drm/v3d: add missing mutex_destroy

v3d_perfmon_open_file() instantiates a mutex for a particular file
instance, but it never destroys it by calling mutex_destroy() in
v3d_perfmon_close_file().

Similarly, v3d_perfmon_create_ioctl() instantiates a mutex for a
particular perfmon, but it never destroys it by calling mutex_destroy()
in v3d_perfmon_destroy_ioctl().

So, add the missing mutex_destroy on both cases.

Signed-off-by: Maíra Canal <mcanal@igalia.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Melissa Wen <melissa.srw@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221108175425.39819-3-mcanal@igalia.com

drm/v3d: use idr_init_base() to initialize v3d_priv->perfmon.idr

idr_init_base(), implemented by commit 6ce711f27500 ("idr: Make 1-based
IDRs more efficient"), let us set an arbitrary base other than
idr_init(), which uses base 0.

Since, for this IDR, no ID < 1 is ever requested/allocated, using
idr_init_base(&idr, 1) avoids unnecessary tree walks.

Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220701190227.284783-1-dakr@redhat.com

drm/v3d: Fix null pointer dereference of pointer perfmon

In the unlikely event that pointer perfmon is null the WARN_ON return path
occurs after the pointer has already been deferenced. Fix this by only
dereferencing perfmon after it has been null checked.

Fixes: 26a4dc29b74a ("drm/v3d: Expose performance counters to userspace")
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: Juan A. Suarez <jasuarez@igalia.com>
Signed-off-by: Melissa Wen <melissa.srw@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220424183512.1365683-1-colin.i.king@gmail.com

drm/v3d: Expose performance counters to userspace

The V3D engine has several hardware performance counters that can of
interest for userspace performance analysis tools.

This exposes new ioctls to create and destroy performance monitor
objects, as well as to query the counter values.

Each created performance monitor object has an ID that can be attached
to CL/CSD submissions, so the driver enables the requested counters when
the job is submitted, and updates the performance monitor values when
the job is done.

It is up to the user to ensure all the jobs have been finished before
getting the performance monitor values. It is also up to the user to
properly synchronize BCL jobs when submitting jobs with different
performance monitors attached.

Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: Emma Anholt <emma@anholt.net>
To: dri-devel@lists.freedesktop.org
Signed-off-by: Juan A. Suarez Romero <jasuarez@igalia.com>
Acked-by: Melissa Wen <mwen@igalia.com>
Signed-off-by: Melissa Wen <melissa.srw@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210608111541.461991-1-jasuarez@igalia.com