[PATCH v2] drm/amdkfd: Update return value of config_dequeue_wait_counts

Kasiviswanathan, Harish Harish.Kasiviswanathan at amd.com
Fri Mar 14 21:04:17 UTC 2025


[Public]

-----Original Message-----
From: Kim, Jonathan <Jonathan.Kim at amd.com>
Sent: Friday, March 14, 2025 4:41 PM
To: Kasiviswanathan, Harish <Harish.Kasiviswanathan at amd.com>; amd-gfx at lists.freedesktop.org
Cc: Kasiviswanathan, Harish <Harish.Kasiviswanathan at amd.com>
Subject: RE: [PATCH v2] drm/amdkfd: Update return value of config_dequeue_wait_counts

[Public]

> -----Original Message-----
> From: amd-gfx <amd-gfx-bounces at lists.freedesktop.org> On Behalf Of Harish
> Kasiviswanathan
> Sent: Friday, March 14, 2025 4:22 PM
> To: amd-gfx at lists.freedesktop.org
> Cc: Kasiviswanathan, Harish <Harish.Kasiviswanathan at amd.com>
> Subject: [PATCH v2] drm/amdkfd: Update return value of
> config_dequeue_wait_counts
>
> .config_dequeue_wait_counts returns a nop case. Modify return parameter
> to reflect that since the caller also needs to ignore this condition.
>
> v2: Removed redudant code.
>     Tidy up code based on review comments
>
> Fixes: <98a5af8103f> ("drm/amdkfd: Add pm_config_dequeue_wait_counts API")
>
> Signed-off-by: Harish Kasiviswanathan <Harish.Kasiviswanathan at amd.com>
> ---
>  .../gpu/drm/amd/amdkfd/kfd_packet_manager.c   | 14 ++++----
>  .../drm/amd/amdkfd/kfd_packet_manager_v9.c    | 36 +++++++++++--------
>  2 files changed, 29 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_packet_manager.c
> b/drivers/gpu/drm/amd/amdkfd/kfd_packet_manager.c
> index 3f574d82b5fc..502b89639a9f 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_packet_manager.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_packet_manager.c
> @@ -436,19 +436,19 @@ int pm_config_dequeue_wait_counts(struct
> packet_manager *pm,
>
>               retval = pm->pmf->config_dequeue_wait_counts(pm, buffer,
>                                                            cmd, value);
> -             if (!retval)
> +             if (retval > 0) {
>                       retval = kq_submit_packet(pm->priv_queue);
> +
> +                     /* If default value is modified, cache that in dqm->wait_times
> */
> +                     if (!retval && cmd == KFD_DEQUEUE_WAIT_INIT)
> +                             update_dqm_wait_times(pm->dqm);
> +             }
>               else
>                       kq_rollback_packet(pm->priv_queue);
>       }
> -
> -     /* If default value is modified, cache that value in dqm->wait_times */
> -     if (!retval && cmd == KFD_DEQUEUE_WAIT_INIT)
> -             update_dqm_wait_times(pm->dqm);
> -
>  out:
>       mutex_unlock(&pm->lock);
> -     return retval;
> +     return retval < 0 ? retval : 0;
>  }
>
>  int pm_send_unmap_queue(struct packet_manager *pm,
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_packet_manager_v9.c
> b/drivers/gpu/drm/amd/amdkfd/kfd_packet_manager_v9.c
> index d440df602393..3c6134d61b2b 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_packet_manager_v9.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_packet_manager_v9.c
> @@ -310,6 +310,13 @@ static inline void
> pm_build_dequeue_wait_counts_packet_info(struct packet_manage
>               reg_data);
>  }
>
> +/* pm_config_dequeue_wait_counts_v9: Builds WRITE_DATA packet with
> + *    register/value for configuring dequeue wait counts
> + *
> + * @return: -ve for failure, 0 for nop and +ve for success and buffer is
> + *  filled in with packet
> + *
> + **/
>  static int pm_config_dequeue_wait_counts_v9(struct packet_manager *pm,
>               uint32_t *buffer,
>               enum kfd_config_dequeue_wait_counts_cmd cmd,
> @@ -321,24 +328,25 @@ static int pm_config_dequeue_wait_counts_v9(struct
> packet_manager *pm,
>
>       switch (cmd) {
>       case KFD_DEQUEUE_WAIT_INIT: {
> -             uint32_t sch_wave = 0, que_sleep = 0;
> -             /* Reduce CP_IQ_WAIT_TIME2.QUE_SLEEP to 0x1 from default
> 0x40.
> +             uint32_t sch_wave = 0, que_sleep = 1;
> +
> +             if (KFD_GC_VERSION(pm->dqm->dev) < IP_VERSION(9, 4, 1) ||
> +                 KFD_GC_VERSION(pm->dqm->dev) > IP_VERSION(10, 0, 0))
> +                     return 0;

>From my last comment, I suggested to put this at the beginning of the non-v9 pm_config_dequeue_wait_counts call that calls this function.
Then you don't have to make the return value more complicated than it currently is.

[HK]: Ah ok. I didn't really want to put asic specific code in there but in this case code it is fine as you mentioned we have already overloading these functions.

Also KFD_GC_VERSION(pm->dqm->dev) > IP_VERSION(10, 0, 0) is incorrect and should be >= because want to also exclude anything with a major version of 10.
[HK]: good catch

Jon

> +
> +             /* For all other gfx9 ASICs,
> +              * Reduce CP_IQ_WAIT_TIME2.QUE_SLEEP to 0x1 from default
> 0x40.
>                * On a 1GHz machine this is roughly 1 microsecond, which is
>                * about how long it takes to load data out of memory during
>                * queue connect
>                * QUE_SLEEP: Wait Count for Dequeue Retry.
> +              *
> +              * Set CWSR grace period to 1x1000 cycle for GFX9.4.3 APU
>                */
> -             if (KFD_GC_VERSION(pm->dqm->dev) >= IP_VERSION(9, 4, 1) &&
> -                 KFD_GC_VERSION(pm->dqm->dev) < IP_VERSION(10, 0, 0)) {
> -                     que_sleep = 1;
> -
> -                     /* Set CWSR grace period to 1x1000 cycle for GFX9.4.3 APU
> */
> -                     if (amdgpu_emu_mode == 0 && pm->dqm->dev->adev-
> >gmc.is_app_apu &&
> -                     (KFD_GC_VERSION(pm->dqm->dev) == IP_VERSION(9, 4,
> 3)))
> -                             sch_wave = 1;
> -             } else {
> -                     return 0;
> -             }
> +             if (amdgpu_emu_mode == 0 && pm->dqm->dev->adev-
> >gmc.is_app_apu &&
> +                 (KFD_GC_VERSION(pm->dqm->dev) == IP_VERSION(9, 4, 3)))
> +                     sch_wave = 1;
> +
>               pm_build_dequeue_wait_counts_packet_info(pm, sch_wave,
> que_sleep,
>                       &reg_offset, &reg_data);
>
> @@ -377,7 +385,7 @@ static int pm_config_dequeue_wait_counts_v9(struct
> packet_manager *pm,
>
>       packet->data = reg_data;
>
> -     return 0;
> +     return sizeof(struct pm4_mec_write_data_mmio);
>  }
>
>  static int pm_unmap_queues_v9(struct packet_manager *pm, uint32_t *buffer,
> --
> 2.34.1




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