Merge branch 'stmmac-DMA-burst'

Niklas Cassel says:

====================
net: stmmac: make DMA programmable burst length more configurable

Make DMA programmable burst length more configurable in the stmmac driver.

This is done by adding support for independent pbl for tx/rx through DT.
More fine grained tuning of pbl is possible thanks to a DT property saying
that we should NOT multiply pbl values by x8/x4 in hardware.

All new DT properties are optional, and created in a way that it will not
affect any existing DT configurations.

Changes since V1:
Created cover-letter.
Rebased patch set against next-20161205, since conflicting patches to
stmmac_platform.c has been merged since V1.

Changes since V2:
Moved default value initialization of pbl to stmmac_platform.c
and added a check for pbl != 0 in stmmac_main.c,
to catch a possble pbl == 0 from pci glue.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/devicetree/bindings/net/stmmac.txt

@@ -34,7 +34,13 @@ Optional properties:
   platforms.
 - tx-fifo-depth: See ethernet.txt file in the same directory
 - rx-fifo-depth: See ethernet.txt file in the same directory
-- snps,pbl		Programmable Burst Length
+- snps,pbl		Programmable Burst Length (tx and rx)
+- snps,txpbl		Tx Programmable Burst Length. Only for GMAC and newer.
+			If set, DMA tx will use this value rather than snps,pbl.
+- snps,rxpbl		Rx Programmable Burst Length. Only for GMAC and newer.
+			If set, DMA rx will use this value rather than snps,pbl.
+- snps,no-pbl-x8	Don't multiply the pbl/txpbl/rxpbl values by 8.
+			For core rev < 3.50, don't multiply the values by 4.
 - snps,aal		Address-Aligned Beats
 - snps,fixed-burst	Program the DMA to use the fixed burst mode
 - snps,mixed-burst	Program the DMA to use the mixed burst mode

Documentation/networking/stmmac.txt

@@ -152,8 +152,10 @@ Where:
  o dma_cfg: internal DMA parameters
    o pbl: the Programmable Burst Length is maximum number of beats to
        be transferred in one DMA transaction.
-       GMAC also enables the 4xPBL by default.
-   o fixed_burst/mixed_burst/burst_len
+       GMAC also enables the 4xPBL by default. (8xPBL for GMAC 3.50 and newer)
+   o txpbl/rxpbl: GMAC and newer supports independent DMA pbl for tx/rx.
+   o pblx8: Enable 8xPBL (4xPBL for core rev < 3.50). Enabled by default.
+   o fixed_burst/mixed_burst/aal
  o clk_csr: fixed CSR Clock range selection.
  o has_gmac: uses the GMAC core.
  o enh_desc: if sets the MAC will use the enhanced descriptor structure.
@@ -205,16 +207,24 @@ tuned according to the HW capabilities.
 
 struct stmmac_dma_cfg {
 	int pbl;
+	int txpbl;
+	int rxpbl;
+	bool pblx8;
 	int fixed_burst;
-	int burst_len_supported;
+	int mixed_burst;
+	bool aal;
 };
 
 Where:
- o pbl: Programmable Burst Length
+ o pbl: Programmable Burst Length (tx and rx)
+ o txpbl: Transmit Programmable Burst Length. Only for GMAC and newer.
+	 If set, DMA tx will use this value rather than pbl.
+ o rxpbl: Receive Programmable Burst Length. Only for GMAC and newer.
+	 If set, DMA rx will use this value rather than pbl.
+ o pblx8: Enable 8xPBL (4xPBL for core rev < 3.50). Enabled by default.
  o fixed_burst: program the DMA to use the fixed burst mode
- o burst_len: this is the value we put in the register
-	      supported values are provided as macros in
-	      linux/stmmac.h header file.
+ o mixed_burst: program the DMA to use the mixed burst mode
+ o aal: Address-Aligned Beats
 
 ---
 

drivers/net/ethernet/stmicro/stmmac/common.h

@@ -412,8 +412,8 @@ extern const struct stmmac_desc_ops ndesc_ops;
 struct stmmac_dma_ops {
 	/* DMA core initialization */
 	int (*reset)(void __iomem *ioaddr);
-	void (*init)(void __iomem *ioaddr, int pbl, int fb, int mb,
-		     int aal, u32 dma_tx, u32 dma_rx, int atds);
+	void (*init)(void __iomem *ioaddr, struct stmmac_dma_cfg *dma_cfg,
+		     u32 dma_tx, u32 dma_rx, int atds);
 	/* Configure the AXI Bus Mode Register */
 	void (*axi)(void __iomem *ioaddr, struct stmmac_axi *axi);
 	/* Dump DMA registers */

drivers/net/ethernet/stmicro/stmmac/dwmac1000.h

@@ -225,7 +225,7 @@ enum rx_tx_priority_ratio {
 
 #define DMA_BUS_MODE_FB		0x00010000	/* Fixed burst */
 #define DMA_BUS_MODE_MB		0x04000000	/* Mixed burst */
-#define DMA_BUS_MODE_RPBL_MASK	0x003e0000	/* Rx-Programmable Burst Len */
+#define DMA_BUS_MODE_RPBL_MASK	0x007e0000	/* Rx-Programmable Burst Len */
 #define DMA_BUS_MODE_RPBL_SHIFT	17
 #define DMA_BUS_MODE_USP	0x00800000
 #define DMA_BUS_MODE_MAXPBL	0x01000000

drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c

@@ -84,37 +84,39 @@ static void dwmac1000_dma_axi(void __iomem *ioaddr, struct stmmac_axi *axi)
 	writel(value, ioaddr + DMA_AXI_BUS_MODE);
 }
 
-static void dwmac1000_dma_init(void __iomem *ioaddr, int pbl, int fb, int mb,
-			       int aal, u32 dma_tx, u32 dma_rx, int atds)
+static void dwmac1000_dma_init(void __iomem *ioaddr,
+			       struct stmmac_dma_cfg *dma_cfg,
+			       u32 dma_tx, u32 dma_rx, int atds)
 {
 	u32 value = readl(ioaddr + DMA_BUS_MODE);
+	int txpbl = dma_cfg->txpbl ?: dma_cfg->pbl;
+	int rxpbl = dma_cfg->rxpbl ?: dma_cfg->pbl;
 
 	/*
 	 * Set the DMA PBL (Programmable Burst Length) mode.
 	 *
 	 * Note: before stmmac core 3.50 this mode bit was 4xPBL, and
 	 * post 3.5 mode bit acts as 8*PBL.
-	 *
-	 * This configuration doesn't take care about the Separate PBL
-	 * so only the bits: 13-8 are programmed with the PBL passed from the
-	 * platform.
 	 */
-	value |= DMA_BUS_MODE_MAXPBL;
-	value &= ~DMA_BUS_MODE_PBL_MASK;
-	value |= (pbl << DMA_BUS_MODE_PBL_SHIFT);
+	if (dma_cfg->pblx8)
+		value |= DMA_BUS_MODE_MAXPBL;
+	value |= DMA_BUS_MODE_USP;
+	value &= ~(DMA_BUS_MODE_PBL_MASK | DMA_BUS_MODE_RPBL_MASK);
+	value |= (txpbl << DMA_BUS_MODE_PBL_SHIFT);
+	value |= (rxpbl << DMA_BUS_MODE_RPBL_SHIFT);
 
 	/* Set the Fixed burst mode */
-	if (fb)
+	if (dma_cfg->fixed_burst)
 		value |= DMA_BUS_MODE_FB;
 
 	/* Mixed Burst has no effect when fb is set */
-	if (mb)
+	if (dma_cfg->mixed_burst)
 		value |= DMA_BUS_MODE_MB;
 
 	if (atds)
 		value |= DMA_BUS_MODE_ATDS;
 
-	if (aal)
+	if (dma_cfg->aal)
 		value |= DMA_BUS_MODE_AAL;
 
 	writel(value, ioaddr + DMA_BUS_MODE);

drivers/net/ethernet/stmicro/stmmac/dwmac100_dma.c

@@ -32,11 +32,12 @@
 #include "dwmac100.h"
 #include "dwmac_dma.h"
 
-static void dwmac100_dma_init(void __iomem *ioaddr, int pbl, int fb, int mb,
-			      int aal, u32 dma_tx, u32 dma_rx, int atds)
+static void dwmac100_dma_init(void __iomem *ioaddr,
+			      struct stmmac_dma_cfg *dma_cfg,
+			      u32 dma_tx, u32 dma_rx, int atds)
 {
 	/* Enable Application Access by writing to DMA CSR0 */
-	writel(DMA_BUS_MODE_DEFAULT | (pbl << DMA_BUS_MODE_PBL_SHIFT),
+	writel(DMA_BUS_MODE_DEFAULT | (dma_cfg->pbl << DMA_BUS_MODE_PBL_SHIFT),
 	       ioaddr + DMA_BUS_MODE);
 
 	/* Mask interrupts by writing to CSR7 */

drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c

@@ -71,25 +71,29 @@ static void dwmac4_dma_axi(void __iomem *ioaddr, struct stmmac_axi *axi)
 	writel(value, ioaddr + DMA_SYS_BUS_MODE);
 }
 
-static void dwmac4_dma_init_channel(void __iomem *ioaddr, int pbl,
+static void dwmac4_dma_init_channel(void __iomem *ioaddr,
+				    struct stmmac_dma_cfg *dma_cfg,
 				    u32 dma_tx_phy, u32 dma_rx_phy,
 				    u32 channel)
 {
 	u32 value;
+	int txpbl = dma_cfg->txpbl ?: dma_cfg->pbl;
+	int rxpbl = dma_cfg->rxpbl ?: dma_cfg->pbl;
 
 	/* set PBL for each channels. Currently we affect same configuration
 	 * on each channel
 	 */
 	value = readl(ioaddr + DMA_CHAN_CONTROL(channel));
-	value = value | DMA_BUS_MODE_PBL;
+	if (dma_cfg->pblx8)
+		value = value | DMA_BUS_MODE_PBL;
 	writel(value, ioaddr + DMA_CHAN_CONTROL(channel));
 
 	value = readl(ioaddr + DMA_CHAN_TX_CONTROL(channel));
-	value = value | (pbl << DMA_BUS_MODE_PBL_SHIFT);
+	value = value | (txpbl << DMA_BUS_MODE_PBL_SHIFT);
 	writel(value, ioaddr + DMA_CHAN_TX_CONTROL(channel));
 
 	value = readl(ioaddr + DMA_CHAN_RX_CONTROL(channel));
-	value = value | (pbl << DMA_BUS_MODE_RPBL_SHIFT);
+	value = value | (rxpbl << DMA_BUS_MODE_RPBL_SHIFT);
 	writel(value, ioaddr + DMA_CHAN_RX_CONTROL(channel));
 
 	/* Mask interrupts by writing to CSR7 */
@@ -99,27 +103,28 @@ static void dwmac4_dma_init_channel(void __iomem *ioaddr, int pbl,
 	writel(dma_rx_phy, ioaddr + DMA_CHAN_RX_BASE_ADDR(channel));
 }
 
-static void dwmac4_dma_init(void __iomem *ioaddr, int pbl, int fb, int mb,
-			    int aal, u32 dma_tx, u32 dma_rx, int atds)
+static void dwmac4_dma_init(void __iomem *ioaddr,
+			    struct stmmac_dma_cfg *dma_cfg,
+			    u32 dma_tx, u32 dma_rx, int atds)
 {
 	u32 value = readl(ioaddr + DMA_SYS_BUS_MODE);
 	int i;
 
 	/* Set the Fixed burst mode */
-	if (fb)
+	if (dma_cfg->fixed_burst)
 		value |= DMA_SYS_BUS_FB;
 
 	/* Mixed Burst has no effect when fb is set */
-	if (mb)
+	if (dma_cfg->mixed_burst)
 		value |= DMA_SYS_BUS_MB;
 
-	if (aal)
+	if (dma_cfg->aal)
 		value |= DMA_SYS_BUS_AAL;
 
 	writel(value, ioaddr + DMA_SYS_BUS_MODE);
 
 	for (i = 0; i < DMA_CHANNEL_NB_MAX; i++)
-		dwmac4_dma_init_channel(ioaddr, pbl, dma_tx, dma_rx, i);
+		dwmac4_dma_init_channel(ioaddr, dma_cfg, dma_tx, dma_rx, i);
 }
 
 static void _dwmac4_dump_dma_regs(void __iomem *ioaddr, u32 channel)

drivers/net/ethernet/stmicro/stmmac/stmmac_main.c

@@ -1578,16 +1578,12 @@ static void stmmac_check_ether_addr(struct stmmac_priv *priv)
  */
 static int stmmac_init_dma_engine(struct stmmac_priv *priv)
 {
-	int pbl = DEFAULT_DMA_PBL, fixed_burst = 0, aal = 0;
-	int mixed_burst = 0;
 	int atds = 0;
 	int ret = 0;
 
-	if (priv->plat->dma_cfg) {
-		pbl = priv->plat->dma_cfg->pbl;
-		fixed_burst = priv->plat->dma_cfg->fixed_burst;
-		mixed_burst = priv->plat->dma_cfg->mixed_burst;
-		aal = priv->plat->dma_cfg->aal;
+	if (!priv->plat->dma_cfg || !priv->plat->dma_cfg->pbl) {
+		dev_err(priv->device, "Invalid DMA configuration\n");
+		return -EINVAL;
 	}
 
 	if (priv->extend_desc && (priv->mode == STMMAC_RING_MODE))
@@ -1599,8 +1595,8 @@ static int stmmac_init_dma_engine(struct stmmac_priv *priv)
 		return ret;
 	}
 
-	priv->hw->dma->init(priv->ioaddr, pbl, fixed_burst, mixed_burst,
-			    aal, priv->dma_tx_phy, priv->dma_rx_phy, atds);
+	priv->hw->dma->init(priv->ioaddr, priv->plat->dma_cfg,
+			    priv->dma_tx_phy, priv->dma_rx_phy, atds);
 
 	if (priv->synopsys_id >= DWMAC_CORE_4_00) {
 		priv->rx_tail_addr = priv->dma_rx_phy +

drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c

@@ -81,6 +81,7 @@ static void stmmac_default_data(struct plat_stmmacenet_data *plat)
 	plat->mdio_bus_data->phy_mask = 0;
 
 	plat->dma_cfg->pbl = 32;
+	plat->dma_cfg->pblx8 = true;
 	/* TODO: AXI */
 
 	/* Set default value for multicast hash bins */
@@ -115,6 +116,7 @@ static int quark_default_data(struct plat_stmmacenet_data *plat,
 	plat->mdio_bus_data->phy_mask = 0;
 
 	plat->dma_cfg->pbl = 16;
+	plat->dma_cfg->pblx8 = true;
 	plat->dma_cfg->fixed_burst = 1;
 	/* AXI (TODO) */
 

drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c

@@ -304,21 +304,25 @@ stmmac_probe_config_dt(struct platform_device *pdev, const char **mac)
 		plat->force_sf_dma_mode = 1;
 	}
 
-	if (of_find_property(np, "snps,pbl", NULL)) {
-		dma_cfg = devm_kzalloc(&pdev->dev, sizeof(*dma_cfg),
-				       GFP_KERNEL);
-		if (!dma_cfg) {
-			stmmac_remove_config_dt(pdev, plat);
-			return ERR_PTR(-ENOMEM);
-		}
-		plat->dma_cfg = dma_cfg;
-		of_property_read_u32(np, "snps,pbl", &dma_cfg->pbl);
-		dma_cfg->aal = of_property_read_bool(np, "snps,aal");
-		dma_cfg->fixed_burst =
-			of_property_read_bool(np, "snps,fixed-burst");
-		dma_cfg->mixed_burst =
-			of_property_read_bool(np, "snps,mixed-burst");
+	dma_cfg = devm_kzalloc(&pdev->dev, sizeof(*dma_cfg),
+			       GFP_KERNEL);
+	if (!dma_cfg) {
+		stmmac_remove_config_dt(pdev, plat);
+		return ERR_PTR(-ENOMEM);
 	}
+	plat->dma_cfg = dma_cfg;
+
+	of_property_read_u32(np, "snps,pbl", &dma_cfg->pbl);
+	if (!dma_cfg->pbl)
+		dma_cfg->pbl = DEFAULT_DMA_PBL;
+	of_property_read_u32(np, "snps,txpbl", &dma_cfg->txpbl);
+	of_property_read_u32(np, "snps,rxpbl", &dma_cfg->rxpbl);
+	dma_cfg->pblx8 = !of_property_read_bool(np, "snps,no-pbl-x8");
+
+	dma_cfg->aal = of_property_read_bool(np, "snps,aal");
+	dma_cfg->fixed_burst = of_property_read_bool(np, "snps,fixed-burst");
+	dma_cfg->mixed_burst = of_property_read_bool(np, "snps,mixed-burst");
+
 	plat->force_thresh_dma_mode = of_property_read_bool(np, "snps,force_thresh_dma_mode");
 	if (plat->force_thresh_dma_mode) {
 		plat->force_sf_dma_mode = 0;

include/linux/stmmac.h

@@ -88,6 +88,9 @@ struct stmmac_mdio_bus_data {
 
 struct stmmac_dma_cfg {
 	int pbl;
+	int txpbl;
+	int rxpbl;
+	bool pblx8;
 	int fixed_burst;
 	int mixed_burst;
 	bool aal;