soc: qcom: smp2p: Introduce tracepoint support

Introduce tracepoint support for smp2p to enable
communication logging between local and remote processors.
Include tracepoints with information about the remote subsystem
name, negotiation details, supported features, bit change
notifications, and ssr activity. These logs are useful for
debugging issues between subsystems.

Signed-off-by: Sudeepgoud Patil <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Bjorn Andersson <[e-mail]>

drivers/soc/qcom/Makefile

···
 obj-$(CONFIG_QCOM_SMD_RPM)	+= rpm-proc.o smd-rpm.o
 obj-$(CONFIG_QCOM_SMEM) +=	smem.o
 obj-$(CONFIG_QCOM_SMEM_STATE) += smem_state.o
+CFLAGS_smp2p.o := -I$(src)
 obj-$(CONFIG_QCOM_SMP2P)	+= smp2p.o
 obj-$(CONFIG_QCOM_SMSM)	+= smsm.o
 obj-$(CONFIG_QCOM_SOCINFO)	+= socinfo.o

drivers/soc/qcom/smp2p.c

···
 	struct list_head outbound;
 };
 
+#define CREATE_TRACE_POINTS
+#include "trace-smp2p.h"
+
 static void qcom_smp2p_kick(struct qcom_smp2p *smp2p)
 {
 	/* Make sure any updated data is written before the kick */
···
 	struct smp2p_smem_item *out = smp2p->out;
 	u32 val;
 
+	trace_smp2p_ssr_ack(smp2p->dev);
 	smp2p->ssr_ack = !smp2p->ssr_ack;
 
 	val = out->flags & ~BIT(SMP2P_FLAGS_RESTART_ACK_BIT);
···
 			smp2p->ssr_ack_enabled = true;
 
 		smp2p->negotiation_done = true;
+		trace_smp2p_negotiate(smp2p->dev, out->features);
 	}
 }
 
···
 
 		status = val ^ entry->last_value;
 		entry->last_value = val;
+
+		trace_smp2p_notify_in(entry, status, val);
 
 		/* No changes of this entry? */
 		if (!status)
···
 	val |= value;
 	writel(val, entry->value);
 	spin_unlock_irqrestore(&entry->lock, flags);
+
+	trace_smp2p_update_bits(entry, orig, val);
 
 	if (val != orig)
 		qcom_smp2p_kick(entry->smp2p);

drivers/soc/qcom/trace-smp2p.h

···
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM qcom_smp2p
+
+#if !defined(__QCOM_SMP2P_TRACE_H__) || defined(TRACE_HEADER_MULTI_READ)
+#define __QCOM_SMP2P_TRACE_H__
+
+#include <linux/device.h>
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(smp2p_ssr_ack,
+	TP_PROTO(const struct device *dev),
+	TP_ARGS(dev),
+	TP_STRUCT__entry(
+		__string(dev_name, dev_name(dev))
+	),
+	TP_fast_assign(
+		__assign_str(dev_name);
+	),
+	TP_printk("%s: SSR detected", __get_str(dev_name))
+);
+
+TRACE_EVENT(smp2p_negotiate,
+	TP_PROTO(const struct device *dev, unsigned int features),
+	TP_ARGS(dev, features),
+	TP_STRUCT__entry(
+		__string(dev_name, dev_name(dev))
+		__field(u32, out_features)
+	),
+	TP_fast_assign(
+		__assign_str(dev_name);
+		__entry->out_features = features;
+	),
+	TP_printk("%s: state=open out_features=%s", __get_str(dev_name),
+		__print_flags(__entry->out_features, "|",
+			{SMP2P_FEATURE_SSR_ACK, "SMP2P_FEATURE_SSR_ACK"})
+	)
+);
+
+TRACE_EVENT(smp2p_notify_in,
+	TP_PROTO(struct smp2p_entry *smp2p_entry, unsigned long status, u32 val),
+	TP_ARGS(smp2p_entry, status, val),
+	TP_STRUCT__entry(
+		__string(dev_name, dev_name(smp2p_entry->smp2p->dev))
+		__string(client_name, smp2p_entry->name)
+		__field(unsigned long, status)
+		__field(u32, val)
+	),
+	TP_fast_assign(
+		__assign_str(dev_name);
+		__assign_str(client_name);
+		__entry->status = status;
+		__entry->val = val;
+	),
+	TP_printk("%s: %s: status:0x%0lx val:0x%0x",
+		__get_str(dev_name),
+		__get_str(client_name),
+		__entry->status,
+		__entry->val
+	)
+);
+
+TRACE_EVENT(smp2p_update_bits,
+	TP_PROTO(struct smp2p_entry *smp2p_entry, u32 orig, u32 val),
+	TP_ARGS(smp2p_entry, orig, val),
+	TP_STRUCT__entry(
+		__string(dev_name, dev_name(smp2p_entry->smp2p->dev))
+		__string(client_name, smp2p_entry->name)
+		__field(u32, orig)
+		__field(u32, val)
+	),
+	TP_fast_assign(
+		__assign_str(dev_name);
+		__assign_str(client_name);
+		__entry->orig = orig;
+		__entry->val = val;
+	),
+	TP_printk("%s: %s: orig:0x%0x new:0x%0x",
+		__get_str(dev_name),
+		__get_str(client_name),
+		__entry->orig,
+		__entry->val
+	)
+);
+
+#endif /* __QCOM_SMP2P_TRACE_H__ */
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_FILE trace-smp2p
+
+#include <trace/define_trace.h>