mali_kbase: platform: Add PM event log to SSCD

Add a PM event log recording state transitions.  This log can be read in
ramdumps, and is also included in SSCDs.

Bug: 221885391
Test: Trigger SSCD, check core dump sections
Signed-off-by: Sean Callanan <spyffe@google.com>
Change-Id: I79151064e1b5075bc07caa261eff0fbc6e8778ec

1 files changed, 108 insertions, 0 deletions

diff --git a/mali_kbase/backend/gpu/mali_kbase_pm_event_log.c b/mali_kbase/backend/gpu/mali_kbase_pm_event_log.c
new file mode 100644
index 0000000..b752af8
--- /dev/null
+++ b/mali_kbase/backend/gpu/mali_kbase_pm_event_log.c
@@ -0,0 +1,108 @@
+// SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note
+/*
+ *
+ * (C) COPYRIGHT 2022 Google LLC. All rights reserved.
+ *
+ * This program is free software and is provided to you under the terms of the
+ * GNU General Public License version 2 as published by the Free Software
+ * Foundation, and any use by you of this program is subject to the terms
+ * of such GNU license.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, you can access it online at
+ * http://www.gnu.org/licenses/gpl-2.0.html.
+ *
+ */
+
+#include <backend/gpu/mali_kbase_pm_event_log.h>
+
+static inline u32 kbase_pm_next_log_event(
+	struct kbase_pm_event_log *log)
+{
+	u32 ret = log->last_event;
+	++ret;
+	ret %= EVENT_LOG_MAX;
+	log->last_event = ret;
+	return ret;
+}
+
+struct kbase_pm_event_log_event *kbase_pm_add_log_event(
+	struct kbase_device *kbdev)
+{
+	struct kbase_pm_event_log *log = &kbdev->pm.backend.event_log;
+	struct kbase_pm_event_log_event *ret = NULL;
+
+	lockdep_assert_held(&kbdev->hwaccess_lock);
+	ret = &log->events[kbase_pm_next_log_event(log)];
+
+	memset(ret, 0, sizeof(*ret));
+	ret->timestamp = ktime_get();
+	return ret;
+}
+
+/**
+ * struct kbase_pm_event_log_metadata - Info about the event log.
+ *
+ * @magic: always 'kpel', helps find the log in memory dumps
+ * @version: updated whenever the binary layout changes
+ * @events_address: the memory address of the log, or in a file the offset
+ *                  from the start of the metadata to the log
+ * @num_events: the capacity of the event log
+ * @event_stride: distance between log entries, to aid in parsing if only some
+ *                entry types are supported by the parser
+ **/
+struct kbase_pm_event_log_metadata {
+	char magic[4];
+	u8 version;
+	u64 events_address;
+	u32 num_events;
+	u32 event_stride;
+} __attribute__((packed));
+
+static struct kbase_pm_event_log_metadata global_event_log_metadata;
+
+void kbase_pm_init_event_log(struct kbase_device *kbdev)
+{
+	struct kbase_pm_event_log_metadata *md =
+			&global_event_log_metadata;
+	kbdev->pm.backend.event_log.last_event = -1;
+	md->magic[0] = 'k';
+	md->magic[1] = 'p';
+	md->magic[2] = 'e';
+	md->magic[3] = 'l';
+	md->version = 1;
+	md->num_events = EVENT_LOG_MAX;
+	md->events_address = (u64)kbdev->pm.backend.event_log.events;
+	md->event_stride = ((u8*)&kbdev->pm.backend.event_log.events[1] -
+			    (u8*)&kbdev->pm.backend.event_log.events[0]);
+}
+
+u64 kbase_pm_max_event_log_size(struct kbase_device *kbdev)
+{
+	return sizeof(struct kbase_pm_event_log_metadata)
+			+ sizeof(kbdev->pm.backend.event_log.events);
+}
+
+int kbase_pm_copy_event_log(struct kbase_device *kbdev,
+		void *buffer, u64 size)
+{
+	lockdep_assert_held(&kbdev->hwaccess_lock);
+	if (size < kbase_pm_max_event_log_size(kbdev)) {
+		return -EINVAL;
+	}
+	memcpy(buffer, &global_event_log_metadata,
+	       sizeof(global_event_log_metadata));
+	memcpy(((u8*)buffer) + sizeof(global_event_log_metadata),
+	       &kbdev->pm.backend.event_log.events,
+	       sizeof(kbdev->pm.backend.event_log.events));
+	((struct kbase_pm_event_log_metadata*)buffer)->events_address =
+			sizeof(struct kbase_pm_event_log_metadata);
+
+	return 0;
+}
+