1 files changed, 56 insertions, 1 deletions

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 132b76fa7ca6..ae9d66e75f43 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -18,6 +18,8 @@
 #include <linux/slab.h>
 #include <linux/dmi.h>
 #include <linux/dma-mapping.h>
+#include <linux/dma-map-ops.h>
+#include <linux/genalloc.h>
 
 #include "xhci.h"
 #include "xhci-trace.h"
@@ -1273,6 +1275,55 @@ static void xhci_unmap_temp_buf(struct usb_hcd *hcd, struct urb *urb)
 	urb->transfer_buffer = NULL;
 }
 
+static void xhci_map_urb_local(struct usb_hcd *hcd, struct urb *urb,
+				gfp_t mem_flags)
+{
+	void *buffer;
+	dma_addr_t dma_handle;
+	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+	struct xhci_lowmem_pool *lowmem_pool = &xhci->lowmem_pool;
+
+	if (lowmem_pool->pool
+		&& (usb_endpoint_type(&urb->ep->desc) == USB_ENDPOINT_XFER_BULK)
+		&& (urb->transfer_buffer_length > PAGE_SIZE)
+		&& urb->num_sgs && urb->sg && (sg_phys(urb->sg) > 0xffffffff)) {
+		buffer = gen_pool_dma_alloc(lowmem_pool->pool,
+			urb->transfer_buffer_length, &dma_handle);
+		if (buffer) {
+			urb->transfer_dma = dma_handle;
+			urb->transfer_buffer = buffer;
+			urb->transfer_flags |= URB_MAP_LOCAL;
+			if (usb_urb_dir_out(urb))
+				sg_copy_to_buffer(urb->sg, urb->num_sgs,
+					(void *)buffer,
+					urb->transfer_buffer_length);
+		}
+	}
+
+}
+
+static void xhci_unmap_urb_local(struct usb_hcd *hcd, struct urb *urb)
+{
+	dma_addr_t dma_handle;
+	u64 cached_buffer;
+	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+	struct xhci_lowmem_pool *lowmem_pool = &xhci->lowmem_pool;
+
+	if (urb->transfer_flags & URB_MAP_LOCAL) {
+		dma_handle = urb->transfer_dma;
+		cached_buffer = lowmem_pool->cached_base +
+			((u32)urb->transfer_dma & (lowmem_pool->size - 1));
+		if (usb_urb_dir_in(urb))
+			sg_copy_from_buffer(urb->sg, urb->num_sgs,
+				(void *)cached_buffer, urb->transfer_buffer_length);
+		gen_pool_free(lowmem_pool->pool, (unsigned long)urb->transfer_buffer,
+				urb->transfer_buffer_length);
+		urb->transfer_flags &= ~URB_MAP_LOCAL;
+		urb->transfer_buffer = NULL;
+	}
+}
+
+
 /*
  * Bypass the DMA mapping if URB is suitable for Immediate Transfer (IDT),
  * we'll copy the actual data into the TRB address register. This is limited to
@@ -1293,9 +1344,11 @@ static int xhci_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
 		if (xhci_urb_temp_buffer_required(hcd, urb))
 			return xhci_map_temp_buffer(hcd, urb);
 	}
+	xhci_map_urb_local(hcd, urb, mem_flags);
 	return usb_hcd_map_urb_for_dma(hcd, urb, mem_flags);
 }
 
+
 static void xhci_unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
 {
 	struct xhci_hcd *xhci;
@@ -1308,8 +1361,10 @@ static void xhci_unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
 
 	if ((xhci->quirks & XHCI_SG_TRB_CACHE_SIZE_QUIRK) && unmap_temp_buf)
 		xhci_unmap_temp_buf(hcd, urb);
-	else
+	else {
+		xhci_unmap_urb_local(hcd, urb);
 		usb_hcd_unmap_urb_for_dma(hcd, urb);
+	}
 }
 
 /**