[PATCH net-next v4 0/2] net: stmmac: Enhanced addressing mode for DWMAC 4.10

[PATCH net-next v4 0/2] net: stmmac: Enhanced addressing mode for DWMAC 4.10

[Thierry Reding]

From: Thierry Reding <treding@nvidia.com>

The DWMAC 4.10 supports the same enhanced addressing mode as later
generations. Parse this capability from the hardware feature registers
and set the EAME (Enhanced Addressing Mode Enable) bit when necessary.

Thierry

Thierry Reding (2):
  net: stmmac: Only enable enhanced addressing mode when needed
  net: stmmac: Support enhanced addressing mode for DWMAC 4.10

 drivers/net/ethernet/stmicro/stmmac/dwmac4.h  |  1 +
 .../ethernet/stmicro/stmmac/dwmac4_descs.c    |  4 +--
 .../net/ethernet/stmicro/stmmac/dwmac4_dma.c  | 28 +++++++++++++++++++
 .../net/ethernet/stmicro/stmmac/dwmac4_dma.h  |  3 ++
 .../ethernet/stmicro/stmmac/dwxgmac2_dma.c    |  5 +++-
 .../net/ethernet/stmicro/stmmac/stmmac_main.c |  7 +++++
 include/linux/stmmac.h                        |  1 +
 7 files changed, 46 insertions(+), 3 deletions(-)

-- 
2.23.0

[PATCH net-next v4 1/2] net: stmmac: Only enable enhanced addressing mode when needed

[Thierry Reding]

From: Thierry Reding <treding@nvidia.com>

Enhanced addressing mode is only required when more than 32 bits need to
be addressed. Add a DMA configuration parameter to enable this mode only
when needed.

Signed-off-by: Thierry Reding <treding@nvidia.com>
---
Changes in v4:
- enable EAME only if DMA addresses can be larger than 32 bits

 drivers/net/ethernet/stmicro/stmmac/dwxgmac2_dma.c | 5 ++++-
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c  | 7 +++++++
 include/linux/stmmac.h                             | 1 +
 3 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_dma.c b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_dma.c
index 965cbe3e6f51..7cc331996cd8 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_dma.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_dma.c
@@ -27,7 +27,10 @@ static void dwxgmac2_dma_init(void __iomem *ioaddr,
 	if (dma_cfg->aal)
 		value |= XGMAC_AAL;
 
-	writel(value | XGMAC_EAME, ioaddr + XGMAC_DMA_SYSBUS_MODE);
+	if (dma_cfg->eame)
+		value |= XGMAC_EAME;
+
+	writel(value, ioaddr + XGMAC_DMA_SYSBUS_MODE);
 }
 
 static void dwxgmac2_dma_init_chan(void __iomem *ioaddr,
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index c76a1336a451..b8ac1744950e 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -4515,6 +4515,13 @@ int stmmac_dvr_probe(struct device *device,
 		if (!ret) {
 			dev_info(priv->device, "Using %d bits DMA width\n",
 				 priv->dma_cap.addr64);
+
+			/*
+			 * If more than 32 bits can be addressed, make sure to
+			 * enable enhanced addressing mode.
+			 */
+			if (IS_ENABLED(CONFIG_ARCH_DMA_ADDR_T_64BIT))
+				priv->plat->dma_cfg->eame = true;
 		} else {
 			ret = dma_set_mask_and_coherent(device, DMA_BIT_MASK(32));
 			if (ret) {
diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
index dc60d03c4b60..86f9464c3f5d 100644
--- a/include/linux/stmmac.h
+++ b/include/linux/stmmac.h
@@ -92,6 +92,7 @@ struct stmmac_dma_cfg {
 	int fixed_burst;
 	int mixed_burst;
 	bool aal;
+	bool eame;
 };
 
 #define AXI_BLEN	7
-- 
2.23.0

[PATCH net-next v4 2/2] net: stmmac: Support enhanced addressing mode for DWMAC 4.10

[Thierry Reding]

From: Thierry Reding <treding@nvidia.com>

The address width of the controller can be read from hardware feature
registers much like on XGMAC. Add support for parsing the ADDR64 field
so that the DMA mask can be set accordingly.

This avoids getting swiotlb involved for DMA on Tegra186 and later.

Also make sure that the upper 32 bits of the DMA address are written to
the DMA descriptors when enhanced addressing mode is used. Similarily,
for each channel, the upper 32 bits of the DMA descriptor ring's base
address also need to be programmed to make sure the correct memory can
be fetched when the DMA descriptor ring is located beyond the 32-bit
boundary.

Signed-off-by: Thierry Reding <treding@nvidia.com>
---
Changes in v4:
- only write upper 32 bits when necessary

Changes in v3:
- unconditionally write upper 32 bits

Changes in v2:
- also program the upper 32 bits of the DMA descriptor base address for
  each channel

 drivers/net/ethernet/stmicro/stmmac/dwmac4.h  |  1 +
 .../ethernet/stmicro/stmmac/dwmac4_descs.c    |  4 +--
 .../net/ethernet/stmicro/stmmac/dwmac4_dma.c  | 28 +++++++++++++++++++
 .../net/ethernet/stmicro/stmmac/dwmac4_dma.h  |  3 ++
 4 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4.h b/drivers/net/ethernet/stmicro/stmmac/dwmac4.h
index 89a3420eba42..2fe45fa3c482 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4.h
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4.h
@@ -205,6 +205,7 @@ enum power_event {
 #define GMAC_HW_HASH_TB_SZ		GENMASK(25, 24)
 #define GMAC_HW_FEAT_AVSEL		BIT(20)
 #define GMAC_HW_TSOEN			BIT(18)
+#define GMAC_HW_ADDR64			GENMASK(15, 14)
 #define GMAC_HW_TXFIFOSIZE		GENMASK(10, 6)
 #define GMAC_HW_RXFIFOSIZE		GENMASK(4, 0)
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c
index 15eb1abba91d..707ab5eba8da 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c
@@ -431,8 +431,8 @@ static void dwmac4_get_addr(struct dma_desc *p, unsigned int *addr)
 
 static void dwmac4_set_addr(struct dma_desc *p, dma_addr_t addr)
 {
-	p->des0 = cpu_to_le32(addr);
-	p->des1 = 0;
+	p->des0 = cpu_to_le32(lower_32_bits(addr));
+	p->des1 = cpu_to_le32(upper_32_bits(addr));
 }
 
 static void dwmac4_clear(struct dma_desc *p)
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
index 68c157979b94..229059cef949 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
@@ -79,6 +79,10 @@ static void dwmac4_dma_init_rx_chan(void __iomem *ioaddr,
 	value = value | (rxpbl << DMA_BUS_MODE_RPBL_SHIFT);
 	writel(value, ioaddr + DMA_CHAN_RX_CONTROL(chan));
 
+	if (IS_ENABLED(CONFIG_ARCH_DMA_ADDR_T_64BIT) && likely(dma_cfg->eame))
+		writel(upper_32_bits(dma_rx_phy),
+		       ioaddr + DMA_CHAN_RX_BASE_ADDR_HI(chan));
+
 	writel(lower_32_bits(dma_rx_phy), ioaddr + DMA_CHAN_RX_BASE_ADDR(chan));
 }
 
@@ -97,6 +101,10 @@ static void dwmac4_dma_init_tx_chan(void __iomem *ioaddr,
 
 	writel(value, ioaddr + DMA_CHAN_TX_CONTROL(chan));
 
+	if (IS_ENABLED(CONFIG_ARCH_DMA_ADDR_T_64BIT) && likely(dma_cfg->eame))
+		writel(upper_32_bits(dma_tx_phy),
+		       ioaddr + DMA_CHAN_TX_BASE_ADDR_HI(chan));
+
 	writel(lower_32_bits(dma_tx_phy), ioaddr + DMA_CHAN_TX_BASE_ADDR(chan));
 }
 
@@ -132,6 +140,9 @@ static void dwmac4_dma_init(void __iomem *ioaddr,
 	if (dma_cfg->aal)
 		value |= DMA_SYS_BUS_AAL;
 
+	if (dma_cfg->eame)
+		value |= DMA_SYS_BUS_EAME;
+
 	writel(value, ioaddr + DMA_SYS_BUS_MODE);
 }
 
@@ -356,6 +367,23 @@ static void dwmac4_get_hw_feature(void __iomem *ioaddr,
 	dma_cap->hash_tb_sz = (hw_cap & GMAC_HW_HASH_TB_SZ) >> 24;
 	dma_cap->av = (hw_cap & GMAC_HW_FEAT_AVSEL) >> 20;
 	dma_cap->tsoen = (hw_cap & GMAC_HW_TSOEN) >> 18;
+
+	dma_cap->addr64 = (hw_cap & GMAC_HW_ADDR64) >> 14;
+	switch (dma_cap->addr64) {
+	case 0:
+		dma_cap->addr64 = 32;
+		break;
+	case 1:
+		dma_cap->addr64 = 40;
+		break;
+	case 2:
+		dma_cap->addr64 = 48;
+		break;
+	default:
+		dma_cap->addr64 = 32;
+		break;
+	}
+
 	/* RX and TX FIFO sizes are encoded as log2(n / 128). Undo that by
 	 * shifting and store the sizes in bytes.
 	 */
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.h b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.h
index b66da0237d2a..5299fa1001a3 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.h
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.h
@@ -65,6 +65,7 @@
 #define DMA_SYS_BUS_MB			BIT(14)
 #define DMA_AXI_1KBBE			BIT(13)
 #define DMA_SYS_BUS_AAL			BIT(12)
+#define DMA_SYS_BUS_EAME		BIT(11)
 #define DMA_AXI_BLEN256			BIT(7)
 #define DMA_AXI_BLEN128			BIT(6)
 #define DMA_AXI_BLEN64			BIT(5)
@@ -91,7 +92,9 @@
 #define DMA_CHAN_CONTROL(x)		DMA_CHANX_BASE_ADDR(x)
 #define DMA_CHAN_TX_CONTROL(x)		(DMA_CHANX_BASE_ADDR(x) + 0x4)
 #define DMA_CHAN_RX_CONTROL(x)		(DMA_CHANX_BASE_ADDR(x) + 0x8)
+#define DMA_CHAN_TX_BASE_ADDR_HI(x)	(DMA_CHANX_BASE_ADDR(x) + 0x10)
 #define DMA_CHAN_TX_BASE_ADDR(x)	(DMA_CHANX_BASE_ADDR(x) + 0x14)
+#define DMA_CHAN_RX_BASE_ADDR_HI(x)	(DMA_CHANX_BASE_ADDR(x) + 0x18)
 #define DMA_CHAN_RX_BASE_ADDR(x)	(DMA_CHANX_BASE_ADDR(x) + 0x1c)
 #define DMA_CHAN_TX_END_ADDR(x)		(DMA_CHANX_BASE_ADDR(x) + 0x20)
 #define DMA_CHAN_RX_END_ADDR(x)		(DMA_CHANX_BASE_ADDR(x) + 0x28)
-- 
2.23.0

Re: [PATCH net-next v4 0/2] net: stmmac: Enhanced addressing mode for DWMAC 4.10

[David Miller]

From: Thierry Reding <thierry.reding@gmail.com>
Date: Wed,  2 Oct 2019 16:52:56 +0200

> From: Thierry Reding <treding@nvidia.com>
> 
> The DWMAC 4.10 supports the same enhanced addressing mode as later
> generations. Parse this capability from the hardware feature registers
> and set the EAME (Enhanced Addressing Mode Enable) bit when necessary.

Series applied.