Re: [igt-dev] [PATCH i-g-t v3 09/21] lib/igt_vc4: Add helpers for converting linear to T-tiled RGB buffers

Paul Kocialkowski
2019-01-22T16:07:39Z

Hi and thanks for the review,

On Tue, 2019-01-15 at 16:20 -0500, Lyude Paul wrote:
> On Fri, 2019-01-11 at 10:05 +0100, Paul Kocialkowski wrote:
> > In order to integrate testing of T-tiled buffers, the easiest path is to
> > generate patterns (with the already-existing functions) in linear
> > buffers and convert them to T-tiled subsequently.
> >
> > Add helpers to do that conversion, with a first helper that returns the
> > memory offset for a given position in a T-tiled buffer and a second
> > helper that uses it for converting between framebuffers.
> >
> > Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
> > ---
> > lib/igt_vc4.c | 131 ++++++++++++++++++++++++++++++++++++++++++++++++++
> > lib/igt_vc4.h | 4 ++
> > 2 files changed, 135 insertions(+)
> >
> > diff --git a/lib/igt_vc4.c b/lib/igt_vc4.c
> > index 16dfe67a44b1..b4b9c2fc6914 100644
> > --- a/lib/igt_vc4.c
> > +++ b/lib/igt_vc4.c
> > @@ -34,6 +34,7 @@
> > #include "drmtest.h"
> > #include "igt_aux.h"
> > #include "igt_core.h"
> > +#include "igt_fb.h"
> > #include "igt_vc4.h"
> > #include "ioctl_wrappers.h"
> > #include "intel_reg.h"
> > @@ -176,3 +177,133 @@ bool igt_vc4_purgeable_bo(int fd, int handle, bool
> > purgeable)
> >
> > return arg.retained;
> > }
> > +
> > +unsigned int igt_vc4_fb_t_tiled_convert(struct igt_fb *dst, struct igt_fb
> > *src)
> > +{
> > + unsigned int fb_id;
> > + unsigned int i, j;
> > + void *src_buf;
> > + void *dst_buf;
> > + size_t bpp = src->plane_bpp[0];
> > + size_t dst_stride = ALIGN(src->strides[0], 128);
> > +
> > + fb_id = igt_create_fb_with_bo_size(src->fd, src->width, src->height,
> > + src->drm_format,
> > + DRM_FORMAT_MOD_BROADCOM_VC4_T_TILED
> > ,
> > + dst, 0, dst_stride);
> > + igt_assert(fb_id > 0);
> > +
> > + src_buf = igt_fb_map_buffer(src->fd, src);
> > + igt_assert(src_buf);
> > +
> > + dst_buf = igt_fb_map_buffer(dst->fd, dst);
> > + igt_assert(dst_buf);
> > +
> > + for (i = 0; i < src->height; i++) {
> > + for (j = 0; j < src->width; j++) {
> > + size_t src_offset = src->offsets[0];
> > + size_t dst_offset = dst->offsets[0];
> > +
> > + src_offset += src->strides[0] * i + j * bpp / 8;
> > + dst_offset += igt_vc4_t_tiled_offset(dst_stride,
> > + src->height,
> > + bpp, j, i);
> > +
> > + switch (bpp) {
> > + case 16:
> > + *(uint16_t *)(dst_buf + dst_offset) =
> > + *(uint16_t *)(src_buf + src_offset);
> > + break;
> > + case 32:
> > + *(uint32_t *)(dst_buf + dst_offset) =
> > + *(uint32_t *)(src_buf + src_offset);
> > + break;
> > + default:
> Maybe we should also have the two igt_fb_unmap_buffer() calls below this get
> invoked before calling igt_assert(false) so we don't leak FBs if this fails

If that's fine with you, I'd rather have an igt_assert(bpp == 16 || bpp
== 32) earlier so we don't reach mapping the buffers if the condition
cannot be guaranteed.

Cheers!

Paul

> With that fixed:
>
> Acked-by: Lyude Paul <lyude@redhat.com>
> > + igt_assert(false);
> > + }
> > + }
> > + }
> > +
> > + igt_fb_unmap_buffer(src, src_buf);
> > + igt_fb_unmap_buffer(dst, dst_buf);
> > +
> > + return fb_id;
> > +}
> > +
> > +/* Calculate the t-tile width so that size = width * height * bpp / 8. */
> > +#define VC4_T_TILE_W(size, height, bpp) ((size) / (height) / ((bpp) / 8))
> > +
> > +size_t igt_vc4_t_tiled_offset(size_t stride, size_t height, size_t bpp,
> > + size_t x, size_t y)
> > +{
> > + const size_t t1k_map_even[] = { 0, 3, 1, 2 };
> > + const size_t t1k_map_odd[] = { 2, 1, 3, 0 };
> > + const size_t t4k_t_h = 32;
> > + const size_t t1k_t_h = 16;
> > + const size_t t64_t_h = 4;
> > + size_t offset = 0;
> > + size_t t4k_t_w, t4k_w, t4k_x, t4k_y;
> > + size_t t1k_t_w, t1k_x, t1k_y;
> > + size_t t64_t_w, t64_x, t64_y;
> > + size_t pix_x, pix_y;
> > + unsigned int index;
> > +
> > + /* T-tiling is only supported for 16 and 32 bpp. */
> > + igt_assert(bpp == 16 || bpp == 32);
> > +
> > + /* T-tiling stride must be aligned to the 4K tiles strides. */
> > + igt_assert((stride % (4096 / t4k_t_h)) == 0);
> > +
> > + /* Calculate the tile width for the bpp. */
> > + t4k_t_w = VC4_T_TILE_W(4096, t4k_t_h, bpp);
> > + t1k_t_w = VC4_T_TILE_W(1024, t1k_t_h, bpp);
> > + t64_t_w = VC4_T_TILE_W(64, t64_t_h, bpp);
> > +
> > + /* Aligned total width in number of 4K tiles. */
> > + t4k_w = (stride / (bpp / 8)) / t4k_t_w;
> > +
> > + /* X and y coordinates in number of 4K tiles. */
> > + t4k_x = x / t4k_t_w;
> > + t4k_y = y / t4k_t_h;
> > +
> > + /* Increase offset to the beginning of the 4K tile row. */
> > + offset += t4k_y * t4k_w * 4096;
> > +
> > + /* X and Y coordinates in number of 1K tiles within the 4K tile. */
> > + t1k_x = (x % t4k_t_w) / t1k_t_w;
> > + t1k_y = (y % t4k_t_h) / t1k_t_h;
> > +
> > + /* Index for 1K tile map lookup. */
> > + index = 2 * t1k_y + t1k_x;
> > +
> > + /* Odd rows start from the right, even rows from the left. */
> > + if (t4k_y % 2) {
> > + /* Increase offset to the 4K tile (starting from the right).
> > */
> > + offset += (t4k_w - t4k_x - 1) * 4096;
> > +
> > + /* Incrase offset to the beginning of the (odd) 1K tile. */
> > + offset += t1k_map_odd[index] * 1024;
> > + } else {
> > + /* Increase offset to the 4K tile (starting from the left). */
> > + offset += t4k_x * 4096;
> > +
> > + /* Incrase offset to the beginning of the (even) 1K tile. */
> > + offset += t1k_map_even[index] * 1024;
> > + }
> > +
> > + /* X and Y coordinates in number of 64 byte tiles within the 1K tile.
> > */
> > + t64_x = (x % t1k_t_w) / t64_t_w;
> > + t64_y = (y % t1k_t_h) / t64_t_h;
> > +
> > + /* Increase offset to the beginning of the 64-byte tile. */
> > + offset += (t64_y * (t1k_t_w / t64_t_w) + t64_x) * 64;
> > +
> > + /* X and Y coordinates in number of pixels within the 64-byte tile. */
> > + pix_x = x % t64_t_w;
> > + pix_y = y % t64_t_h;
> > +
> > + /* Increase offset to the correct pixel. */
> > + offset += (pix_y * t64_t_w + pix_x) * bpp / 8;
> > +
> > + return offset;
> > +}
> > diff --git a/lib/igt_vc4.h b/lib/igt_vc4.h
> > index ebc8a3881b5e..d5c529bbccda 100644
> > --- a/lib/igt_vc4.h
> > +++ b/lib/igt_vc4.h
> > @@ -33,4 +33,8 @@ bool igt_vc4_purgeable_bo(int fd, int handle, bool
> > purgeable);
> > void igt_vc4_set_tiling(int fd, uint32_t handle, uint64_t modifier);
> > uint64_t igt_vc4_get_tiling(int fd, uint32_t handle);
> >
> > +unsigned int igt_vc4_fb_t_tiled_convert(struct igt_fb *dst, struct igt_fb
> > *src);
> > +size_t igt_vc4_t_tiled_offset(size_t stride, size_t height, size_t bpp,
> > + size_t x, size_t y);
> > +
> > #endif /* IGT_VC4_H */
--
Paul Kocialkowski, Bootlin
Embedded Linux and kernel engineering