Implement bus_dmamem_alloc_size() and bus_dmamem_free_size() as

counterparts to bus_dmamem_alloc() and bus_dmamem_free().  This allows
the caller to specify the size of the allocation instead of it defaulting
to the max_size field of the busdma tag.

This is intended to aid in converting drivers to busdma.  Lots of
hardware cannot understand scatter/gather lists, which forces the
driver to copy the i/o buffers to a single contiguous region
before sending it to the hardware.  Without these new methods, this
would require a new busdma tag for each operation, or a complex
internal allocator/cache for each driver.

Allocations greater than PAGE_SIZE are rounded up to the next
PAGE_SIZE by contigmalloc(), so this is not suitable for multiple
static allocations that would be better served by a single
fixed-length subdivided allocation.

Reviewed by:	jake (sparc64)

1 files changed, 25 insertions, 0 deletions

diff --git a/sys/sparc64/sbus/sbus.c b/sys/sparc64/sbus/sbus.c
index d76efb5..2689090 100644
--- a/sys/sparc64/sbus/sbus.c
+++ b/sys/sparc64/sbus/sbus.c
@@ -244,8 +244,12 @@ static int sbus_dmamap_load_uio(bus_dma_tag_t, bus_dma_tag_t, bus_dmamap_t,
 static void sbus_dmamap_unload(bus_dma_tag_t, bus_dma_tag_t, bus_dmamap_t);
 static void sbus_dmamap_sync(bus_dma_tag_t, bus_dma_tag_t, bus_dmamap_t,
     bus_dmasync_op_t);
+static int sbus_dmamem_alloc_size(bus_dma_tag_t, bus_dma_tag_t, void **, int,
+    bus_dmamap_t *, bus_size_t size);
 static int sbus_dmamem_alloc(bus_dma_tag_t, bus_dma_tag_t, void **, int,
     bus_dmamap_t *);
+static void sbus_dmamem_free_size(bus_dma_tag_t, bus_dma_tag_t, void *,
+    bus_dmamap_t, bus_size_t);
 static void sbus_dmamem_free(bus_dma_tag_t, bus_dma_tag_t, void *,
     bus_dmamap_t);
 
@@ -349,7 +353,9 @@ sbus_probe(device_t dev)
 	sc->sc_cdmatag->dt_dmamap_load_uio = sbus_dmamap_load_uio;
 	sc->sc_cdmatag->dt_dmamap_unload = sbus_dmamap_unload;
 	sc->sc_cdmatag->dt_dmamap_sync = sbus_dmamap_sync;
+	sc->sc_cdmatag->dt_dmamem_alloc_size = sbus_dmamem_alloc_size;
 	sc->sc_cdmatag->dt_dmamem_alloc = sbus_dmamem_alloc;
+	sc->sc_cdmatag->dt_dmamem_free_size = sbus_dmamem_free_size;
 	sc->sc_cdmatag->dt_dmamem_free = sbus_dmamem_free;
 	/* XXX: register as root dma tag (kluge). */
 	sparc64_root_dma_tag = sc->sc_cdmatag;
@@ -988,6 +994,16 @@ sbus_dmamap_sync(bus_dma_tag_t pdmat, bus_dma_tag_t ddmat, bus_dmamap_t map,
 }
 
 static int
+sbus_dmamem_alloc_size(bus_dma_tag_t pdmat, bus_dma_tag_t ddmat, void **vaddr,
+    int flags, bus_dmamap_t *mapp, bus_size_t size)
+{
+	struct sbus_softc *sc = (struct sbus_softc *)pdmat->cookie;
+
+	return (iommu_dvmamem_alloc_size(pdmat, ddmat, &sc->sc_is, vaddr, flags,
+		    mapp, size));
+}
+
+static int
 sbus_dmamem_alloc(bus_dma_tag_t pdmat, bus_dma_tag_t ddmat, void **vaddr,
     int flags, bus_dmamap_t *mapp)
 {
@@ -998,6 +1014,15 @@ sbus_dmamem_alloc(bus_dma_tag_t pdmat, bus_dma_tag_t ddmat, void **vaddr,
 }
 
 static void
+sbus_dmamem_free_size(bus_dma_tag_t pdmat, bus_dma_tag_t ddmat, void *vaddr,
+    bus_dmamap_t map, bus_size_t size)
+{
+	struct sbus_softc *sc = (struct sbus_softc *)pdmat->cookie;
+
+	iommu_dvmamem_free_size(pdmat, ddmat, &sc->sc_is, vaddr, map, size);
+}
+
+static void
 sbus_dmamem_free(bus_dma_tag_t pdmat, bus_dma_tag_t ddmat, void *vaddr,
     bus_dmamap_t map)
 {