Sync with i386's busdma backend. This fixes a few bugs and adds

support for the BUS_DMA_NOWAIT flag in bus_dmamap_load().

1 files changed, 48 insertions, 33 deletions

diff --git a/sys/alpha/alpha/busdma_machdep.c b/sys/alpha/alpha/busdma_machdep.c
index 4df7bd2..e540e1c 100644
--- a/sys/alpha/alpha/busdma_machdep.c
+++ b/sys/alpha/alpha/busdma_machdep.c
@@ -106,12 +106,21 @@ static struct bus_dmamap nobounce_dmamap;
 
 static void init_bounce_pages(void *dummy);
 static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages);
-static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map);
-static vm_offset_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map,
+static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
+				int commit);
+static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map,
 				   vm_offset_t vaddr, bus_size_t size);
 static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
 static __inline int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr);
 
+/*
+ * Return true if a match is made.
+ *
+ * To find a match walk the chain of bus_dma_tag_t's looking for 'paddr'.
+ *
+ * If paddr is within the bounds of the dma tag then call the filter callback
+ * to check for a match, if there is no filter callback then assume a match.
+ */
 static __inline int
 run_filter(bus_dma_tag_t dmat, bus_addr_t paddr)
 {
@@ -282,8 +291,14 @@ bus_dma_tag_destroy(bus_dma_tag_t dmat)
 			atomic_subtract_int(&dmat->ref_count, 1);
 			if (dmat->ref_count == 0) {
 				free(dmat, M_DEVBUF);
-			}
-			dmat = parent;
+				/*
+				 * Last reference count, so
+				 * release our reference
+				 * count on our parent.
+				 */
+				dmat = parent;
+			} else
+				dmat = NULL;
 		}
 	}
 	return (0);
@@ -379,16 +394,9 @@ bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
 		sgmap_free_region(chipset.sgmap, map->sgmaphandle);
 	}
 
-	if (map != NULL) {
+	if (map != NULL && map != &nobounce_dmamap) {
 		if (STAILQ_FIRST(&map->bpages) != NULL)
 			return (EBUSY);
-		/*
-		 * The nobounce_dmamap map is not dynamically
-		 * allocated, thus we should on no account try to
-		 * free it.
-		 */
-		if (map != &nobounce_dmamap)
-			free(map, M_DEVBUF);
 	}
 	dmat->map_count--;
 	return (0);
@@ -430,7 +438,7 @@ bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
 
 /*
  * Free a piece of memory and it's allociated dmamap, that was allocated
- * via bus_dmamem_alloc.
+ * via bus_dmamem_alloc.  Make the same choice for free/contigfree.
  */
 void
 bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
@@ -525,18 +533,24 @@ bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
 	/* Reserve Necessary Bounce Pages */
 	if (map->pagesneeded != 0) {
 		mtx_lock(&bounce_lock);
-	 	if (reserve_bounce_pages(dmat, map) != 0) {
-
-			/* Queue us for resources */
-			map->dmat = dmat;
-			map->buf = buf;
-			map->buflen = buflen;
-			map->callback = callback;
-			map->callback_arg = callback_arg;
-
-			STAILQ_INSERT_TAIL(&bounce_map_waitinglist, map, links);
-			mtx_unlock(&bounce_lock);
-			return (EINPROGRESS);
+		if (flags & BUS_DMA_NOWAIT) {
+			if (reserve_bounce_pages(dmat, map, 0) != 0) {
+				mtx_unlock(&bounce_lock);
+				return (ENOMEM);
+			}
+		} else {
+			if (reserve_bounce_pages(dmat, map, 1) != 0) {
+				/* Queue us for resources */
+				map->dmat = dmat;
+				map->buf = buf;
+				map->buflen = buflen;
+				map->callback = callback;
+				map->callback_arg = callback_arg;
+				STAILQ_INSERT_TAIL(&bounce_map_waitinglist,
+				    map, links);
+				mtx_unlock(&bounce_lock);
+				return (EINPROGRESS);
+			}
 		}
 		mtx_unlock(&bounce_lock);
 	}
@@ -619,7 +633,7 @@ _bus_dmamap_load_buffer(bus_dma_tag_t dmat,
 		pmap = NULL;
 
 	lastaddr = *lastaddrp;
-	bmask  = ~(dmat->boundary - 1);
+	bmask = ~(dmat->boundary - 1);
 
 	for (seg = *segp; buflen > 0 ; ) {
 		/*
@@ -706,7 +720,7 @@ bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map,
 	error = 0;
 	if (m0->m_pkthdr.len <= dmat->maxsize) {
 		int first = 1;
-		vm_offset_t lastaddr = 0;
+		bus_addr_t lastaddr = 0;
 		struct mbuf *m;
 
 		for (m = m0; m != NULL && error == 0; m = m->m_next) {
@@ -742,7 +756,7 @@ bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map,
 		    bus_dmamap_callback2_t *callback, void *callback_arg,
 		    int flags)
 {
-	vm_offset_t lastaddr;
+	bus_addr_t lastaddr;
 #ifdef __GNUC__
 	bus_dma_segment_t dm_segments[dmat->nsegments];
 #else
@@ -825,7 +839,6 @@ _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
 	struct bounce_page *bpage;
 
 	if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
-		
 		/*
 		 * Handle data bouncing.  We might also
 		 * want to add support for invalidating
@@ -887,7 +900,7 @@ alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
 							 PAGE_SIZE,
 							 dmat->boundary);
 		mtx_unlock(&Giant);
-		if (bpage->vaddr == NULL) {
+		if (bpage->vaddr == 0) {
 			free(bpage, M_DEVBUF);
 			break;
 		}
@@ -904,12 +917,14 @@ alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
 }
 
 static int
-reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map)
+reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
 {
 	int pages;
 
 	mtx_assert(&bounce_lock, MA_OWNED);
 	pages = MIN(free_bpages, map->pagesneeded - map->pagesreserved);
+	if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
+		return (map->pagesneeded - (map->pagesreserved + pages));
 	free_bpages -= pages;
 	reserved_bpages += pages;
 	map->pagesreserved += pages;
@@ -918,7 +933,7 @@ reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map)
 	return (pages);
 }
 
-static vm_offset_t
+static bus_addr_t
 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
 		bus_size_t size)
 {
@@ -961,7 +976,7 @@ free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
 	free_bpages++;
 	active_bpages--;
 	if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
-		if (reserve_bounce_pages(map->dmat, map) == 0) {
+		if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
 			STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
 			STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
 					   map, links);