ASoC: Intel: avs: Introduce debug-context aware helpers

Debug-related fields and log-dumping are useful when debugfs is enabled.
Define them under CONFIG_DEBUG_FS and provide stubs when the config is
disabled so that the code that makes use of these needs not to be
complicated unnecessarily.

Members that are duplicated by this patch will be removed by the follow
up changes.
Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>
Link: https://lore.kernel.org/r/20221202152841.672536-7-cezary.rojewski@intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/intel/avs/Makefile

@@ -9,6 +9,10 @@ snd-soc-avs-objs += trace.o
 # tell define_trace.h where to find the trace header
 CFLAGS_trace.o := -I$(src)
 
+ifneq ($(CONFIG_DEBUG_FS),)
+snd-soc-avs-objs += debugfs.o
+endif
+
 obj-$(CONFIG_SND_SOC_INTEL_AVS) += snd-soc-avs.o
 
 # Machine support

sound/soc/intel/avs/avs.h

@@ -9,6 +9,7 @@
 #ifndef __SOUND_SOC_INTEL_AVS_H
 #define __SOUND_SOC_INTEL_AVS_H
 
+#include <linux/debugfs.h>
 #include <linux/device.h>
 #include <linux/firmware.h>
 #include <linux/kfifo.h>
@@ -146,6 +147,14 @@ struct avs_dev {
 	struct mutex path_mutex;
 
 	struct avs_debug dbg;
+	spinlock_t trace_lock;	/* serialize debug window I/O between each LOG_BUFFER_STATUS */
+#ifdef CONFIG_DEBUG_FS
+	struct kfifo trace_fifo;
+	wait_queue_head_t trace_waitq;
+	u32 aging_timer_period;
+	u32 fifo_full_timer_period;
+	u32 logged_resources;	/* context dependent: core or library */
+#endif
 };
 
 /* from hda_bus to avs_dev */
@@ -366,4 +375,24 @@ struct apl_log_buffer_layout {
 #define apl_log_payload_addr(addr) \
 	(addr + sizeof(struct apl_log_buffer_layout))
 
+#ifdef CONFIG_DEBUG_FS
+bool avs_logging_fw(struct avs_dev *adev);
+void avs_dump_fw_log(struct avs_dev *adev, const void __iomem *src, unsigned int len);
+void avs_dump_fw_log_wakeup(struct avs_dev *adev, const void __iomem *src, unsigned int len);
+#else
+static inline bool avs_logging_fw(struct avs_dev *adev)
+{
+	return false;
+}
+
+static inline void avs_dump_fw_log(struct avs_dev *adev, const void __iomem *src, unsigned int len)
+{
+}
+
+static inline void
+avs_dump_fw_log_wakeup(struct avs_dev *adev, const void __iomem *src, unsigned int len)
+{
+}
+#endif
+
 #endif /* __SOUND_SOC_INTEL_AVS_H */

sound/soc/intel/avs/debugfs.c

+// SPDX-License-Identifier: GPL-2.0-only
+//
+// Copyright(c) 2021-2022 Intel Corporation. All rights reserved.
+//
+// Authors: Cezary Rojewski <cezary.rojewski@intel.com>
+//          Amadeusz Slawinski <amadeuszx.slawinski@linux.intel.com>
+//
+
+#include <linux/debugfs.h>
+#include <linux/kfifo.h>
+#include <linux/wait.h>
+#include "avs.h"
+
+bool avs_logging_fw(struct avs_dev *adev)
+{
+	return kfifo_initialized(&adev->trace_fifo);
+}
+
+void avs_dump_fw_log(struct avs_dev *adev, const void __iomem *src, unsigned int len)
+{
+	__kfifo_fromio(&adev->trace_fifo, src, len);
+}
+
+void avs_dump_fw_log_wakeup(struct avs_dev *adev, const void __iomem *src, unsigned int len)
+{
+	avs_dump_fw_log(adev, src, len);
+	wake_up(&adev->trace_waitq);
+}