Merge branch 'axienet-Update-error-handling-and-add-64-bit-DMA-support'

Andre Przywara says:

====================
net: axienet: Update error handling and add 64-bit DMA support

a minor update, fixing the 32-bit build breakage, and brightening up
Dave's christmas tree. Rebased against latest net-next/master.

This series is based on net-next as of today (9970de8b), which
includes Russell's fixes [1], solving the SGMII issues I have had.

[1] https://lore.kernel.org/netdev/E1j6trA-0003GY-N1@rmk-PC.armlinux.org.uk/

Changelog v2 .. v3:
- Use two "left-shifts by 16" to fix builds with 32-bit phys_addr_t
- reorder variable declarations

Changelog v1 .. v2:
- Add Reviewed-by: tags from Radhey
- Extend kerndoc documentation
- Convert DMA error handler tasklet to work queue
- log DMA mapping errors
- mark DMA mapping error checks as unlikely (in "hot" paths)
- return NETDEV_TX_OK on TX DMA mapping error (increasing TX drop counter)
- Request eth IRQ as an optional IRQ
- Remove no longer needed MDIO IRQ register names
- Drop DT propery check for address width, assume full 64 bit

This series updates the Xilinx Axienet driver to work on our board
here. One big issue was broken SGMII support, which Russell fixed already
(in net-next).
While debugging and understanding the driver, I found several problems
in the error handling and cleanup paths, which patches 2-7 address.
Patch 8 removes a annoying error message, patch 9 paves the way for newer
revisions of the IP. The next patch adds mii-tool support, just for good
measure.

The next four patches add support for 64-bit DMA. This is an integration
option on newer IP revisions (>= v7.1), and expects MSB bits in formerly
reserved registers. Without writing to those MSB registers, the state
machine won't trigger, so it's mandatory to access them, even if they
are zero. Patches 11 and 12 prepare the code by adding accessors, to
wrap this properly and keep it working on older IP revisions.
Patch 13 enables access to the MSB registers, by trying to write a
non-zero value to them and checking if that sticks. Older IP revisions
always read those registers as zero.
Patch 14 then adjusts the DMA mask, based on the autodetected MSB
feature. It uses the full 64 bits in this case, the rest of the system
(actual physical addresses in use) should provide a natural limit if the
chip has connected fewer address lines. If not, the parent DT node can
use a dma-range property.

The Xilinx PG138 and PG021 documents (in versions 7.1 in both cases)
were used for this series.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/xilinx/Kconfig

@@ -32,7 +32,6 @@ config XILINX_AXI_EMAC
 
 config XILINX_LL_TEMAC
 	tristate "Xilinx LL TEMAC (LocalLink Tri-mode Ethernet MAC) driver"
-	depends on PPC || MICROBLAZE || X86 || COMPILE_TEST
 	select PHYLIB
 	---help---
 	  This driver supports the Xilinx 10/100/1000 LocalLink TEMAC

drivers/net/ethernet/xilinx/xilinx_axienet.h

@@ -161,17 +161,11 @@
 #define XAE_FCC_OFFSET		0x0000040C /* Flow Control Configuration */
 #define XAE_EMMC_OFFSET		0x00000410 /* EMAC mode configuration */
 #define XAE_PHYC_OFFSET		0x00000414 /* RGMII/SGMII configuration */
+#define XAE_ID_OFFSET		0x000004F8 /* Identification register */
 #define XAE_MDIO_MC_OFFSET	0x00000500 /* MII Management Config */
 #define XAE_MDIO_MCR_OFFSET	0x00000504 /* MII Management Control */
 #define XAE_MDIO_MWD_OFFSET	0x00000508 /* MII Management Write Data */
 #define XAE_MDIO_MRD_OFFSET	0x0000050C /* MII Management Read Data */
-#define XAE_MDIO_MIS_OFFSET	0x00000600 /* MII Management Interrupt Status */
-/* MII Mgmt Interrupt Pending register offset */
-#define XAE_MDIO_MIP_OFFSET	0x00000620
-/* MII Management Interrupt Enable register offset */
-#define XAE_MDIO_MIE_OFFSET	0x00000640
-/* MII Management Interrupt Clear register offset. */
-#define XAE_MDIO_MIC_OFFSET	0x00000660
 #define XAE_UAW0_OFFSET		0x00000700 /* Unicast address word 0 */
 #define XAE_UAW1_OFFSET		0x00000704 /* Unicast address word 1 */
 #define XAE_FMI_OFFSET		0x00000708 /* Filter Mask Index */
@@ -335,6 +329,7 @@
 #define XAE_FEATURE_PARTIAL_TX_CSUM	(1 << 1)
 #define XAE_FEATURE_FULL_RX_CSUM	(1 << 2)
 #define XAE_FEATURE_FULL_TX_CSUM	(1 << 3)
+#define XAE_FEATURE_DMA_64BIT		(1 << 4)
 
 #define XAE_NO_CSUM_OFFLOAD		0
 
@@ -347,9 +342,9 @@
 /**
  * struct axidma_bd - Axi Dma buffer descriptor layout
  * @next:         MM2S/S2MM Next Descriptor Pointer
- * @reserved1:    Reserved and not used
+ * @next_msb:     MM2S/S2MM Next Descriptor Pointer (high 32 bits)
  * @phys:         MM2S/S2MM Buffer Address
- * @reserved2:    Reserved and not used
+ * @phys_msb:     MM2S/S2MM Buffer Address (high 32 bits)
  * @reserved3:    Reserved and not used
  * @reserved4:    Reserved and not used
  * @cntrl:        MM2S/S2MM Control value
@@ -362,9 +357,9 @@
  */
 struct axidma_bd {
 	u32 next;	/* Physical address of next buffer descriptor */
-	u32 reserved1;
+	u32 next_msb;	/* high 32 bits for IP >= v7.1, reserved on older IP */
 	u32 phys;
-	u32 reserved2;
+	u32 phys_msb;	/* for IP >= v7.1, reserved for older IP */
 	u32 reserved3;
 	u32 reserved4;
 	u32 cntrl;
@@ -435,7 +430,7 @@ struct axienet_local {
 	void __iomem *regs;
 	void __iomem *dma_regs;
 
-	struct tasklet_struct dma_err_tasklet;
+	struct work_struct dma_err_task;
 
 	int tx_irq;
 	int rx_irq;