net: stmmac: remove tx_tail_addr

There is only one place where tx_q->tx_tail_addr is used - the new
stmmac_set_queue_tx_tail_ptr(). Make this a local variable and remove
it from struct stmmac_tx_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_tx_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.

Also change the type of desc_size to size_t, as this variable is
initialised from sizeof().

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://patch.msgid.link/E1w1LWt-0000000DGT2-1oeO@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 2f24d5c584e6a013b1e075b48a27db970f6cd7cc..b9d849a3f06ecfba1c48182a97737a60027a9dc5 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
@@ -79,7 +79,6 @@ struct stmmac_tx_queue {
        unsigned int cur_tx;
        unsigned int dirty_tx;
        dma_addr_t dma_tx_phy;
-       dma_addr_t tx_tail_addr;
        u32 mss;
 };
 

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index dc7b19063564a0e8e944fd088b2313e2d921bed9..f096d52a16726605dc159b851780509e9dcc9f26 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -389,12 +389,13 @@ static void stmmac_set_queue_tx_tail_ptr(struct stmmac_priv *priv,
                                         struct stmmac_tx_queue *tx_q,
                                         unsigned int chan, unsigned int index)
 {
-       int desc_size;
+       size_t desc_size;
+       u32 tx_tail_addr;
 
        desc_size = stmmac_get_tx_desc_size(priv, tx_q);
 
-       tx_q->tx_tail_addr = tx_q->dma_tx_phy + index * desc_size;
-       stmmac_set_tx_tail_ptr(priv, priv->ioaddr, tx_q->tx_tail_addr, chan);
+       tx_tail_addr = tx_q->dma_tx_phy + index * desc_size;
+       stmmac_set_tx_tail_ptr(priv, priv->ioaddr, tx_tail_addr, chan);
 }
 
 static size_t stmmac_get_rx_desc_size(struct stmmac_priv *priv)