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>

diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index 59a715a..beda9bf 100644 (file)
--- 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();