[ar71xx] ag71xx driver: align descriptors on cache_line boundary

[openwrt.git] / target / linux / ar71xx / files / drivers / net / ag71xx / ag71xx_main.c

diff --git a/target/linux/ar71xx/files/drivers/net/ag71xx/ag71xx_main.c b/target/linux/ar71xx/files/drivers/net/ag71xx/ag71xx_main.c
index 6302bf6..1aa24b3 100644 (file)
--- a/target/linux/ar71xx/files/drivers/net/ag71xx/ag71xx_main.c
+++ b/target/linux/ar71xx/files/drivers/net/ag71xx/ag71xx_main.c
@@ -11,6 +11,7 @@
  *  by the Free Software Foundation.
  */
 
+#include <linux/cache.h>
 #include "ag71xx.h"
 
 #define AG71XX_DEFAULT_MSG_ENABLE      \
@@ -86,7 +87,7 @@ static void ag71xx_ring_free(struct ag71xx_ring *ring)
        kfree(ring->buf);
 
        if (ring->descs_cpu)
-               dma_free_coherent(NULL, ring->size * sizeof(struct ag71xx_desc),
+               dma_free_coherent(NULL, ring->size * ring->desc_size,
                                  ring->descs_cpu, ring->descs_dma);
 }
 
@@ -95,10 +96,16 @@ static int ag71xx_ring_alloc(struct ag71xx_ring *ring, unsigned int size)
        int err;
        int i;
 
-       ring->descs_cpu = dma_alloc_coherent(NULL,
-                                            size * sizeof(struct ag71xx_desc),
-                                            &ring->descs_dma,
-                                            GFP_ATOMIC);
+       ring->desc_size = sizeof(struct ag71xx_desc);
+       if (ring->desc_size % cache_line_size()) {
+               DBG("ag71xx: ring %p, desc size %u rounded to %u\n",
+                       ring, ring->desc_size,
+                       roundup(ring->desc_size, cache_line_size()));
+               ring->desc_size = roundup(ring->desc_size, cache_line_size());
+       }
+
+       ring->descs_cpu = dma_alloc_coherent(NULL, size * ring->desc_size,
+                                            &ring->descs_dma, GFP_ATOMIC);
        if (!ring->descs_cpu) {
                err = -ENOMEM;
                goto err;
@@ -113,8 +120,9 @@ static int ag71xx_ring_alloc(struct ag71xx_ring *ring, unsigned int size)
        }
 
        for (i = 0; i < size; i++) {
-               struct ag71xx_desc *descs = (struct ag71xx_desc *) ring->descs_cpu;
-               ring->buf[i].desc = &descs[i];
+               ring->buf[i].desc = (struct ag71xx_desc *)&ring->descs_cpu[i * ring->desc_size];
+               DBG("ag71xx: ring %p, desc %d at %p\n",
+                       ring, i, ring->buf[i].desc);
        }
 
        return 0;
@@ -156,7 +164,7 @@ static void ag71xx_ring_tx_init(struct ag71xx *ag)
 
        for (i = 0; i < AG71XX_TX_RING_SIZE; i++) {
                ring->buf[i].desc->next = (u32) (ring->descs_dma +
-                       sizeof(struct ag71xx_desc) * ((i + 1) % AG71XX_TX_RING_SIZE));
+                       ring->desc_size * ((i + 1) % AG71XX_TX_RING_SIZE));
 
                ring->buf[i].desc->ctrl = DESC_EMPTY;
                ring->buf[i].skb = NULL;
@@ -190,9 +198,14 @@ static int ag71xx_ring_rx_init(struct ag71xx *ag)
        int ret;
 
        ret = 0;
-       for (i = 0; i < AG71XX_RX_RING_SIZE; i++)
+       for (i = 0; i < AG71XX_RX_RING_SIZE; i++) {
                ring->buf[i].desc->next = (u32) (ring->descs_dma +
-                       sizeof(struct ag71xx_desc) * ((i + 1) % AG71XX_RX_RING_SIZE));
+                       ring->desc_size * ((i + 1) % AG71XX_RX_RING_SIZE));
+
+               DBG("ag71xx: RX desc at %p, next is %08x\n",
+                       ring->buf[i].desc,
+                       ring->buf[i].desc->next);
+       }
 
        for (i = 0; i < AG71XX_RX_RING_SIZE; i++) {
                struct sk_buff *skb;