diff options
Diffstat (limited to 'drivers/xen/grant-table.c')
| -rw-r--r-- | drivers/xen/grant-table.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index 8ccccace2a4f..1a1aec0a88a1 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -66,8 +66,6 @@ #include <asm/sync_bitops.h> -/* External tools reserve first few grant table entries. */ -#define NR_RESERVED_ENTRIES 8 #define GNTTAB_LIST_END 0xffffffff static grant_ref_t **gnttab_list; @@ -209,6 +207,10 @@ static inline void check_free_callbacks(void) static void put_free_entry(grant_ref_t ref) { unsigned long flags; + + if (unlikely(ref < GNTTAB_NR_RESERVED_ENTRIES)) + return; + spin_lock_irqsave(&gnttab_list_lock, flags); gnttab_entry(ref) = gnttab_free_head; gnttab_free_head = ref; @@ -1465,12 +1467,12 @@ int gnttab_init(void) nr_init_grefs = nr_grant_frames * gnttab_interface->grefs_per_grant_frame; - for (i = NR_RESERVED_ENTRIES; i < nr_init_grefs - 1; i++) + for (i = GNTTAB_NR_RESERVED_ENTRIES; i < nr_init_grefs - 1; i++) gnttab_entry(i) = i + 1; gnttab_entry(nr_init_grefs - 1) = GNTTAB_LIST_END; - gnttab_free_count = nr_init_grefs - NR_RESERVED_ENTRIES; - gnttab_free_head = NR_RESERVED_ENTRIES; + gnttab_free_count = nr_init_grefs - GNTTAB_NR_RESERVED_ENTRIES; + gnttab_free_head = GNTTAB_NR_RESERVED_ENTRIES; printk("Grant table initialized\n"); return 0; |