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
v3:
- Add panthor_gpu_read_64bit_counter
- Change panthor_gpu_read_timestamp to use
panthor_gpu_read_64bit_counter
Signed-off-by: Mary Guillemard <mary.guillemard@xxxxxxxxxxxxx>
---
drivers/gpu/drm/panthor/panthor_drv.c | 43 +++++++++++++++++++++++-
drivers/gpu/drm/panthor/panthor_gpu.c | 47 +++++++++++++++++++++++++++
drivers/gpu/drm/panthor/panthor_gpu.h | 2 ++
include/uapi/drm/panthor_drm.h | 19 +++++++++++
4 files changed, 110 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/panthor/panthor_drv.c b/drivers/gpu/drm/panthor/panthor_drv.c
index b5e7b919f241..444e3bb1cfb5 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@xxxxxxxxxx> */
/* 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_query_timestamp_info(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_query_timestamp_info(ptdev, ×tamp_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..ef66cfea6f1f 100644
--- a/drivers/gpu/drm/panthor/panthor_gpu.c
+++ b/drivers/gpu/drm/panthor/panthor_gpu.c
@@ -480,3 +480,50 @@ 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_64bit_counter() - Read a 64-bit counter at a given offset.
+ * @ptdev: Device.
+ * @reg: The offset of the register to read.
+ *
+ * Return: The counter value.
+ */
+static unsigned long long
+panthor_gpu_read_64bit_counter(struct panthor_device *ptdev, u32 reg)
+{
+ u32 hi, lo;
+
+ do {
+ hi = gpu_read(ptdev, reg + 0x4);
+ lo = gpu_read(ptdev, reg);
+ } while (hi != gpu_read(ptdev, reg + 0x4));
+
+ return ((u64)hi << 32) | lo;
+}
+
+/**
+ * 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)
+{
+ return panthor_gpu_read_64bit_counter(ptdev, GPU_TIMESTAMP_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 926b1deb1116..944f5618aa05 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: 3e828c670b0ac8a9564c69f5c5ecf637b22a58d6
--
2.46.0
