On 11.12.2024 16:50, 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 | 7 +++
> drivers/gpu/drm/panthor/panthor_device.h | 5 +-
> drivers/gpu/drm/panthor/panthor_perf.c | 77 ++++++++++++++++++++++++
> drivers/gpu/drm/panthor/panthor_perf.h | 3 +
> 4 files changed, 91 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/panthor/panthor_device.c
> b/drivers/gpu/drm/panthor/panthor_device.c
> index 00f7b8ce935a..1a81a436143b 100644
> --- a/drivers/gpu/drm/panthor/panthor_device.c
> +++ b/drivers/gpu/drm/panthor/panthor_device.c
> @@ -19,6 +19,7 @@
> #include "panthor_fw.h"
> #include "panthor_gpu.h"
> #include "panthor_mmu.h"
> +#include "panthor_perf.h"
> #include "panthor_regs.h"
> #include "panthor_sched.h"
>
> @@ -97,6 +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);
> @@ -262,6 +264,10 @@ int panthor_device_init(struct panthor_device *ptdev)
> if (ret)
> goto err_unplug_fw;
>
> + ret = panthor_perf_init(ptdev);
> + if (ret)
> + goto err_unplug_fw;
> +
> /* ~3 frames */
> pm_runtime_set_autosuspend_delay(ptdev->base.dev, 50);
> pm_runtime_use_autosuspend(ptdev->base.dev);
> @@ -275,6 +281,7 @@ 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 636542c1dcbd..aca33d03036c 100644
> --- a/drivers/gpu/drm/panthor/panthor_device.h
> +++ b/drivers/gpu/drm/panthor/panthor_device.h
> @@ -26,7 +26,7 @@ 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;
>
> @@ -137,6 +137,9 @@ 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 0e3d769c1805..e0dc6c4b0cf1 100644
> --- a/drivers/gpu/drm/panthor/panthor_perf.c
> +++ b/drivers/gpu/drm/panthor/panthor_perf.c
> @@ -13,6 +13,24 @@
> #include "panthor_perf.h"
> #include "panthor_regs.h"
>
> +struct panthor_perf {
> + /**
> + * @block_set: The global counter set configured onto the HW.
> + */
> + u8 block_set;
> +
> + /** @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;
> +};
> +
> /**
> * PANTHOR_PERF_COUNTERS_PER_BLOCK - On CSF architectures pre-11.x, the
> number of counters
> * per block was hardcoded to be 64. Arch 11.0 onwards supports the
> PRFCNT_FEATURES GPU register,
> @@ -45,3 +63,62 @@ void panthor_perf_info_init(struct panthor_device *ptdev)
> perf_info->shader_blocks = hweight64(ptdev->gpu_info.shader_present);
> }
>
> +/**
> + * 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;
> +
> + if (!ptdev)
> + return -EINVAL;
> +
> + perf = devm_kzalloc(ptdev->base.dev, sizeof(*perf), GFP_KERNEL);
> + if (ZERO_OR_NULL_PTR(perf))
> + return -ENOMEM;
> +
> + xa_init_flags(&perf->sessions, XA_FLAGS_ALLOC);
> +
> + /* Currently, we only support a single session at a time. */
> + perf->session_range = (struct xa_limit) {
> + .min = 0,
> + .max = 1,
> + };
> +
> + drm_info(&ptdev->base, "Performance counter subsystem initialized");
> +
> + ptdev->perf = perf;
> +
> + return 0;
> +}
> +
> +/**
> + * 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);
> +
> + devm_kfree(ptdev->base.dev, ptdev->perf);
> +
> + ptdev->perf = NULL;
I thought this could be racy with the perfcnt IRQ handler, but maybe if the
sessions array is
already empty by then then it doesn't matter.
> +}
> diff --git a/drivers/gpu/drm/panthor/panthor_perf.h
> b/drivers/gpu/drm/panthor/panthor_perf.h
> index cff537a370c9..90af8b18358c 100644
> --- a/drivers/gpu/drm/panthor/panthor_perf.h
> +++ b/drivers/gpu/drm/panthor/panthor_perf.h
> @@ -9,4 +9,7 @@ struct panthor_device;
>
> void panthor_perf_info_init(struct panthor_device *ptdev);
>
> +int panthor_perf_init(struct panthor_device *ptdev);
> +void panthor_perf_unplug(struct panthor_device *ptdev);
> +
> #endif /* __PANTHOR_PERF_H__ */
> --
> 2.25.1
Adrian Larumbe
