[src/trunk]: src/sys/arch/arm Make IS_BOUNCING a map flag and use it to simpl...

[matt <matt%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/3172616e720a
branches:  trunk
changeset: 782167:3172616e720a
user:      matt <matt%NetBSD.org@localhost>
date:      Fri Oct 19 13:46:07 2012 +0000

description:
Make IS_BOUNCING a map flag and use it to simplify code and to avoid calling
the sync routines if (COHERENT|IS_BOUNCING) == COHERENT.  (this eeks out a
little bit more performance).

diffstat:

 sys/arch/arm/arm32/bus_dma.c     |  26 +++++++++++++-------------
 sys/arch/arm/include/bus_defs.h  |   3 ++-
 sys/arch/arm/include/bus_funcs.h |   4 +++-
 3 files changed, 18 insertions(+), 15 deletions(-)

diffs (136 lines):

diff -r 1e2ede38618a -r 3172616e720a sys/arch/arm/arm32/bus_dma.c
--- a/sys/arch/arm/arm32/bus_dma.c      Fri Oct 19 12:44:39 2012 +0000
+++ b/sys/arch/arm/arm32/bus_dma.c      Fri Oct 19 13:46:07 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: bus_dma.c,v 1.62 2012/10/19 11:57:58 matt Exp $        */
+/*     $NetBSD: bus_dma.c,v 1.63 2012/10/19 13:46:07 matt Exp $        */
 
 /*-
  * Copyright (c) 1996, 1997, 1998 The NetBSD Foundation, Inc.
@@ -33,7 +33,7 @@
 #define _ARM32_BUS_DMA_PRIVATE
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: bus_dma.c,v 1.62 2012/10/19 11:57:58 matt Exp $");
+__KERNEL_RCSID(0, "$NetBSD: bus_dma.c,v 1.63 2012/10/19 13:46:07 matt Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -270,6 +270,7 @@
        map->_dm_buftype = buftype;
 
        /* ...so _bus_dmamap_sync() knows we're bouncing */
+       map->_dm_flags |= _BUS_DMAMAP_IS_BOUNCING;
        cookie->id_flags |= _BUS_DMA_IS_BOUNCING;
        return 0;
 }
@@ -436,6 +437,7 @@
                        if (cookie->id_flags & _BUS_DMA_IS_BOUNCING) {
                                STAT_INCR(bounced_unloads);
                                cookie->id_flags &= ~_BUS_DMA_IS_BOUNCING;
+                               map->_dm_flags &= ~_BUS_DMAMAP_IS_BOUNCING;
                        }
                } else
 #endif
@@ -502,6 +504,7 @@
                        if (cookie->id_flags & _BUS_DMA_IS_BOUNCING) {
                                STAT_INCR(bounced_unloads);
                                cookie->id_flags &= ~_BUS_DMA_IS_BOUNCING;
+                               map->_dm_flags &= ~_BUS_DMAMAP_IS_BOUNCING;
                        }
                } else
 #endif
@@ -760,14 +763,11 @@
 _bus_dmamap_sync_linear(bus_dma_tag_t t, bus_dmamap_t map, bus_addr_t offset,
     bus_size_t len, int ops)
 {
-#ifdef _ARM32_NEED_BUS_DMA_BOUNCE
-       struct arm32_bus_dma_cookie * const cookie = map->_dm_cookie;
-       bool bouncing = (cookie != NULL && (cookie->id_flags & _BUS_DMA_IS_BOUNCING));
-#endif
        bus_dma_segment_t *ds = map->dm_segs;
        vaddr_t va = (vaddr_t) map->_dm_origbuf;
 #ifdef _ARM32_NEED_BUS_DMA_BOUNCE
-       if (bouncing) {
+       if (map->_dm_flags & _BUS_DMAMAP_IS_BOUNCING) {
+               struct arm32_bus_dma_cookie * const cookie = map->_dm_cookie;
                va = (vaddr_t) cookie->id_bouncebuf;
        }
 #endif
@@ -902,8 +902,6 @@
 _bus_dmamap_sync(bus_dma_tag_t t, bus_dmamap_t map, bus_addr_t offset,
     bus_size_t len, int ops)
 {
-       bool bouncing = false;
-
 #ifdef DEBUG_DMA
        printf("dmamap_sync: t=%p map=%p offset=%lx len=%lx ops=%x\n",
            t, map, offset, len, ops);
@@ -940,8 +938,9 @@
         *      POSTWRITE -- Nothing.
         */
 #ifdef _ARM32_NEED_BUS_DMA_BOUNCE
-       struct arm32_bus_dma_cookie * const cookie = map->_dm_cookie;
-       bouncing = (cookie != NULL && (cookie->id_flags & _BUS_DMA_IS_BOUNCING));
+       const bool bouncing = (map->_dm_flags & _BUS_DMA_IS_BOUNCING);
+#else
+       const bool bouncing = false;
 #endif
 
        const int pre_ops = ops & (BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE);
@@ -951,6 +950,7 @@
 
 #ifdef _ARM32_NEED_BUS_DMA_BOUNCE
        if (bouncing && (ops & BUS_DMASYNC_PREWRITE)) {
+               struct arm32_bus_dma_cookie * const cookie = map->_dm_cookie;
                STAT_INCR(write_bounces);
                char * const dataptr = (char *)cookie->id_bouncebuf + offset;
                /*
@@ -1045,10 +1045,10 @@
 #ifdef _ARM32_NEED_BUS_DMA_BOUNCE
   bounce_it:
        if ((ops & BUS_DMASYNC_POSTREAD) == 0
-           || cookie == NULL
-           || (cookie->id_flags & _BUS_DMA_IS_BOUNCING) == 0)
+           || (map->_dm_flags & _BUS_DMAMAP_IS_BOUNCING) == 0)
                return;
 
+       struct arm32_bus_dma_cookie * const cookie = map->_dm_cookie;
        char * const dataptr = (char *)cookie->id_bouncebuf + offset;
        STAT_INCR(read_bounces);
        /*
diff -r 1e2ede38618a -r 3172616e720a sys/arch/arm/include/bus_defs.h
--- a/sys/arch/arm/include/bus_defs.h   Fri Oct 19 12:44:39 2012 +0000
+++ b/sys/arch/arm/include/bus_defs.h   Fri Oct 19 13:46:07 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: bus_defs.h,v 1.3 2012/10/17 20:17:18 matt Exp $        */
+/*     $NetBSD: bus_defs.h,v 1.4 2012/10/19 13:46:07 matt Exp $        */
 
 /*-
  * Copyright (c) 1996, 1997, 1998, 2001 The NetBSD Foundation, Inc.
@@ -300,6 +300,7 @@
  * Private flags stored in the DMA map.
  */
 #define        _BUS_DMAMAP_COHERENT    0x10000 /* no cache flush necessary on sync */
+#define        _BUS_DMAMAP_IS_BOUNCING 0x20000 /* is bouncing current xfer */
 
 /* Forwards needed by prototypes below. */
 struct mbuf;
diff -r 1e2ede38618a -r 3172616e720a sys/arch/arm/include/bus_funcs.h
--- a/sys/arch/arm/include/bus_funcs.h  Fri Oct 19 12:44:39 2012 +0000
+++ b/sys/arch/arm/include/bus_funcs.h  Fri Oct 19 13:46:07 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: bus_funcs.h,v 1.3 2012/09/18 05:47:27 matt Exp $       */
+/*     $NetBSD: bus_funcs.h,v 1.4 2012/10/19 13:46:07 matt Exp $       */
 
 /*-
  * Copyright (c) 1996, 1997, 1998, 2001 The NetBSD Foundation, Inc.
@@ -587,6 +587,8 @@
        (*(t)->_dmamap_unload)((t), (p))
 #define        bus_dmamap_sync(t, p, o, l, ops)                        \
 do {                                                                   \
+       if (((p)->_dm_flags & (_BUS_DMAMAP_COHERENT|_BUS_DMAMAP_IS_BOUNCING)) == _BUS_DMAMAP_COHERENT) \
+               break;                                                  \
        if (((ops) & (BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE)) != 0   \
            && (t)->_dmamap_sync_pre != NULL)                           \
                (*(t)->_dmamap_sync_pre)((t), (p), (o), (l), (ops));    \