ASoC: SOF: mediatek: add debug dump

Merge series from Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>:

Add the ability to generate debug dumps on MediaTek SOF implementations.

sound/soc/sof/mediatek/Makefile

@@ -1,3 +1,4 @@
 # SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause)
+obj-$(CONFIG_SND_SOC_SOF_MTK_COMMON) += mtk-adsp-common.o
 obj-$(CONFIG_SND_SOC_SOF_MT8195) += mt8195/
 obj-$(CONFIG_SND_SOC_SOF_MT8186) += mt8186/

sound/soc/sof/mediatek/mt8195/mt8195.c

@@ -24,6 +24,7 @@
 #include "../../sof-of-dev.h"
 #include "../../sof-audio.h"
 #include "../adsp_helper.h"
+#include "../mtk-adsp-common.h"
 #include "mt8195.h"
 #include "mt8195-clk.h"
 
@@ -485,6 +486,31 @@ static int mt8195_ipc_msg_data(struct snd_sof_dev *sdev,
 	return 0;
 }
 
+static void mt8195_adsp_dump(struct snd_sof_dev *sdev, u32 flags)
+{
+	u32 dbg_pc, dbg_data, dbg_bus0, dbg_bus1, dbg_inst;
+	u32 dbg_ls0stat, dbg_ls1stat, faultbus, faultinfo, swrest;
+
+	/* dump debug registers */
+	dbg_pc = snd_sof_dsp_read(sdev, DSP_REG_BAR, DSP_PDEBUGPC);
+	dbg_data = snd_sof_dsp_read(sdev, DSP_REG_BAR, DSP_PDEBUGDATA);
+	dbg_bus0 = snd_sof_dsp_read(sdev, DSP_REG_BAR, DSP_PDEBUGBUS0);
+	dbg_bus1 = snd_sof_dsp_read(sdev, DSP_REG_BAR, DSP_PDEBUGBUS1);
+	dbg_inst = snd_sof_dsp_read(sdev, DSP_REG_BAR, DSP_PDEBUGINST);
+	dbg_ls0stat = snd_sof_dsp_read(sdev, DSP_REG_BAR, DSP_PDEBUGLS0STAT);
+	dbg_ls1stat = snd_sof_dsp_read(sdev, DSP_REG_BAR, DSP_PDEBUGLS1STAT);
+	faultbus = snd_sof_dsp_read(sdev, DSP_REG_BAR, DSP_PFAULTBUS);
+	faultinfo = snd_sof_dsp_read(sdev, DSP_REG_BAR, DSP_PFAULTINFO);
+	swrest = snd_sof_dsp_read(sdev, DSP_REG_BAR, DSP_RESET_SW);
+
+	dev_info(sdev->dev, "adsp dump : pc %#x, data %#x, bus0 %#x, bus1 %#x, swrest %#x",
+		 dbg_pc, dbg_data, dbg_bus0, dbg_bus1, swrest);
+	dev_info(sdev->dev, "dbg_inst %#x, ls0stat %#x, ls1stat %#x, faultbus %#x, faultinfo %#x",
+		 dbg_inst, dbg_ls0stat, dbg_ls1stat, faultbus, faultinfo);
+
+	mtk_adsp_dump(sdev, flags);
+}
+
 static struct snd_soc_dai_driver mt8195_dai[] = {
 {
 	.name = "SOF_DL2",
@@ -552,6 +578,9 @@ static struct snd_sof_dsp_ops sof_mt8195_ops = {
 	/* Firmware ops */
 	.dsp_arch_ops = &sof_xtensa_arch_ops,
 
+	/* Debug information */
+	.dbg_dump = mt8195_adsp_dump,
+
 	/* DAI drivers */
 	.drv = mt8195_dai,
 	.num_drv = ARRAY_SIZE(mt8195_dai),

sound/soc/sof/mediatek/mtk-adsp-common.c

@@ -0,0 +1,84 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause)
+//
+// This file is provided under a dual BSD/GPLv2 license. When using or
+// redistributing this file, you may do so under either license.
+//
+// Copyright(c) 2022 MediaTek Inc. All rights reserved.
+//
+// Author: YC Hung <yc.hung@mediatek.com>
+
+/*
+ * Common helpers for the audio DSP on MediaTek platforms
+ */
+
+#include <linux/module.h>
+#include <sound/sof/xtensa.h>
+#include "../ops.h"
+#include "mtk-adsp-common.h"
+
+/**
+ * mtk_adsp_get_registers() - This function is called in case of DSP oops
+ * in order to gather information about the registers, filename and
+ * linenumber and stack.
+ * @sdev: SOF device
+ * @xoops: Stores information about registers.
+ * @panic_info: Stores information about filename and line number.
+ * @stack: Stores the stack dump.
+ * @stack_words: Size of the stack dump.
+ */
+static void mtk_adsp_get_registers(struct snd_sof_dev *sdev,
+				   struct sof_ipc_dsp_oops_xtensa *xoops,
+				   struct sof_ipc_panic_info *panic_info,
+				   u32 *stack, size_t stack_words)
+{
+	u32 offset = sdev->dsp_oops_offset;
+
+	/* first read registers */
+	sof_mailbox_read(sdev, offset, xoops, sizeof(*xoops));
+
+	/* then get panic info */
+	if (xoops->arch_hdr.totalsize > EXCEPT_MAX_HDR_SIZE) {
+		dev_err(sdev->dev, "invalid header size 0x%x\n",
+			xoops->arch_hdr.totalsize);
+		return;
+	}
+	offset += xoops->arch_hdr.totalsize;
+	sof_mailbox_read(sdev, offset, panic_info, sizeof(*panic_info));
+
+	/* then get the stack */
+	offset += sizeof(*panic_info);
+	sof_mailbox_read(sdev, offset, stack, stack_words * sizeof(u32));
+}
+
+/**
+ * mtk_adsp_dump() - This function is called when a panic message is
+ * received from the firmware.
+ * @sdev: SOF device
+ * @flags: parameter not used but required by ops prototype
+ */
+void mtk_adsp_dump(struct snd_sof_dev *sdev, u32 flags)
+{
+	char *level = (flags & SOF_DBG_DUMP_OPTIONAL) ? KERN_DEBUG : KERN_ERR;
+	struct sof_ipc_dsp_oops_xtensa xoops;
+	struct sof_ipc_panic_info panic_info;
+	u32 stack[MTK_ADSP_STACK_DUMP_SIZE];
+	u32 status;
+
+	/* Get information about the panic status from the debug box area.
+	 * Compute the trace point based on the status.
+	 */
+	sof_mailbox_read(sdev, sdev->debug_box.offset + 0x4, &status, 4);
+
+	/* Get information about the registers, the filename and line
+	 * number and the stack.
+	 */
+	mtk_adsp_get_registers(sdev, &xoops, &panic_info, stack,
+			       MTK_ADSP_STACK_DUMP_SIZE);
+
+	/* Print the information to the console */
+	sof_print_oops_and_stack(sdev, level, status, status, &xoops, &panic_info,
+				 stack, MTK_ADSP_STACK_DUMP_SIZE);
+}
+EXPORT_SYMBOL(mtk_adsp_dump);
+
+MODULE_LICENSE("Dual BSD/GPL");

sound/soc/sof/mediatek/mtk-adsp-common.h

@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause) */
+
+#ifndef __MEDIATEK_ADSP_COMMON_H__
+#define __MEDIATEK_ADSP_COMMON_H__
+
+#define EXCEPT_MAX_HDR_SIZE	0x400
+#define MTK_ADSP_STACK_DUMP_SIZE 32
+
+void mtk_adsp_dump(struct snd_sof_dev *sdev, u32 flags);
+#endif