[PATCH v3 24/24] dmaengine: dw-edma: Add trace support

[Koichiro Den]

From: Frank Li <Frank.Li@xxxxxxx>

The circular LL ring has separate producer and consumer positions. Add
tracepoints for LL publication, descriptor append and completion,
IRQ-paired LL events, and engine recovery. The LL events cover both eDMA
and HDMA.

The recovery event records configured LL channels before a direction
reset. When disabled, static keys leave only a branch at each trace
site.

Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
Co-developed-by: Koichiro Den <den@xxxxxxxxxxxxx>
Signed-off-by: Koichiro Den <den@xxxxxxxxxxxxx>
---
Changes in v3:
  - Record the full pending-entry count in recovery traces. (Sashiko)
  - Trace the recorded LL event snapshot and update recovery tracing for
    the revised recovery flow. (Sashiko)
  - Replace single-use event classes with direct trace events.

 drivers/dma/dw-edma/Makefile        |   2 +
 drivers/dma/dw-edma/dw-edma-core.c  |  49 ++++++++
 drivers/dma/dw-edma/dw-edma-core.h  |   2 +
 drivers/dma/dw-edma/dw-edma-trace.c |   4 +
 drivers/dma/dw-edma/dw-edma-trace.h | 169 ++++++++++++++++++++++++++++
 5 files changed, 226 insertions(+)
 create mode 100644 drivers/dma/dw-edma/dw-edma-trace.c
 create mode 100644 drivers/dma/dw-edma/dw-edma-trace.h

diff --git a/drivers/dma/dw-edma/Makefile b/drivers/dma/dw-edma/Makefile
index 83ab58f87760..5f395fa1ede4 100644
--- a/drivers/dma/dw-edma/Makefile
+++ b/drivers/dma/dw-edma/Makefile
@@ -1,8 +1,10 @@
 # SPDX-License-Identifier: GPL-2.0
 
+CFLAGS_dw-edma-trace.o		:= -I$(src)
 obj-$(CONFIG_DW_EDMA)		+= dw-edma.o
 dw-edma-$(CONFIG_DEBUG_FS)	:= dw-edma-v0-debugfs.o	\
 				   dw-hdma-v0-debugfs.o
+dw-edma-$(CONFIG_TRACING)	+= dw-edma-trace.o
 dw-edma-objs			:= dw-edma-core.o	\
 				   dw-edma-v0-core.o	\
 				   dw-hdma-v0-core.o $(dw-edma-y)
diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
index 262ea893174f..e94557d79d4c 100644
--- a/drivers/dma/dw-edma/dw-edma-core.c
+++ b/drivers/dma/dw-edma/dw-edma-core.c
@@ -414,6 +414,12 @@ static void dw_edma_core_ll_start(struct dw_edma_desc *desc)
 				     chan->ll_head, chan->cb,
 				     dw_edma_core_enable_ll_irq(desc, i, free));
 
+		trace_edma_fill_ll(chan, chan->ll_head,
+				   desc->vd.tx.cookie,
+				   desc->burst[i].sar,
+				   desc->burst[i].dar, desc->burst[i].sz,
+				   chan->cb);
+
 		chan->ll_head++;
 
 		if (chan->ll_head == chan->ll_max) {
@@ -475,6 +481,7 @@ static int dw_edma_start_transfer(struct dw_edma_chan *chan)
 		if (desc->start_burst == desc->nburst)
 			continue;
 
+		trace_edma_append_desc(desc);
 		dw_edma_core_start(desc);
 		ret = 1;
 	}
@@ -604,6 +611,7 @@ static bool dw_edma_ll_clean_pending(struct dw_edma_chan *chan, int idx)
 		/* Hardware has consumed this descriptor's LL entries. */
 		dw_hdma_set_callback_result(vd, DMA_TRANS_NOERROR);
 		list_del(&vd->node);
+		trace_edma_complete_desc(desc);
 		vchan_cookie_complete(vd);
 	}
 
@@ -939,6 +947,44 @@ dw_edma_engine_recovery_drain_irqs(struct dw_edma_engine_recovery *rec)
 	}
 }
 
+static void
+dw_edma_trace_engine_recovery(struct dw_edma_engine_recovery *rec)
+{
+	struct dw_edma *dw = rec->dw;
+	u16 off = rec->dir == EDMA_DIR_WRITE ? 0 : dw->wr_ch_cnt;
+	u16 cnt = rec->dir == EDMA_DIR_WRITE ? dw->wr_ch_cnt : dw->rd_ch_cnt;
+	struct dw_edma_chan *chan;
+	u16 i;
+
+	if (!trace_edma_engine_recovery_enabled())
+		return;
+
+	for (i = 0; i < cnt; i++) {
+		enum dw_edma_request request;
+		enum dw_edma_status status;
+		bool configured_ll;
+		u32 ll_head, ll_done, pending;
+
+		chan = &dw->chan[off + i];
+		scoped_guard(spinlock_irqsave, &chan->vc.lock) {
+			configured_ll = chan->configured && !chan->non_ll;
+			if (configured_ll) {
+				request = chan->request;
+				status = chan->status;
+				ll_head = chan->ll_head;
+				ll_done = chan->ll_done;
+				pending = dw_edma_core_get_used_num(chan);
+			}
+		}
+		if (!configured_ll)
+			continue;
+
+		trace_edma_engine_recovery(chan, dw_edma_core_ch_status(chan),
+					   request, status, ll_head, ll_done,
+					   pending);
+	}
+}
+
 static void dw_edma_engine_recovery_work(struct work_struct *work)
 {
 	struct dw_edma_engine_recovery *rec =
@@ -1064,6 +1110,8 @@ static void dw_edma_engine_recovery_work(struct work_struct *work)
 		return;
 	}
 
+	dw_edma_trace_engine_recovery(rec);
+
 	if (!dw->core->engine_reset(dw, rec->dir)) {
 		/*
 		 * Keep channels gated and do not re-enable the engine unless
@@ -1683,6 +1731,7 @@ static void dw_edma_ll_interrupt(struct dw_edma_chan *chan)
 	if (!dw_edma_ll_snapshot_take(chan, &snapshot))
 		return;
 
+	trace_edma_irq(chan, &snapshot);
 	if (chan->status == EDMA_ST_PAUSE)
 		return;
 
diff --git a/drivers/dma/dw-edma/dw-edma-core.h b/drivers/dma/dw-edma/dw-edma-core.h
index 0c9c17edd835..ca0f60ad5ab5 100644
--- a/drivers/dma/dw-edma/dw-edma-core.h
+++ b/drivers/dma/dw-edma/dw-edma-core.h
@@ -206,6 +206,8 @@ struct dw_edma {
 	const struct dw_edma_core_ops	*core;
 };
 
+#include "dw-edma-trace.h"
+
 typedef void (*dw_edma_handler_t)(struct dw_edma_chan *chan,
 				  unsigned int events);
 
diff --git a/drivers/dma/dw-edma/dw-edma-trace.c b/drivers/dma/dw-edma/dw-edma-trace.c
new file mode 100644
index 000000000000..2620ad61a943
--- /dev/null
+++ b/drivers/dma/dw-edma/dw-edma-trace.c
@@ -0,0 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define CREATE_TRACE_POINTS
+#include "dw-edma-core.h"
diff --git a/drivers/dma/dw-edma/dw-edma-trace.h b/drivers/dma/dw-edma/dw-edma-trace.h
new file mode 100644
index 000000000000..e5b3eb57df06
--- /dev/null
+++ b/drivers/dma/dw-edma/dw-edma-trace.h
@@ -0,0 +1,169 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright 2023 NXP.
+ */
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM dw_edma
+
+#if !defined(__LINUX_DW_EDMA_TRACE) || defined(TRACE_HEADER_MULTI_READ)
+#define __LINUX_DW_EDMA_TRACE
+
+#include <linux/types.h>
+#include <linux/tracepoint.h>
+
+DECLARE_EVENT_CLASS(edma_desc_info,
+	TP_PROTO(struct dw_edma_desc *desc),
+	TP_ARGS(desc),
+	TP_STRUCT__entry(
+		__field(size_t, nburst)
+		__field(size_t, start_burst)
+		__field(dma_cookie_t, cookie)
+		__field(u32, id)
+		__field(u8, dir)
+	),
+	TP_fast_assign(
+		__entry->nburst = desc->nburst;
+		__entry->start_burst = desc->start_burst;
+		__entry->id = desc->chan->id;
+		__entry->dir = desc->chan->dir;
+		__entry->cookie = desc->vd.tx.cookie;
+	),
+	TP_printk("chan %u%c desc %d nburst %zu start_burst %zu",
+		__entry->id,
+		__entry->dir ? 'R' : 'W',
+		__entry->cookie,
+		__entry->nburst,
+		__entry->start_burst)
+);
+
+DEFINE_EVENT(edma_desc_info, edma_append_desc,
+	TP_PROTO(struct dw_edma_desc *desc),
+	TP_ARGS(desc)
+);
+
+DEFINE_EVENT(edma_desc_info, edma_complete_desc,
+	TP_PROTO(struct dw_edma_desc *desc),
+	TP_ARGS(desc)
+);
+
+TRACE_EVENT(edma_irq,
+	TP_PROTO(struct dw_edma_chan *chan,
+		 const struct dw_edma_ll_snapshot *snapshot),
+	TP_ARGS(chan, snapshot),
+	TP_STRUCT__entry(
+		__field(u32, head)
+		__field(u32, done)
+		__field(u32, total)
+		__field(int, index)
+		__field(int, event)
+		__field(dma_cookie_t, completed_cookie)
+		__field(dma_cookie_t, cookie)
+		__field(u32, id)
+		__field(u8, dir)
+	),
+	TP_fast_assign(
+		__entry->head = chan->ll_head;
+		__entry->done = chan->ll_done;
+		__entry->total = chan->ll_max;
+		__entry->index = snapshot->idx;
+		__entry->event = snapshot->event;
+		__entry->completed_cookie = chan->vc.chan.completed_cookie;
+		__entry->cookie = chan->vc.chan.cookie;
+		__entry->id = chan->id;
+		__entry->dir = chan->dir;
+	),
+	TP_printk("chan %u%c event %s head %u done %u total %u idx %d completed %d cookie %d",
+		  __entry->id,
+		  __entry->dir ? 'R' : 'W',
+		  __entry->event == DW_EDMA_LL_EVENT_STOP ? "stop" : "progress",
+		  __entry->head,
+		  __entry->done,
+		  __entry->total,
+		  __entry->index,
+		  __entry->completed_cookie,
+		  __entry->cookie)
+);
+
+TRACE_EVENT(edma_engine_recovery,
+	TP_PROTO(struct dw_edma_chan *chan, enum dma_status hw_status,
+		 enum dw_edma_request request, enum dw_edma_status status,
+		 u32 ll_head, u32 ll_done, u32 pending),
+	TP_ARGS(chan, hw_status, request, status, ll_head, ll_done, pending),
+	TP_STRUCT__entry(
+		__field(u32, id)
+		__field(u32, head)
+		__field(u32, done)
+		__field(u32, pending)
+		__field(int, hw_status)
+		__field(int, request)
+		__field(int, status)
+		__field(u8, dir)
+	),
+	TP_fast_assign(
+		__entry->id = chan->id;
+		__entry->dir = chan->dir;
+		__entry->hw_status = hw_status;
+		__entry->request = request;
+		__entry->status = status;
+		__entry->head = ll_head;
+		__entry->done = ll_done;
+		__entry->pending = pending;
+	),
+	TP_printk("chan %u%c hw %d request %d status %d head %u done %u pending %u",
+		__entry->id,
+		__entry->dir ? 'R' : 'W',
+		__entry->hw_status,
+		__entry->request,
+		__entry->status,
+		__entry->head,
+		__entry->done,
+		__entry->pending)
+);
+
+TRACE_EVENT(edma_fill_ll,
+	TP_PROTO(struct dw_edma_chan *chan, u32 idx, dma_cookie_t cookie, u64 src,
+		 u64 dest, u32 sz, bool flag),
+	TP_ARGS(chan, idx, cookie, src, dest, sz, flag),
+	TP_STRUCT__entry(
+		__field(u32, idx)
+		__field(u64, src)
+		__field(u64, dest)
+		__field(u32, sz)
+		__field(u32, id)
+		__field(dma_cookie_t, cookie)
+		__field(bool, flag)
+		__field(u8, dir)
+	),
+	TP_fast_assign(
+		__entry->idx = idx;
+		__entry->src = src;
+		__entry->dest = dest;
+		__entry->sz = sz;
+		__entry->id = chan->id;
+		__entry->dir = chan->dir;
+		__entry->cookie = cookie;
+		__entry->flag = flag;
+	),
+	TP_printk("chan %u%c %d [%u] %c src: %08llx dest: %08llx sz: %04x",
+		__entry->id,
+		__entry->dir ? 'R' : 'W',
+		__entry->cookie,
+		__entry->idx,
+		__entry->flag ? 'C' : 'c',
+		__entry->src,
+		__entry->dest,
+		__entry->sz)
+);
+
+#endif
+
+/* This part must be outside the header guard. */
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_FILE dw-edma-trace
+
+#include <trace/define_trace.h>
-- 
2.51.0