tg3: Consider rx_std_prod_idx a hw mailbox

This patch changes how the code uses the rx_std_prod_idx member.  In the
following patch, the code will be changed so that it will act just like
a hardware mailbox.  This patch prepares the code so that memory barriers
can be more easily inserted.

Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Reviewed-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 6 deletions

diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index 59a715a25623..beda9bf0767b 100644
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -4537,6 +4537,7 @@ static int tg3_rx(struct tg3_napi *tnapi, int budget)
 {
         struct tg3 *tp = tnapi->tp;
         u32 work_mask, rx_std_posted = 0;
+        u32 std_prod_idx, jmb_prod_idx;
         u32 sw_idx = tnapi->rx_rcb_ptr;
         u16 hw_idx;
         int received;
@@ -4550,6 +4551,8 @@ static int tg3_rx(struct tg3_napi *tnapi, int budget)
         rmb();
         work_mask = 0;
         received = 0;
+        std_prod_idx = tpr->rx_std_prod_idx;
+        jmb_prod_idx = tpr->rx_jmb_prod_idx;
         while (sw_idx != hw_idx && budget > 0) {
                 struct ring_info *ri;
                 struct tg3_rx_buffer_desc *desc = &tnapi->rx_rcb[sw_idx];
@@ -4564,13 +4567,13 @@ static int tg3_rx(struct tg3_napi *tnapi, int budget)
                         ri = &tpr->rx_std_buffers[desc_idx];
                         dma_addr = pci_unmap_addr(ri, mapping);
                         skb = ri->skb;
-                        post_ptr = &tpr->rx_std_prod_idx;
+                        post_ptr = &std_prod_idx;
                         rx_std_posted++;
                 } else if (opaque_key == RXD_OPAQUE_RING_JUMBO) {
                         ri = &tpr->rx_jmb_buffers[desc_idx];
                         dma_addr = pci_unmap_addr(ri, mapping);
                         skb = ri->skb;
-                        post_ptr = &tpr->rx_jmb_prod_idx;
+                        post_ptr = &jmb_prod_idx;
                 } else
                         goto next_pkt_nopost;
 
@@ -4687,14 +4690,14 @@ next_pkt_nopost:
 
         /* Refill RX ring(s). */
         if (work_mask & RXD_OPAQUE_RING_STD) {
-                sw_idx = tpr->rx_std_prod_idx % TG3_RX_RING_SIZE;
+                tpr->rx_std_prod_idx = std_prod_idx % TG3_RX_RING_SIZE;
                 tw32_rx_mbox(MAILBOX_RCV_STD_PROD_IDX + TG3_64BIT_REG_LOW,
-                             sw_idx);
+                             tpr->rx_std_prod_idx);
         }
         if (work_mask & RXD_OPAQUE_RING_JUMBO) {
-                sw_idx = tpr->rx_jmb_prod_idx % TG3_RX_JUMBO_RING_SIZE;
+                tpr->rx_jmb_prod_idx = jmb_prod_idx % TG3_RX_JUMBO_RING_SIZE;
                 tw32_rx_mbox(MAILBOX_RCV_JUMBO_PROD_IDX + TG3_64BIT_REG_LOW,
-                             sw_idx);
+                             tpr->rx_jmb_prod_idx);
         }
         mmiowb();