Commit a778028c authored by Mary Guillemard's avatar Mary Guillemard Committed by Boris Brezillon
Browse files

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

v3:
- Add panthor_gpu_read_64bit_counter
- Change panthor_gpu_read_timestamp to use
  panthor_gpu_read_64bit_counter

v4:
- Fix multiple typos in uAPI documentation
- Mention behavior when the timestamp frequency is unknown
- Use u64 instead of unsigned long long
  for panthor_gpu_read_timestamp
- Apply r-b from Mihail

Signed-off-by: default avatarMary Guillemard <mary.guillemard@collabora.com>
Reviewed-by: default avatarMihail Atanassov <mihail.atanassov@arm.com>
Reviewed-by: default avatarBoris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: default avatarBoris Brezillon <boris.brezillon@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240830080349.24736-2-mary.guillemard@collabora.com
parent c6430a8e

drivers/gpu/drm/panthor/panthor_drv.c

+42 −1
Original line number Diff line number Diff line
@@ -3,6 +3,10 @@ 
/* Copyright 2019 Linaro, Ltd., Rob Herring <robh@kernel.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_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, &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,

drivers/gpu/drm/panthor/panthor_gpu.c

+47 −0
Original line number Diff line number Diff line
@@ -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 u64

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 timestamp register.

 * @ptdev: Device.

 *

 * Return: The GPU timestamp value.

 */

u64 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 timestamp offset register.

 * @ptdev: Device.

 *

 * Return: The GPU timestamp offset value.

 */

u64 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;

}

drivers/gpu/drm/panthor/panthor_gpu.h

+4 −0
Original line number Diff line number Diff line
@@ -5,6 +5,8 @@ 
#ifndef __PANTHOR_GPU_H__

#define __PANTHOR_GPU_H__



#include <linux/types.h>



struct panthor_device;



int panthor_gpu_init(struct panthor_device *ptdev);
@@ -48,5 +50,7 @@ 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);

u64 panthor_gpu_read_timestamp(struct panthor_device *ptdev);

u64 panthor_gpu_read_timestamp_offset(struct panthor_device *ptdev);



#endif

include/uapi/drm/panthor_drm.h

+22 −0
Original line number Diff line number Diff line
@@ -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 +380,25 @@ 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 or 0 if

	 * unknown.

	 */

	__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

 */