igc: Add support for Tx/Rx rings

This change adds the defines and structures necessary to support both Tx
and Rx descriptor rings.

Signed-off-by: Sasha Neftin <sasha.neftin@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Author: Sasha Neftin

drivers/net/ethernet/intel/igc/Makefile

@@ -7,4 +7,4 @@
 
 obj-$(CONFIG_IGC) += igc.o
 
-igc-objs := igc_main.o igc_mac.o
+igc-objs := igc_main.o igc_mac.o igc_base.o

drivers/net/ethernet/intel/igc/igc.h

@@ -46,13 +46,79 @@ extern char igc_driver_version[];
 #define MAX_Q_VECTORS			8
 #define MAX_STD_JUMBO_FRAME_SIZE	9216
 
+/* Supported Rx Buffer Sizes */
+#define IGC_RXBUFFER_256		256
+#define IGC_RXBUFFER_2048		2048
+#define IGC_RXBUFFER_3072		3072
+
+#define IGC_RX_HDR_LEN			IGC_RXBUFFER_256
+
+/* RX and TX descriptor control thresholds.
+ * PTHRESH - MAC will consider prefetch if it has fewer than this number of
+ *           descriptors available in its onboard memory.
+ *           Setting this to 0 disables RX descriptor prefetch.
+ * HTHRESH - MAC will only prefetch if there are at least this many descriptors
+ *           available in host memory.
+ *           If PTHRESH is 0, this should also be 0.
+ * WTHRESH - RX descriptor writeback threshold - MAC will delay writing back
+ *           descriptors until either it has this many to write back, or the
+ *           ITR timer expires.
+ */
+#define IGC_RX_PTHRESH			8
+#define IGC_RX_HTHRESH			8
+#define IGC_TX_PTHRESH			8
+#define IGC_TX_HTHRESH			1
+#define IGC_RX_WTHRESH			4
+#define IGC_TX_WTHRESH			16
+
+#define IGC_RX_DMA_ATTR \
+	(DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_WEAK_ORDERING)
+
+#define IGC_TS_HDR_LEN			16
+
+#define IGC_SKB_PAD			(NET_SKB_PAD + NET_IP_ALIGN)
+
+#if (PAGE_SIZE < 8192)
+#define IGC_MAX_FRAME_BUILD_SKB \
+	(SKB_WITH_OVERHEAD(IGC_RXBUFFER_2048) - IGC_SKB_PAD - IGC_TS_HDR_LEN)
+#else
+#define IGC_MAX_FRAME_BUILD_SKB (IGC_RXBUFFER_2048 - IGC_TS_HDR_LEN)
+#endif
+
 enum igc_state_t {
 	__IGC_TESTING,
 	__IGC_RESETTING,
 	__IGC_DOWN,
 	__IGC_PTP_TX_IN_PROGRESS,
 };
 
+/* wrapper around a pointer to a socket buffer,
+ * so a DMA handle can be stored along with the buffer
+ */
+struct igc_tx_buffer {
+	union igc_adv_tx_desc *next_to_watch;
+	unsigned long time_stamp;
+	struct sk_buff *skb;
+	unsigned int bytecount;
+	u16 gso_segs;
+	__be16 protocol;
+
+	DEFINE_DMA_UNMAP_ADDR(dma);
+	DEFINE_DMA_UNMAP_LEN(len);
+	u32 tx_flags;
+};
+
+struct igc_rx_buffer {
+	dma_addr_t dma;
+	struct page *page;
+#if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536)
+	__u32 page_offset;
+#else
+	__u16 page_offset;
+#endif
+	__u16 pagecnt_bias;
+};
+
 struct igc_tx_queue_stats {
 	u64 packets;
 	u64 bytes;
@@ -214,4 +280,63 @@ struct igc_adapter {
 	struct igc_mac_addr *mac_table;
 };
 
+/* igc_desc_unused - calculate if we have unused descriptors */
+static inline u16 igc_desc_unused(const struct igc_ring *ring)
+{
+	u16 ntc = ring->next_to_clean;
+	u16 ntu = ring->next_to_use;
+
+	return ((ntc > ntu) ? 0 : ring->count) + ntc - ntu - 1;
+}
+
+static inline struct netdev_queue *txring_txq(const struct igc_ring *tx_ring)
+{
+	return netdev_get_tx_queue(tx_ring->netdev, tx_ring->queue_index);
+}
+
+enum igc_ring_flags_t {
+	IGC_RING_FLAG_RX_3K_BUFFER,
+	IGC_RING_FLAG_RX_BUILD_SKB_ENABLED,
+	IGC_RING_FLAG_RX_SCTP_CSUM,
+	IGC_RING_FLAG_RX_LB_VLAN_BSWAP,
+	IGC_RING_FLAG_TX_CTX_IDX,
+	IGC_RING_FLAG_TX_DETECT_HANG
+};
+
+#define ring_uses_large_buffer(ring) \
+	test_bit(IGC_RING_FLAG_RX_3K_BUFFER, &(ring)->flags)
+
+#define ring_uses_build_skb(ring) \
+	test_bit(IGC_RING_FLAG_RX_BUILD_SKB_ENABLED, &(ring)->flags)
+
+static inline unsigned int igc_rx_bufsz(struct igc_ring *ring)
+{
+#if (PAGE_SIZE < 8192)
+	if (ring_uses_large_buffer(ring))
+		return IGC_RXBUFFER_3072;
+
+	if (ring_uses_build_skb(ring))
+		return IGC_MAX_FRAME_BUILD_SKB + IGC_TS_HDR_LEN;
+#endif
+	return IGC_RXBUFFER_2048;
+}
+
+static inline unsigned int igc_rx_pg_order(struct igc_ring *ring)
+{
+#if (PAGE_SIZE < 8192)
+	if (ring_uses_large_buffer(ring))
+		return 1;
+#endif
+	return 0;
+}
+
+#define igc_rx_pg_size(_ring) (PAGE_SIZE << igc_rx_pg_order(_ring))
+
+#define IGC_RX_DESC(R, i)       \
+	(&(((union igc_adv_rx_desc *)((R)->desc))[i]))
+#define IGC_TX_DESC(R, i)       \
+	(&(((union igc_adv_tx_desc *)((R)->desc))[i]))
+#define IGC_TX_CTXTDESC(R, i)   \
+	(&(((struct igc_adv_tx_context_desc *)((R)->desc))[i]))
+
 #endif /* _IGC_H_ */

drivers/net/ethernet/intel/igc/igc_base.c

@@ -0,0 +1,83 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c)  2018 Intel Corporation */
+
+#include <linux/delay.h>
+
+#include "igc_hw.h"
+#include "igc_i225.h"
+
+/**
+ * igc_rx_fifo_flush_base - Clean rx fifo after Rx enable
+ * @hw: pointer to the HW structure
+ *
+ * After Rx enable, if manageability is enabled then there is likely some
+ * bad data at the start of the fifo and possibly in the DMA fifo.  This
+ * function clears the fifos and flushes any packets that came in as rx was
+ * being enabled.
+ */
+void igc_rx_fifo_flush_base(struct igc_hw *hw)
+{
+	u32 rctl, rlpml, rxdctl[4], rfctl, temp_rctl, rx_enabled;
+	int i, ms_wait;
+
+	/* disable IPv6 options as per hardware errata */
+	rfctl = rd32(IGC_RFCTL);
+	rfctl |= IGC_RFCTL_IPV6_EX_DIS;
+	wr32(IGC_RFCTL, rfctl);
+
+	if (!(rd32(IGC_MANC) & IGC_MANC_RCV_TCO_EN))
+		return;
+
+	/* Disable all Rx queues */
+	for (i = 0; i < 4; i++) {
+		rxdctl[i] = rd32(IGC_RXDCTL(i));
+		wr32(IGC_RXDCTL(i),
+		     rxdctl[i] & ~IGC_RXDCTL_QUEUE_ENABLE);
+	}
+	/* Poll all queues to verify they have shut down */
+	for (ms_wait = 0; ms_wait < 10; ms_wait++) {
+		usleep_range(1000, 2000);
+		rx_enabled = 0;
+		for (i = 0; i < 4; i++)
+			rx_enabled |= rd32(IGC_RXDCTL(i));
+		if (!(rx_enabled & IGC_RXDCTL_QUEUE_ENABLE))
+			break;
+	}
+
+	if (ms_wait == 10)
+		pr_debug("Queue disable timed out after 10ms\n");
+
+	/* Clear RLPML, RCTL.SBP, RFCTL.LEF, and set RCTL.LPE so that all
+	 * incoming packets are rejected.  Set enable and wait 2ms so that
+	 * any packet that was coming in as RCTL.EN was set is flushed
+	 */
+	wr32(IGC_RFCTL, rfctl & ~IGC_RFCTL_LEF);
+
+	rlpml = rd32(IGC_RLPML);
+	wr32(IGC_RLPML, 0);
+
+	rctl = rd32(IGC_RCTL);
+	temp_rctl = rctl & ~(IGC_RCTL_EN | IGC_RCTL_SBP);
+	temp_rctl |= IGC_RCTL_LPE;
+
+	wr32(IGC_RCTL, temp_rctl);
+	wr32(IGC_RCTL, temp_rctl | IGC_RCTL_EN);
+	wrfl();
+	usleep_range(2000, 3000);
+
+	/* Enable Rx queues that were previously enabled and restore our
+	 * previous state
+	 */
+	for (i = 0; i < 4; i++)
+		wr32(IGC_RXDCTL(i), rxdctl[i]);
+	wr32(IGC_RCTL, rctl);
+	wrfl();
+
+	wr32(IGC_RLPML, rlpml);
+	wr32(IGC_RFCTL, rfctl);
+
+	/* Flush receive errors generated by workaround */
+	rd32(IGC_ROC);
+	rd32(IGC_RNBC);
+	rd32(IGC_MPC);
+}

drivers/net/ethernet/intel/igc/igc_base.h

@@ -0,0 +1,89 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c)  2018 Intel Corporation */
+
+#ifndef _IGC_BASE_H
+#define _IGC_BASE_H
+
+/* forward declaration */
+void igc_rx_fifo_flush_base(struct igc_hw *hw);
+
+/* Transmit Descriptor - Advanced */
+union igc_adv_tx_desc {
+	struct {
+		__le64 buffer_addr;    /* Address of descriptor's data buf */
+		__le32 cmd_type_len;
+		__le32 olinfo_status;
+	} read;
+	struct {
+		__le64 rsvd;       /* Reserved */
+		__le32 nxtseq_seed;
+		__le32 status;
+	} wb;
+};
+
+struct igc_adv_data_desc {
+	__le64 buffer_addr;    /* Address of the descriptor's data buffer */
+	union {
+		u32 data;
+		struct {
+			u32 datalen:16; /* Data buffer length */
+			u32 rsvd:4;
+			u32 dtyp:4;  /* Descriptor type */
+			u32 dcmd:8;  /* Descriptor command */
+		} config;
+	} lower;
+	union {
+		u32 data;
+		struct {
+			u32 status:4;  /* Descriptor status */
+			u32 idx:4;
+			u32 popts:6;  /* Packet Options */
+			u32 paylen:18; /* Payload length */
+		} options;
+	} upper;
+};
+
+/* Receive Descriptor - Advanced */
+union igc_adv_rx_desc {
+	struct {
+		__le64 pkt_addr; /* Packet buffer address */
+		__le64 hdr_addr; /* Header buffer address */
+	} read;
+	struct {
+		struct {
+			union {
+				__le32 data;
+				struct {
+					__le16 pkt_info; /*RSS type, Pkt type*/
+					/* Split Header, header buffer len */
+					__le16 hdr_info;
+				} hs_rss;
+			} lo_dword;
+			union {
+				__le32 rss; /* RSS Hash */
+				struct {
+					__le16 ip_id; /* IP id */
+					__le16 csum; /* Packet Checksum */
+				} csum_ip;
+			} hi_dword;
+		} lower;
+		struct {
+			__le32 status_error; /* ext status/error */
+			__le16 length; /* Packet length */
+			__le16 vlan; /* VLAN tag */
+		} upper;
+	} wb;  /* writeback */
+};
+
+/* Additional Transmit Descriptor Control definitions */
+#define IGC_TXDCTL_QUEUE_ENABLE	0x02000000 /* Ena specific Tx Queue */
+
+/* Additional Receive Descriptor Control definitions */
+#define IGC_RXDCTL_QUEUE_ENABLE	0x02000000 /* Ena specific Rx Queue */
+
+/* SRRCTL bit definitions */
+#define IGC_SRRCTL_BSIZEPKT_SHIFT		10 /* Shift _right_ */
+#define IGC_SRRCTL_BSIZEHDRSIZE_SHIFT		2  /* Shift _left_ */
+#define IGC_SRRCTL_DESCTYPE_ADV_ONEBUF	0x02000000
+
+#endif /* _IGC_BASE_H */

drivers/net/ethernet/intel/igc/igc_defines.h

@@ -51,6 +51,10 @@
 #define IGC_ICR_RXO		BIT(6)	/* Rx overrun */
 #define IGC_ICR_RXT0		BIT(7)	/* Rx timer intr (ring 0) */
 #define IGC_ICR_DRSTA		BIT(30)	/* Device Reset Asserted */
+
+/* If this bit asserted, the driver should claim the interrupt */
+#define IGC_ICR_INT_ASSERTED	BIT(31)
+
 #define IGC_ICS_RXT0		IGC_ICR_RXT0 /* Rx timer intr */
 
 #define IMS_ENABLE_MASK ( \
@@ -80,6 +84,45 @@
 #define IGC_GPIE_EIAME		0x40000000
 #define IGC_GPIE_PBA		0x80000000
 
+/* Transmit Control */
+#define IGC_TCTL_EN		0x00000002 /* enable Tx */
+#define IGC_TCTL_PSP		0x00000008 /* pad short packets */
+#define IGC_TCTL_CT		0x00000ff0 /* collision threshold */
+#define IGC_TCTL_COLD		0x003ff000 /* collision distance */
+#define IGC_TCTL_RTLC		0x01000000 /* Re-transmit on late collision */
+#define IGC_TCTL_MULR		0x10000000 /* Multiple request support */
+
+#define IGC_CT_SHIFT			4
+#define IGC_COLLISION_THRESHOLD		15
+
+/* Management Control */
+#define IGC_MANC_RCV_TCO_EN	0x00020000 /* Receive TCO Packets Enabled */
+
+/* Receive Control */
+#define IGC_RCTL_RST		0x00000001 /* Software reset */
+#define IGC_RCTL_EN		0x00000002 /* enable */
+#define IGC_RCTL_SBP		0x00000004 /* store bad packet */
+#define IGC_RCTL_UPE		0x00000008 /* unicast promisc enable */
+#define IGC_RCTL_MPE		0x00000010 /* multicast promisc enable */
+#define IGC_RCTL_LPE		0x00000020 /* long packet enable */
+#define IGC_RCTL_LBM_MAC	0x00000040 /* MAC loopback mode */
+#define IGC_RCTL_LBM_TCVR	0x000000C0 /* tcvr loopback mode */
+
+#define IGC_RCTL_RDMTS_HALF	0x00000000 /* Rx desc min thresh size */
+#define IGC_RCTL_BAM		0x00008000 /* broadcast enable */
+
+/* Header split receive */
+#define IGC_RFCTL_IPV6_EX_DIS	0x00010000
+#define IGC_RFCTL_LEF		0x00040000
+
+#define IGC_RCTL_SZ_256		0x00030000 /* Rx buffer size 256 */
+
+#define IGC_RCTL_MO_SHIFT	12 /* multicast offset shift */
+#define IGC_RCTL_CFIEN		0x00080000 /* canonical form enable */
+#define IGC_RCTL_DPF		0x00400000 /* discard pause frames */
+#define IGC_RCTL_PMCF		0x00800000 /* pass MAC control frames */
+#define IGC_RCTL_SECRC		0x04000000 /* Strip Ethernet CRC */
+
 #define IGC_N0_QUEUE -1
 
 #endif /* _IGC_DEFINES_H_ */

drivers/net/ethernet/intel/igc/igc_hw.h

@@ -10,6 +10,7 @@
 #include "igc_defines.h"
 #include "igc_mac.h"
 #include "igc_i225.h"
+#include "igc_base.h"
 
 #define IGC_DEV_ID_I225_LM			0x15F2
 #define IGC_DEV_ID_I225_V			0x15F3