openbsd_network & drivers: Implement the real bus_dmamem functions.

This required the addition of some slight modifications to the main
(FreeBSD compat) bus_dma implementation.

Allows some #ifdefs from iaxwifi/idualwifi to be dropped, and will
ease the porting of some future drivers.

Tested with idualwifi7260, seems to work as before.

src/add-ons/kernel/drivers/network/wlan/iaxwifi200/dev/pci/if_iwx.c

@@ -1819,17 +1819,6 @@ iwx_dma_contig_alloc(bus_dma_tag_t tag, struct iwx_dma_info *dma,
 	dma->tag = tag;
 	dma->size = size;
 
-#ifdef __FreeBSD_version
-	err = bus_dmamap_create_obsd(tag, size, 1, size, 0, alignment, BUS_DMA_NOWAIT,
-		&dma->map, 1);
-	if (err)
-		goto fail;
-
-	err = bus_dmamem_alloc(dma->map->_dmat, (void **)&dma->vaddr,
-		BUS_DMA_NOWAIT | BUS_DMA_ZERO | BUS_DMA_COHERENT, &dma->map->_dmamp);
-	if (err)
-		goto fail;
-#else
 	err = bus_dmamap_create(tag, size, 1, size, 0, BUS_DMA_NOWAIT,
 	    &dma->map);
 	if (err)
@@ -1839,9 +1828,7 @@ iwx_dma_contig_alloc(bus_dma_tag_t tag, struct iwx_dma_info *dma,
 	    BUS_DMA_NOWAIT | BUS_DMA_ZERO);
 	if (err)
 		goto fail;
-#endif
 
-#ifndef __FreeBSD_version
 	if (nsegs > 1) {
 		err = ENOMEM;
 		goto fail;
@@ -1852,20 +1839,12 @@ iwx_dma_contig_alloc(bus_dma_tag_t tag, struct iwx_dma_info *dma,
 	if (err)
 		goto fail;
 	dma->vaddr = va;
-#endif
 
 	err = bus_dmamap_load(tag, dma->map, dma->vaddr, size, NULL,
 	    BUS_DMA_NOWAIT);
 	if (err)
 		goto fail;
 
-#ifdef __FreeBSD_version
-	if (dma->map->dm_nsegs > 1) {
-		err = ENOMEM;
-		goto fail;
-	}
-#endif
-
 	bus_dmamap_sync(tag, dma->map, 0, size, BUS_DMASYNC_PREWRITE);
 	dma->paddr = dma->map->dm_segs[0].ds_addr;
 
@@ -1883,13 +1862,8 @@ iwx_dma_contig_free(struct iwx_dma_info *dma)
 			bus_dmamap_sync(dma->tag, dma->map, 0, dma->size,
 			    BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
 			bus_dmamap_unload(dma->tag, dma->map);
-#ifdef __FreeBSD_version
-			bus_dmamem_free(dma->tag, dma->vaddr, dma->map->_dmamp);
-			dma->map->_dmamp = NULL;
-#else
 			bus_dmamem_unmap(dma->tag, dma->vaddr, dma->size);
 			bus_dmamem_free(dma->tag, &dma->seg, 1);
-#endif
 			dma->vaddr = NULL;
 		}
 		bus_dmamap_destroy(dma->tag, dma->map);

src/add-ons/kernel/drivers/network/wlan/idualwifi7260/dev/pci/if_iwm.c

@@ -1235,17 +1235,6 @@ iwm_dma_contig_alloc(bus_dma_tag_t tag, struct iwm_dma_info *dma,
 	dma->tag = tag;
 	dma->size = size;
 
-#ifdef __FreeBSD_version
-	err = bus_dmamap_create_obsd(tag, size, 1, size, 0, alignment, BUS_DMA_NOWAIT,
-		&dma->map, 1);
-	if (err)
-		goto fail;
-
-	err = bus_dmamem_alloc(dma->map->_dmat, (void **)&dma->vaddr,
-		BUS_DMA_NOWAIT | BUS_DMA_ZERO | BUS_DMA_COHERENT, &dma->map->_dmamp);
-	if (err)
-		goto fail;
-#else
 	err = bus_dmamap_create(tag, size, 1, size, 0, BUS_DMA_NOWAIT,
 	    &dma->map);
 	if (err)
@@ -1261,7 +1250,6 @@ iwm_dma_contig_alloc(bus_dma_tag_t tag, struct iwm_dma_info *dma,
 	if (err)
 		goto fail;
 	dma->vaddr = va;
-#endif
 
 	err = bus_dmamap_load(tag, dma->map, dma->vaddr, size, NULL,
 	    BUS_DMA_NOWAIT);
@@ -1286,13 +1274,8 @@ iwm_dma_contig_free(struct iwm_dma_info *dma)
 			bus_dmamap_sync(dma->tag, dma->map, 0, dma->size,
 			    BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
 			bus_dmamap_unload(dma->tag, dma->map);
-#ifdef __FreeBSD_version
-			bus_dmamem_free(dma->tag, dma->vaddr, dma->map->_dmamp);
-			dma->map->_dmamp = NULL;
-#else
 			bus_dmamem_unmap(dma->tag, dma->vaddr, dma->size);
 			bus_dmamem_free(dma->tag, &dma->seg, 1);
-#endif
 			dma->vaddr = NULL;
 		}
 		bus_dmamap_destroy(dma->tag, dma->map);

src/libs/compat/freebsd_network/bus_dma.cpp

@@ -253,10 +253,13 @@ bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
 	if (flags & BUS_DMA_ZERO)
 		mflags |= M_ZERO;
 
-	bus_dmamap_create(dmat, flags, mapp);
+	// FreeBSD does not permit the "mapp" argument to be NULL, but we do.
+	if (mapp != NULL) {
+		bus_dmamap_create(dmat, flags, mapp);
 
-	// Drivers assume dmamem will never be bounced, so ensure that.
+		// Drivers assume dmamem will never be bounced, so ensure that.
-	(*mapp)->buffer_type = bus_dmamap::BUFFER_PROHIBITED;
+		(*mapp)->buffer_type = bus_dmamap::BUFFER_PROHIBITED;
+	}
 
 	// FreeBSD uses standard malloc() for the case where maxsize <= PAGE_SIZE,
 	// but we want to keep DMA'd memory a bit more separate, so we always use
@@ -289,17 +292,24 @@ bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
 	} else if (vtophys(*vaddr) & (dmat->alignment - 1)) {
 		dprintf("bus_dmamem_alloc: failed to align memory: wanted %#x, got %#x\n",
 			dmat->alignment, vtophys(vaddr));
-		bus_dmamem_free(dmat, *vaddr, *mapp);
+		bus_dmamem_free(dmat, *vaddr, (mapp != NULL) ? *mapp : NULL);
 		return ENOMEM;
 	}
 	return 0;
 }
 
 
+extern "C" void
+bus_dmamem_free_tagless(void* vaddr, size_t size)
+{
+	kernel_contigfree(vaddr, size, M_DEVBUF);
+}
+
+
 extern "C" void
 bus_dmamem_free(bus_dma_tag_t dmat, void* vaddr, bus_dmamap_t map)
 {
-	kernel_contigfree(vaddr, dmat->maxsize, M_DEVBUF);
+	bus_dmamem_free_tagless(vaddr, dmat->maxsize);
 	bus_dmamap_destroy(dmat, map);
 }
 

src/libs/compat/freebsd_network/compat/sys/bus_dma.h

@@ -211,6 +211,9 @@ int bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
  */
 void bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map);
 
+/* Haiku extension, OpenBSD compatibility */
+void bus_dmamem_free_tagless(void *vaddr, size_t size);
+
 /*
  * Map the buffer buf into bus space using the dmamap map.
  */
@@ -245,8 +248,10 @@ int bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map,
  * is NULL we have a fully IO-coherent system.
  */
 void bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t dmamap, bus_dmasync_op_t op);
+
+/* Haiku extension, OpenBSD compatibility */
 void bus_dmamap_sync_etc(bus_dma_tag_t dmat, bus_dmamap_t dmamap,
-	bus_addr_t offset, bus_size_t length, bus_dmasync_op_t op); /* Haiku extension */
+	bus_addr_t offset, bus_size_t length, bus_dmasync_op_t op);
 
 /*
  * Release the mapping held by map.

src/libs/compat/openbsd_network/compat/machine/bus.h

@@ -28,26 +28,24 @@ typedef struct bus_dmamap_obsd* bus_dmamap_obsd_t;
 
 static int
 bus_dmamap_create_obsd(bus_dma_tag_t tag, bus_size_t maxsize,
-	int nsegments, bus_size_t maxsegsz, bus_size_t boundary, bus_size_t alignment,
+	int nsegments, bus_size_t maxsegsz, bus_size_t boundary,
-	int flags, bus_dmamap_t* dmamp, int no_alloc_map)
+	int flags, bus_dmamap_t* dmamp)
 {
 	*dmamp = calloc(sizeof(struct bus_dmamap_obsd) + (sizeof(bus_dma_segment_t) * nsegments), 1);
 	if ((*dmamp) == NULL)
 		return ENOMEM;
 
-	int error = bus_dma_tag_create(tag, alignment, boundary,
+	int error = bus_dma_tag_create(tag, 1, boundary,
 		BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR, NULL, NULL,
 		maxsize, nsegments, maxsegsz, flags, NULL, NULL,
 		&(*dmamp)->_dmat);
 	if (error != 0)
 		return error;
 
-	if (!no_alloc_map)
+	error = bus_dmamap_create((*dmamp)->_dmat, flags, &(*dmamp)->_dmamp);
-		error = bus_dmamap_create((*dmamp)->_dmat, flags, &(*dmamp)->_dmamp);
 	return error;
 }
-#define bus_dmamap_create(tag, maxsize, nsegments, maxsegsz, boundary, flags, dmamp) \
+#define bus_dmamap_create bus_dmamap_create_obsd
-	bus_dmamap_create_obsd(tag, maxsize, nsegments, maxsegsz, boundary, 1, flags, dmamp, 0)
 
 
 static void
@@ -111,4 +109,65 @@ bus_dmamap_sync_obsd(bus_dma_tag_t tag, bus_dmamap_t dmam,
 #define bus_dmamap_sync bus_dmamap_sync_obsd
 
 
+static int
+bus_dmamem_alloc_obsd(bus_dma_tag_t tag, bus_size_t size, bus_size_t alignment, bus_size_t boundary,
+	bus_dma_segment_t* segs, int nsegs, int* rsegs, int flags)
+{
+	// OpenBSD distinguishes between three different types of addresses:
+	//     1. virtual addresses (caddr_t)
+	//     2. opaque "bus" addresses
+	//     3. physical addresses
+	// This function returns the second type. We simply return the virtual address for it.
+
+	bus_dma_tag_t local;
+	int error = bus_dma_tag_create(tag, alignment, boundary,
+		BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR, NULL, NULL,
+		size, nsegs, size, flags, NULL, NULL, &local);
+	if (error)
+		return error;
+
+	error = bus_dmamem_alloc(local, (void**)&segs[0].ds_addr, flags, NULL);
+	if (error)
+		return error;
+	segs[0].ds_len = size;
+
+	error = bus_dma_tag_destroy(local);
+	if (error)
+		return error;
+
+	*rsegs = 1;
+	return 0;
+}
+#define bus_dmamem_alloc bus_dmamem_alloc_obsd
+
+
+static void
+bus_dmamem_free_obsd(bus_dma_tag_t tag, bus_dma_segment_t* segs, int nsegs)
+{
+	for (int i = 0; i < nsegs; i++)
+		bus_dmamem_free_tagless(segs[i].ds_addr, segs[i].ds_len);
+}
+#define bus_dmamem_free bus_dmamem_free_obsd
+
+
+static int
+bus_dmamem_map_obsd(bus_dma_tag_t tag, bus_dma_segment_t* segs, int nsegs, size_t size, caddr_t* kvap, int flags)
+{
+	if (nsegs != 1)
+		return EINVAL;
+
+	*kvap = (caddr_t)segs[0].ds_addr;
+	return 0;
+}
+#define bus_dmamem_map bus_dmamem_map_obsd
+
+
+static void
+bus_dmamem_unmap_obsd(bus_dma_tag_t tag, caddr_t kva, size_t size)
+{
+	// Nothing to do.
+}
+#define bus_dmamem_unmap bus_dmamem_unmap_obsd
+
+
 #endif	/* _OBSD_COMPAT_MACHINE_BUS_H_ */