[PATCH v4 2/9] media: hantro: Add support of compressed reference buffers

From: Benjamin Gaignard
Date: Fri Jun 25 2021 - 10:12:16 EST


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.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@xxxxxxxxxxxxx>
---
version 4:
- Fix typos

version 2:
- Define the value for compression storage size
- Add comments about registers usage

.../staging/media/hantro/hantro_g2_hevc_dec.c | 31 ++++++++++++--
drivers/staging/media/hantro/hantro_g2_regs.h | 4 ++
drivers/staging/media/hantro/hantro_hevc.c | 41 ++++++++++++++++++-
drivers/staging/media/hantro/hantro_hw.h | 2 +
4 files changed, 74 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 fef16d1724da..d8c83eb37e64 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[] = {
@@ -458,15 +460,28 @@ static int set_ref(struct hantro_ctx *ctx)
if (!luma_addr)
return -ENOMEM;

+ /*
+ * An allocated frame stores Y and UV planes, motion vectors and
+ * compressed Y and UV planes. Compute all these offsets given
+ * the frame resolution and the pixel format.
+ */
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);

+ /*
+ * For each reference frame Y, UV, motion vector and
+ * compressed Y, UV buffers addresses must be set.
+ */
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);
}

luma_addr = hantro_hevc_get_ref_buf(ctx, decode_params->pic_order_cnt_val);
@@ -475,7 +490,12 @@ 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;

+ /* The next decoded frame as to be put as the last reference frame entry */
+ 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);
@@ -483,13 +503,18 @@ 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);

+ /* Unused reference frames entries most be cleared */
for (; i < V4L2_HEVC_DPB_ENTRIES_NUM_MAX; i++) {
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 +605,8 @@ 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..78e5ceda520c 100644
--- a/drivers/staging/media/hantro/hantro_hevc.c
+++ b/drivers/staging/media/hantro/hantro_hevc.c
@@ -27,6 +27,13 @@

#define G2_ALIGN 16

+#define CBS_SIZE 16 /* compression table size in bytes */
+#define CBS_LUMA 8 /* luminance CBS is composed of 1 8x8 coded block */
+#define CBS_CHROMA_W (8 * 2) /* chrominance CBS is composed of two 8x4 coded
+ * blocks, with Cb CB first then Cr CB following
+ */
+#define CBS_CHROMA_H 4
+
size_t hantro_hevc_chroma_offset(const struct v4l2_ctrl_hevc_sps *sps)
{
int bytes_per_pixel = sps->bit_depth_luma_minus8 == 0 ? 1 : 2;
@@ -61,12 +68,44 @@ 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 + CBS_LUMA - 1) / CBS_LUMA, CBS_SIZE);
+ u32 pic_height_in_cbsy = (sps->pic_height_in_luma_samples + CBS_LUMA - 1) / CBS_LUMA;
+
+ return round_up(pic_width_in_cbsy * pic_height_in_cbsy, CBS_SIZE);
+}
+
+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 + CBS_CHROMA_W - 1)
+ / CBS_CHROMA_W, CBS_SIZE);
+ u32 pic_height_in_cbsc = (sps->pic_height_in_luma_samples / 2 + CBS_CHROMA_H - 1)
+ / CBS_CHROMA_H;
+
+ return round_up(pic_width_in_cbsc * pic_height_in_cbsc, CBS_SIZE);
+}
+
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 5a455dd28aa6..460e86efa7a4 100644
--- a/drivers/staging/media/hantro/hantro_hw.h
+++ b/drivers/staging/media/hantro/hantro_hw.h
@@ -248,6 +248,8 @@ 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)
--
2.25.1