On 12/12, Maíra Canal wrote:
> As the BOs used by VC4 have DMA Reservation Objects attached to it,
> there is no need to use seqnos wait for the BOs availability. Instead,
> we can use `dma_gem_dma_resv_wait()`.
typo: drm_gem_dma_resc_wait()
>
> Signed-off-by: Maíra Canal <mcanal@xxxxxxxxxx>
> ---
> drivers/gpu/drm/vc4/vc4_drv.h | 10 ++++++++++
> drivers/gpu/drm/vc4/vc4_gem.c | 31 +++++++++++++++++++------------
> 2 files changed, 29 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/gpu/drm/vc4/vc4_drv.h b/drivers/gpu/drm/vc4/vc4_drv.h
> index 4a078ffd9f82..03ed40ab9a93 100644
> --- a/drivers/gpu/drm/vc4/vc4_drv.h
> +++ b/drivers/gpu/drm/vc4/vc4_drv.h
> @@ -924,6 +924,16 @@ struct vc4_validated_shader_info {
> (Wmax))
> #define wait_for(COND, MS) _wait_for((COND), (MS) * 1000, 10, 1000)
>
> +static inline unsigned long nsecs_to_jiffies_timeout(const u64 n)
> +{
> + /* nsecs_to_jiffies64() does not guard against overflow */
> + if ((NSEC_PER_SEC % HZ) != 0 &&
> + div_u64(n, NSEC_PER_SEC) >= MAX_JIFFY_OFFSET / HZ)
> + return MAX_JIFFY_OFFSET;
> +
> + return min_t(u64, MAX_JIFFY_OFFSET, nsecs_to_jiffies64(n) + 1);
> +}
> +
Should nsecs_to_jiffies_timeout become common code?
> /* vc4_bo.c */
> struct drm_gem_object *vc4_create_object(struct drm_device *dev, size_t size);
> struct vc4_bo *vc4_bo_create(struct drm_device *dev, size_t size,
> diff --git a/drivers/gpu/drm/vc4/vc4_gem.c b/drivers/gpu/drm/vc4/vc4_gem.c
> index 1021f45cb53c..4037c65eb269 100644
> --- a/drivers/gpu/drm/vc4/vc4_gem.c
> +++ b/drivers/gpu/drm/vc4/vc4_gem.c
> @@ -1017,11 +1017,13 @@ int
> vc4_wait_bo_ioctl(struct drm_device *dev, void *data,
> struct drm_file *file_priv)
> {
> - struct vc4_dev *vc4 = to_vc4_dev(dev);
> int ret;
> + struct vc4_dev *vc4 = to_vc4_dev(dev);
> struct drm_vc4_wait_bo *args = data;
> - struct drm_gem_object *gem_obj;
> - struct vc4_bo *bo;
> + unsigned long timeout_jiffies =
> + nsecs_to_jiffies_timeout(args->timeout_ns);
> + ktime_t start = ktime_get();
> + u64 delta_ns;
>
> if (WARN_ON_ONCE(vc4->gen > VC4_GEN_4))
> return -ENODEV;
> @@ -1029,17 +1031,22 @@ vc4_wait_bo_ioctl(struct drm_device *dev, void *data,
> if (args->pad != 0)
> return -EINVAL;
>
> - gem_obj = drm_gem_object_lookup(file_priv, args->handle);
> - if (!gem_obj) {
> - DRM_DEBUG("Failed to look up GEM BO %d\n", args->handle);
> - return -EINVAL;
> - }
> - bo = to_vc4_bo(gem_obj);
> + ret = drm_gem_dma_resv_wait(file_priv, args->handle,
> + true, timeout_jiffies);
>
> - ret = vc4_wait_for_seqno_ioctl_helper(dev, bo->seqno,
> - &args->timeout_ns);
> + /* Decrement the user's timeout, in case we got interrupted
> + * such that the ioctl will be restarted.
> + */
> + delta_ns = ktime_to_ns(ktime_sub(ktime_get(), start));
> + if (delta_ns < args->timeout_ns)
> + args->timeout_ns -= delta_ns;
> + else
> + args->timeout_ns = 0;
> +
> + /* Asked to wait beyond the jiffy/scheduler precision? */
> + if (ret == -ETIME && args->timeout_ns)
> + ret = -EAGAIN;
>
> - drm_gem_object_put(gem_obj);
Just left some comments above.
This change sounds sensible and the patch LGTM.
Thanks!
Reviewed-by: Melissa Wen <mwen@xxxxxxxxxx>
> return ret;
> }
>
> --
> 2.47.1
>
