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, 27 insertions, 0 deletions

diff --git a/sys/sparc64/pci/psycho.c b/sys/sparc64/pci/psycho.c
index 9b32b95..418b81c 100644
--- a/sys/sparc64/pci/psycho.c
+++ b/sys/sparc64/pci/psycho.c
@@ -113,8 +113,12 @@ static int psycho_dmamap_load_uio(bus_dma_tag_t, bus_dma_tag_t, bus_dmamap_t,
 static void psycho_dmamap_unload(bus_dma_tag_t, bus_dma_tag_t, bus_dmamap_t);
 static void psycho_dmamap_sync(bus_dma_tag_t, bus_dma_tag_t, bus_dmamap_t,
     bus_dmasync_op_t);
+static int psycho_dmamem_alloc_size(bus_dma_tag_t, bus_dma_tag_t, void **, int,
+    bus_dmamap_t *, bus_size_t size);
 static int psycho_dmamem_alloc(bus_dma_tag_t, bus_dma_tag_t, void **, int,
     bus_dmamap_t *);
+static void psycho_dmamem_free_size(bus_dma_tag_t, bus_dma_tag_t, void *,
+    bus_dmamap_t, bus_size_t size);
 static void psycho_dmamem_free(bus_dma_tag_t, bus_dma_tag_t, void *,
     bus_dmamap_t);
 
@@ -497,7 +501,9 @@ psycho_attach(device_t dev)
 	sc->sc_dmat->dt_dmamap_load_uio = psycho_dmamap_load_uio;
 	sc->sc_dmat->dt_dmamap_unload = psycho_dmamap_unload;
 	sc->sc_dmat->dt_dmamap_sync = psycho_dmamap_sync;
+	sc->sc_dmat->dt_dmamem_alloc_size = psycho_dmamem_alloc_size;
 	sc->sc_dmat->dt_dmamem_alloc = psycho_dmamem_alloc;
+	sc->sc_dmat->dt_dmamem_free_size = psycho_dmamem_free_size;
 	sc->sc_dmat->dt_dmamem_free = psycho_dmamem_free;
 	/* XXX: register as root dma tag (kluge). */
 	sparc64_root_dma_tag = sc->sc_dmat;
@@ -1314,6 +1320,17 @@ psycho_alloc_bus_tag(struct psycho_softc *sc, int type)
  * hooks into the iommu dvma calls.
  */
 static int
+psycho_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 psycho_softc *sc;
+
+	sc = (struct psycho_softc *)pdmat->cookie;
+	return (iommu_dvmamem_alloc_size(pdmat, ddmat, sc->sc_is, vaddr, flags,
+	    mapp, size));
+}
+
+static int
 psycho_dmamem_alloc(bus_dma_tag_t pdmat, bus_dma_tag_t ddmat, void **vaddr,
     int flags, bus_dmamap_t *mapp)
 {
@@ -1325,6 +1342,16 @@ psycho_dmamem_alloc(bus_dma_tag_t pdmat, bus_dma_tag_t ddmat, void **vaddr,
 }
 
 static void
+psycho_dmamem_free_size(bus_dma_tag_t pdmat, bus_dma_tag_t ddmat, void *vaddr,
+    bus_dmamap_t map, bus_size_t size)
+{
+	struct psycho_softc *sc;
+
+	sc = (struct psycho_softc *)pdmat->cookie;
+	iommu_dvmamem_free_size(pdmat, ddmat, sc->sc_is, vaddr, map, size);
+}
+
+static void
 psycho_dmamem_free(bus_dma_tag_t pdmat, bus_dma_tag_t ddmat, void *vaddr,
     bus_dmamap_t map)
 {