Add trace points to the Surface Aggregator subsystem core. These trace
points can be used to track packets, requests, and allocations. They are
further intended for debugging and testing/validation, specifically in
combination with the error injection capabilities introduced in the
subsequent commit.
Signed-off-by: Maximilian Luz
Reviewed-by: Hans de Goede
---
Changes in v1 (from RFC):
- add copyright line
- change SPDX identifier to GPL-2.0+ (was GPL-2.0-or-later)
- pack tracing structs
Changes in v2:
- add compiletime check on SSAM_PTR_UID_LEN
- fix ssam_trace_get_command_field_u8() macro
- use dedicated trace event class for timeout reaper
- use printk specifier for hex prefix instead of hard-coding it
- unify comment style
- run checkpatch --strict, fix warnings and style issues
---
drivers/platform/surface/aggregator/Makefile | 3 +
.../platform/surface/aggregator/controller.c | 5 +
drivers/platform/surface/aggregator/core.c| 3 +
.../surface/aggregator/ssh_packet_layer.c | 26 +-
.../surface/aggregator/ssh_request_layer.c| 18 +
drivers/platform/surface/aggregator/trace.h | 601 ++
6 files changed, 655 insertions(+), 1 deletion(-)
create mode 100644 drivers/platform/surface/aggregator/trace.h
diff --git a/drivers/platform/surface/aggregator/Makefile
b/drivers/platform/surface/aggregator/Makefile
index faad18d4a7f2..b8b24c8ec310 100644
--- a/drivers/platform/surface/aggregator/Makefile
+++ b/drivers/platform/surface/aggregator/Makefile
@@ -1,6 +1,9 @@
# SPDX-License-Identifier: GPL-2.0+
# Copyright (C) 2019-2020 Maximilian Luz
+# For include/trace/define_trace.h to include trace.h
+CFLAGS_core.o = -I$(src)
+
obj-$(CONFIG_SURFACE_AGGREGATOR) += surface_aggregator.o
surface_aggregator-objs := core.o
diff --git a/drivers/platform/surface/aggregator/controller.c
b/drivers/platform/surface/aggregator/controller.c
index 775a4509bece..5bcb59ed579d 100644
--- a/drivers/platform/surface/aggregator/controller.c
+++ b/drivers/platform/surface/aggregator/controller.c
@@ -32,6 +32,8 @@
#include "ssh_msgb.h"
#include "ssh_request_layer.h"
+#include "trace.h"
+
/* -- Safe counters.
*/
@@ -568,6 +570,7 @@ static void __ssam_event_item_free_generic(struct
ssam_event_item *item)
*/
static void ssam_event_item_free(struct ssam_event_item *item)
{
+ trace_ssam_event_item_free(item);
item->ops.free(item);
}
@@ -603,6 +606,8 @@ static struct ssam_event_item *ssam_event_item_alloc(size_t
len, gfp_t flags)
}
item->event.length = len;
+
+ trace_ssam_event_item_alloc(item, len);
return item;
}
diff --git a/drivers/platform/surface/aggregator/core.c
b/drivers/platform/surface/aggregator/core.c
index 37593234fb31..b6a9dea53592 100644
--- a/drivers/platform/surface/aggregator/core.c
+++ b/drivers/platform/surface/aggregator/core.c
@@ -24,6 +24,9 @@
#include
#include "controller.h"
+#define CREATE_TRACE_POINTS
+#include "trace.h"
+
/* -- Static controller reference. --
*/
diff --git a/drivers/platform/surface/aggregator/ssh_packet_layer.c
b/drivers/platform/surface/aggregator/ssh_packet_layer.c
index 23c2e31e7d0e..c4f082e57372 100644
--- a/drivers/platform/surface/aggregator/ssh_packet_layer.c
+++ b/drivers/platform/surface/aggregator/ssh_packet_layer.c
@@ -26,6 +26,8 @@
#include "ssh_packet_layer.h"
#include "ssh_parser.h"
+#include "trace.h"
+
/*
* To simplify reasoning about the code below, we define a few concepts. The
* system below is similar to a state-machine for packets, however, there are
@@ -228,6 +230,8 @@ static void __ssh_ptl_packet_release(struct kref *kref)
{
struct ssh_packet *p = container_of(kref, struct ssh_packet, refcnt);
+ trace_ssam_packet_release(p);
+
ptl_dbg_cond(p->ptl, "ptl: releasing packet %p\n", p);
p->ops->release(p);
}
@@ -356,6 +360,7 @@ static int ssh_ctrl_packet_alloc(struct ssh_packet **packet,
buffer->ptr = (u8 *)(*packet + 1);
buffer->len = SSH_MSG_LEN_CTRL;
+ trace_ssam_ctrl_packet_alloc(*packet, buffer->len);
return 0;
}
@@ -365,6 +370,7 @@ static int ssh_ctrl_packet_alloc(struct ssh_packet **packet,
*/
static void ssh_ctrl_packet_free(struct ssh_packet *p)
{
+ trace_ssam_ctrl_packet_free(p);
kmem_cache_free(ssh_ctrl_packet_cache, p);
}
@@ -398,7 +404,12 @@ static void ssh_packet_next_try(struct ssh_packet *p)
lockdep_assert_held(>ptl->queue.lock);
- p->priority = __SSH_PACKET_PRIORITY(base, try + 1);
+ /*
+* Ensure that we write the priority in one go via WRITE_ONCE() so we
+* can access it via READ_ONCE() for tracing. Note that other access
+* is guarded by the queue lock, so no need to use READ_ONCE() there.
+*/
+ WRITE_ONCE(p->priority, __SSH_PACKET_PRIORITY(base, try + 1));
}
/*
