Message-ID: <20240812122814.177544-2-mary.guillemard@collabora.com>
Date: Mon, 12 Aug 2024 14:28:15 +0200
From: Mary Guillemard <mary.guillemard@...labora.com>
To: linux-kernel@...r.kernel.org
Cc: dri-devel@...ts.freedesktop.org,
	kernel@...labora.com,
	Christopher Healy <healych@...zon.com>,
	Mary Guillemard <mary.guillemard@...labora.com>,
	Boris Brezillon <boris.brezillon@...labora.com>,
	Steven Price <steven.price@....com>,
	Liviu Dudau <liviu.dudau@....com>,
	Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
	Maxime Ripard <mripard@...nel.org>,
	Thomas Zimmermann <tzimmermann@...e.de>,
	David Airlie <airlied@...il.com>,
	Daniel Vetter <daniel@...ll.ch>
Subject: [PATCH v2] drm/panthor: Add DEV_QUERY_TIMESTAMP_INFO dev query

Expose timestamp information supported by the GPU with a new device
query.

Mali uses an external timer as GPU system time. On ARM, this is wired to
the generic arch timer so we wire cntfrq_el0 as device frequency.

This new uAPI will be used in Mesa to implement timestamp queries and
VK_KHR_calibrated_timestamps.

Since this extends the uAPI and because userland needs a way to advertise
those features conditionally, this also bumps the driver minor version.

v2:
- Rewrote to use GPU timestamp register
- Added timestamp_offset to drm_panthor_timestamp_info
- Add missing include for arch_timer_get_cntfrq
- Rework commit message

Signed-off-by: Mary Guillemard <mary.guillemard@...labora.com>
---
 drivers/gpu/drm/panthor/panthor_drv.c | 43 ++++++++++++++++++++++++++-
 drivers/gpu/drm/panthor/panthor_gpu.c | 32 ++++++++++++++++++++
 drivers/gpu/drm/panthor/panthor_gpu.h |  2 ++
 include/uapi/drm/panthor_drm.h        | 19 ++++++++++++
 4 files changed, 95 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/panthor/panthor_drv.c b/drivers/gpu/drm/panthor/panthor_drv.c
index b8a84f26b3ef..7589f2373ec0 100644
--- a/drivers/gpu/drm/panthor/panthor_drv.c
+++ b/drivers/gpu/drm/panthor/panthor_drv.c
@@ -3,6 +3,10 @@
 /* Copyright 2019 Linaro, Ltd., Rob Herring <robh@...nel.org> */
 /* Copyright 2019 Collabora ltd. */
 
+#ifdef CONFIG_ARM_ARCH_TIMER
+#include <asm/arch_timer.h>
+#endif
+
 #include <linux/list.h>
 #include <linux/module.h>
 #include <linux/of_platform.h>
@@ -164,6 +168,7 @@ panthor_get_uobj_array(const struct drm_panthor_obj_array *in, u32 min_stride,
 	_Generic(_obj_name, \
 		 PANTHOR_UOBJ_DECL(struct drm_panthor_gpu_info, tiler_present), \
 		 PANTHOR_UOBJ_DECL(struct drm_panthor_csif_info, pad), \
+		 PANTHOR_UOBJ_DECL(struct drm_panthor_timestamp_info, current_timestamp), \
 		 PANTHOR_UOBJ_DECL(struct drm_panthor_sync_op, timeline_value), \
 		 PANTHOR_UOBJ_DECL(struct drm_panthor_queue_submit, syncs), \
 		 PANTHOR_UOBJ_DECL(struct drm_panthor_queue_create, ringbuf_size), \
@@ -750,10 +755,33 @@ static void panthor_submit_ctx_cleanup(struct panthor_submit_ctx *ctx,
 	kvfree(ctx->jobs);
 }
 
+static int panthor_ioctl_query_timestamp(struct panthor_device *ptdev,
+					 struct drm_panthor_timestamp_info *arg)
+{
+	int ret;
+
+	ret = pm_runtime_resume_and_get(ptdev->base.dev);
+	if (ret)
+		return ret;
+
+#ifdef CONFIG_ARM_ARCH_TIMER
+	arg->timestamp_frequency = arch_timer_get_cntfrq();
+#else
+	arg->timestamp_frequency = 0;
+#endif
+	arg->current_timestamp = panthor_gpu_read_timestamp(ptdev);
+	arg->timestamp_offset = panthor_gpu_read_timestamp_offset(ptdev);
+
+	pm_runtime_put(ptdev->base.dev);
+	return 0;
+}
+
 static int panthor_ioctl_dev_query(struct drm_device *ddev, void *data, struct drm_file *file)
 {
 	struct panthor_device *ptdev = container_of(ddev, struct panthor_device, base);
 	struct drm_panthor_dev_query *args = data;
+	struct drm_panthor_timestamp_info timestamp_info;
+	int ret;
 
 	if (!args->pointer) {
 		switch (args->type) {
@@ -765,6 +793,10 @@ static int panthor_ioctl_dev_query(struct drm_device *ddev, void *data, struct d
 			args->size = sizeof(ptdev->csif_info);
 			return 0;
 
+		case DRM_PANTHOR_DEV_QUERY_TIMESTAMP_INFO:
+			args->size = sizeof(timestamp_info);
+			return 0;
+
 		default:
 			return -EINVAL;
 		}
@@ -777,6 +809,14 @@ static int panthor_ioctl_dev_query(struct drm_device *ddev, void *data, struct d
 	case DRM_PANTHOR_DEV_QUERY_CSIF_INFO:
 		return PANTHOR_UOBJ_SET(args->pointer, args->size, ptdev->csif_info);
 
+	case DRM_PANTHOR_DEV_QUERY_TIMESTAMP_INFO:
+		ret = panthor_ioctl_query_timestamp(ptdev, &timestamp_info);
+
+		if (ret)
+			return ret;
+
+		return PANTHOR_UOBJ_SET(args->pointer, args->size, timestamp_info);
+
 	default:
 		return -EINVAL;
 	}
@@ -1372,6 +1412,7 @@ static void panthor_debugfs_init(struct drm_minor *minor)
 /*
  * PanCSF driver version:
  * - 1.0 - initial interface
+ * - 1.1 - adds DEV_QUERY_TIMESTAMP_INFO query
  */
 static const struct drm_driver panthor_drm_driver = {
 	.driver_features = DRIVER_RENDER | DRIVER_GEM | DRIVER_SYNCOBJ |
@@ -1385,7 +1426,7 @@ static const struct drm_driver panthor_drm_driver = {
 	.desc = "Panthor DRM driver",
 	.date = "20230801",
 	.major = 1,
-	.minor = 0,
+	.minor = 1,
 
 	.gem_create_object = panthor_gem_create_object,
 	.gem_prime_import_sg_table = drm_gem_shmem_prime_import_sg_table,
diff --git a/drivers/gpu/drm/panthor/panthor_gpu.c b/drivers/gpu/drm/panthor/panthor_gpu.c
index 5251d8764e7d..2ffd9fa34486 100644
--- a/drivers/gpu/drm/panthor/panthor_gpu.c
+++ b/drivers/gpu/drm/panthor/panthor_gpu.c
@@ -480,3 +480,35 @@ void panthor_gpu_resume(struct panthor_device *ptdev)
 	panthor_gpu_irq_resume(&ptdev->gpu->irq, GPU_INTERRUPTS_MASK);
 	panthor_gpu_l2_power_on(ptdev);
 }
+
+/**
+ * panthor_gpu_read_timestamp() - Read the timstamp register.
+ * @ptdev: Device.
+ *
+ * Return: The GPU timestamp value.
+ */
+unsigned long long panthor_gpu_read_timestamp(struct panthor_device *ptdev)
+{
+	u32 hi, lo;
+
+	hi = gpu_read(ptdev, GPU_TIMESTAMP_HI);
+	lo = gpu_read(ptdev, GPU_TIMESTAMP_LO);
+
+	return ((u64)hi << 32) | lo;
+}
+
+/**
+ * panthor_gpu_read_timestamp_offset() - Read the timstamp offset register.
+ * @ptdev: Device.
+ *
+ * Return: The GPU timestamp offset value.
+ */
+unsigned long long panthor_gpu_read_timestamp_offset(struct panthor_device *ptdev)
+{
+	u32 hi, lo;
+
+	hi = gpu_read(ptdev, GPU_TIMESTAMP_OFFSET_HI);
+	lo = gpu_read(ptdev, GPU_TIMESTAMP_OFFSET_LO);
+
+	return ((u64)hi << 32) | lo;
+}
diff --git a/drivers/gpu/drm/panthor/panthor_gpu.h b/drivers/gpu/drm/panthor/panthor_gpu.h
index bba7555dd3c6..73d335859db8 100644
--- a/drivers/gpu/drm/panthor/panthor_gpu.h
+++ b/drivers/gpu/drm/panthor/panthor_gpu.h
@@ -48,5 +48,7 @@ int panthor_gpu_l2_power_on(struct panthor_device *ptdev);
 int panthor_gpu_flush_caches(struct panthor_device *ptdev,
 			     u32 l2, u32 lsc, u32 other);
 int panthor_gpu_soft_reset(struct panthor_device *ptdev);
+unsigned long long panthor_gpu_read_timestamp(struct panthor_device *ptdev);
+unsigned long long panthor_gpu_read_timestamp_offset(struct panthor_device *ptdev);
 
 #endif
diff --git a/include/uapi/drm/panthor_drm.h b/include/uapi/drm/panthor_drm.h
index aaed8e12ad0b..d4899d9bd507 100644
--- a/include/uapi/drm/panthor_drm.h
+++ b/include/uapi/drm/panthor_drm.h
@@ -260,6 +260,9 @@ enum drm_panthor_dev_query_type {
 
 	/** @DRM_PANTHOR_DEV_QUERY_CSIF_INFO: Query command-stream interface information. */
 	DRM_PANTHOR_DEV_QUERY_CSIF_INFO,
+
+	/** @DRM_PANTHOR_DEV_QUERY_TIMESTAMP_INFO: Query timestamp information. */
+	DRM_PANTHOR_DEV_QUERY_TIMESTAMP_INFO,
 };
 
 /**
@@ -377,6 +380,22 @@ struct drm_panthor_csif_info {
 	__u32 pad;
 };
 
+/**
+ * struct drm_panthor_timestamp_info - Timestamp information
+ *
+ * Structure grouping all queryable information relating to the GPU timestamp.
+ */
+struct drm_panthor_timestamp_info {
+	/** @timestamp_frequency: The frequency of the timestamp timer. */
+	__u64 timestamp_frequency;
+
+	/** @current_timestamp: The current timestamp. */
+	__u64 current_timestamp;
+
+	/** @timestamp_offset: The offset of the timestamp timer. */
+	__u64 timestamp_offset;
+};
+
 /**
  * struct drm_panthor_dev_query - Arguments passed to DRM_PANTHOR_IOCTL_DEV_QUERY
  */

base-commit: 219b45d023ed0902b05c5902a4f31c2c38bcf68c
-- 
2.45.2

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