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, 17 insertions, 9 deletions

diff --git a/drivers/usb/host/ehci-mem.c b/drivers/usb/host/ehci-mem.c
index 10d52919abbb..aeda96e0af67 100644
--- a/drivers/usb/host/ehci-mem.c
+++ b/drivers/usb/host/ehci-mem.c
@@ -75,7 +75,8 @@ static void qh_destroy(struct ehci_qh *qh)
         }
         if (qh->dummy)
                 ehci_qtd_free (ehci, qh->dummy);
-        dma_pool_free (ehci->qh_pool, qh, qh->qh_dma);
+        dma_pool_free(ehci->qh_pool, qh->hw, qh->qh_dma);
+        kfree(qh);
 }
 
 static struct ehci_qh *ehci_qh_alloc (struct ehci_hcd *ehci, gfp_t flags)
@@ -83,12 +84,14 @@ static struct ehci_qh *ehci_qh_alloc (struct ehci_hcd *ehci, gfp_t flags)
         struct ehci_qh          *qh;
         dma_addr_t              dma;
 
-        qh = (struct ehci_qh *)
-                dma_pool_alloc (ehci->qh_pool, flags, &dma);
+        qh = kzalloc(sizeof *qh, GFP_ATOMIC);
         if (!qh)
-                return qh;
-
-        memset (qh, 0, sizeof *qh);
+                goto done;
+        qh->hw = (struct ehci_qh_hw *)
+                dma_pool_alloc(ehci->qh_pool, flags, &dma);
+        if (!qh->hw)
+                goto fail;
+        memset(qh->hw, 0, sizeof *qh->hw);
         qh->refcount = 1;
         qh->ehci = ehci;
         qh->qh_dma = dma;
@@ -99,10 +102,15 @@ static struct ehci_qh *ehci_qh_alloc (struct ehci_hcd *ehci, gfp_t flags)
         qh->dummy = ehci_qtd_alloc (ehci, flags);
         if (qh->dummy == NULL) {
                 ehci_dbg (ehci, "no dummy td\n");
-                dma_pool_free (ehci->qh_pool, qh, qh->qh_dma);
-                qh = NULL;
+                goto fail1;
         }
+done:
         return qh;
+fail1:
+        dma_pool_free(ehci->qh_pool, qh->hw, qh->qh_dma);
+fail:
+        kfree(qh);
+        return NULL;
 }
 
 /* to share a qh (cpu threads, or hc) */
@@ -180,7 +188,7 @@ static int ehci_mem_init (struct ehci_hcd *ehci, gfp_t flags)
         /* QHs for control/bulk/intr transfers */
         ehci->qh_pool = dma_pool_create ("ehci_qh",
                         ehci_to_hcd(ehci)->self.controller,
-                        sizeof (struct ehci_qh),
+                        sizeof(struct ehci_qh_hw),
                         32 /* byte alignment (for hw parts) */,
                         4096 /* can't cross 4K */);
         if (!ehci->qh_pool) {