Author: hselasky
Date: Thu Nov 19 09:54:28 2015
New Revision: 291063
URL: https://svnweb.freebsd.org/changeset/base/291063
Log:
MFC r290489:
Add helper function to check if a USB page cache buffer is properly
aligned to reduce the use of bounce buffers in PIO mode.
Modified:
stable/9/sys/dev/usb/usb_busdma.c
stable/9/sys/dev/usb/usb_busdma.h
Directory Properties:
stable/9/sys/ (props changed)
stable/9/sys/dev/ (props changed)
Modified: stable/9/sys/dev/usb/usb_busdma.c
==============================================================================
--- stable/9/sys/dev/usb/usb_busdma.c Thu Nov 19 09:52:46 2015
(r291062)
+++ stable/9/sys/dev/usb/usb_busdma.c Thu Nov 19 09:54:28 2015
(r291063)
@@ -130,6 +130,35 @@ usbd_get_page(struct usb_page_cache *pc,
}
/*------------------------------------------------------------------------*
+ * usb_pc_buffer_is_aligned - verify alignment
+ *
+ * This function is used to check if a page cache buffer is properly
+ * aligned to reduce the use of bounce buffers in PIO mode.
+ *------------------------------------------------------------------------*/
+uint8_t
+usb_pc_buffer_is_aligned(struct usb_page_cache *pc, usb_frlength_t offset,
+ usb_frlength_t len, usb_frlength_t mask)
+{
+ struct usb_page_search buf_res;
+
+ while (len != 0) {
+
+ usbd_get_page(pc, offset, &buf_res);
+
+ if (buf_res.length > len)
+ buf_res.length = len;
+ if (USB_P2U(buf_res.buffer) & mask)
+ return (0);
+ if (buf_res.length & mask)
+ return (0);
+
+ offset += buf_res.length;
+ len -= buf_res.length;
+ }
+ return (1);
+}
+
+/*------------------------------------------------------------------------*
* usbd_copy_in - copy directly to DMA-able memory
*------------------------------------------------------------------------*/
void
Modified: stable/9/sys/dev/usb/usb_busdma.h
==============================================================================
--- stable/9/sys/dev/usb/usb_busdma.h Thu Nov 19 09:52:46 2015
(r291062)
+++ stable/9/sys/dev/usb/usb_busdma.h Thu Nov 19 09:54:28 2015
(r291063)
@@ -157,5 +157,8 @@ void usb_pc_cpu_flush(struct usb_page_ca
void usb_pc_cpu_invalidate(struct usb_page_cache *pc);
void usb_pc_dmamap_destroy(struct usb_page_cache *pc);
void usb_pc_free_mem(struct usb_page_cache *pc);
+uint8_t usb_pc_buffer_is_aligned(struct usb_page_cache *pc,
+ usb_frlength_t offset, usb_frlength_t len,
+ usb_frlength_t mask);
#endif /* _USB_BUSDMA_H_ */
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