diff options
Diffstat (limited to 'drivers/xen/gntdev.c')
| -rw-r--r-- | drivers/xen/gntdev.c | 24 |
1 files changed, 7 insertions, 17 deletions
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c index 3d40f8074dbb..ad621ec1912c 100644 --- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -55,12 +55,10 @@ MODULE_AUTHOR("Derek G. Murray <Derek.Murray@cl.cam.ac.uk>, " "Gerd Hoffmann <kraxel@redhat.com>"); MODULE_DESCRIPTION("User-space granted page access driver"); -static int limit = 1024*1024; -module_param(limit, int, 0644); -MODULE_PARM_DESC(limit, "Maximum number of grants that may be mapped by " - "the gntdev device"); - -static atomic_t pages_mapped = ATOMIC_INIT(0); +static unsigned int limit = 64*1024; +module_param(limit, uint, 0644); +MODULE_PARM_DESC(limit, + "Maximum number of grants that may be mapped by one mapping request"); static int use_ptemod; @@ -71,9 +69,9 @@ static struct miscdevice gntdev_miscdev; /* ------------------------------------------------------------------ */ -bool gntdev_account_mapped_pages(int count) +bool gntdev_test_page_count(unsigned int count) { - return atomic_add_return(count, &pages_mapped) > limit; + return !count || count > limit; } static void gntdev_print_maps(struct gntdev_priv *priv, @@ -241,8 +239,6 @@ void gntdev_put_map(struct gntdev_priv *priv, struct gntdev_grant_map *map) if (!refcount_dec_and_test(&map->users)) return; - atomic_sub(map->count, &pages_mapped); - if (map->notify.flags & UNMAP_NOTIFY_SEND_EVENT) { notify_remote_via_evtchn(map->notify.event); evtchn_put(map->notify.event); @@ -568,7 +564,7 @@ static long gntdev_ioctl_map_grant_ref(struct gntdev_priv *priv, if (copy_from_user(&op, u, sizeof(op)) != 0) return -EFAULT; pr_debug("priv %p, add %d\n", priv, op.count); - if (unlikely(op.count <= 0)) + if (unlikely(gntdev_test_page_count(op.count))) return -EINVAL; err = -ENOMEM; @@ -576,12 +572,6 @@ static long gntdev_ioctl_map_grant_ref(struct gntdev_priv *priv, if (!map) return err; - if (unlikely(gntdev_account_mapped_pages(op.count))) { - pr_debug("can't map: over limit\n"); - 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(NULL, map); |