d+%d (%lx %lx), range %lx %lx, mrange %lx %lx\n", - map->index, map->count, - map->vma->vm_start, map->vma->vm_end, - start, end, mstart, mend); - err = unmap_grant_pages(map, - (mstart - map->vma->vm_start) >> PAGE_SHIFT, - (mend - mstart) >> PAGE_SHIFT); - WARN_ON(err); + unmap_if_in_range(map, start, end); + } + list_for_each_entry(map, &priv->freeable_maps, next) { + unmap_if_in_range(map, start, end); } spin_unlock(&priv->lock); } @@ -458,6 +479,15 @@ static void mn_release(struct mmu_notifier *mn, err = unmap_grant_pages(map, /* offset */ 0, map->count); WARN_ON(err); } + list_for_each_entry(map, &priv->freeable_maps, next) { + if (!map->vma) + continue; + pr_debug("map %d+%d (%lx %lx)\n", + map->index, map->count, + map->vma->vm_start, map->vma->vm_end); + err = unmap_grant_pages(map, /* offset */ 0, map->count); + WARN_ON(err); + } spin_unlock(&priv->lock); } @@ -479,6 +509,7 @@ static int gntdev_open(struct inode *inode, struct file *flip) return -ENOMEM; INIT_LIST_HEAD(&priv->maps); + INIT_LIST_HEAD(&priv->freeable_maps); spin_lock_init(&priv->lock); if (use_ptemod) { @@ -513,8 +544,9 @@ static int gntdev_release(struct inode *inode, struct file *flip) while (!list_empty(&priv->maps)) { map = list_entry(priv->maps.next, struct grant_map, next); list_del(&map->next); - gntdev_put_map(map); + gntdev_put_map(NULL /* already removed */, map); } + WARN_ON(!list_empty(&priv->freeable_maps)); if (use_ptemod) mmu_notifier_unregister(&priv->mn, priv->mm); @@ -542,14 +574,14 @@ static long gntdev_ioctl_map_grant_ref(struct gntdev_priv *priv, if (unlikely(atomic_add_return(op.count, &pages_mapped) > limit)) { pr_debug("can't map: over limit\n"); - gntdev_put_map(map); + gntdev_put_map(NULL, map); return err; } if (copy_from_user(map->grants, &u->refs, sizeof(map->grants[0]) * op.count) != 0) { - gntdev_put_map(map); - return err; + gntdev_put_map(NULL, map); + return -EFAULT; } spin_lock(&priv->lock); @@ -578,11 +610,13 @@ static long gntdev_ioctl_unmap_grant_ref(struct gntdev_priv *priv, map = gntdev_find_map_index(priv, op.index >> PAGE_SHIFT, op.count); if (map) { list_del(&map->next); + if (populate_freeable_maps) + list_add_tail(&map->next, &priv->freeable_maps); err = 0; } spin_unlock(&priv->lock); if (map) - gntdev_put_map(map); + gntdev_put_map(priv, map); return err; } @@ -797,7 +831,7 @@ out_unlock_put: out_put_map: if (use_ptemod) map->vma = NULL; - gntdev_put_map(map); + gntdev_put_map(priv, map); return err; } |