USB: whci-hcd: support urbs with scatter-gather lists

Support urbs with scatter-gather lists by trying to fit sg list elements
into page lists in one or more qTDs.  qTDs must end on a wMaxPacketSize
boundary so if this isn't possible the urb's sg list must be copied into
bounce buffers.
Signed-off-by: David Vrabel <david.vrabel@csr.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/host/whci/hcd.c

@@ -250,6 +250,7 @@ static int whc_probe(struct umc_dev *umc)
 	}
 
 	usb_hcd->wireless = 1;
+	usb_hcd->self.sg_tablesize = 2048; /* somewhat arbitrary */
 
 	wusbhc = usb_hcd_to_wusbhc(usb_hcd);
 	whc = wusbhc_to_whc(wusbhc);

drivers/usb/host/whci/whcd.h

@@ -84,6 +84,11 @@ struct whc {
  * @len: the length of data in the associated TD.
  * @ntds_remaining: number of TDs (starting from this one) in this transfer.
  *
+ * @bounce_buf: a bounce buffer if the std was from an urb with a sg
+ * list that could not be mapped to qTDs directly.
+ * @bounce_sg: the first scatterlist element bounce_buf is for.
+ * @bounce_offset: the offset into bounce_sg for the start of bounce_buf.
+ *
  * Queued URBs may require more TDs than are available in a qset so we
  * use a list of these "software TDs" (sTDs) to hold per-TD data.
  */
@@ -97,6 +102,10 @@ struct whc_std {
 	int num_pointers;
 	dma_addr_t dma_addr;
 	struct whc_page_list_entry *pl_virt;
+
+	void *bounce_buf;
+	struct scatterlist *bounce_sg;
+	unsigned bounce_offset;
 };
 
 /**

drivers/usb/host/whci/whci-hc.h

@@ -267,8 +267,9 @@ struct whc_qset {
 	unsigned reset:1;
 	struct urb *pause_after_urb;
 	struct completion remove_complete;
-	int max_burst;
-	int max_seq;
+	uint16_t max_packet;
+	uint8_t max_burst;
+	uint8_t max_seq;
 };
 
 static inline void whc_qset_set_link_ptr(u64 *ptr, u64 target)