Re: [PATCH 2/8] media: hantro: Add support of compressed reference buffers

[Benjamin Gaignard <benjamin.gaignard@xxxxxxxxxxxxx>]

Le 04/06/2021 à 18:32, Ezequiel Garcia a écrit :
> Hi Benjamin,
>
> Thanks for the patches, they looks really nice!
>
> On Fri, 2021-06-04 at 15:06 +0200, Benjamin Gaignard wrote:
> > Reference frame compression is a feature added in G2 decoder to compress
> > frame buffers so that the bandwidth of storing/loading reference frames
> > can be reduced, especially when the resolution of decoded stream is of
> > high definition.
> Can you do some tracing using the performance counters in patch 1,
> with and without this patch, while we are here, it would be interesting
> to run some experiments.
>
> If I understand correctly, the G2 HEVC engine is producing tiled buffers,
> which are then post-processed to NV12.
>
> So this compression feature is compressing the tiled buffers,
> the NV12 are still uncompressed. If this is the case, could add
> some comments somewhere about the different sets of buffers involved?

I will do that

> Also, I believe I mentioned this before, is there a plan
> to be able to expose the tiled buffers to userspace (i.e. without
> the NV12 linear post-processing)? I think the display controller
> can take compressed tiled-buffers.

Yes it could be possible to use vb2 buffers instead of internally
allocated buffers but that would means define a new format/modifier
before doing that.

> > Signed-off-by: Benjamin Gaignard <benjamin.gaignard@xxxxxxxxxxxxx>
> > ---
> >   .../staging/media/hantro/hantro_g2_hevc_dec.c | 20 ++++++++++--
> >   drivers/staging/media/hantro/hantro_g2_regs.h |  4 +++
> >   drivers/staging/media/hantro/hantro_hevc.c    | 32 ++++++++++++++++++-
> >   drivers/staging/media/hantro/hantro_hw.h      |  2 ++
> >   4 files changed, 54 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/staging/media/hantro/hantro_g2_hevc_dec.c b/drivers/staging/media/hantro/hantro_g2_hevc_dec.c
> > index 89fac5146433..9a715e803037 100644
> > --- a/drivers/staging/media/hantro/hantro_g2_hevc_dec.c
> > +++ b/drivers/staging/media/hantro/hantro_g2_hevc_dec.c
> > @@ -382,10 +382,12 @@ static int set_ref(struct hantro_ctx *ctx)
> >          const struct v4l2_ctrl_hevc_pps *pps = ctrls->pps;
> >          const struct v4l2_ctrl_hevc_decode_params *decode_params = ctrls->decode_params;
> >          const struct v4l2_hevc_dpb_entry *dpb = decode_params->dpb;
> > -       dma_addr_t luma_addr, chroma_addr, mv_addr = 0;
> > +       dma_addr_t luma_addr, chroma_addr, mv_addr, compress_luma_addr, compress_chroma_addr = 0;
> >          struct hantro_dev *vpu = ctx->dev;
> >          size_t cr_offset = hantro_hevc_chroma_offset(sps);
> >          size_t mv_offset = hantro_hevc_motion_vectors_offset(sps);
> > +       size_t compress_luma_offset = hantro_hevc_luma_compress_offset(sps);
> > +       size_t compress_chroma_offset = hantro_hevc_chroma_compress_offset(sps);
> >          u32 max_ref_frames;
> >          u16 dpb_longterm_e;
> >          static const struct hantro_reg cur_poc[] = {
> > @@ -460,6 +462,8 @@ static int set_ref(struct hantro_ctx *ctx)
> >   
> >                  chroma_addr = luma_addr + cr_offset;
> >                  mv_addr = luma_addr + mv_offset;
> > +               compress_luma_addr = luma_addr + compress_luma_offset;
> > +               compress_chroma_addr = luma_addr + compress_chroma_offset;
> >   
> >                  if (dpb[i].rps == V4L2_HEVC_DPB_ENTRY_RPS_LT_CURR)
> >                          dpb_longterm_e |= BIT(V4L2_HEVC_DPB_ENTRIES_NUM_MAX - 1 - i);
> > @@ -467,6 +471,8 @@ static int set_ref(struct hantro_ctx *ctx)
> >                  hantro_write_addr(vpu, G2_REG_ADDR_REF(i), luma_addr);
> >                  hantro_write_addr(vpu, G2_REG_CHR_REF(i), chroma_addr);
> >                  hantro_write_addr(vpu, G2_REG_DMV_REF(i), mv_addr);
> > +               hantro_write_addr(vpu, G2_COMP_ADDR_REF(i), compress_luma_addr);
> > +               hantro_write_addr(vpu, G2_COMP_CHR_REF(i), compress_chroma_addr);
> I'm a bit confused here, you are seeing luma_addr and also compress_luma_addr
> for references??

Yes both are need to make this work. It also done like that in vendor stack.

> I'm not saying this is wrong, just would like some comments in the code
> so the intention is a bit more clear and I can understand what's going on.

I will add comments to clarify that point.

Benjamin

> >          }
> >   
> >          luma_addr = hantro_hevc_get_ref_buf(ctx, decode_params->pic_order_cnt_val);
> > @@ -475,7 +481,11 @@ static int set_ref(struct hantro_ctx *ctx)
> >   
> >          chroma_addr = luma_addr + cr_offset;
> >          mv_addr = luma_addr + mv_offset;
> > +       compress_luma_addr = luma_addr + compress_luma_offset;
> > +       compress_chroma_addr = luma_addr + compress_chroma_offset;
> >   
> > +       hantro_write_addr(vpu, G2_COMP_ADDR_REF(i), compress_luma_addr);
> > +       hantro_write_addr(vpu, G2_COMP_CHR_REF(i), compress_chroma_addr);
> >          hantro_write_addr(vpu, G2_REG_ADDR_REF(i), luma_addr);
> >          hantro_write_addr(vpu, G2_REG_CHR_REF(i), chroma_addr);
> >          hantro_write_addr(vpu, G2_REG_DMV_REF(i++), mv_addr);
> > @@ -483,6 +493,8 @@ static int set_ref(struct hantro_ctx *ctx)
> >          hantro_write_addr(vpu, G2_ADDR_DST, luma_addr);
> >          hantro_write_addr(vpu, G2_ADDR_DST_CHR, chroma_addr);
> >          hantro_write_addr(vpu, G2_ADDR_DST_MV, mv_addr);
> > +       hantro_write_addr(vpu, G2_COMP_ADDR_DST, compress_luma_addr);
> > +       hantro_write_addr(vpu, G2_COMP_CHR, compress_chroma_addr);
> >   
> >          hantro_hevc_ref_remove_unused(ctx);
> >   
> > @@ -490,6 +502,8 @@ static int set_ref(struct hantro_ctx *ctx)
> >                  hantro_write_addr(vpu, G2_REG_ADDR_REF(i), 0);
> >                  hantro_write_addr(vpu, G2_REG_CHR_REF(i), 0);
> >                  hantro_write_addr(vpu, G2_REG_DMV_REF(i), 0);
> > +               hantro_write_addr(vpu, G2_COMP_ADDR_REF(i), 0);
> > +               hantro_write_addr(vpu, G2_COMP_CHR_REF(i), 0);
> >          }
> >   
> >          hantro_reg_write(vpu, &g2_refer_lterm_e, dpb_longterm_e);
> > @@ -580,8 +594,8 @@ int hantro_g2_hevc_dec_run(struct hantro_ctx *ctx)
> >          /* Don't disable output */
> >          hantro_reg_write(vpu, &g2_out_dis, 0);
> >   
> > -       /* Don't compress buffers */
> > -       hantro_reg_write(vpu, &g2_ref_compress_bypass, 1);
> > +       /* Compress buffers */
> > +       hantro_reg_write(vpu, &g2_ref_compress_bypass, 0);
> >   
> >          /* use NV12 as output format */
> >          hantro_reg_write(vpu, &g2_out_rs_e, 1);
> > diff --git a/drivers/staging/media/hantro/hantro_g2_regs.h b/drivers/staging/media/hantro/hantro_g2_regs.h
> > index 17d84ec9c5c2..0414d92e3860 100644
> > --- a/drivers/staging/media/hantro/hantro_g2_regs.h
> > +++ b/drivers/staging/media/hantro/hantro_g2_regs.h
> > @@ -192,6 +192,10 @@
> >   #define G2_TILE_FILTER         (G2_SWREG(179))
> >   #define G2_TILE_SAO            (G2_SWREG(181))
> >   #define G2_TILE_BSD            (G2_SWREG(183))
> > +#define G2_COMP_ADDR_DST       (G2_SWREG(190))
> > +#define G2_COMP_ADDR_REF(i)    (G2_SWREG(192) + ((i) * 0x8))
> > +#define G2_COMP_CHR            (G2_SWREG(224))
> > +#define G2_COMP_CHR_REF(i)     (G2_SWREG(226) + ((i) * 0x8))
> >   
> >   #define g2_strm_buffer_len     G2_DEC_REG(258, 0, 0xffffffff)
> >   #define g2_strm_start_offset   G2_DEC_REG(259, 0, 0xffffffff)
> > diff --git a/drivers/staging/media/hantro/hantro_hevc.c b/drivers/staging/media/hantro/hantro_hevc.c
> > index 5347f5a41c2a..1b2da990fbf0 100644
> > --- a/drivers/staging/media/hantro/hantro_hevc.c
> > +++ b/drivers/staging/media/hantro/hantro_hevc.c
> > @@ -61,12 +61,42 @@ static size_t hantro_hevc_mv_size(const struct v4l2_ctrl_hevc_sps *sps)
> >          return mv_size;
> >   }
> >   
> > +size_t hantro_hevc_luma_compress_offset(const struct v4l2_ctrl_hevc_sps *sps)
> > +{
> > +       return hantro_hevc_motion_vectors_offset(sps) + hantro_hevc_mv_size(sps);
> > +}
> > +
> > +static size_t hantro_hevc_luma_compress_size(const struct v4l2_ctrl_hevc_sps *sps)
> > +{
> > +       u32 pic_width_in_cbsy =
> > +               round_up((sps->pic_width_in_luma_samples + 8 - 1) / 8, 16);
> > +       u32 pic_height_in_cbsy = (sps->pic_height_in_luma_samples + 8 - 1) / 8;
> > +
> > +       return round_up(pic_width_in_cbsy * pic_height_in_cbsy, 16);
> > +}
> > +
> > +size_t hantro_hevc_chroma_compress_offset(const struct v4l2_ctrl_hevc_sps *sps)
> > +{
> > +       return hantro_hevc_luma_compress_offset(sps) + hantro_hevc_luma_compress_size(sps);
> > +}
> > +
> > +static size_t hantro_hevc_chroma_compress_size(const struct v4l2_ctrl_hevc_sps *sps)
> > +{
> > +       u32 pic_width_in_cbsc =
> > +               round_up((sps->pic_width_in_luma_samples + 16 - 1) / 16, 16);
> > +       u32 pic_height_in_cbsc = (sps->pic_height_in_luma_samples / 2 + 4 - 1) / 4;
> > +
> Can we get some #defines for these magic numbers?
>
> > +       return round_up(pic_width_in_cbsc * pic_height_in_cbsc, 16);
> > +}
> > +
> >   static size_t hantro_hevc_ref_size(struct hantro_ctx *ctx)
> >   {
> >          const struct hantro_hevc_dec_ctrls *ctrls = &ctx->hevc_dec.ctrls;
> >          const struct v4l2_ctrl_hevc_sps *sps = ctrls->sps;
> >   
> > -       return hantro_hevc_motion_vectors_offset(sps) + hantro_hevc_mv_size(sps);
> > +       return hantro_hevc_motion_vectors_offset(sps) + hantro_hevc_mv_size(sps) +
> > +              hantro_hevc_luma_compress_size(sps) +
> > +              hantro_hevc_chroma_compress_size(sps);
> >   }
> >   
> >   static void hantro_hevc_ref_free(struct hantro_ctx *ctx)
> > diff --git a/drivers/staging/media/hantro/hantro_hw.h b/drivers/staging/media/hantro/hantro_hw.h
> > index 8fa0aacb61cd..c5374cd74d66 100644
> > --- a/drivers/staging/media/hantro/hantro_hw.h
> > +++ b/drivers/staging/media/hantro/hantro_hw.h
> > @@ -246,6 +246,8 @@ dma_addr_t hantro_hevc_get_ref_buf(struct hantro_ctx *ctx, int poc);
> >   void hantro_hevc_ref_remove_unused(struct hantro_ctx *ctx);
> >   size_t hantro_hevc_chroma_offset(const struct v4l2_ctrl_hevc_sps *sps);
> >   size_t hantro_hevc_motion_vectors_offset(const struct v4l2_ctrl_hevc_sps *sps);
> > +size_t hantro_hevc_luma_compress_offset(const struct v4l2_ctrl_hevc_sps *sps);
> > +size_t hantro_hevc_chroma_compress_offset(const struct v4l2_ctrl_hevc_sps *sps);
> >   
> >   static inline size_t
> >   hantro_h264_mv_size(unsigned int width, unsigned int height)
> Thanks,
> Ezequiel