wifi: mt76: mt7996: enable coredump support

Host triggered and catastrophic event triggered firmware core dumping
for basic firmware issues triage, including state reporting, function
calltrace and MCU memory dump.

Signed-off-by: Ryder Lee <[email protected]>
Signed-off-by: Felix Fietkau <[email protected]>

Author: ryderlee1110

drivers/net/wireless/mediatek/mt76/mt7996/Kconfig

@@ -2,6 +2,7 @@
 config MT7996E
 	tristate "MediaTek MT7996 (PCIe) support"
 	select MT76_CONNAC_LIB
+	select WANT_DEV_COREDUMP
 	select RELAY
 	depends on MAC80211
 	depends on PCI

drivers/net/wireless/mediatek/mt76/mt7996/Makefile

@@ -4,3 +4,5 @@ obj-$(CONFIG_MT7996E) += mt7996e.o
 
 mt7996e-y := pci.o init.o dma.o eeprom.o main.o mcu.o mac.o \
 	     debugfs.o mmio.o
+
+mt7996e-$(CONFIG_DEV_COREDUMP) += coredump.o

drivers/net/wireless/mediatek/mt76/mt7996/coredump.c

@@ -0,0 +1,268 @@
+// SPDX-License-Identifier: ISC
+/* Copyright (C) 2023 MediaTek Inc. */
+
+#include <linux/devcoredump.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/utsname.h>
+#include "coredump.h"
+
+static bool coredump_memdump;
+module_param(coredump_memdump, bool, 0644);
+MODULE_PARM_DESC(coredump_memdump, "Optional ability to dump firmware memory");
+
+static const struct mt7996_mem_region mt7996_mem_regions[] = {
+	{
+		.start = 0x00800000,
+		.len = 0x0004ffff,
+		.name = "ULM0",
+	},
+	{
+		.start = 0x00900000,
+		.len = 0x00037fff,
+		.name = "ULM1",
+	},
+	{
+		.start = 0x02200000,
+		.len = 0x0003ffff,
+		.name = "ULM2",
+	},
+	{
+		.start = 0x00400000,
+		.len = 0x00067fff,
+		.name = "SRAM",
+	},
+	{
+		.start = 0xe0000000,
+		.len = 0x0015ffff,
+		.name = "CRAM0",
+	},
+	{
+		.start = 0xe0160000,
+		.len = 0x0011bfff,
+		.name = "CRAM1",
+	},
+};
+
+const struct mt7996_mem_region*
+mt7996_coredump_get_mem_layout(struct mt7996_dev *dev, u32 *num)
+{
+	switch (mt76_chip(&dev->mt76)) {
+	case 0x7990:
+	case 0x7991:
+		*num = ARRAY_SIZE(mt7996_mem_regions);
+		return &mt7996_mem_regions[0];
+	default:
+		return NULL;
+	}
+}
+
+static int mt7996_coredump_get_mem_size(struct mt7996_dev *dev)
+{
+	const struct mt7996_mem_region *mem_region;
+	size_t size = 0;
+	u32 num;
+	int i;
+
+	mem_region = mt7996_coredump_get_mem_layout(dev, &num);
+	if (!mem_region)
+		return 0;
+
+	for (i = 0; i < num; i++) {
+		size += mem_region->len;
+		mem_region++;
+	}
+
+	/* reserve space for the headers */
+	size += num * sizeof(struct mt7996_mem_hdr);
+	/* make sure it is aligned 4 bytes for debug message print out */
+	size = ALIGN(size, 4);
+
+	return size;
+}
+
+struct mt7996_crash_data *mt7996_coredump_new(struct mt7996_dev *dev)
+{
+	struct mt7996_crash_data *crash_data = dev->coredump.crash_data;
+
+	lockdep_assert_held(&dev->dump_mutex);
+
+	if (coredump_memdump &&
+	    !mt76_poll_msec(dev, MT_FW_DUMP_STATE, 0x3, 0x2, 500))
+		return NULL;
+
+	guid_gen(&crash_data->guid);
+	ktime_get_real_ts64(&crash_data->timestamp);
+
+	return crash_data;
+}
+
+static void
+mt7996_coredump_fw_state(struct mt7996_dev *dev, struct mt7996_coredump *dump,
+			 bool *exception)
+{
+	u32 count;
+
+	count = mt76_rr(dev, MT_FW_ASSERT_CNT);
+
+	/* normal mode: driver can manually trigger assert for detail info */
+	if (!count)
+		strscpy(dump->fw_state, "normal", sizeof(dump->fw_state));
+	else
+		strscpy(dump->fw_state, "exception", sizeof(dump->fw_state));
+
+	*exception = !!count;
+}
+
+static void
+mt7996_coredump_fw_stack(struct mt7996_dev *dev, struct mt7996_coredump *dump,
+			 bool exception)
+{
+	u32 oldest, i, idx;
+
+	strscpy(dump->pc_current, "program counter", sizeof(dump->pc_current));
+
+	/* 0: WM PC log output */
+	mt76_wr(dev, MT_CONN_DBG_CTL_OUT_SEL, 0);
+	/* choose 33th PC log buffer to read current PC index */
+	mt76_wr(dev, MT_CONN_DBG_CTL_PC_LOG_SEL, 0x3f);
+
+	/* read current PC */
+	dump->pc_stack[0] = mt76_rr(dev, MT_CONN_DBG_CTL_PC_LOG);
+
+	/* stop call stack record */
+	if (!exception) {
+		mt76_clear(dev, MT_MCU_WM_EXCP_PC_CTRL, BIT(0));
+		mt76_clear(dev, MT_MCU_WM_EXCP_LR_CTRL, BIT(0));
+	}
+
+	oldest = (u32)mt76_get_field(dev, MT_MCU_WM_EXCP_PC_CTRL,
+				     GENMASK(20, 16)) + 2;
+	for (i = 0; i < 16; i++) {
+		idx = ((oldest + 2 * i + 1) % 32);
+		dump->pc_stack[i + 1] =
+			mt76_rr(dev, MT_MCU_WM_EXCP_PC_LOG + idx * 4);
+	}
+
+	oldest = (u32)mt76_get_field(dev, MT_MCU_WM_EXCP_LR_CTRL,
+				     GENMASK(20, 16)) + 2;
+	for (i = 0; i < 16; i++) {
+		idx = ((oldest + 2 * i + 1) % 32);
+		dump->lr_stack[i] =
+			mt76_rr(dev, MT_MCU_WM_EXCP_LR_LOG + idx * 4);
+	}
+
+	/* start call stack record */
+	if (!exception) {
+		mt76_set(dev, MT_MCU_WM_EXCP_PC_CTRL, BIT(0));
+		mt76_set(dev, MT_MCU_WM_EXCP_LR_CTRL, BIT(0));
+	}
+}
+
+static struct mt7996_coredump *mt7996_coredump_build(struct mt7996_dev *dev)
+{
+	struct mt7996_crash_data *crash_data = dev->coredump.crash_data;
+	struct mt7996_coredump *dump;
+	struct mt7996_coredump_mem *dump_mem;
+	size_t len, sofar = 0, hdr_len = sizeof(*dump);
+	unsigned char *buf;
+	bool exception;
+
+	len = hdr_len;
+
+	if (coredump_memdump && crash_data->memdump_buf_len)
+		len += sizeof(*dump_mem) + crash_data->memdump_buf_len;
+
+	sofar += hdr_len;
+
+	/* this is going to get big when we start dumping memory and such,
+	 * so go ahead and use vmalloc.
+	 */
+	buf = vzalloc(len);
+	if (!buf)
+		return NULL;
+
+	mutex_lock(&dev->dump_mutex);
+
+	dump = (struct mt7996_coredump *)(buf);
+	dump->len = len;
+
+	/* plain text */
+	strscpy(dump->magic, "mt76-crash-dump", sizeof(dump->magic));
+	strscpy(dump->kernel, init_utsname()->release, sizeof(dump->kernel));
+	strscpy(dump->fw_ver, dev->mt76.hw->wiphy->fw_version,
+		sizeof(dump->fw_ver));
+
+	guid_copy(&dump->guid, &crash_data->guid);
+	dump->tv_sec = crash_data->timestamp.tv_sec;
+	dump->tv_nsec = crash_data->timestamp.tv_nsec;
+	dump->device_id = mt76_chip(&dev->mt76);
+
+	mt7996_coredump_fw_state(dev, dump, &exception);
+	mt7996_coredump_fw_stack(dev, dump, exception);
+
+	/* gather memory content */
+	dump_mem = (struct mt7996_coredump_mem *)(buf + sofar);
+	dump_mem->len = crash_data->memdump_buf_len;
+	if (coredump_memdump && crash_data->memdump_buf_len)
+		memcpy(dump_mem->data, crash_data->memdump_buf,
+		       crash_data->memdump_buf_len);
+
+	mutex_unlock(&dev->dump_mutex);
+
+	return dump;
+}
+
+int mt7996_coredump_submit(struct mt7996_dev *dev)
+{
+	struct mt7996_coredump *dump;
+
+	dump = mt7996_coredump_build(dev);
+	if (!dump) {
+		dev_warn(dev->mt76.dev, "no crash dump data found\n");
+		return -ENODATA;
+	}
+
+	dev_coredumpv(dev->mt76.dev, dump, dump->len, GFP_KERNEL);
+
+	return 0;
+}
+
+int mt7996_coredump_register(struct mt7996_dev *dev)
+{
+	struct mt7996_crash_data *crash_data;
+
+	crash_data = vzalloc(sizeof(*dev->coredump.crash_data));
+	if (!crash_data)
+		return -ENOMEM;
+
+	dev->coredump.crash_data = crash_data;
+
+	if (coredump_memdump) {
+		crash_data->memdump_buf_len = mt7996_coredump_get_mem_size(dev);
+		if (!crash_data->memdump_buf_len)
+			/* no memory content */
+			return 0;
+
+		crash_data->memdump_buf = vzalloc(crash_data->memdump_buf_len);
+		if (!crash_data->memdump_buf) {
+			vfree(crash_data);
+			return -ENOMEM;
+		}
+	}
+
+	return 0;
+}
+
+void mt7996_coredump_unregister(struct mt7996_dev *dev)
+{
+	if (dev->coredump.crash_data->memdump_buf) {
+		vfree(dev->coredump.crash_data->memdump_buf);
+		dev->coredump.crash_data->memdump_buf = NULL;
+		dev->coredump.crash_data->memdump_buf_len = 0;
+	}
+
+	vfree(dev->coredump.crash_data);
+	dev->coredump.crash_data = NULL;
+}
+

drivers/net/wireless/mediatek/mt76/mt7996/coredump.h

@@ -0,0 +1,97 @@
+/* SPDX-License-Identifier: ISC */
+/* Copyright (C) 2023 MediaTek Inc. */
+
+#ifndef _COREDUMP_H_
+#define _COREDUMP_H_
+
+#include "mt7996.h"
+
+struct mt7996_coredump {
+	char magic[16];
+
+	u32 len;
+
+	guid_t guid;
+
+	/* time-of-day stamp */
+	u64 tv_sec;
+	/* time-of-day stamp, nano-seconds */
+	u64 tv_nsec;
+	/* kernel version */
+	char kernel[64];
+	/* firmware version */
+	char fw_ver[ETHTOOL_FWVERS_LEN];
+
+	u32 device_id;
+
+	/* exception state */
+	char fw_state[12];
+
+	/* program counters */
+	char pc_current[16];
+	u32 pc_stack[17];
+	/* link registers */
+	u32 lr_stack[16];
+
+	/* memory content */
+	u8 data[];
+} __packed;
+
+struct mt7996_coredump_mem {
+	u32 len;
+	u8 data[];
+} __packed;
+
+struct mt7996_mem_hdr {
+	u32 start;
+	u32 len;
+	u8 data[];
+};
+
+struct mt7996_mem_region {
+	u32 start;
+	size_t len;
+
+	const char *name;
+};
+
+#ifdef CONFIG_DEV_COREDUMP
+
+const struct mt7996_mem_region *
+mt7996_coredump_get_mem_layout(struct mt7996_dev *dev, u32 *num);
+struct mt7996_crash_data *mt7996_coredump_new(struct mt7996_dev *dev);
+int mt7996_coredump_submit(struct mt7996_dev *dev);
+int mt7996_coredump_register(struct mt7996_dev *dev);
+void mt7996_coredump_unregister(struct mt7996_dev *dev);
+
+#else /* CONFIG_DEV_COREDUMP */
+
+static inline const struct mt7996_mem_region *
+mt7996_coredump_get_mem_layout(struct mt7996_dev *dev, u32 *num)
+{
+	return NULL;
+}
+
+static inline int mt7996_coredump_submit(struct mt7996_dev *dev)
+{
+	return 0;
+}
+
+static inline struct
+mt7996_crash_data *mt7996_coredump_new(struct mt7996_dev *dev)
+{
+	return NULL;
+}
+
+static inline int mt7996_coredump_register(struct mt7996_dev *dev)
+{
+	return 0;
+}
+
+static inline void mt7996_coredump_unregister(struct mt7996_dev *dev)
+{
+}
+
+#endif /* CONFIG_DEV_COREDUMP */
+
+#endif /* _COREDUMP_H_ */