net: stmmac: Parse FIFO sizes from feature registers

New version of this core encode the FIFO sizes in one of the feature
registers. Use these sizes as default, but still allow device tree to
override them for backwards compatibility.

Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/stmicro/stmmac/common.h b/drivers/net/ethernet/stmicro/stmmac/common.h
index 04d9245..3ca3674 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/common.h
+++ b/drivers/net/ethernet/stmicro/stmmac/common.h
@@ -324,6 +324,9 @@ struct dma_features {
        unsigned int number_tx_queues;
        /* Alternate (enhanced) DESC mode */
        unsigned int enh_desc;
+       /* TX and RX FIFO sizes */
+       unsigned int tx_fifo_size;
+       unsigned int rx_fifo_size;
 };
 
 /* GMAC TX FIFO is 8K, Rx FIFO is 16K */

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4.h b/drivers/net/ethernet/stmicro/stmmac/dwmac4.h
index db45134..83f5e95 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4.h
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4.h
@@ -148,6 +148,8 @@ enum power_event {
 /* MAC HW features1 bitmap */
 #define GMAC_HW_FEAT_AVSEL             BIT(20)
 #define GMAC_HW_TSOEN                  BIT(18)
+#define GMAC_HW_TXFIFOSIZE             GENMASK(10, 6)
+#define GMAC_HW_RXFIFOSIZE             GENMASK(4, 0)
 
 /* MAC HW features2 bitmap */
 #define GMAC_HW_FEAT_TXCHCNT           GENMASK(21, 18)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
index f97b0d5..5527093 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
@@ -294,6 +294,11 @@ static void dwmac4_get_hw_feature(void __iomem *ioaddr,
        hw_cap = readl(ioaddr + GMAC_HW_FEATURE1);
        dma_cap->av = (hw_cap & GMAC_HW_FEAT_AVSEL) >> 20;
        dma_cap->tsoen = (hw_cap & GMAC_HW_TSOEN) >> 18;
+       /* RX and TX FIFO sizes are encoded as log2(n / 128). Undo that by
+        * shifting and store the sizes in bytes.
+        */
+       dma_cap->tx_fifo_size = 128 << ((hw_cap & GMAC_HW_TXFIFOSIZE) >> 6);
+       dma_cap->rx_fifo_size = 128 << ((hw_cap & GMAC_HW_RXFIFOSIZE) >> 0);
        /* MAC HW feature2 */
        hw_cap = readl(ioaddr + GMAC_HW_FEATURE2);
        /* TX and RX number of channels */

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index eba9088..78f6ec2 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1281,6 +1281,9 @@ static void stmmac_dma_operation_mode(struct stmmac_priv *priv)
 {
        int rxfifosz = priv->plat->rx_fifo_size;
 
+       if (rxfifosz == 0)
+               rxfifosz = priv->dma_cap.rx_fifo_size;
+
        if (priv->plat->force_thresh_dma_mode)
                priv->hw->dma->dma_mode(priv->ioaddr, tc, tc, rxfifosz);
        else if (priv->plat->force_sf_dma_mode || priv->plat->tx_coe) {