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.zapols...@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
