USB: EHCI: split ehci_qh into hw and sw parts

The ehci_qh structure merged hw and sw together which is not good:
1. More and more items are being added into ehci_qh, the ehci_qh software
   part are unnecessary to be allocated in DMA qh_pool.
2. If HCD has local SRAM, the sw part will consume it too, and it won't
   bring any benefit.
3. For non-cache-coherence system, the entire ehci_qh is uncachable, actually
   we only need the hw part to be uncacheable. Spliting them will let the sw
   part to be cacheable.

Signed-off-by: Alek Du <alek.du@intel.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
CC: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 6 insertions, 3 deletions

diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index acec10894078..fa12f20fbfe2 100644
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -299,8 +299,8 @@ union ehci_shadow {
  * These appear in both the async and (for interrupt) periodic schedules.
  */
 
-struct ehci_qh {
-        /* first part defined by EHCI spec */
+/* first part defined by EHCI spec */
+struct ehci_qh_hw {
         __hc32                  hw_next;        /* see EHCI 3.6.1 */
         __hc32                  hw_info1;       /* see EHCI 3.6.2 */
 #define QH_HEAD         0x00008000
@@ -318,7 +318,10 @@ struct ehci_qh {
         __hc32                  hw_token;
         __hc32                  hw_buf [5];
         __hc32                  hw_buf_hi [5];
+} __attribute__ ((aligned(32)));
 
+struct ehci_qh {
+        struct ehci_qh_hw       *hw;
         /* the rest is HCD-private */
         dma_addr_t              qh_dma;         /* address of qh */
         union ehci_shadow       qh_next;        /* ptr to qh; or periodic */
@@ -358,7 +361,7 @@ struct ehci_qh {
 
         struct usb_device       *dev;           /* access to TT */
         unsigned                clearing_tt:1;  /* Clear-TT-Buf in progress */
-} __attribute__ ((aligned (32)));
+};
 
 /*-------------------------------------------------------------------------*/