Convert BSD code to mostly use bus_dma, the dma abstraction for dealing

    with IOMMUs and such. There is one usage of the forbidden vtophys()
    left in drm_scatter.c which will be fixed up soon. This required a KPI
    change for drm_pci_alloc/free() to return/use a drm_dma_handle_t that
    keeps track of os-specific bits, rather than just passing around the
    vaddr/busaddr/size.
Submitted by: Tonnerre Lombard (partially) Tested on: FreeBSD: Rage128
    AGP/PCI Linux: Savage4 AGP/PCI

1 files changed, 80 insertions, 13 deletions

diff --git a/bsd-core/drm_pci.c b/bsd-core/drm_pci.c
index 29ed4790..0f431dd6 100644
--- a/bsd-core/drm_pci.c
+++ b/bsd-core/drm_pci.c
@@ -34,34 +34,101 @@
 /** \name PCI memory */
 /*@{*/
 
+#if defined(__FreeBSD__)
+static void
+drm_pci_busdma_callback(void *arg, bus_dma_segment_t *segs, int nsegs, int error)
+{
+	drm_dma_handle_t *dmah = arg;
+
+	if (error != 0)
+		return;
+
+	KASSERT(nsegs == 1, ("drm_pci_busdma_callback: bad dma segment count"));
+	dmah->busaddr = segs[0].ds_addr;
+}
+#endif
+
 /**
  * \brief Allocate a physically contiguous DMA-accessible consistent 
  * memory block.
  */
-void *
-drm_pci_alloc(drm_device_t *dev, size_t size, size_t align, dma_addr_t maxaddr,
-    dma_addr_t *busaddr)
+drm_dma_handle_t *
+drm_pci_alloc(drm_device_t *dev, size_t size, size_t align, dma_addr_t maxaddr)
 {
-	void *vaddr;
+	drm_dma_handle_t *dmah;
+	int ret;
+
+	dmah = malloc(sizeof(drm_dma_handle_t), M_DRM, M_ZERO | M_NOWAIT);
+	if (dmah == NULL)
+		return NULL;
 
-	vaddr = contigmalloc(size, M_DRM, M_NOWAIT, 0ul, maxaddr, align,
-	    0);
-	*busaddr = vtophys(vaddr);
-	
-	return vaddr;
+#ifdef __FreeBSD__
+	ret = bus_dma_tag_create(NULL, align, 0, /* tag, align, boundary */
+	    maxaddr, BUS_SPACE_MAXADDR, /* lowaddr, highaddr */
+	    NULL, NULL, /* filtfunc, filtfuncargs */
+	    size, 1, size, /* maxsize, nsegs, maxsegsize */
+	    BUS_DMA_ALLOCNOW, NULL, NULL, /* flags, lockfunc, lockfuncargs */
+	    &dmah->tag);
+	if (ret != 0) {
+		free(dmah, M_DRM);
+		return NULL;
+	}
+
+	ret = bus_dmamem_alloc(dmah->tag, &dmah->vaddr, BUS_DMA_NOWAIT,
+	    &dmah->map);
+	if (ret != 0) {
+		bus_dma_tag_destroy(dmah->tag);
+		free(dmah, M_DRM);
+		return NULL;
+	}
+
+	ret = bus_dmamap_load(dmah->tag, dmah->map, dmah->vaddr, size,
+	    drm_pci_busdma_callback, dmah, 0);
+	if (ret != 0) {
+		bus_dmamem_free(dmah->tag, dmah->vaddr, dmah->map);
+		bus_dma_tag_destroy(dmah->tag);
+		free(dmah, M_DRM);
+		return NULL;
+	}
+#elif defined(__NetBSD__)
+	ret = bus_dmamem_alloc(dev->dma_tag, size, align, PAGE_SIZE,
+	    &dmah->seg, 1, &nsegs, BUS_DMA_NOWAIT);
+	if ((ret != 0) || (nsegs != 1)) {
+		free(dmah, M_DRM);
+		return NULL;
+	}
+
+	ret = bus_dmamem_map(dev->dma_tag, &dmah->seg, 1, size, &dmah->addr,
+	    BUS_DMA_NOWAIT);
+	if (ret != 0) {
+		bus_dmamem_free(dev->dma_tag, &dmah->seg, 1);
+		free(dmah, M_DRM);
+		return NULL;
+	}
+
+	dmah->dmaaddr = h->seg.ds_addr;
+#endif
+
+	return dmah;
 }
 
 /**
  * \brief Free a DMA-accessible consistent memory block.
  */
 void
-drm_pci_free(drm_device_t *dev, size_t size, void *vaddr, dma_addr_t busaddr)
+drm_pci_free(drm_device_t *dev, drm_dma_handle_t *dmah)
 {
-#if __FreeBSD_version > 500000
-	if (vaddr == NULL)
+	if (dmah == NULL)
 		return;
-	contigfree(vaddr, size, M_DRM);	/* Not available on 4.x */
+
+#if defined(__FreeBSD__)
+	bus_dmamem_free(dmah->tag, dmah->vaddr, dmah->map);
+	bus_dma_tag_destroy(dmah->tag);
+#elif defined(__NetBSD__)
+	bus_dmamem_free(dev->dma_tag, &dmah->seg, 1);
 #endif
+
+	free(dmah, M_DRM);
 }
 
 /*@}*/