From 89ab75bf7253271c0ca805931105a298bc22bfdf Mon Sep 17 00:00:00 2001
From: Niklas Cassel <niklas.cassel@axis.com>
Date: Wed, 7 Dec 2016 15:20:03 +0100
Subject: [PATCH 1/6] net: stmmac: return error if no DMA configuration is
 found

All drivers except pci glue layer calls stmmac_probe_config_dt.
stmmac_probe_config_dt does a kzalloc dma_cfg.

pci glue layer does kzalloc dma_cfg explicitly, so all current
drivers does a kzalloc dma_cfg.

Return an error if no DMA configuration is found, that way
we can assume that the DMA configuration always exists.

Signed-off-by: Niklas Cassel <niklas.cassel@axis.com>
Acked-by: Alexandre Torgue <alexandre.torgue@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 .../net/ethernet/stmicro/stmmac/stmmac_main.c  | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 982c95213da4..14366800e5e6 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/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) {
+		dev_err(priv->device, "DMA configuration not found\n");
+		return -EINVAL;
 	}
 
 	if (priv->extend_desc && (priv->mode == STMMAC_RING_MODE))
@@ -1599,8 +1595,12 @@ 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->pbl,
+			    priv->plat->dma_cfg->fixed_burst,
+			    priv->plat->dma_cfg->mixed_burst,
+			    priv->plat->dma_cfg->aal,
+			    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 +

From 50ca903afc2a4ccf7efd25744577fecb0ce6fb49 Mon Sep 17 00:00:00 2001
From: Niklas Cassel <niklas.cassel@axis.com>
Date: Wed, 7 Dec 2016 15:20:04 +0100
Subject: [PATCH 2/6] net: stmmac: simplify the common DMA init API

Use struct stmmac_dma_cfg *dma_cfg as an argument rather
than using all the struct members as individual arguments.

Signed-off-by: Niklas Cassel <niklas.cassel@axis.com>
Acked-by: Alexandre Torgue <alexandre.torgue@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 drivers/net/ethernet/stmicro/stmmac/common.h       |  4 ++--
 .../net/ethernet/stmicro/stmmac/dwmac1000_dma.c    | 13 +++++++------
 drivers/net/ethernet/stmicro/stmmac/dwmac100_dma.c |  7 ++++---
 drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c   | 14 ++++++++------
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c  |  6 +-----
 5 files changed, 22 insertions(+), 22 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/common.h b/drivers/net/ethernet/stmicro/stmmac/common.h
index 3ced2e1703c1..b13a144f72ad 100644
--- a/drivers/net/ethernet/stmicro/stmmac/common.h
+++ b/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 */
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c
index f35385266fbf..318ae9f10104 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c
@@ -84,8 +84,9 @@ 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);
 
@@ -101,20 +102,20 @@ static void dwmac1000_dma_init(void __iomem *ioaddr, int pbl, int fb, int mb,
 	 */
 	value |= DMA_BUS_MODE_MAXPBL;
 	value &= ~DMA_BUS_MODE_PBL_MASK;
-	value |= (pbl << DMA_BUS_MODE_PBL_SHIFT);
+	value |= (dma_cfg->pbl << DMA_BUS_MODE_PBL_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);
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac100_dma.c b/drivers/net/ethernet/stmicro/stmmac/dwmac100_dma.c
index 61f54c99a7de..e5664da382f3 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac100_dma.c
+++ b/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 */
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
index e81b6e565c29..7d82a3464097 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
@@ -99,27 +99,29 @@ 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->pbl,
+					dma_tx, dma_rx, i);
 }
 
 static void _dwmac4_dump_dma_regs(void __iomem *ioaddr, u32 channel)
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 14366800e5e6..b1e42ddf0370 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1595,11 +1595,7 @@ static int stmmac_init_dma_engine(struct stmmac_priv *priv)
 		return ret;
 	}
 
-	priv->hw->dma->init(priv->ioaddr,
-			    priv->plat->dma_cfg->pbl,
-			    priv->plat->dma_cfg->fixed_burst,
-			    priv->plat->dma_cfg->mixed_burst,
-			    priv->plat->dma_cfg->aal,
+	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) {

From a332e2fa56343ca5f11f05f90e53d0d471384e0e Mon Sep 17 00:00:00 2001
From: Niklas Cassel <niklas.cassel@axis.com>
Date: Wed, 7 Dec 2016 15:20:05 +0100
Subject: [PATCH 3/6] net: stmmac: stmmac_platform: fix parsing of DT binding

commit 64c3b252e9fc ("net: stmmac: fixed the pbl setting with DT")
changed the parsing of the DT binding.

Before 64c3b252e9fc, snps,fixed-burst and snps,mixed-burst were parsed
regardless if the property snps,pbl existed or not.
After the commit, fixed burst and mixed burst are only parsed if
snps,pbl exists. Now when snps,aal has been added, it too is only
parsed if snps,pbl exists.

Since the DT binding does not specify that fixed burst, mixed burst
or aal depend on snps,pbl being specified, undo changes introduced
by 64c3b252e9fc.

The issue commit 64c3b252e9fc ("net: stmmac: fixed the pbl setting with
DT") tries to address is solved in another way:
The databook specifies that all values other than
1, 2, 4, 8, 16, or 32 results in undefined behavior,
so snps,pbl = <0> is invalid.

If pbl is 0 after parsing, set pbl to DEFAULT_DMA_PBL.
This handles the case where the property is omitted, and also handles
the case where the property is specified without any data.

Signed-off-by: Niklas Cassel <niklas.cassel@axis.com>
Acked-by: Alexandre Torgue <alexandre.torgue@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 .../net/ethernet/stmicro/stmmac/stmmac_main.c |  4 +--
 .../ethernet/stmicro/stmmac/stmmac_platform.c | 29 ++++++++++---------
 2 files changed, 17 insertions(+), 16 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index b1e42ddf0370..b5188122bc15 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1581,8 +1581,8 @@ static int stmmac_init_dma_engine(struct stmmac_priv *priv)
 	int atds = 0;
 	int ret = 0;
 
-	if (!priv->plat->dma_cfg) {
-		dev_err(priv->device, "DMA configuration not found\n");
+	if (!priv->plat->dma_cfg || !priv->plat->dma_cfg->pbl) {
+		dev_err(priv->device, "Invalid DMA configuration\n");
 		return -EINVAL;
 	}
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
index d3b6f92f350a..81800f23a9c4 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
@@ -304,21 +304,22 @@ 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;
+
+	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;

From 825658a27361c67c14c10bfa0359fc23d76a42b8 Mon Sep 17 00:00:00 2001
From: Niklas Cassel <niklas.cassel@axis.com>
Date: Wed, 7 Dec 2016 15:20:06 +0100
Subject: [PATCH 4/6] net: stmmac: dwmac1000: fix define DMA_BUS_MODE_RPBL_MASK

DMA_BUS_MODE_RPBL_MASK is really 6 bits,
just like DMA_BUS_MODE_PBL_MASK.

Signed-off-by: Niklas Cassel <niklas.cassel@axis.com>
Acked-by: Alexandre Torgue <alexandre.torgue@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 drivers/net/ethernet/stmicro/stmmac/dwmac1000.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac1000.h b/drivers/net/ethernet/stmicro/stmmac/dwmac1000.h
index ff3e5ab39bd0..52b9407a8a39 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac1000.h
+++ b/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

From 89caaa2d80b7bf9bd8632cd3137254f8c685e5db Mon Sep 17 00:00:00 2001
From: Niklas Cassel <niklas.cassel@axis.com>
Date: Wed, 7 Dec 2016 15:20:07 +0100
Subject: [PATCH 5/6] net: stmmac: add support for independent DMA pbl for
 tx/rx

GMAC and newer supports independent programmable burst lengths for
DMA tx/rx. Add new optional devicetree properties representing this.

To be backwards compatible, snps,pbl will still be valid, but
snps,txpbl/snps,rxpbl will override the value in snps,pbl if set.

If the IP is synthesized to use the AXI interface, there is a register
and a matching DT property inside the optional stmmac-axi-config DT node
for controlling burst lengths, named snps,blen.
However, using this register, it is not possible to control tx and rx
independently. Also, this register is not available if the IP was
synthesized with, e.g., the AHB interface.

Signed-off-by: Niklas Cassel <niklas.cassel@axis.com>
Acked-by: Alexandre Torgue <alexandre.torgue@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 .../devicetree/bindings/net/stmmac.txt        |  6 +++++-
 Documentation/networking/stmmac.txt           | 19 +++++++++++++------
 .../ethernet/stmicro/stmmac/dwmac1000_dma.c   | 12 ++++++------
 .../net/ethernet/stmicro/stmmac/dwmac4_dma.c  | 12 +++++++-----
 .../ethernet/stmicro/stmmac/stmmac_platform.c |  2 ++
 include/linux/stmmac.h                        |  2 ++
 6 files changed, 35 insertions(+), 18 deletions(-)

diff --git a/Documentation/devicetree/bindings/net/stmmac.txt b/Documentation/devicetree/bindings/net/stmmac.txt
index b95ff998ba73..8080038ff1b2 100644
--- a/Documentation/devicetree/bindings/net/stmmac.txt
+++ b/Documentation/devicetree/bindings/net/stmmac.txt
@@ -34,7 +34,11 @@ 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,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
diff --git a/Documentation/networking/stmmac.txt b/Documentation/networking/stmmac.txt
index 014f4f756cb7..6add57374f70 100644
--- a/Documentation/networking/stmmac.txt
+++ b/Documentation/networking/stmmac.txt
@@ -153,7 +153,8 @@ Where:
    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
+   o txpbl/rxpbl: GMAC and newer supports independent DMA pbl for tx/rx.
+   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 +206,22 @@ tuned according to the HW capabilities.
 
 struct stmmac_dma_cfg {
 	int pbl;
+	int txpbl;
+	int rxpbl;
 	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 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
 
 ---
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c
index 318ae9f10104..99b8040af592 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c
@@ -89,20 +89,20 @@ static void dwmac1000_dma_init(void __iomem *ioaddr,
 			       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 |= (dma_cfg->pbl << DMA_BUS_MODE_PBL_SHIFT);
+	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 (dma_cfg->fixed_burst)
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
index 7d82a3464097..2c3b2098f350 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
@@ -71,11 +71,14 @@ 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
@@ -85,11 +88,11 @@ static void dwmac4_dma_init_channel(void __iomem *ioaddr, int 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 */
@@ -120,8 +123,7 @@ static void dwmac4_dma_init(void __iomem *ioaddr,
 	writel(value, ioaddr + DMA_SYS_BUS_MODE);
 
 	for (i = 0; i < DMA_CHANNEL_NB_MAX; i++)
-		dwmac4_dma_init_channel(ioaddr, dma_cfg->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)
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
index 81800f23a9c4..96afe0561c99 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
@@ -315,6 +315,8 @@ stmmac_probe_config_dt(struct platform_device *pdev, const char **mac)
 	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->aal = of_property_read_bool(np, "snps,aal");
 	dma_cfg->fixed_burst = of_property_read_bool(np, "snps,fixed-burst");
diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
index 3537fb33cc90..e6d7a5940819 100644
--- a/include/linux/stmmac.h
+++ b/include/linux/stmmac.h
@@ -88,6 +88,8 @@ struct stmmac_mdio_bus_data {
 
 struct stmmac_dma_cfg {
 	int pbl;
+	int txpbl;
+	int rxpbl;
 	int fixed_burst;
 	int mixed_burst;
 	bool aal;

From 4022d039a315951e59d95d22e79198d861ce4490 Mon Sep 17 00:00:00 2001
From: Niklas Cassel <niklas.cassel@axis.com>
Date: Wed, 7 Dec 2016 15:20:08 +0100
Subject: [PATCH 6/6] net: smmac: allow configuring lower pbl values

The driver currently always sets the PBLx8/PBLx4 bit, which means that
the pbl values configured via the pbl/txpbl/rxpbl DT properties are
always multiplied by 8/4 in the hardware.

In order to allow the DT to configure lower pbl values, while at the
same time not changing behavior of any existing device trees using the
pbl/txpbl/rxpbl settings, add a property to disable the multiplication
of the pbl by 8/4 in the hardware.

Suggested-by: Rabin Vincent <rabinv@axis.com>
Signed-off-by: Niklas Cassel <niklas.cassel@axis.com>
Acked-by: Alexandre Torgue <alexandre.torgue@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 Documentation/devicetree/bindings/net/stmmac.txt      | 2 ++
 Documentation/networking/stmmac.txt                   | 5 ++++-
 drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c   | 3 ++-
 drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c      | 3 ++-
 drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c      | 2 ++
 drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c | 1 +
 include/linux/stmmac.h                                | 1 +
 7 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/net/stmmac.txt b/Documentation/devicetree/bindings/net/stmmac.txt
index 8080038ff1b2..128da752fec9 100644
--- a/Documentation/devicetree/bindings/net/stmmac.txt
+++ b/Documentation/devicetree/bindings/net/stmmac.txt
@@ -39,6 +39,8 @@ Optional properties:
 			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
diff --git a/Documentation/networking/stmmac.txt b/Documentation/networking/stmmac.txt
index 6add57374f70..2bb07078f535 100644
--- a/Documentation/networking/stmmac.txt
+++ b/Documentation/networking/stmmac.txt
@@ -152,8 +152,9 @@ 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.
+       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.
@@ -208,6 +209,7 @@ struct stmmac_dma_cfg {
 	int pbl;
 	int txpbl;
 	int rxpbl;
+	bool pblx8;
 	int fixed_burst;
 	int mixed_burst;
 	bool aal;
@@ -219,6 +221,7 @@ Where:
 	 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 mixed_burst: program the DMA to use the mixed burst mode
  o aal: Address-Aligned Beats
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c
index 99b8040af592..612d3aaac9a4 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c
@@ -98,7 +98,8 @@ static void dwmac1000_dma_init(void __iomem *ioaddr,
 	 * Note: before stmmac core 3.50 this mode bit was 4xPBL, and
 	 * post 3.5 mode bit acts as 8*PBL.
 	 */
-	value |= DMA_BUS_MODE_MAXPBL;
+	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);
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
index 2c3b2098f350..8196ab5fc33c 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
@@ -84,7 +84,8 @@ static void dwmac4_dma_init_channel(void __iomem *ioaddr,
 	 * 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));
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c
index 56c8a2342c14..a2831773431a 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c
+++ b/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) */
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
index 96afe0561c99..082cd48db6a7 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
@@ -317,6 +317,7 @@ stmmac_probe_config_dt(struct platform_device *pdev, const char **mac)
 		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");
diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
index e6d7a5940819..266dab9ad782 100644
--- a/include/linux/stmmac.h
+++ b/include/linux/stmmac.h
@@ -90,6 +90,7 @@ struct stmmac_dma_cfg {
 	int pbl;
 	int txpbl;
 	int rxpbl;
+	bool pblx8;
 	int fixed_burst;
 	int mixed_burst;
 	bool aal;