net: stmmac: remove rx_tail_addr

There is only one place where rx_q->rx_tail_addr is used - the new
stmmac_set_queue_rx_tail_ptr(). Make this a local variable and remove
it from struct stmmac_rx_queue.

This commit does not change the semantics - the hardware relies upon
the descriptor ring not crossing a 4GiB boundary as the high address
bits are programmed into a separate register via stmmac_init_rx_chan().
Hence, truncating the DMA address to 32-bit is fine as the register it
will be programmed into is 32-bit, and the high bits are handled
elsewhere.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://patch.msgid.link/E1w1LWJ-0000000DGSL-2jWd@rmk-PC.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
index a2dc167adb6c278cbc1b417dacf899f6441c751c..2f24d5c584e6a013b1e075b48a27db970f6cd7cc 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
@@ -131,7 +131,6 @@ struct stmmac_rx_queue {
        unsigned int buf_alloc_num;
        unsigned int napi_skb_frag_size;
        dma_addr_t dma_rx_phy;
-       u32 rx_tail_addr;
        unsigned int state_saved;
        struct {
                struct sk_buff *skb;

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index d4129e9a0fb639e7d40ef3deeef2e19096a434de..dafd3a3e984426e42211f410d2fda74f512a6f53 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -388,8 +388,9 @@ static void stmmac_set_queue_rx_tail_ptr(struct stmmac_priv *priv,
         * descriptiors are only supported with dwmac1000 (<v4.0) which
         * does not implement .set_rx_tail_ptr
         */
-       rx_q->rx_tail_addr = rx_q->dma_rx_phy + index * sizeof(struct dma_desc);
-       stmmac_set_rx_tail_ptr(priv, priv->ioaddr, rx_q->rx_tail_addr, chan);
+       u32 rx_tail_addr = rx_q->dma_rx_phy + index * sizeof(struct dma_desc);
+
+       stmmac_set_rx_tail_ptr(priv, priv->ioaddr, rx_tail_addr, chan);
 }
 
 /**