Spidernet DMA coalescing

The current driver code performs 512 DMA mappings of a bunch of
32-byte ring descriptor structures. This is silly, as they are
all in contiguous memory. This patch changes the code to
dma_map_coherent() each rx/tx ring as a whole.

Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Cc: James K Lewis <jklewis@us.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 5 insertions, 12 deletions

diff --git a/drivers/net/spider_net.h b/drivers/net/spider_net.h
index 3e196df29790..4b76ef9524d1 100644
--- a/drivers/net/spider_net.h
+++ b/drivers/net/spider_net.h
@@ -378,6 +378,9 @@ struct spider_net_descr_chain {
         spinlock_t lock;
         struct spider_net_descr *head;
         struct spider_net_descr *tail;
+        struct spider_net_descr *ring;
+        int num_desc;
+        dma_addr_t dma_addr;
 };
 
 /* descriptor data_status bits */
@@ -397,8 +400,6 @@ struct spider_net_descr_chain {
  * 701b8000 would be correct, but every packets gets that flag */
 #define SPIDER_NET_DESTROY_RX_FLAGS     0x700b8000
 
-#define SPIDER_NET_DESCR_SIZE           32
-
 /* this will be bigger some time */
 struct spider_net_options {
         int rx_csum; /* for rx: if 0 ip_summed=NONE,
@@ -441,25 +442,17 @@ struct spider_net_card {
         struct spider_net_descr_chain rx_chain;
         struct spider_net_descr *low_watermark;
 
-        struct net_device_stats netdev_stats;
-
-        struct spider_net_options options;
-
-        spinlock_t intmask_lock;
         struct tasklet_struct rxram_full_tl;
         struct timer_list tx_timer;
-
         struct work_struct tx_timeout_task;
         atomic_t tx_timeout_task_counter;
         wait_queue_head_t waitq;
 
         /* for ethtool */
         int msg_enable;
-        int num_rx_desc;
-        int num_tx_desc;
+        struct net_device_stats netdev_stats;
         struct spider_net_extra_stats spider_stats;
-
-        struct spider_net_descr descr[0];
+        struct spider_net_options options;
 };
 
 #define pr_err(fmt,arg...) \