diff options
Diffstat (limited to 'sys/sparc64/include/bus_private.h')
| -rw-r--r-- | sys/sparc64/include/bus_private.h | 24 |
1 files changed, 20 insertions, 4 deletions
diff --git a/sys/sparc64/include/bus_private.h b/sys/sparc64/include/bus_private.h index 71c8b76..55f6e53 100644 --- a/sys/sparc64/include/bus_private.h +++ b/sys/sparc64/include/bus_private.h @@ -54,13 +54,29 @@ struct bus_dmamap_res { SLIST_ENTRY(bus_dmamap_res) dr_link; }; +/* + * Callers of the bus_dma interfaces must always protect their tags and maps + * appropriately against concurrent access. However, when a map is on a LRU + * queue, there is a second access path to it; for this case, the locking rules + * are given in the parenthesized comments below: + * q - locked by the mutex protecting the queue. + * p - private to the owner of the map, no access through the queue. + * * - comment refers to pointer target. + * Only the owner of the map is allowed to insert the map into a queue. Removal + * and repositioning (i.e. temporal removal and reinsertion) is allowed to all + * if the queue lock is held. + */ struct bus_dmamap { - TAILQ_ENTRY(bus_dmamap) dm_maplruq; - SLIST_HEAD(, bus_dmamap_res) dm_reslist; - int dm_onq; - int dm_loaded; + TAILQ_ENTRY(bus_dmamap) dm_maplruq; /* (q) */ + SLIST_HEAD(, bus_dmamap_res) dm_reslist; /* (q, *q) */ + int dm_onq; /* (q) */ + int dm_flags; /* (p) */ }; +/* Flag values. */ +#define DMF_LOADED 1 /* Map is loaded */ +#define DMF_COHERENT 2 /* Coherent mapping requested */ + int sparc64_dma_alloc_map(bus_dma_tag_t dmat, bus_dmamap_t *mapp); void sparc64_dma_free_map(bus_dma_tag_t dmat, bus_dmamap_t map); |
