net: marvell: prestera: Add driver for Prestera family ASIC devices

Marvell Prestera 98DX326x integrates up to 24 ports of 1GbE with 8
ports of 10GbE uplinks or 2 ports of 40Gbps stacking for a largely
wireless SMB deployment.

The current implementation supports only boards designed for the Marvell
Switchdev solution and requires special firmware.

The core Prestera switching logic is implemented in prestera_main.c,
there is an intermediate hw layer between core logic and firmware. It is
implemented in prestera_hw.c, the purpose of it is to encapsulate hw
related logic, in future there is a plan to support more devices with
different HW related configurations.

This patch contains only basic switch initialization and RX/TX support
over SDMA mechanism.

Currently supported devices have DMA access range <= 32bit and require
ZONE_DMA to be enabled, for such cases SDMA driver checks if the skb
allocated in proper range supported by the Prestera device.

Also meanwhile there is no TX interrupt support in current firmware
version so recycling work is scheduled on each xmit.

Port's mac address is generated from the switch base mac which may be
provided via device-tree (static one or as nvme cell), or randomly
generated. This is required by the firmware.

Co-developed-by: Andrii Savka <andrii.savka@plvision.eu>
Signed-off-by: Andrii Savka <andrii.savka@plvision.eu>
Co-developed-by: Oleksandr Mazur <oleksandr.mazur@plvision.eu>
Signed-off-by: Oleksandr Mazur <oleksandr.mazur@plvision.eu>
Co-developed-by: Serhiy Boiko <serhiy.boiko@plvision.eu>
Signed-off-by: Serhiy Boiko <serhiy.boiko@plvision.eu>
Co-developed-by: Serhiy Pshyk <serhiy.pshyk@plvision.eu>
Signed-off-by: Serhiy Pshyk <serhiy.pshyk@plvision.eu>
Co-developed-by: Taras Chornyi <taras.chornyi@plvision.eu>
Signed-off-by: Taras Chornyi <taras.chornyi@plvision.eu>
Co-developed-by: Volodymyr Mytnyk <volodymyr.mytnyk@plvision.eu>
Signed-off-by: Volodymyr Mytnyk <volodymyr.mytnyk@plvision.eu>
Signed-off-by: Vadym Kochan <vadym.kochan@plvision.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 104 insertions, 0 deletions

diff --git a/drivers/net/ethernet/marvell/prestera/prestera_dsa.c b/drivers/net/ethernet/marvell/prestera/prestera_dsa.c
new file mode 100644
index 000000000000..a5e01c7a307b
--- /dev/null
+++ b/drivers/net/ethernet/marvell/prestera/prestera_dsa.c
@@ -0,0 +1,104 @@
+// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
+/* Copyright (c) 2020 Marvell International Ltd. All rights reserved */
+
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+
+#include "prestera_dsa.h"
+
+#define PRESTERA_DSA_W0_CMD		GENMASK(31, 30)
+#define PRESTERA_DSA_W0_IS_TAGGED	BIT(29)
+#define PRESTERA_DSA_W0_DEV_NUM		GENMASK(28, 24)
+#define PRESTERA_DSA_W0_PORT_NUM	GENMASK(23, 19)
+#define PRESTERA_DSA_W0_VPT		GENMASK(15, 13)
+#define PRESTERA_DSA_W0_EXT_BIT		BIT(12)
+#define PRESTERA_DSA_W0_VID		GENMASK(11, 0)
+
+#define PRESTERA_DSA_W1_EXT_BIT		BIT(31)
+#define PRESTERA_DSA_W1_CFI_BIT		BIT(30)
+#define PRESTERA_DSA_W1_PORT_NUM	GENMASK(11, 10)
+
+#define PRESTERA_DSA_W2_EXT_BIT		BIT(31)
+#define PRESTERA_DSA_W2_PORT_NUM	BIT(20)
+
+#define PRESTERA_DSA_W3_VID		GENMASK(30, 27)
+#define PRESTERA_DSA_W3_DST_EPORT	GENMASK(23, 7)
+#define PRESTERA_DSA_W3_DEV_NUM		GENMASK(6, 0)
+
+#define PRESTERA_DSA_VID		GENMASK(15, 12)
+#define PRESTERA_DSA_DEV_NUM		GENMASK(11, 5)
+
+int prestera_dsa_parse(struct prestera_dsa *dsa, const u8 *dsa_buf)
+{
+	__be32 *dsa_words = (__be32 *)dsa_buf;
+	enum prestera_dsa_cmd cmd;
+	u32 words[4];
+	u32 field;
+
+	words[0] = ntohl(dsa_words[0]);
+	words[1] = ntohl(dsa_words[1]);
+	words[2] = ntohl(dsa_words[2]);
+	words[3] = ntohl(dsa_words[3]);
+
+	/* set the common parameters */
+	cmd = (enum prestera_dsa_cmd)FIELD_GET(PRESTERA_DSA_W0_CMD, words[0]);
+
+	/* only to CPU is supported */
+	if (unlikely(cmd != PRESTERA_DSA_CMD_TO_CPU))
+		return -EINVAL;
+
+	if (FIELD_GET(PRESTERA_DSA_W0_EXT_BIT, words[0]) == 0)
+		return -EINVAL;
+	if (FIELD_GET(PRESTERA_DSA_W1_EXT_BIT, words[1]) == 0)
+		return -EINVAL;
+	if (FIELD_GET(PRESTERA_DSA_W2_EXT_BIT, words[2]) == 0)
+		return -EINVAL;
+
+	field = FIELD_GET(PRESTERA_DSA_W3_VID, words[3]);
+
+	dsa->vlan.is_tagged = FIELD_GET(PRESTERA_DSA_W0_IS_TAGGED, words[0]);
+	dsa->vlan.cfi_bit = FIELD_GET(PRESTERA_DSA_W1_CFI_BIT, words[1]);
+	dsa->vlan.vpt = FIELD_GET(PRESTERA_DSA_W0_VPT, words[0]);
+	dsa->vlan.vid = FIELD_GET(PRESTERA_DSA_W0_VID, words[0]);
+	dsa->vlan.vid &= ~PRESTERA_DSA_VID;
+	dsa->vlan.vid |= FIELD_PREP(PRESTERA_DSA_VID, field);
+
+	field = FIELD_GET(PRESTERA_DSA_W3_DEV_NUM, words[3]);
+
+	dsa->hw_dev_num = FIELD_GET(PRESTERA_DSA_W0_DEV_NUM, words[0]);
+	dsa->hw_dev_num |= FIELD_PREP(PRESTERA_DSA_DEV_NUM, field);
+
+	dsa->port_num = (FIELD_GET(PRESTERA_DSA_W0_PORT_NUM, words[0]) << 0) |
+			(FIELD_GET(PRESTERA_DSA_W1_PORT_NUM, words[1]) << 5) |
+			(FIELD_GET(PRESTERA_DSA_W2_PORT_NUM, words[2]) << 7);
+
+	return 0;
+}
+
+int prestera_dsa_build(const struct prestera_dsa *dsa, u8 *dsa_buf)
+{
+	__be32 *dsa_words = (__be32 *)dsa_buf;
+	u32 dev_num = dsa->hw_dev_num;
+	u32 words[4] = { 0 };
+
+	words[0] |= FIELD_PREP(PRESTERA_DSA_W0_CMD, PRESTERA_DSA_CMD_FROM_CPU);
+
+	words[0] |= FIELD_PREP(PRESTERA_DSA_W0_DEV_NUM, dev_num);
+	dev_num = FIELD_GET(PRESTERA_DSA_DEV_NUM, dev_num);
+	words[3] |= FIELD_PREP(PRESTERA_DSA_W3_DEV_NUM, dev_num);
+
+	words[3] |= FIELD_PREP(PRESTERA_DSA_W3_DST_EPORT, dsa->port_num);
+
+	words[0] |= FIELD_PREP(PRESTERA_DSA_W0_EXT_BIT, 1);
+	words[1] |= FIELD_PREP(PRESTERA_DSA_W1_EXT_BIT, 1);
+	words[2] |= FIELD_PREP(PRESTERA_DSA_W2_EXT_BIT, 1);
+
+	dsa_words[0] = htonl(words[0]);
+	dsa_words[1] = htonl(words[1]);
+	dsa_words[2] = htonl(words[2]);
+	dsa_words[3] = htonl(words[3]);
+
+	return 0;
+}