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[PATCH v4 3/7] drm/panthor: Add panthor perf initialization and termination

Lukas Zapolskas posted 7 patches 7 months, 1 week ago
There is a newer version of this series
[PATCH v4 3/7] drm/panthor: Add panthor perf initialization and termination
Posted by Lukas Zapolskas 7 months, 1 week ago 
Added the panthor_perf system initialization and unplug code to allow
for the handling of userspace sessions to be added in follow-up
patches.

Signed-off-by: Lukas Zapolskas <lukas.zapolskas@arm.com>
---
 drivers/gpu/drm/panthor/panthor_device.c |  2 +
 drivers/gpu/drm/panthor/panthor_device.h |  5 +-
 drivers/gpu/drm/panthor/panthor_perf.c   | 62 +++++++++++++++++++++++-
 drivers/gpu/drm/panthor/panthor_perf.h   |  1 +
 4 files changed, 68 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/panthor/panthor_device.c b/drivers/gpu/drm/panthor/panthor_device.c
index 76b4cf3dc391..7ac985d44655 100644
--- a/drivers/gpu/drm/panthor/panthor_device.c
+++ b/drivers/gpu/drm/panthor/panthor_device.c
@@ -98,6 +98,7 @@ void panthor_device_unplug(struct panthor_device *ptdev)
 	/* Now, try to cleanly shutdown the GPU before the device resources
 	 * get reclaimed.
 	 */
+	panthor_perf_unplug(ptdev);
 	panthor_sched_unplug(ptdev);
 	panthor_fw_unplug(ptdev);
 	panthor_mmu_unplug(ptdev);
@@ -277,6 +278,7 @@ int panthor_device_init(struct panthor_device *ptdev)

 err_disable_autosuspend:
 	pm_runtime_dont_use_autosuspend(ptdev->base.dev);
+	panthor_perf_unplug(ptdev);
 	panthor_sched_unplug(ptdev);

 err_unplug_fw:
diff --git a/drivers/gpu/drm/panthor/panthor_device.h b/drivers/gpu/drm/panthor/panthor_device.h
index 657ccc39568c..818c4d96d448 100644
--- a/drivers/gpu/drm/panthor/panthor_device.h
+++ b/drivers/gpu/drm/panthor/panthor_device.h
@@ -27,7 +27,7 @@ struct panthor_heap_pool;
 struct panthor_job;
 struct panthor_mmu;
 struct panthor_fw;
-struct panthor_perfcnt;
+struct panthor_perf;
 struct panthor_vm;
 struct panthor_vm_pool;

@@ -138,6 +138,9 @@ struct panthor_device {
 	/** @devfreq: Device frequency scaling management data. */
 	struct panthor_devfreq *devfreq;

+	/** @perf: Performance counter management data. */
+	struct panthor_perf *perf;
+
 	/** @unplug: Device unplug related fields. */
 	struct {
 		/** @lock: Lock used to serialize unplug operations. */
diff --git a/drivers/gpu/drm/panthor/panthor_perf.c b/drivers/gpu/drm/panthor/panthor_perf.c
index 66e9a197ac1f..9365ce9fed04 100644
--- a/drivers/gpu/drm/panthor/panthor_perf.c
+++ b/drivers/gpu/drm/panthor/panthor_perf.c
@@ -9,6 +9,19 @@
 #include "panthor_fw.h"
 #include "panthor_perf.h"

+struct panthor_perf {
+	/** @next_session: The ID of the next session. */
+	u32 next_session;
+
+	/** @session_range: The number of sessions supported at a time. */
+	struct xa_limit session_range;
+
+	/**
+	 * @sessions: Global map of sessions, accessed by their ID.
+	 */
+	struct xarray sessions;
+};
+
 struct panthor_perf_counter_block {
 	struct drm_panthor_perf_block_header header;
 	u64 counters[];
@@ -63,14 +76,61 @@ static void panthor_perf_info_init(struct panthor_device *ptdev)
  * panthor_perf_init - Initialize the performance counter subsystem.
  * @ptdev: Panthor device
  *
+ * The performance counters require the FW interface to be available to setup the
+ * sampling ringbuffers, so this must be called only after FW is initialized.
+ *
  * Return: 0 on success, negative error code on failure.
  */
 int panthor_perf_init(struct panthor_device *ptdev)
 {
+	struct panthor_perf *perf __free(kfree) = NULL;
+	int ret = 0;
+
 	if (!ptdev)
 		return -EINVAL;

 	panthor_perf_info_init(ptdev);

-	return 0;
+	perf = kzalloc(sizeof(*perf), GFP_KERNEL);
+	if (ZERO_OR_NULL_PTR(perf))
+		return -ENOMEM;
+
+	xa_init_flags(&perf->sessions, XA_FLAGS_ALLOC);
+
+	perf->session_range = (struct xa_limit) {
+		.min = 0,
+		.max = 1,
+	};
+
+	drm_info(&ptdev->base, "Performance counter subsystem initialized");
+
+	ptdev->perf = no_free_ptr(perf);
+
+	return ret;
+}
+
+/**
+ * panthor_perf_unplug - Terminate the performance counter subsystem.
+ * @ptdev: Panthor device.
+ *
+ * This function will terminate the performance counter control structures and any remaining
+ * sessions, after waiting for any pending interrupts.
+ */
+void panthor_perf_unplug(struct panthor_device *ptdev)
+{
+	struct panthor_perf *perf = ptdev->perf;
+
+	if (!perf)
+		return;
+
+	if (!xa_empty(&perf->sessions)) {
+		drm_err(&ptdev->base,
+			"Performance counter sessions active when unplugging the driver!");
+	}
+
+	xa_destroy(&perf->sessions);
+
+	kfree(ptdev->perf);
+
+	ptdev->perf = NULL;
 }
diff --git a/drivers/gpu/drm/panthor/panthor_perf.h b/drivers/gpu/drm/panthor/panthor_perf.h
index 3c32c24c164c..e4805727b9e7 100644
--- a/drivers/gpu/drm/panthor/panthor_perf.h
+++ b/drivers/gpu/drm/panthor/panthor_perf.h
@@ -10,6 +10,7 @@
 struct panthor_device;

 int panthor_perf_init(struct panthor_device *ptdev);
+void panthor_perf_unplug(struct panthor_device *ptdev);

 #endif /* __PANTHOR_PERF_H__ */

--
2.33.0.dirty
Re: [PATCH v4 3/7] drm/panthor: Add panthor perf initialization and termination
Posted by Adrián Larumbe 5 months ago 
On 16.05.2025 16:49, Lukas Zapolskas wrote:
> Added the panthor_perf system initialization and unplug code to allow
> for the handling of userspace sessions to be added in follow-up
> patches.
>
> Signed-off-by: Lukas Zapolskas <lukas.zapolskas@arm.com>
> ---
>  drivers/gpu/drm/panthor/panthor_device.c |  2 +
>  drivers/gpu/drm/panthor/panthor_device.h |  5 +-
>  drivers/gpu/drm/panthor/panthor_perf.c   | 62 +++++++++++++++++++++++-
>  drivers/gpu/drm/panthor/panthor_perf.h   |  1 +
>  4 files changed, 68 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/panthor/panthor_device.c b/drivers/gpu/drm/panthor/panthor_device.c
> index 76b4cf3dc391..7ac985d44655 100644
> --- a/drivers/gpu/drm/panthor/panthor_device.c
> +++ b/drivers/gpu/drm/panthor/panthor_device.c
> @@ -98,6 +98,7 @@ void panthor_device_unplug(struct panthor_device *ptdev)
>  	/* Now, try to cleanly shutdown the GPU before the device resources
>  	 * get reclaimed.
>  	 */
> +	panthor_perf_unplug(ptdev);
>  	panthor_sched_unplug(ptdev);
>  	panthor_fw_unplug(ptdev);
>  	panthor_mmu_unplug(ptdev);
> @@ -277,6 +278,7 @@ int panthor_device_init(struct panthor_device *ptdev)
>
>  err_disable_autosuspend:
>  	pm_runtime_dont_use_autosuspend(ptdev->base.dev);
> +	panthor_perf_unplug(ptdev);
>  	panthor_sched_unplug(ptdev);
>
>  err_unplug_fw:
> diff --git a/drivers/gpu/drm/panthor/panthor_device.h b/drivers/gpu/drm/panthor/panthor_device.h
> index 657ccc39568c..818c4d96d448 100644
> --- a/drivers/gpu/drm/panthor/panthor_device.h
> +++ b/drivers/gpu/drm/panthor/panthor_device.h
> @@ -27,7 +27,7 @@ struct panthor_heap_pool;
>  struct panthor_job;
>  struct panthor_mmu;
>  struct panthor_fw;
> -struct panthor_perfcnt;
> +struct panthor_perf;
>  struct panthor_vm;
>  struct panthor_vm_pool;
>
> @@ -138,6 +138,9 @@ struct panthor_device {
>  	/** @devfreq: Device frequency scaling management data. */
>  	struct panthor_devfreq *devfreq;
>
> +	/** @perf: Performance counter management data. */
> +	struct panthor_perf *perf;
> +
>  	/** @unplug: Device unplug related fields. */
>  	struct {
>  		/** @lock: Lock used to serialize unplug operations. */
> diff --git a/drivers/gpu/drm/panthor/panthor_perf.c b/drivers/gpu/drm/panthor/panthor_perf.c
> index 66e9a197ac1f..9365ce9fed04 100644
> --- a/drivers/gpu/drm/panthor/panthor_perf.c
> +++ b/drivers/gpu/drm/panthor/panthor_perf.c
> @@ -9,6 +9,19 @@
>  #include "panthor_fw.h"
>  #include "panthor_perf.h"

You must include "panthor_regs.h" here or else GPU_MEM_FEATURES_L2_SLICES() won't be available.
However, it seems this is something that should be done in the previous patch.

>
> +struct panthor_perf {
> +	/** @next_session: The ID of the next session. */
> +	u32 next_session;
> +
> +	/** @session_range: The number of sessions supported at a time. */
> +	struct xa_limit session_range;
> +
> +	/**
> +	 * @sessions: Global map of sessions, accessed by their ID.
> +	 */
> +	struct xarray sessions;
> +};
> +
>  struct panthor_perf_counter_block {
>  	struct drm_panthor_perf_block_header header;
>  	u64 counters[];
> @@ -63,14 +76,61 @@ static void panthor_perf_info_init(struct panthor_device *ptdev)
>   * panthor_perf_init - Initialize the performance counter subsystem.
>   * @ptdev: Panthor device
>   *
> + * The performance counters require the FW interface to be available to setup the
> + * sampling ringbuffers, so this must be called only after FW is initialized.
> + *
>   * Return: 0 on success, negative error code on failure.
>   */
>  int panthor_perf_init(struct panthor_device *ptdev)
>  {
> +	struct panthor_perf *perf __free(kfree) = NULL;
> +	int ret = 0;
> +
>  	if (!ptdev)
>  		return -EINVAL;
>
>  	panthor_perf_info_init(ptdev);
>
> -	return 0;
> +	perf = kzalloc(sizeof(*perf), GFP_KERNEL);
> +	if (ZERO_OR_NULL_PTR(perf))
> +		return -ENOMEM;
> +
> +	xa_init_flags(&perf->sessions, XA_FLAGS_ALLOC);
> +
> +	perf->session_range = (struct xa_limit) {
> +		.min = 0,
> +		.max = 1,
> +	};
> +
> +	drm_info(&ptdev->base, "Performance counter subsystem initialized");
> +
> +	ptdev->perf = no_free_ptr(perf);
> +
> +	return ret;
> +}
> +
> +/**
> + * panthor_perf_unplug - Terminate the performance counter subsystem.
> + * @ptdev: Panthor device.
> + *
> + * This function will terminate the performance counter control structures and any remaining
> + * sessions, after waiting for any pending interrupts.
> + */
> +void panthor_perf_unplug(struct panthor_device *ptdev)
> +{
> +	struct panthor_perf *perf = ptdev->perf;
> +
> +	if (!perf)
> +		return;
> +
> +	if (!xa_empty(&perf->sessions)) {
> +		drm_err(&ptdev->base,
> +			"Performance counter sessions active when unplugging the driver!");
> +	}

I think this could only happen if someone forces module unload, even
though there might still be processes which haven't yet closed the DRM
file?

> +
> +	xa_destroy(&perf->sessions);
> +
> +	kfree(ptdev->perf);
> +
> +	ptdev->perf = NULL;
>  }
> diff --git a/drivers/gpu/drm/panthor/panthor_perf.h b/drivers/gpu/drm/panthor/panthor_perf.h
> index 3c32c24c164c..e4805727b9e7 100644
> --- a/drivers/gpu/drm/panthor/panthor_perf.h
> +++ b/drivers/gpu/drm/panthor/panthor_perf.h
> @@ -10,6 +10,7 @@
>  struct panthor_device;
>
>  int panthor_perf_init(struct panthor_device *ptdev);
> +void panthor_perf_unplug(struct panthor_device *ptdev);
>
>  #endif /* __PANTHOR_PERF_H__ */
>
> --
> 2.33.0.dirty

Adrian Larumbe
Re: [PATCH v4 3/7] drm/panthor: Add panthor perf initialization and termination
Posted by Lukas Zapolskas 5 months ago 

On 18/07/2025 04:10, Adrián Larumbe wrote:
> On 16.05.2025 16:49, Lukas Zapolskas wrote:
>> Added the panthor_perf system initialization and unplug code to allow
>> for the handling of userspace sessions to be added in follow-up
>> patches.
>>
>> Signed-off-by: Lukas Zapolskas <lukas.zapolskas@arm.com>
>> ---
>>  drivers/gpu/drm/panthor/panthor_device.c |  2 +
>>  drivers/gpu/drm/panthor/panthor_device.h |  5 +-
>>  drivers/gpu/drm/panthor/panthor_perf.c   | 62 +++++++++++++++++++++++-
>>  drivers/gpu/drm/panthor/panthor_perf.h   |  1 +
>>  4 files changed, 68 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/panthor/panthor_device.c b/drivers/gpu/drm/panthor/panthor_device.c
>> index 76b4cf3dc391..7ac985d44655 100644
>> --- a/drivers/gpu/drm/panthor/panthor_device.c
>> +++ b/drivers/gpu/drm/panthor/panthor_device.c
>> @@ -98,6 +98,7 @@ void panthor_device_unplug(struct panthor_device *ptdev)
>>  	/* Now, try to cleanly shutdown the GPU before the device resources
>>  	 * get reclaimed.
>>  	 */
>> +	panthor_perf_unplug(ptdev);
>>  	panthor_sched_unplug(ptdev);
>>  	panthor_fw_unplug(ptdev);
>>  	panthor_mmu_unplug(ptdev);
>> @@ -277,6 +278,7 @@ int panthor_device_init(struct panthor_device *ptdev)
>>
>>  err_disable_autosuspend:
>>  	pm_runtime_dont_use_autosuspend(ptdev->base.dev);
>> +	panthor_perf_unplug(ptdev);
>>  	panthor_sched_unplug(ptdev);
>>
>>  err_unplug_fw:
>> diff --git a/drivers/gpu/drm/panthor/panthor_device.h b/drivers/gpu/drm/panthor/panthor_device.h
>> index 657ccc39568c..818c4d96d448 100644
>> --- a/drivers/gpu/drm/panthor/panthor_device.h
>> +++ b/drivers/gpu/drm/panthor/panthor_device.h
>> @@ -27,7 +27,7 @@ struct panthor_heap_pool;
>>  struct panthor_job;
>>  struct panthor_mmu;
>>  struct panthor_fw;
>> -struct panthor_perfcnt;
>> +struct panthor_perf;
>>  struct panthor_vm;
>>  struct panthor_vm_pool;
>>
>> @@ -138,6 +138,9 @@ struct panthor_device {
>>  	/** @devfreq: Device frequency scaling management data. */
>>  	struct panthor_devfreq *devfreq;
>>
>> +	/** @perf: Performance counter management data. */
>> +	struct panthor_perf *perf;
>> +
>>  	/** @unplug: Device unplug related fields. */
>>  	struct {
>>  		/** @lock: Lock used to serialize unplug operations. */
>> diff --git a/drivers/gpu/drm/panthor/panthor_perf.c b/drivers/gpu/drm/panthor/panthor_perf.c
>> index 66e9a197ac1f..9365ce9fed04 100644
>> --- a/drivers/gpu/drm/panthor/panthor_perf.c
>> +++ b/drivers/gpu/drm/panthor/panthor_perf.c
>> @@ -9,6 +9,19 @@
>>  #include "panthor_fw.h"
>>  #include "panthor_perf.h"
> 
> You must include "panthor_regs.h" here or else GPU_MEM_FEATURES_L2_SLICES() won't be available.
> However, it seems this is something that should be done in the previous patch.
> 

Will add that to the perf_info patch.

>>
>> +struct panthor_perf {
>> +	/** @next_session: The ID of the next session. */
>> +	u32 next_session;
>> +
>> +	/** @session_range: The number of sessions supported at a time. */
>> +	struct xa_limit session_range;
>> +
>> +	/**
>> +	 * @sessions: Global map of sessions, accessed by their ID.
>> +	 */
>> +	struct xarray sessions;
>> +};
>> +
>>  struct panthor_perf_counter_block {
>>  	struct drm_panthor_perf_block_header header;
>>  	u64 counters[];
>> @@ -63,14 +76,61 @@ static void panthor_perf_info_init(struct panthor_device *ptdev)
>>   * panthor_perf_init - Initialize the performance counter subsystem.
>>   * @ptdev: Panthor device
>>   *
>> + * The performance counters require the FW interface to be available to setup the
>> + * sampling ringbuffers, so this must be called only after FW is initialized.
>> + *
>>   * Return: 0 on success, negative error code on failure.
>>   */
>>  int panthor_perf_init(struct panthor_device *ptdev)
>>  {
>> +	struct panthor_perf *perf __free(kfree) = NULL;
>> +	int ret = 0;
>> +
>>  	if (!ptdev)
>>  		return -EINVAL;
>>
>>  	panthor_perf_info_init(ptdev);
>>
>> -	return 0;
>> +	perf = kzalloc(sizeof(*perf), GFP_KERNEL);
>> +	if (ZERO_OR_NULL_PTR(perf))
>> +		return -ENOMEM;
>> +
>> +	xa_init_flags(&perf->sessions, XA_FLAGS_ALLOC);
>> +
>> +	perf->session_range = (struct xa_limit) {
>> +		.min = 0,
>> +		.max = 1,
>> +	};
>> +
>> +	drm_info(&ptdev->base, "Performance counter subsystem initialized");
>> +
>> +	ptdev->perf = no_free_ptr(perf);
>> +
>> +	return ret;
>> +}
>> +
>> +/**
>> + * panthor_perf_unplug - Terminate the performance counter subsystem.
>> + * @ptdev: Panthor device.
>> + *
>> + * This function will terminate the performance counter control structures and any remaining
>> + * sessions, after waiting for any pending interrupts.
>> + */
>> +void panthor_perf_unplug(struct panthor_device *ptdev)
>> +{
>> +	struct panthor_perf *perf = ptdev->perf;
>> +
>> +	if (!perf)
>> +		return;
>> +
>> +	if (!xa_empty(&perf->sessions)) {
>> +		drm_err(&ptdev->base,
>> +			"Performance counter sessions active when unplugging the driver!");
>> +	}
> 
> I think this could only happen if someone forces module unload, even
> though there might still be processes which haven't yet closed the DRM
> file?
> 

That sounds about right. The only time I have seen that warning was in development when 
the session cleanup was not being done properly on process termination.

>> +
>> +	xa_destroy(&perf->sessions);
>> +
>> +	kfree(ptdev->perf);
>> +
>> +	ptdev->perf = NULL;
>>  }
>> diff --git a/drivers/gpu/drm/panthor/panthor_perf.h b/drivers/gpu/drm/panthor/panthor_perf.h
>> index 3c32c24c164c..e4805727b9e7 100644
>> --- a/drivers/gpu/drm/panthor/panthor_perf.h
>> +++ b/drivers/gpu/drm/panthor/panthor_perf.h
>> @@ -10,6 +10,7 @@
>>  struct panthor_device;
>>
>>  int panthor_perf_init(struct panthor_device *ptdev);
>> +void panthor_perf_unplug(struct panthor_device *ptdev);
>>
>>  #endif /* __PANTHOR_PERF_H__ */
>>
>> --
>> 2.33.0.dirty
> 
> Adrian Larumbe

Patchew 2.1-devel-b67e4c2

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