Hello, This patch set implements initial support for performance counter sampling in Panthor, as a follow-up for Adrián Larumbe's patch set [1]. Existing performance counter workflows, such as those in game engines, and user-space power models/governor implementations require the ability to simultaneously obtain counter data. The hardware and firmware interfaces support a single global configuration, meaning the kernel must allow for the multiplexing. It is also in the best position to supplement the counter data with contextual information about elapsed sampling periods, information on the power state transitions undergone during the sampling period, and cycles elapsed on specific clocks chosen by the integrator. Each userspace client creates a session, providing an enable mask of counter values it requires, a BO for a ring buffer, and a separate BO for the insert and extract indices, along with an eventfd to signal counter capture, all of which are kept fixed for the lifetime of the session. When emitting a sample for a session, counters that were not requested are stripped out, and non-counter information needed to interpret counter values is added to either the sample header, or the block header, which are stored in-line with the counter values in the sample. The proposed uAPI specifies two major sources of supplemental information: - coarse-grained block state transitions are provided on newer FW versions which support the metadata block, a FW-provided counter block which indicates the reason a sample was taken when entering or existing a non-counting region, or when a shader core has powered down. - the clock assignments to individual blocks is done by integrators, and in order to normalize counter values which count cycles, userspace must know both the clock cycles elapsed over the sampling period, and which of the clocks that particular block is associated with. All of the sessions are then aggregated by the sampler, which handles the programming of the FW interface and subsequent handling of the samples coming from FW. [1]: https://lore.kernel.org/lkml/20240305165820.585245-1-adrian.larumbe@xxxxxxxxxxxxx/T/#m67d1f89614fe35dc0560e8304d6731eb1a6942b6 Signed-off-by: Adrián Larumbe <adrian.larumbe@xxxxxxxxxxxxx> Co-developed-by: Mihail Atanassov <mihail.atanassov@xxxxxxx> Signed-off-by: Mihail Atanassov <mihail.atanassov@xxxxxxx> Co-developed-by: Lukas Zapolskas <lukas.zapolskas@xxxxxxx> Signed-off-by: Lukas Zapolskas <lukas.zapolskas@xxxxxxx> Adrián Larumbe (1): drm/panthor: Implement the counter sampler and sample handling Lukas Zapolskas (7): drm/panthor: Add performance counter uAPI drm/panthor: Add DEV_QUERY.PERF_INFO handling for Gx10 drm/panthor: Add panthor_perf_init and panthor_perf_unplug drm/panthor: Add panthor perf ioctls drm/panthor: Introduce sampling sessions to handle userspace clients drm/panthor: Add suspend/resume handling for the performance counters drm/panthor: Expose the panthor perf ioctls drivers/gpu/drm/panthor/Makefile | 1 + drivers/gpu/drm/panthor/panthor_device.c | 10 + drivers/gpu/drm/panthor/panthor_device.h | 11 +- drivers/gpu/drm/panthor/panthor_drv.c | 167 +- drivers/gpu/drm/panthor/panthor_fw.c | 9 + drivers/gpu/drm/panthor/panthor_fw.h | 11 +- drivers/gpu/drm/panthor/panthor_perf.c | 1773 ++++++++++++++++++++++ drivers/gpu/drm/panthor/panthor_perf.h | 38 + include/uapi/drm/panthor_drm.h | 538 +++++++ 9 files changed, 2553 insertions(+), 5 deletions(-) create mode 100644 drivers/gpu/drm/panthor/panthor_perf.c create mode 100644 drivers/gpu/drm/panthor/panthor_perf.h -- 2.25.1
