Re: [PATCH 2/4] drm/msm/dpu: Refactor rm iterator

[Stephen Boyd]

Quoting Drew Davenport (2020-02-19 09:42:25)
> Make iterator implementation private, and add function to
> query resources assigned to an encoder.
> 
> Signed-off-by: Drew Davenport <ddavenport@xxxxxxxxxxxx>

> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> index f8ac3bf60fd60..6cadeff456f09 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> @@ -957,11 +957,11 @@ static void dpu_encoder_virt_mode_set(struct drm_encoder *drm_enc,
>         struct drm_connector *conn = NULL, *conn_iter;
>         struct drm_crtc *drm_crtc;
>         struct dpu_crtc_state *cstate;
> -       struct dpu_rm_hw_iter hw_iter;
>         struct msm_display_topology topology;
> -       struct dpu_hw_ctl *hw_ctl[MAX_CHANNELS_PER_ENC] = { NULL };
> -       struct dpu_hw_mixer *hw_lm[MAX_CHANNELS_PER_ENC] = { NULL };
> -       int num_lm = 0, num_ctl = 0;
> +       struct dpu_hw_blk *hw_pp[MAX_CHANNELS_PER_ENC];
> +       struct dpu_hw_blk *hw_ctl[MAX_CHANNELS_PER_ENC];
> +       struct dpu_hw_blk *hw_lm[MAX_CHANNELS_PER_ENC];
> +       int num_lm, num_ctl, num_pp;

All these should be unsigned too?

>         int i, j, ret;
>  
>         if (!drm_enc) {
> @@ -1005,42 +1005,31 @@ static void dpu_encoder_virt_mode_set(struct drm_encoder *drm_enc,
>                 return;
>         }
>  
> -       dpu_rm_init_hw_iter(&hw_iter, drm_enc->base.id, DPU_HW_BLK_PINGPONG);
> -       for (i = 0; i < MAX_CHANNELS_PER_ENC; i++) {
> -               dpu_enc->hw_pp[i] = NULL;
> -               if (!dpu_rm_get_hw(&dpu_kms->rm, &hw_iter))
> -                       break;
> -               dpu_enc->hw_pp[i] = (struct dpu_hw_pingpong *) hw_iter.hw;
> -       }
> -
> -       dpu_rm_init_hw_iter(&hw_iter, drm_enc->base.id, DPU_HW_BLK_CTL);
> -       for (i = 0; i < MAX_CHANNELS_PER_ENC; i++) {
> -               if (!dpu_rm_get_hw(&dpu_kms->rm, &hw_iter))
> -                       break;
> -               hw_ctl[i] = (struct dpu_hw_ctl *)hw_iter.hw;

Why cast? Isn't it void pointer?

> -               num_ctl++;
> -       }
> +       num_pp = dpu_rm_get_assigned_resources(&dpu_kms->rm, drm_enc->base.id,
> +               DPU_HW_BLK_PINGPONG, hw_pp, ARRAY_SIZE(hw_pp));
> +       num_ctl = dpu_rm_get_assigned_resources(&dpu_kms->rm, drm_enc->base.id,
> +               DPU_HW_BLK_CTL, hw_ctl, ARRAY_SIZE(hw_ctl));
> +       num_lm = dpu_rm_get_assigned_resources(&dpu_kms->rm, drm_enc->base.id,
> +               DPU_HW_BLK_LM, hw_lm, ARRAY_SIZE(hw_lm));
>  
> -       dpu_rm_init_hw_iter(&hw_iter, drm_enc->base.id, DPU_HW_BLK_LM);
> -       for (i = 0; i < MAX_CHANNELS_PER_ENC; i++) {
> -               if (!dpu_rm_get_hw(&dpu_kms->rm, &hw_iter))
> -                       break;
> -               hw_lm[i] = (struct dpu_hw_mixer *)hw_iter.hw;

Why cast?

> -               num_lm++;
> -       }
> +       for (i = 0; i < MAX_CHANNELS_PER_ENC; i++)
> +               dpu_enc->hw_pp[i] = i < num_pp ? to_dpu_hw_pingpong(hw_pp[i])
> +                                               : NULL;

This line is pretty hard to read. Maybe use an if/else?

>  
>         cstate = to_dpu_crtc_state(drm_crtc->state);
>  
>         for (i = 0; i < num_lm; i++) {
>                 int ctl_idx = (i < num_ctl) ? i : (num_ctl-1);
>  
> -               cstate->mixers[i].hw_lm = hw_lm[i];
> -               cstate->mixers[i].lm_ctl = hw_ctl[ctl_idx];
> +               cstate->mixers[i].hw_lm = to_dpu_hw_mixer(hw_lm[i]);
> +               cstate->mixers[i].lm_ctl = to_dpu_hw_ctl(hw_ctl[ctl_idx]);
>         }
>  
>         cstate->num_mixers = num_lm;
>  
>         for (i = 0; i < dpu_enc->num_phys_encs; i++) {
> +               int num_blk;

unsigned int?

> +               struct dpu_hw_blk *hw_blk[MAX_CHANNELS_PER_ENC];
>                 struct dpu_encoder_phys *phys = dpu_enc->phys_encs[i];
>  
>                 if (!dpu_enc->hw_pp[i]) {
> @@ -1056,17 +1045,15 @@ static void dpu_encoder_virt_mode_set(struct drm_encoder *drm_enc,
>                 }
>  
>                 phys->hw_pp = dpu_enc->hw_pp[i];
> -               phys->hw_ctl = hw_ctl[i];
> +               phys->hw_ctl = to_dpu_hw_ctl(hw_ctl[i]);
>  
> -               dpu_rm_init_hw_iter(&hw_iter, drm_enc->base.id,
> -                                   DPU_HW_BLK_INTF);
> -               for (j = 0; j < MAX_CHANNELS_PER_ENC; j++) {
> +               num_blk = dpu_rm_get_assigned_resources(&dpu_kms->rm,
> +                       drm_enc->base.id, DPU_HW_BLK_INTF, hw_blk,
> +                       ARRAY_SIZE(hw_blk));
> +               for (j = 0; j < num_blk; j++) {
>                         struct dpu_hw_intf *hw_intf;
>  
> -                       if (!dpu_rm_get_hw(&dpu_kms->rm, &hw_iter))
> -                               break;
> -
> -                       hw_intf = (struct dpu_hw_intf *)hw_iter.hw;
> +                       hw_intf = to_dpu_hw_intf(hw_blk[i]);
>                         if (hw_intf->idx == phys->intf_idx)
>                                 phys->hw_intf = hw_intf;
>                 }
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c
> index dea1dba441fe7..779df26dc81ae 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c
> @@ -83,7 +97,7 @@ static bool _dpu_rm_get_hw_locked(struct dpu_rm *rm, struct dpu_rm_hw_iter *i)
>         return false;
>  }
>  
> -bool dpu_rm_get_hw(struct dpu_rm *rm, struct dpu_rm_hw_iter *i)
> +static bool dpu_rm_get_hw(struct dpu_rm *rm, struct dpu_rm_hw_iter *i)
>  {
>         bool ret;
>  
> @@ -635,3 +649,16 @@ int dpu_rm_reserve(
>  
>         return ret;
>  }
> +
> +int dpu_rm_get_assigned_resources(struct dpu_rm *rm, uint32_t enc_id,

Return unsigned int?

> +       enum dpu_hw_blk_type type, struct dpu_hw_blk **blks, int blks_size)

unsigned int blks_size?

> +{
> +       struct dpu_rm_hw_iter hw_iter;
> +       int num_blks = 0;

unsigned int?

> +
> +       dpu_rm_init_hw_iter(&hw_iter, enc_id, type);
> +       while (num_blks < blks_size && dpu_rm_get_hw(rm, &hw_iter))
> +               blks[num_blks++] = hw_iter.blk->hw;
> +
> +       return num_blks;

It's not possible for it to be negative number right?

> +}
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.h
> index 9c580a0170946..982b91e272275 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.h
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.h
> @@ -24,26 +24,6 @@ struct dpu_rm {
>         struct mutex rm_lock;
>  };
>  
> -/**
> - *  struct dpu_rm_hw_blk - resource manager internal structure
> - *     forward declaration for single iterator definition without void pointer
> - */
> -struct dpu_rm_hw_blk;
> -
> -/**
> - * struct dpu_rm_hw_iter - iterator for use with dpu_rm
> - * @hw: dpu_hw object requested, or NULL on failure
> - * @blk: dpu_rm internal block representation. Clients ignore. Used as iterator.
> - * @enc_id: DRM ID of Encoder client wishes to search for, or 0 for Any Encoder

Why is Encoder and Any capitalized?

> - * @type: Hardware Block Type client wishes to search for.
> - */
> -struct dpu_rm_hw_iter {
> -       void *hw;
> -       struct dpu_rm_hw_blk *blk;
> -       uint32_t enc_id;
> -       enum dpu_hw_blk_type type;
> -};
> -
>  /**
>   * dpu_rm_init - Read hardware catalog and create reservation tracking objects
>   *     for all HW blocks.
> @@ -93,28 +73,9 @@ int dpu_rm_reserve(struct dpu_rm *rm,
>  void dpu_rm_release(struct dpu_rm *rm, struct drm_encoder *enc);
>  
>  /**
> - * dpu_rm_init_hw_iter - setup given iterator for new iteration over hw list
> - *     using dpu_rm_get_hw
> - * @iter: iter object to initialize
> - * @enc_id: DRM ID of Encoder client wishes to search for, or 0 for Any Encoder
> - * @type: Hardware Block Type client wishes to search for.

Ah I guess it's copied from here.