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, 44 insertions, 22 deletions

diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c
index edd61ee90323..327437af2122 100644
--- a/drivers/usb/host/ehci-sched.c
+++ b/drivers/usb/host/ehci-sched.c
@@ -60,6 +60,20 @@ periodic_next_shadow(struct ehci_hcd *ehci, union ehci_shadow *periodic,
         }
 }
 
+static __hc32 *
+shadow_next_periodic(struct ehci_hcd *ehci, union ehci_shadow *periodic,
+                __hc32 tag)
+{
+        switch (hc32_to_cpu(ehci, tag)) {
+        /* our ehci_shadow.qh is actually software part */
+        case Q_TYPE_QH:
+                return &periodic->qh->hw->hw_next;
+        /* others are hw parts */
+        default:
+                return periodic->hw_next;
+        }
+}
+
 /* caller must hold ehci->lock */
 static void periodic_unlink (struct ehci_hcd *ehci, unsigned frame, void *ptr)
 {
@@ -71,7 +85,8 @@ static void periodic_unlink (struct ehci_hcd *ehci, unsigned frame, void *ptr)
         while (here.ptr && here.ptr != ptr) {
                 prev_p = periodic_next_shadow(ehci, prev_p,
                                 Q_NEXT_TYPE(ehci, *hw_p));
-                hw_p = here.hw_next;
+                hw_p = shadow_next_periodic(ehci, &here,
+                                Q_NEXT_TYPE(ehci, *hw_p));
                 here = *prev_p;
         }
         /* an interrupt entry (at list end) could have been shared */
@@ -83,7 +98,7 @@ static void periodic_unlink (struct ehci_hcd *ehci, unsigned frame, void *ptr)
          */
         *prev_p = *periodic_next_shadow(ehci, &here,
                         Q_NEXT_TYPE(ehci, *hw_p));
-        *hw_p = *here.hw_next;
+        *hw_p = *shadow_next_periodic(ehci, &here, Q_NEXT_TYPE(ehci, *hw_p));
 }
 
 /* how many of the uframe's 125 usecs are allocated? */
@@ -93,18 +108,20 @@ periodic_usecs (struct ehci_hcd *ehci, unsigned frame, unsigned uframe)
         __hc32                  *hw_p = &ehci->periodic [frame];
         union ehci_shadow       *q = &ehci->pshadow [frame];
         unsigned                usecs = 0;
+        struct ehci_qh_hw       *hw;
 
         while (q->ptr) {
                 switch (hc32_to_cpu(ehci, Q_NEXT_TYPE(ehci, *hw_p))) {
                 case Q_TYPE_QH:
+                        hw = q->qh->hw;
                         /* is it in the S-mask? */
-                        if (q->qh->hw_info2 & cpu_to_hc32(ehci, 1 << uframe))
+                        if (hw->hw_info2 & cpu_to_hc32(ehci, 1 << uframe))
                                 usecs += q->qh->usecs;
                         /* ... or C-mask? */
-                        if (q->qh->hw_info2 & cpu_to_hc32(ehci,
+                        if (hw->hw_info2 & cpu_to_hc32(ehci,
                                         1 << (8 + uframe)))
                                 usecs += q->qh->c_usecs;
-                        hw_p = &q->qh->hw_next;
+                        hw_p = &hw->hw_next;
                         q = &q->qh->qh_next;
                         break;
                 // case Q_TYPE_FSTN:
@@ -237,10 +254,10 @@ periodic_tt_usecs (
                         continue;
                 case Q_TYPE_QH:
                         if (same_tt(dev, q->qh->dev)) {
-                                uf = tt_start_uframe(ehci, q->qh->hw_info2);
+                                uf = tt_start_uframe(ehci, q->qh->hw->hw_info2);
                                 tt_usecs[uf] += q->qh->tt_usecs;
                         }
-                        hw_p = &q->qh->hw_next;
+                        hw_p = &q->qh->hw->hw_next;
                         q = &q->qh->qh_next;
                         continue;
                 case Q_TYPE_SITD:
@@ -375,6 +392,7 @@ static int tt_no_collision (
         for (; frame < ehci->periodic_size; frame += period) {
                 union ehci_shadow       here;
                 __hc32                  type;
+                struct ehci_qh_hw       *hw;
 
                 here = ehci->pshadow [frame];
                 type = Q_NEXT_TYPE(ehci, ehci->periodic [frame]);
@@ -385,17 +403,18 @@ static int tt_no_collision (
                                 here = here.itd->itd_next;
                                 continue;
                         case Q_TYPE_QH:
+                                hw = here.qh->hw;
                                 if (same_tt (dev, here.qh->dev)) {
                                         u32             mask;
 
                                         mask = hc32_to_cpu(ehci,
-                                                        here.qh->hw_info2);
+                                                        hw->hw_info2);
                                         /* "knows" no gap is needed */
                                         mask |= mask >> 8;
                                         if (mask & uf_mask)
                                                 break;
                                 }
-                                type = Q_NEXT_TYPE(ehci, here.qh->hw_next);
+                                type = Q_NEXT_TYPE(ehci, hw->hw_next);
                                 here = here.qh->qh_next;
                                 continue;
                         case Q_TYPE_SITD:
@@ -498,7 +517,8 @@ static int qh_link_periodic (struct ehci_hcd *ehci, struct ehci_qh *qh)
 
         dev_dbg (&qh->dev->dev,
                 "link qh%d-%04x/%p start %d [%d/%d us]\n",
-                period, hc32_to_cpup(ehci, &qh->hw_info2) & (QH_CMASK | QH_SMASK),
+                period, hc32_to_cpup(ehci, &qh->hw->hw_info2)
+                        & (QH_CMASK | QH_SMASK),
                 qh, qh->start, qh->usecs, qh->c_usecs);
 
         /* high bandwidth, or otherwise every microframe */
@@ -517,7 +537,7 @@ static int qh_link_periodic (struct ehci_hcd *ehci, struct ehci_qh *qh)
                         if (type == cpu_to_hc32(ehci, Q_TYPE_QH))
                                 break;
                         prev = periodic_next_shadow(ehci, prev, type);
-                        hw_p = &here.qh->hw_next;
+                        hw_p = shadow_next_periodic(ehci, &here, type);
                         here = *prev;
                 }
 
@@ -528,14 +548,14 @@ static int qh_link_periodic (struct ehci_hcd *ehci, struct ehci_qh *qh)
                         if (qh->period > here.qh->period)
                                 break;
                         prev = &here.qh->qh_next;
-                        hw_p = &here.qh->hw_next;
+                        hw_p = &here.qh->hw->hw_next;
                         here = *prev;
                 }
                 /* link in this qh, unless some earlier pass did that */
                 if (qh != here.qh) {
                         qh->qh_next = here;
                         if (here.qh)
-                                qh->hw_next = *hw_p;
+                                qh->hw->hw_next = *hw_p;
                         wmb ();
                         prev->qh = qh;
                         *hw_p = QH_NEXT (ehci, qh->qh_dma);
@@ -581,7 +601,7 @@ static int qh_unlink_periodic(struct ehci_hcd *ehci, struct ehci_qh *qh)
         dev_dbg (&qh->dev->dev,
                 "unlink qh%d-%04x/%p start %d [%d/%d us]\n",
                 qh->period,
-                hc32_to_cpup(ehci, &qh->hw_info2) & (QH_CMASK | QH_SMASK),
+                hc32_to_cpup(ehci, &qh->hw->hw_info2) & (QH_CMASK | QH_SMASK),
                 qh, qh->start, qh->usecs, qh->c_usecs);
 
         /* qh->qh_next still "live" to HC */
@@ -596,6 +616,7 @@ static int qh_unlink_periodic(struct ehci_hcd *ehci, struct ehci_qh *qh)
 static void intr_deschedule (struct ehci_hcd *ehci, struct ehci_qh *qh)
 {
         unsigned        wait;
+        struct ehci_qh_hw *hw = qh->hw;
 
         qh_unlink_periodic (ehci, qh);
 
@@ -606,14 +627,14 @@ static void intr_deschedule (struct ehci_hcd *ehci, struct ehci_qh *qh)
          */
         if (list_empty (&qh->qtd_list)
                         || (cpu_to_hc32(ehci, QH_CMASK)
-                                        & qh->hw_info2) != 0)
+                                        & hw->hw_info2) != 0)
                 wait = 2;
         else
                 wait = 55;      /* worst case: 3 * 1024 */
 
         udelay (wait);
         qh->qh_state = QH_STATE_IDLE;
-        qh->hw_next = EHCI_LIST_END(ehci);
+        hw->hw_next = EHCI_LIST_END(ehci);
         wmb ();
 }
 
@@ -739,14 +760,15 @@ static int qh_schedule(struct ehci_hcd *ehci, struct ehci_qh *qh)
         unsigned        uframe;
         __hc32          c_mask;
         unsigned        frame;          /* 0..(qh->period - 1), or NO_FRAME */
+        struct ehci_qh_hw       *hw = qh->hw;
 
         qh_refresh(ehci, qh);
-        qh->hw_next = EHCI_LIST_END(ehci);
+        hw->hw_next = EHCI_LIST_END(ehci);
         frame = qh->start;
 
         /* reuse the previous schedule slots, if we can */
         if (frame < qh->period) {
-                uframe = ffs(hc32_to_cpup(ehci, &qh->hw_info2) & QH_SMASK);
+                uframe = ffs(hc32_to_cpup(ehci, &hw->hw_info2) & QH_SMASK);
                 status = check_intr_schedule (ehci, frame, --uframe,
                                 qh, &c_mask);
         } else {
@@ -784,11 +806,11 @@ static int qh_schedule(struct ehci_hcd *ehci, struct ehci_qh *qh)
                 qh->start = frame;
 
                 /* reset S-frame and (maybe) C-frame masks */
-                qh->hw_info2 &= cpu_to_hc32(ehci, ~(QH_CMASK | QH_SMASK));
-                qh->hw_info2 |= qh->period
+                hw->hw_info2 &= cpu_to_hc32(ehci, ~(QH_CMASK | QH_SMASK));
+                hw->hw_info2 |= qh->period
                         ? cpu_to_hc32(ehci, 1 << uframe)
                         : cpu_to_hc32(ehci, QH_SMASK);
-                qh->hw_info2 |= c_mask;
+                hw->hw_info2 |= c_mask;
         } else
                 ehci_dbg (ehci, "reused qh %p schedule\n", qh);
 
@@ -2188,7 +2210,7 @@ restart:
                         case Q_TYPE_QH:
                                 /* handle any completions */
                                 temp.qh = qh_get (q.qh);
-                                type = Q_NEXT_TYPE(ehci, q.qh->hw_next);
+                                type = Q_NEXT_TYPE(ehci, q.qh->hw->hw_next);
                                 q = q.qh->qh_next;
                                 modified = qh_completions (ehci, temp.qh);
                                 if (unlikely (list_empty (&temp.qh->qtd_list)))