ASoC: SOF: mediatek: Add mediatek common debug dump

1.Add mtk-adsp-common.c file for mediatek platforms common usage.
2.Add mtk_adsp_dump implementation in mtk-adsp-common.c for general
  debug dump.
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Signed-off-by: YC Hung <yc.hung@mediatek.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20220517173109.468568-2-pierre-louis.bossart@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sof/mediatek/Makefile

 # 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/mtk-adsp-common.c

+// 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

+/* 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