Implement bus dma support for loading raw mappings so that we can use

xhci(4) on ARM.  The only way the load raw operation can get to know
about the coherent flag is via the segments.  Store it there when the
memory is initially mapped.  Also store the virtual address which we
need to know when we have to flush the caches on a non-coherent mapping.

ok kettenis@

2 files changed, 136 insertions, 3 deletions

diff --git a/sys/arch/arm/arm/bus_dma.c b/sys/arch/arm/arm/bus_dma.c
index d0c37dcdb0e..ad64afdded0 100644
--- a/sys/arch/arm/arm/bus_dma.c
+++ b/sys/arch/arm/arm/bus_dma.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: bus_dma.c,v 1.33 2016/08/26 21:14:58 patrick Exp $	*/
+/*	$OpenBSD: bus_dma.c,v 1.34 2016/08/26 21:50:42 patrick Exp $	*/
 /*	$NetBSD: bus_dma.c,v 1.38 2003/10/30 08:44:13 scw Exp $	*/
 
 /*-
@@ -342,8 +342,109 @@ int
 _bus_dmamap_load_raw(bus_dma_tag_t t, bus_dmamap_t map,
     bus_dma_segment_t *segs, int nsegs, bus_size_t size, int flags)
 {
+	struct arm32_dma_range *dr;
+	bus_addr_t paddr, baddr, bmask, lastaddr = 0;
+	bus_size_t plen, sgsize, mapsize;
+	int first = 1;
+	int i, seg = 0;
+
+	/*
+	 * Make sure that on error condition we return "no valid mappings".
+	 */
+	map->dm_mapsize = 0;
+	map->dm_nsegs = 0;
+
+	if (nsegs > map->_dm_segcnt || size > map->_dm_size)
+		return (EINVAL);
+
+	mapsize = size;
+	bmask = ~(map->_dm_boundary - 1);
+
+	/*
+	 * Assume to be coherent at first.  If one of the segments
+	 * isn't, we clear the flag for the whole map.
+	 */
+	map->_dm_flags |= ARM32_DMAMAP_COHERENT;
+
+	for (i = 0; i < nsegs && size > 0; i++) {
+		paddr = segs[i].ds_addr;
+		plen = MIN(segs[i].ds_len, size);
+
+		if (!segs[i]._ds_coherent)
+			map->_dm_flags &= ~ARM32_DMAMAP_COHERENT;
 
-	panic("_bus_dmamap_load_raw: not implemented");
+		while (plen > 0) {
+			/*
+			 * Make sure we're in an allowed DMA range.
+			 */
+			if (t->_ranges != NULL) {
+				/* XXX cache last result? */
+				dr = _bus_dma_inrange(t->_ranges, t->_nranges,
+				    paddr);
+				if (dr == NULL)
+					return (EINVAL);
+
+				/*
+				 * In a valid DMA range.  Translate the physical
+				 * memory address to an address in the DMA window.
+				 */
+				paddr = (paddr - dr->dr_sysbase) + dr->dr_busbase;
+			}
+
+			/*
+			 * Compute the segment size, and adjust counts.
+			 */
+			sgsize = PAGE_SIZE - ((u_long)paddr & PGOFSET);
+			if (plen < sgsize)
+				sgsize = plen;
+
+			/*
+			 * Make sure we don't cross any boundaries.
+			 */
+			if (map->_dm_boundary > 0) {
+				baddr = (paddr + map->_dm_boundary) & bmask;
+				if (sgsize > (baddr - paddr))
+					sgsize = (baddr - paddr);
+			}
+
+			/*
+			 * Insert chunk into a segment, coalescing with
+			 * previous segment if possible.
+			 */
+			if (first) {
+				map->dm_segs[seg].ds_addr = paddr;
+				map->dm_segs[seg].ds_len = sgsize;
+				first = 0;
+			} else {
+				if (paddr == lastaddr &&
+				    (map->dm_segs[seg].ds_len + sgsize) <=
+				     map->_dm_maxsegsz &&
+				    (map->_dm_boundary == 0 ||
+				     (map->dm_segs[seg].ds_addr & bmask) ==
+				     (paddr & bmask)))
+					map->dm_segs[seg].ds_len += sgsize;
+				else {
+					if (++seg >= map->_dm_segcnt)
+						return (EINVAL);
+					map->dm_segs[seg].ds_addr = paddr;
+					map->dm_segs[seg].ds_len = sgsize;
+				}
+			}
+
+			paddr += sgsize;
+			plen -= sgsize;
+			size -= sgsize;
+
+			lastaddr = paddr;
+		}
+	}
+
+	map->dm_mapsize = mapsize;
+	map->dm_nsegs = seg + 1;
+	map->_dm_buftype = ARM32_BUFTYPE_RAW;
+	map->_dm_origbuf = NULL;
+	map->_dm_proc = NULL;
+	return (0);
 }
 
 /*
@@ -553,6 +654,29 @@ _bus_dmamap_sync_uio(bus_dma_tag_t t, bus_dmamap_t map, bus_addr_t offset,
 	}
 }
 
+static __inline void
+_bus_dmamap_sync_raw(bus_dma_tag_t t, bus_dmamap_t map, bus_addr_t offset,
+    bus_size_t len, int ops)
+{
+	bus_dma_segment_t *ds = map->dm_segs;
+
+	while (len > 0) {
+		while (offset >= ds->ds_len) {
+			offset -= ds->ds_len;
+			ds++;
+		}
+
+		vaddr_t va = ds->_ds_vaddr + offset;
+		paddr_t pa = _bus_dma_busaddr_to_paddr(t, ds->ds_addr + offset);
+		size_t seglen = min(len, ds->ds_len - offset);
+
+		_bus_dmamap_sync_segment(va, pa, seglen, ops);
+
+		offset += seglen;
+		len -= seglen;
+	}
+}
+
 /*
  * Common function for DMA map synchronization.  May be called
  * by bus-specific DMA map synchronization functions.
@@ -638,6 +762,10 @@ _bus_dmamap_sync(bus_dma_tag_t t, bus_dmamap_t map, bus_addr_t offset,
 		_bus_dmamap_sync_uio(t, map, offset, len, ops);
 		break;
 
+	case ARM32_BUFTYPE_RAW:
+		_bus_dmamap_sync_raw(t, map, offset, len, ops);
+		break;
+
 	case ARM32_BUFTYPE_INVALID:
 		panic("_bus_dmamap_sync: ARM32_BUFTYPE_INVALID");
 		break;
@@ -766,6 +894,9 @@ _bus_dmamem_map(bus_dma_tag_t t, bus_dma_segment_t *segs, int nsegs,
 #endif	/* DEBUG_DMA */
 			if (size == 0)
 				panic("_bus_dmamem_map: size botch");
+			segs[curseg]._ds_coherent =
+			    !!(flags & BUS_DMA_COHERENT);
+			segs[curseg]._ds_vaddr = va;
 			pmap_kenter_cache(va, addr,
 			    PROT_READ | PROT_WRITE,
 			    !(flags & BUS_DMA_COHERENT));
diff --git a/sys/arch/arm/include/bus.h b/sys/arch/arm/include/bus.h
index 6fdcdf83a87..f00c897d4be 100644
--- a/sys/arch/arm/include/bus.h
+++ b/sys/arch/arm/include/bus.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: bus.h,v 1.14 2011/03/23 16:54:34 pirofti Exp $	*/
+/*	$OpenBSD: bus.h,v 1.15 2016/08/26 21:50:43 patrick Exp $	*/
 /*	$NetBSD: bus.h,v 1.12 2003/10/23 15:03:24 scw Exp $	*/
 
 /*-
@@ -657,6 +657,7 @@ struct arm32_bus_dma_segment {
 	 */
 	bus_addr_t	_ds_vaddr;	/* Virtual mapped address
 					 * Used by bus_dmamem_sync() */
+	int		_ds_coherent;	/* Coherently mapped */
 };
 typedef struct arm32_bus_dma_segment	bus_dma_segment_t;
 
@@ -790,6 +791,7 @@ struct arm32_bus_dmamap {
 #define	ARM32_BUFTYPE_LINEAR		1
 #define	ARM32_BUFTYPE_MBUF		2
 #define	ARM32_BUFTYPE_UIO		3
+#define	ARM32_BUFTYPE_RAW		4
 
 int	arm32_dma_range_intersect(struct arm32_dma_range *, int,
 	    paddr_t pa, psize_t size, paddr_t *pap, psize_t *sizep);