1 files changed, 465 insertions, 24 deletions

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index d64f5724bfc..fd9e03afd91 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -41,13 +41,13 @@ static struct xhci_segment *xhci_segment_alloc(struct xhci_hcd *xhci, gfp_t flag
 
 	seg = kzalloc(sizeof *seg, flags);
 	if (!seg)
-		return 0;
+		return NULL;
 	xhci_dbg(xhci, "Allocating priv segment structure at %p\n", seg);
 
 	seg->trbs = dma_pool_alloc(xhci->segment_pool, flags, &dma);
 	if (!seg->trbs) {
 		kfree(seg);
-		return 0;
+		return NULL;
 	}
 	xhci_dbg(xhci, "// Allocating segment at %p (virtual) 0x%llx (DMA)\n",
 			seg->trbs, (unsigned long long)dma);
@@ -159,7 +159,7 @@ static struct xhci_ring *xhci_ring_alloc(struct xhci_hcd *xhci,
 	ring = kzalloc(sizeof *(ring), flags);
 	xhci_dbg(xhci, "Allocating ring at %p\n", ring);
 	if (!ring)
-		return 0;
+		return NULL;
 
 	INIT_LIST_HEAD(&ring->td_list);
 	if (num_segs == 0)
@@ -196,7 +196,7 @@ static struct xhci_ring *xhci_ring_alloc(struct xhci_hcd *xhci,
 
 fail:
 	xhci_ring_free(xhci, ring);
-	return 0;
+	return NULL;
 }
 
 void xhci_free_or_cache_endpoint_ring(struct xhci_hcd *xhci,
@@ -247,7 +247,7 @@ static void xhci_reinit_cached_ring(struct xhci_hcd *xhci,
 
 #define CTX_SIZE(_hcc) (HCC_64BYTE_CONTEXT(_hcc) ? 64 : 32)
 
-struct xhci_container_ctx *xhci_alloc_container_ctx(struct xhci_hcd *xhci,
+static struct xhci_container_ctx *xhci_alloc_container_ctx(struct xhci_hcd *xhci,
 						    int type, gfp_t flags)
 {
 	struct xhci_container_ctx *ctx = kzalloc(sizeof(*ctx), flags);
@@ -265,7 +265,7 @@ struct xhci_container_ctx *xhci_alloc_container_ctx(struct xhci_hcd *xhci,
 	return ctx;
 }
 
-void xhci_free_container_ctx(struct xhci_hcd *xhci,
+static void xhci_free_container_ctx(struct xhci_hcd *xhci,
 			     struct xhci_container_ctx *ctx)
 {
 	if (!ctx)
@@ -304,6 +304,422 @@ struct xhci_ep_ctx *xhci_get_ep_ctx(struct xhci_hcd *xhci,
 		(ctx->bytes + (ep_index * CTX_SIZE(xhci->hcc_params)));
 }
 
+
+/***************** Streams structures manipulation *************************/
+
+void xhci_free_stream_ctx(struct xhci_hcd *xhci,
+		unsigned int num_stream_ctxs,
+		struct xhci_stream_ctx *stream_ctx, dma_addr_t dma)
+{
+	struct pci_dev *pdev = to_pci_dev(xhci_to_hcd(xhci)->self.controller);
+
+	if (num_stream_ctxs > MEDIUM_STREAM_ARRAY_SIZE)
+		pci_free_consistent(pdev,
+				sizeof(struct xhci_stream_ctx)*num_stream_ctxs,
+				stream_ctx, dma);
+	else if (num_stream_ctxs <= SMALL_STREAM_ARRAY_SIZE)
+		return dma_pool_free(xhci->small_streams_pool,
+				stream_ctx, dma);
+	else
+		return dma_pool_free(xhci->medium_streams_pool,
+				stream_ctx, dma);
+}
+
+/*
+ * The stream context array for each endpoint with bulk streams enabled can
+ * vary in size, based on:
+ *  - how many streams the endpoint supports,
+ *  - the maximum primary stream array size the host controller supports,
+ *  - and how many streams the device driver asks for.
+ *
+ * The stream context array must be a power of 2, and can be as small as
+ * 64 bytes or as large as 1MB.
+ */
+struct xhci_stream_ctx *xhci_alloc_stream_ctx(struct xhci_hcd *xhci,
+		unsigned int num_stream_ctxs, dma_addr_t *dma,
+		gfp_t mem_flags)
+{
+	struct pci_dev *pdev = to_pci_dev(xhci_to_hcd(xhci)->self.controller);
+
+	if (num_stream_ctxs > MEDIUM_STREAM_ARRAY_SIZE)
+		return pci_alloc_consistent(pdev,
+				sizeof(struct xhci_stream_ctx)*num_stream_ctxs,
+				dma);
+	else if (num_stream_ctxs <= SMALL_STREAM_ARRAY_SIZE)
+		return dma_pool_alloc(xhci->small_streams_pool,
+				mem_flags, dma);
+	else
+		return dma_pool_alloc(xhci->medium_streams_pool,
+				mem_flags, dma);
+}
+
+struct xhci_ring *xhci_dma_to_transfer_ring(
+		struct xhci_virt_ep *ep,
+		u64 address)
+{
+	if (ep->ep_state & EP_HAS_STREAMS)
+		return radix_tree_lookup(&ep->stream_info->trb_address_map,
+				address >> SEGMENT_SHIFT);
+	return ep->ring;
+}
+
+/* Only use this when you know stream_info is valid */
+#ifdef CONFIG_USB_XHCI_HCD_DEBUGGING
+static struct xhci_ring *dma_to_stream_ring(
+		struct xhci_stream_info *stream_info,
+		u64 address)
+{
+	return radix_tree_lookup(&stream_info->trb_address_map,
+			address >> SEGMENT_SHIFT);
+}
+#endif	/* CONFIG_USB_XHCI_HCD_DEBUGGING */
+
+struct xhci_ring *xhci_stream_id_to_ring(
+		struct xhci_virt_device *dev,
+		unsigned int ep_index,
+		unsigned int stream_id)
+{
+	struct xhci_virt_ep *ep = &dev->eps[ep_index];
+
+	if (stream_id == 0)
+		return ep->ring;
+	if (!ep->stream_info)
+		return NULL;
+
+	if (stream_id > ep->stream_info->num_streams)
+		return NULL;
+	return ep->stream_info->stream_rings[stream_id];
+}
+
+struct xhci_ring *xhci_triad_to_transfer_ring(struct xhci_hcd *xhci,
+		unsigned int slot_id, unsigned int ep_index,
+		unsigned int stream_id)
+{
+	struct xhci_virt_ep *ep;
+
+	ep = &xhci->devs[slot_id]->eps[ep_index];
+	/* Common case: no streams */
+	if (!(ep->ep_state & EP_HAS_STREAMS))
+		return ep->ring;
+
+	if (stream_id == 0) {
+		xhci_warn(xhci,
+				"WARN: Slot ID %u, ep index %u has streams, "
+				"but URB has no stream ID.\n",
+				slot_id, ep_index);
+		return NULL;
+	}
+
+	if (stream_id < ep->stream_info->num_streams)
+		return ep->stream_info->stream_rings[stream_id];
+
+	xhci_warn(xhci,
+			"WARN: Slot ID %u, ep index %u has "
+			"stream IDs 1 to %u allocated, "
+			"but stream ID %u is requested.\n",
+			slot_id, ep_index,
+			ep->stream_info->num_streams - 1,
+			stream_id);
+	return NULL;
+}
+
+/* Get the right ring for the given URB.
+ * If the endpoint supports streams, boundary check the URB's stream ID.
+ * If the endpoint doesn't support streams, return the singular endpoint ring.
+ */
+struct xhci_ring *xhci_urb_to_transfer_ring(struct xhci_hcd *xhci,
+		struct urb *urb)
+{
+	return xhci_triad_to_transfer_ring(xhci, urb->dev->slot_id,
+		xhci_get_endpoint_index(&urb->ep->desc), urb->stream_id);
+}
+
+#ifdef CONFIG_USB_XHCI_HCD_DEBUGGING
+static int xhci_test_radix_tree(struct xhci_hcd *xhci,
+		unsigned int num_streams,
+		struct xhci_stream_info *stream_info)
+{
+	u32 cur_stream;
+	struct xhci_ring *cur_ring;
+	u64 addr;
+
+	for (cur_stream = 1; cur_stream < num_streams; cur_stream++) {
+		struct xhci_ring *mapped_ring;
+		int trb_size = sizeof(union xhci_trb);
+
+		cur_ring = stream_info->stream_rings[cur_stream];
+		for (addr = cur_ring->first_seg->dma;
+				addr < cur_ring->first_seg->dma + SEGMENT_SIZE;
+				addr += trb_size) {
+			mapped_ring = dma_to_stream_ring(stream_info, addr);
+			if (cur_ring != mapped_ring) {
+				xhci_warn(xhci, "WARN: DMA address 0x%08llx "
+						"didn't map to stream ID %u; "
+						"mapped to ring %p\n",
+						(unsigned long long) addr,
+						cur_stream,
+						mapped_ring);
+				return -EINVAL;
+			}
+		}
+		/* One TRB after the end of the ring segment shouldn't return a
+		 * pointer to the current ring (although it may be a part of a
+		 * different ring).
+		 */
+		mapped_ring = dma_to_stream_ring(stream_info, addr);
+		if (mapped_ring != cur_ring) {
+			/* One TRB before should also fail */
+			addr = cur_ring->first_seg->dma - trb_size;
+			mapped_ring = dma_to_stream_ring(stream_info, addr);
+		}
+		if (mapped_ring == cur_ring) {
+			xhci_warn(xhci, "WARN: Bad DMA address 0x%08llx "
+					"mapped to valid stream ID %u; "
+					"mapped ring = %p\n",
+					(unsigned long long) addr,
+					cur_stream,
+					mapped_ring);
+			return -EINVAL;
+		}
+	}
+	return 0;
+}
+#endif	/* CONFIG_USB_XHCI_HCD_DEBUGGING */
+
+/*
+ * Change an endpoint's internal structure so it supports stream IDs.  The
+ * number of requested streams includes stream 0, which cannot be used by device
+ * drivers.
+ *
+ * The number of stream contexts in the stream context array may be bigger than
+ * the number of streams the driver wants to use.  This is because the number of
+ * stream context array entries must be a power of two.
+ *
+ * We need a radix tree for mapping physical addresses of TRBs to which stream
+ * ID they belong to.  We need to do this because the host controller won't tell
+ * us which stream ring the TRB came from.  We could store the stream ID in an
+ * event data TRB, but that doesn't help us for the cancellation case, since the
+ * endpoint may stop before it reaches that event data TRB.
+ *
+ * The radix tree maps the upper portion of the TRB DMA address to a ring
+ * segment that has the same upper portion of DMA addresses.  For example, say I
+ * have segments of size 1KB, that are always 64-byte aligned.  A segment may
+ * start at 0x10c91000 and end at 0x10c913f0.  If I use the upper 10 bits, the
+ * key to the stream ID is 0x43244.  I can use the DMA address of the TRB to
+ * pass the radix tree a key to get the right stream ID:
+ *
+ * 	0x10c90fff >> 10 = 0x43243
+ * 	0x10c912c0 >> 10 = 0x43244
+ * 	0x10c91400 >> 10 = 0x43245
+ *
+ * Obviously, only those TRBs with DMA addresses that are within the segment
+ * will make the radix tree return the stream ID for that ring.
+ *
+ * Caveats for the radix tree:
+ *
+ * The radix tree uses an unsigned long as a key pair.  On 32-bit systems, an
+ * unsigned long will be 32-bits; on a 64-bit system an unsigned long will be
+ * 64-bits.  Since we only request 32-bit DMA addresses, we can use that as the
+ * key on 32-bit or 64-bit systems (it would also be fine if we asked for 64-bit
+ * PCI DMA addresses on a 64-bit system).  There might be a problem on 32-bit
+ * extended systems (where the DMA address can be bigger than 32-bits),
+ * if we allow the PCI dma mask to be bigger than 32-bits.  So don't do that.
+ */
+struct xhci_stream_info *xhci_alloc_stream_info(struct xhci_hcd *xhci,
+		unsigned int num_stream_ctxs,
+		unsigned int num_streams, gfp_t mem_flags)
+{
+	struct xhci_stream_info *stream_info;
+	u32 cur_stream;
+	struct xhci_ring *cur_ring;
+	unsigned long key;
+	u64 addr;
+	int ret;
+
+	xhci_dbg(xhci, "Allocating %u streams and %u "
+			"stream context array entries.\n",
+			num_streams, num_stream_ctxs);
+	if (xhci->cmd_ring_reserved_trbs == MAX_RSVD_CMD_TRBS) {
+		xhci_dbg(xhci, "Command ring has no reserved TRBs available\n");
+		return NULL;
+	}
+	xhci->cmd_ring_reserved_trbs++;
+
+	stream_info = kzalloc(sizeof(struct xhci_stream_info), mem_flags);
+	if (!stream_info)
+		goto cleanup_trbs;
+
+	stream_info->num_streams = num_streams;
+	stream_info->num_stream_ctxs = num_stream_ctxs;
+
+	/* Initialize the array of virtual pointers to stream rings. */
+	stream_info->stream_rings = kzalloc(
+			sizeof(struct xhci_ring *)*num_streams,
+			mem_flags);
+	if (!stream_info->stream_rings)
+		goto cleanup_info;
+
+	/* Initialize the array of DMA addresses for stream rings for the HW. */
+	stream_info->stream_ctx_array = xhci_alloc_stream_ctx(xhci,
+			num_stream_ctxs, &stream_info->ctx_array_dma,
+			mem_flags);
+	if (!stream_info->stream_ctx_array)
+		goto cleanup_ctx;
+	memset(stream_info->stream_ctx_array, 0,
+			sizeof(struct xhci_stream_ctx)*num_stream_ctxs);
+
+	/* Allocate everything needed to free the stream rings later */
+	stream_info->free_streams_command =
+		xhci_alloc_command(xhci, true, true, mem_flags);
+	if (!stream_info->free_streams_command)
+		goto cleanup_ctx;
+
+	INIT_RADIX_TREE(&stream_info->trb_address_map, GFP_ATOMIC);
+
+	/* Allocate rings for all the streams that the driver will use,
+	 * and add their segment DMA addresses to the radix tree.
+	 * Stream 0 is reserved.
+	 */
+	for (cur_stream = 1; cur_stream < num_streams; cur_stream++) {
+		stream_info->stream_rings[cur_stream] =
+			xhci_ring_alloc(xhci, 1, true, mem_flags);
+		cur_ring = stream_info->stream_rings[cur_stream];
+		if (!cur_ring)
+			goto cleanup_rings;
+		cur_ring->stream_id = cur_stream;
+		/* Set deq ptr, cycle bit, and stream context type */
+		addr = cur_ring->first_seg->dma |
+			SCT_FOR_CTX(SCT_PRI_TR) |
+			cur_ring->cycle_state;
+		stream_info->stream_ctx_array[cur_stream].stream_ring = addr;
+		xhci_dbg(xhci, "Setting stream %d ring ptr to 0x%08llx\n",
+				cur_stream, (unsigned long long) addr);
+
+		key = (unsigned long)
+			(cur_ring->first_seg->dma >> SEGMENT_SHIFT);
+		ret = radix_tree_insert(&stream_info->trb_address_map,
+				key, cur_ring);
+		if (ret) {
+			xhci_ring_free(xhci, cur_ring);
+			stream_info->stream_rings[cur_stream] = NULL;
+			goto cleanup_rings;
+		}
+	}
+	/* Leave the other unused stream ring pointers in the stream context
+	 * array initialized to zero.  This will cause the xHC to give us an
+	 * error if the device asks for a stream ID we don't have setup (if it
+	 * was any other way, the host controller would assume the ring is
+	 * "empty" and wait forever for data to be queued to that stream ID).
+	 */
+#if XHCI_DEBUG
+	/* Do a little test on the radix tree to make sure it returns the
+	 * correct values.
+	 */
+	if (xhci_test_radix_tree(xhci, num_streams, stream_info))
+		goto cleanup_rings;
+#endif
+
+	return stream_info;
+
+cleanup_rings:
+	for (cur_stream = 1; cur_stream < num_streams; cur_stream++) {
+		cur_ring = stream_info->stream_rings[cur_stream];
+		if (cur_ring) {
+			addr = cur_ring->first_seg->dma;
+			radix_tree_delete(&stream_info->trb_address_map,
+					addr >> SEGMENT_SHIFT);
+			xhci_ring_free(xhci, cur_ring);
+			stream_info->stream_rings[cur_stream] = NULL;
+		}
+	}
+	xhci_free_command(xhci, stream_info->free_streams_command);
+cleanup_ctx:
+	kfree(stream_info->stream_rings);
+cleanup_info:
+	kfree(stream_info);
+cleanup_trbs:
+	xhci->cmd_ring_reserved_trbs--;
+	return NULL;
+}
+/*
+ * Sets the MaxPStreams field and the Linear Stream Array field.
+ * Sets the dequeue pointer to the stream context array.
+ */
+void xhci_setup_streams_ep_input_ctx(struct xhci_hcd *xhci,
+		struct xhci_ep_ctx *ep_ctx,
+		struct xhci_stream_info *stream_info)
+{
+	u32 max_primary_streams;
+	/* MaxPStreams is the number of stream context array entries, not the
+	 * number we're actually using.  Must be in 2^(MaxPstreams + 1) format.
+	 * fls(0) = 0, fls(0x1) = 1, fls(0x10) = 2, fls(0x100) = 3, etc.
+	 */
+	max_primary_streams = fls(stream_info->num_stream_ctxs) - 2;
+	xhci_dbg(xhci, "Setting number of stream ctx array entries to %u\n",
+			1 << (max_primary_streams + 1));
+	ep_ctx->ep_info &= ~EP_MAXPSTREAMS_MASK;
+	ep_ctx->ep_info |= EP_MAXPSTREAMS(max_primary_streams);
+	ep_ctx->ep_info |= EP_HAS_LSA;
+	ep_ctx->deq  = stream_info->ctx_array_dma;
+}
+
+/*
+ * Sets the MaxPStreams field and the Linear Stream Array field to 0.
+ * Reinstalls the "normal" endpoint ring (at its previous dequeue mark,
+ * not at the beginning of the ring).
+ */
+void xhci_setup_no_streams_ep_input_ctx(struct xhci_hcd *xhci,
+		struct xhci_ep_ctx *ep_ctx,
+		struct xhci_virt_ep *ep)
+{
+	dma_addr_t addr;
+	ep_ctx->ep_info &= ~EP_MAXPSTREAMS_MASK;
+	ep_ctx->ep_info &= ~EP_HAS_LSA;
+	addr = xhci_trb_virt_to_dma(ep->ring->deq_seg, ep->ring->dequeue);
+	ep_ctx->deq  = addr | ep->ring->cycle_state;
+}
+
+/* Frees all stream contexts associated with the endpoint,
+ *
+ * Caller should fix the endpoint context streams fields.
+ */
+void xhci_free_stream_info(struct xhci_hcd *xhci,
+		struct xhci_stream_info *stream_info)
+{
+	int cur_stream;
+	struct xhci_ring *cur_ring;
+	dma_addr_t addr;
+
+	if (!stream_info)
+		return;
+
+	for (cur_stream = 1; cur_stream < stream_info->num_streams;
+			cur_stream++) {
+		cur_ring = stream_info->stream_rings[cur_stream];
+		if (cur_ring) {
+			addr = cur_ring->first_seg->dma;
+			radix_tree_delete(&stream_info->trb_address_map,
+					addr >> SEGMENT_SHIFT);
+			xhci_ring_free(xhci, cur_ring);
+			stream_info->stream_rings[cur_stream] = NULL;
+		}
+	}
+	xhci_free_command(xhci, stream_info->free_streams_command);
+	xhci->cmd_ring_reserved_trbs--;
+	if (stream_info->stream_ctx_array)
+		xhci_free_stream_ctx(xhci,
+				stream_info->num_stream_ctxs,
+				stream_info->stream_ctx_array,
+				stream_info->ctx_array_dma);
+
+	if (stream_info)
+		kfree(stream_info->stream_rings);
+	kfree(stream_info);
+}
+
+
+/***************** Device context manipulation *************************/
+
 static void xhci_init_endpoint_timer(struct xhci_hcd *xhci,
 		struct xhci_virt_ep *ep)
 {
@@ -328,9 +744,13 @@ void xhci_free_virt_device(struct xhci_hcd *xhci, int slot_id)
 	if (!dev)
 		return;
 
-	for (i = 0; i < 31; ++i)
+	for (i = 0; i < 31; ++i) {
 		if (dev->eps[i].ring)
 			xhci_ring_free(xhci, dev->eps[i].ring);
+		if (dev->eps[i].stream_info)
+			xhci_free_stream_info(xhci,
+					dev->eps[i].stream_info);
+	}
 
 	if (dev->ring_cache) {
 		for (i = 0; i < dev->num_rings_cached; i++)
@@ -344,7 +764,7 @@ void xhci_free_virt_device(struct xhci_hcd *xhci, int slot_id)
 		xhci_free_container_ctx(xhci, dev->out_ctx);
 
 	kfree(xhci->devs[slot_id]);
-	xhci->devs[slot_id] = 0;
+	xhci->devs[slot_id] = NULL;
 }
 
 int xhci_alloc_virt_device(struct xhci_hcd *xhci, int slot_id,
@@ -590,9 +1010,9 @@ static inline unsigned int xhci_get_endpoint_interval(struct usb_device *udev,
 static inline u32 xhci_get_endpoint_mult(struct usb_device *udev,
 		struct usb_host_endpoint *ep)
 {
-	if (udev->speed != USB_SPEED_SUPER || !ep->ss_ep_comp)
+	if (udev->speed != USB_SPEED_SUPER)
 		return 0;
-	return ep->ss_ep_comp->desc.bmAttributes;
+	return ep->ss_ep_comp.bmAttributes;
 }
 
 static inline u32 xhci_get_endpoint_type(struct usb_device *udev,
@@ -641,13 +1061,8 @@ static inline u32 xhci_get_max_esit_payload(struct xhci_hcd *xhci,
 			usb_endpoint_xfer_bulk(&ep->desc))
 		return 0;
 
-	if (udev->speed == USB_SPEED_SUPER) {
-		if (ep->ss_ep_comp)
-			return ep->ss_ep_comp->desc.wBytesPerInterval;
-		xhci_warn(xhci, "WARN no SS endpoint companion descriptor.\n");
-		/* Assume no bursts, no multiple opportunities to send. */
-		return ep->desc.wMaxPacketSize;
-	}
+	if (udev->speed == USB_SPEED_SUPER)
+		return ep->ss_ep_comp.wBytesPerInterval;
 
 	max_packet = ep->desc.wMaxPacketSize & 0x3ff;
 	max_burst = (ep->desc.wMaxPacketSize & 0x1800) >> 11;
@@ -655,6 +1070,9 @@ static inline u32 xhci_get_max_esit_payload(struct xhci_hcd *xhci,
 	return max_packet * (max_burst + 1);
 }
 
+/* Set up an endpoint with one ring segment.  Do not allocate stream rings.
+ * Drivers will have to call usb_alloc_streams() to do that.
+ */
 int xhci_endpoint_init(struct xhci_hcd *xhci,
 		struct xhci_virt_device *virt_dev,
 		struct usb_device *udev,
@@ -708,12 +1126,9 @@ int xhci_endpoint_init(struct xhci_hcd *xhci,
 		max_packet = ep->desc.wMaxPacketSize;
 		ep_ctx->ep_info2 |= MAX_PACKET(max_packet);
 		/* dig out max burst from ep companion desc */
-		if (!ep->ss_ep_comp) {
-			xhci_warn(xhci, "WARN no SS endpoint companion descriptor.\n");
-			max_packet = 0;
-		} else {
-			max_packet = ep->ss_ep_comp->desc.bMaxBurst;
-		}
+		max_packet = ep->ss_ep_comp.bMaxBurst;
+		if (!max_packet)
+			xhci_warn(xhci, "WARN no SS endpoint bMaxBurst\n");
 		ep_ctx->ep_info2 |= MAX_BURST(max_packet);
 		break;
 	case USB_SPEED_HIGH:
@@ -1003,6 +1418,16 @@ void xhci_mem_cleanup(struct xhci_hcd *xhci)
 	xhci->device_pool = NULL;
 	xhci_dbg(xhci, "Freed device context pool\n");
 
+	if (xhci->small_streams_pool)
+		dma_pool_destroy(xhci->small_streams_pool);
+	xhci->small_streams_pool = NULL;
+	xhci_dbg(xhci, "Freed small stream array pool\n");
+
+	if (xhci->medium_streams_pool)
+		dma_pool_destroy(xhci->medium_streams_pool);
+	xhci->medium_streams_pool = NULL;
+	xhci_dbg(xhci, "Freed medium stream array pool\n");
+
 	xhci_write_64(xhci, 0, &xhci->op_regs->dcbaa_ptr);
 	if (xhci->dcbaa)
 		pci_free_consistent(pdev, sizeof(*xhci->dcbaa),
@@ -1239,6 +1664,22 @@ int xhci_mem_init(struct xhci_hcd *xhci, gfp_t flags)
 	if (!xhci->segment_pool || !xhci->device_pool)
 		goto fail;
 
+	/* Linear stream context arrays don't have any boundary restrictions,
+	 * and only need to be 16-byte aligned.
+	 */
+	xhci->small_streams_pool =
+		dma_pool_create("xHCI 256 byte stream ctx arrays",
+			dev, SMALL_STREAM_ARRAY_SIZE, 16, 0);
+	xhci->medium_streams_pool =
+		dma_pool_create("xHCI 1KB stream ctx arrays",
+			dev, MEDIUM_STREAM_ARRAY_SIZE, 16, 0);
+	/* Any stream context array bigger than MEDIUM_STREAM_ARRAY_SIZE
+	 * will be allocated with pci_alloc_consistent()
+	 */
+
+	if (!xhci->small_streams_pool || !xhci->medium_streams_pool)
+		goto fail;
+
 	/* Set up the command ring to have one segments for now. */
 	xhci->cmd_ring = xhci_ring_alloc(xhci, 1, true, flags);
 	if (!xhci->cmd_ring)
@@ -1330,7 +1771,7 @@ int xhci_mem_init(struct xhci_hcd *xhci, gfp_t flags)
 	 */
 	init_completion(&xhci->addr_dev);
 	for (i = 0; i < MAX_HC_SLOTS; ++i)
-		xhci->devs[i] = 0;
+		xhci->devs[i] = NULL;
 
 	if (scratchpad_alloc(xhci, flags))
 		goto fail;