eth: fbnic: Add support to dump registers

Add support for the 'ethtool -d <dev>' command to retrieve and print
a register dump for fbnic. The dump defaults to version 1 and consists
of two parts: all the register sections that can be dumped linearly, and
an RPC RAM section that is structured in an interleaved fashion and
requires special handling. For each register section, the dump also
contains the start and end boundary information which can simplify parsing.

Signed-off-by: Mohsin Bashir <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Paolo Abeni <[e-mail]>

drivers/net/ethernet/meta/fbnic/Makefile

···
 
 obj-$(CONFIG_FBNIC) += fbnic.o
 
-fbnic-y := fbnic_devlink.o \
+fbnic-y := fbnic_csr.o \
+	   fbnic_devlink.o \
 	   fbnic_ethtool.o \
 	   fbnic_fw.o \
 	   fbnic_hw_stats.o \

drivers/net/ethernet/meta/fbnic/fbnic.h

···
 void fbnic_get_fw_ver_commit_str(struct fbnic_dev *fbd, char *fw_version,
 				 const size_t str_sz);
 
+void fbnic_csr_get_regs(struct fbnic_dev *fbd, u32 *data, u32 *regs_version);
+int fbnic_csr_regs_len(struct fbnic_dev *fbd);
+
 enum fbnic_boards {
 	fbnic_board_asic
 };

drivers/net/ethernet/meta/fbnic/fbnic_csr.c

···
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) Meta Platforms, Inc. and affiliates. */
+
+#include "fbnic.h"
+
+#define FBNIC_BOUNDS(section) { \
+	.start = FBNIC_CSR_START_##section, \
+	.end = FBNIC_CSR_END_##section + 1, \
+}
+
+struct fbnic_csr_bounds {
+	u32	start;
+	u32	end;
+};
+
+static const struct fbnic_csr_bounds fbnic_csr_sects[] = {
+	FBNIC_BOUNDS(INTR),
+	FBNIC_BOUNDS(INTR_CQ),
+	FBNIC_BOUNDS(QM_TX),
+	FBNIC_BOUNDS(QM_RX),
+	FBNIC_BOUNDS(TCE),
+	FBNIC_BOUNDS(TCE_RAM),
+	FBNIC_BOUNDS(TMI),
+	FBNIC_BOUNDS(PTP),
+	FBNIC_BOUNDS(RXB),
+	FBNIC_BOUNDS(RPC),
+	FBNIC_BOUNDS(FAB),
+	FBNIC_BOUNDS(MASTER),
+	FBNIC_BOUNDS(PCS),
+	FBNIC_BOUNDS(RSFEC),
+	FBNIC_BOUNDS(MAC_MAC),
+	FBNIC_BOUNDS(SIG),
+	FBNIC_BOUNDS(PUL_USER),
+	FBNIC_BOUNDS(QUEUE),
+	FBNIC_BOUNDS(RPC_RAM),
+};
+
+#define FBNIC_RPC_TCAM_ACT_DW_PER_ENTRY			14
+#define FBNIC_RPC_TCAM_ACT_NUM_ENTRIES			64
+
+#define FBNIC_RPC_TCAM_MACDA_DW_PER_ENTRY		4
+#define FBNIC_RPC_TCAM_MACDA_NUM_ENTRIES		32
+
+#define FBNIC_RPC_TCAM_OUTER_IPSRC_DW_PER_ENTRY		9
+#define FBNIC_RPC_TCAM_OUTER_IPSRC_NUM_ENTRIES		8
+
+#define FBNIC_RPC_TCAM_OUTER_IPDST_DW_PER_ENTRY		9
+#define FBNIC_RPC_TCAM_OUTER_IPDST_NUM_ENTRIES		8
+
+#define FBNIC_RPC_TCAM_IPSRC_DW_PER_ENTRY		9
+#define FBNIC_RPC_TCAM_IPSRC_NUM_ENTRIES		8
+
+#define FBNIC_RPC_TCAM_IPDST_DW_PER_ENTRY		9
+#define FBNIC_RPC_TCAM_IPDST_NUM_ENTRIES		8
+
+#define FBNIC_RPC_RSS_TBL_DW_PER_ENTRY			2
+#define FBNIC_RPC_RSS_TBL_NUM_ENTRIES			256
+
+static void fbnic_csr_get_regs_rpc_ram(struct fbnic_dev *fbd, u32 **data_p)
+{
+	u32 start = FBNIC_CSR_START_RPC_RAM;
+	u32 end = FBNIC_CSR_END_RPC_RAM;
+	u32 *data = *data_p;
+	u32 i, j;
+
+	*(data++) = start;
+	*(data++) = end - 1;
+
+	/* FBNIC_RPC_TCAM_ACT */
+	for (i = 0; i < FBNIC_RPC_TCAM_ACT_NUM_ENTRIES; i++) {
+		for (j = 0; j < FBNIC_RPC_TCAM_ACT_DW_PER_ENTRY; j++)
+			*(data++) = rd32(fbd, FBNIC_RPC_TCAM_ACT(i, j));
+	}
+
+	/* FBNIC_RPC_TCAM_MACDA */
+	for (i = 0; i < FBNIC_RPC_TCAM_MACDA_NUM_ENTRIES; i++) {
+		for (j = 0; j < FBNIC_RPC_TCAM_MACDA_DW_PER_ENTRY; j++)
+			*(data++) = rd32(fbd, FBNIC_RPC_TCAM_MACDA(i, j));
+	}
+
+	/* FBNIC_RPC_TCAM_OUTER_IPSRC */
+	for (i = 0; i < FBNIC_RPC_TCAM_OUTER_IPSRC_NUM_ENTRIES; i++) {
+		for (j = 0; j < FBNIC_RPC_TCAM_OUTER_IPSRC_DW_PER_ENTRY; j++)
+			*(data++) = rd32(fbd, FBNIC_RPC_TCAM_OUTER_IPSRC(i, j));
+	}
+
+	/* FBNIC_RPC_TCAM_OUTER_IPDST */
+	for (i = 0; i < FBNIC_RPC_TCAM_OUTER_IPDST_NUM_ENTRIES; i++) {
+		for (j = 0; j < FBNIC_RPC_TCAM_OUTER_IPDST_DW_PER_ENTRY; j++)
+			*(data++) = rd32(fbd, FBNIC_RPC_TCAM_OUTER_IPDST(i, j));
+	}
+
+	/* FBNIC_RPC_TCAM_IPSRC */
+	for (i = 0; i < FBNIC_RPC_TCAM_IPSRC_NUM_ENTRIES; i++) {
+		for (j = 0; j < FBNIC_RPC_TCAM_IPSRC_DW_PER_ENTRY; j++)
+			*(data++) = rd32(fbd, FBNIC_RPC_TCAM_IPSRC(i, j));
+	}
+
+	/* FBNIC_RPC_TCAM_IPDST */
+	for (i = 0; i < FBNIC_RPC_TCAM_IPDST_NUM_ENTRIES; i++) {
+		for (j = 0; j < FBNIC_RPC_TCAM_IPDST_DW_PER_ENTRY; j++)
+			*(data++) = rd32(fbd, FBNIC_RPC_TCAM_IPDST(i, j));
+	}
+
+	/* FBNIC_RPC_RSS_TBL */
+	for (i = 0; i < FBNIC_RPC_RSS_TBL_NUM_ENTRIES; i++) {
+		for (j = 0; j < FBNIC_RPC_RSS_TBL_DW_PER_ENTRY; j++)
+			*(data++) = rd32(fbd, FBNIC_RPC_RSS_TBL(i, j));
+	}
+
+	*data_p = data;
+}
+
+void fbnic_csr_get_regs(struct fbnic_dev *fbd, u32 *data, u32 *regs_version)
+{
+	const struct fbnic_csr_bounds *bound;
+	u32 *start = data;
+	int i, j;
+
+	*regs_version = 1u;
+
+	/* Skip RPC_RAM section which cannot be dumped linearly */
+	for (i = 0, bound = fbnic_csr_sects;
+	     i < ARRAY_SIZE(fbnic_csr_sects) - 1; i++, ++bound) {
+		*(data++) = bound->start;
+		*(data++) = bound->end - 1;
+		for (j = bound->start; j < bound->end; j++)
+			*(data++) = rd32(fbd, j);
+	}
+
+	/* Dump the RPC_RAM as special case registers */
+	fbnic_csr_get_regs_rpc_ram(fbd, &data);
+
+	WARN_ON(data - start != fbnic_csr_regs_len(fbd));
+}
+
+int fbnic_csr_regs_len(struct fbnic_dev *fbd)
+{
+	int i, len = 0;
+
+	/* Dump includes start and end information of each section
+	 * which results in an offset of 2
+	 */
+	for (i = 0; i < ARRAY_SIZE(fbnic_csr_sects); i++)
+		len += fbnic_csr_sects[i].end - fbnic_csr_sects[i].start + 2;
+
+	return len;
+}

drivers/net/ethernet/meta/fbnic/fbnic_csr.h

···
 #define FBNIC_RPC_TCAM_MACDA_VALUE		CSR_GENMASK(15, 0)
 #define FBNIC_RPC_TCAM_MACDA_MASK		CSR_GENMASK(31, 16)
 
+#define FBNIC_RPC_TCAM_OUTER_IPSRC(m, n)\
+	(0x08c00 + 0x08 * (n) + (m))		/* 0x023000 + 32*n + 4*m */
+#define FBNIC_RPC_TCAM_OUTER_IPDST(m, n)\
+	(0x08c48 + 0x08 * (n) + (m))		/* 0x023120 + 32*n + 4*m */
+#define FBNIC_RPC_TCAM_IPSRC(m, n)\
+	(0x08c90 + 0x08 * (n) + (m))		/* 0x023240 + 32*n + 4*m */
+#define FBNIC_RPC_TCAM_IPDST(m, n)\
+	(0x08cd8 + 0x08 * (n) + (m))		/* 0x023360 + 32*n + 4*m */
+
 #define FBNIC_RPC_RSS_TBL(n, m) \
 	(0x08d20 + 0x100 * (n) + (m))		/* 0x023480 + 1024*n + 4*m */
 #define FBNIC_RPC_RSS_TBL_COUNT			2
···
 #define FBNIC_CSR_START_MASTER		0x0C400	/* CSR section delimiter */
 #define FBNIC_MASTER_SPARE_0		0x0C41B		/* 0x3106c */
 #define FBNIC_CSR_END_MASTER		0x0C452	/* CSR section delimiter */
+
+/* MAC PCS registers */
+#define FBNIC_CSR_START_PCS		0x10000 /* CSR section delimiter */
+#define FBNIC_CSR_END_PCS		0x10668 /* CSR section delimiter */
+
+#define FBNIC_CSR_START_RSFEC		0x10800 /* CSR section delimiter */
+#define FBNIC_CSR_END_RSFEC		0x108c8 /* CSR section delimiter */
 
 /* MAC MAC registers (ASIC only) */
 #define FBNIC_CSR_START_MAC_MAC		0x11000 /* CSR section delimiter */

drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c

···
 	}
 }
 
+static void fbnic_get_regs(struct net_device *netdev,
+			   struct ethtool_regs *regs, void *data)
+{
+	struct fbnic_net *fbn = netdev_priv(netdev);
+
+	fbnic_csr_get_regs(fbn->fbd, data, &regs->version);
+}
+
+static int fbnic_get_regs_len(struct net_device *netdev)
+{
+	struct fbnic_net *fbn = netdev_priv(netdev);
+
+	return fbnic_csr_regs_len(fbn->fbd) * sizeof(u32);
+}
+
 static const struct ethtool_ops fbnic_ethtool_ops = {
 	.get_drvinfo		= fbnic_get_drvinfo,
+	.get_regs_len		= fbnic_get_regs_len,
+	.get_regs		= fbnic_get_regs,
 	.get_ts_info		= fbnic_get_ts_info,
 	.get_ts_stats		= fbnic_get_ts_stats,
 	.get_eth_mac_stats	= fbnic_get_eth_mac_stats,