freedreno/a6xx: Allocate lrcfc when needed for direction tracking

On later GPUs this buffer is also used for direction tracking, etc.
Meaning that it is not optional.

Signed-off-by: Rob Clark <robdclark@chromium.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/30304>

src/gallium/drivers/freedreno/a6xx/fd6_gmem.cc

@@ -281,9 +281,14 @@ emit_lrz(struct fd_batch *batch, struct fd_batch_subpass *subpass)
    fd6_emit_lrz_flush(ring);
 
    struct fd_resource *zsbuf = fd_resource(pfb->zsbuf->texture);
-   OUT_REG(ring, A6XX_GRAS_LRZ_BUFFER_BASE(.bo = subpass->lrz),
+   OUT_REG(ring,
-           A6XX_GRAS_LRZ_BUFFER_PITCH(.pitch = zsbuf->lrz_pitch),
+      A6XX_GRAS_LRZ_BUFFER_BASE(.bo = subpass->lrz),
-           A6XX_GRAS_LRZ_FAST_CLEAR_BUFFER_BASE());
+      A6XX_GRAS_LRZ_BUFFER_PITCH(.pitch = zsbuf->lrz_pitch),
+      A6XX_GRAS_LRZ_FAST_CLEAR_BUFFER_BASE(
+         .bo = zsbuf->lrz_fc_offset ? subpass->lrz : NULL,
+         .bo_offset = zsbuf->lrz_fc_offset
+      ),
+   );
    fd_ringbuffer_attach_bo(ring, subpass->lrz);
 }
 

src/gallium/drivers/freedreno/a6xx/fd6_resource.cc

@@ -32,6 +32,7 @@
 #include "a6xx/fd6_blitter.h"
 #include "fd6_resource.h"
 #include "fdl/fd6_format_table.h"
+#include "common/freedreno_lrz.h"
 #include "common/freedreno_ubwc.h"
 
 #include "a6xx.xml.h"
@@ -233,6 +234,7 @@ fd6_validate_format(struct fd_context *ctx, struct fd_resource *rsc,
    }
 }
 
+template <chip CHIP>
 static void
 setup_lrz(struct fd_resource *rsc)
 {
@@ -252,21 +254,43 @@ setup_lrz(struct fd_resource *rsc)
    unsigned lrz_pitch = align(DIV_ROUND_UP(width0, 8), 32);
    unsigned lrz_height = align(DIV_ROUND_UP(height0, 8), 16);
 
-   unsigned size = lrz_pitch * lrz_height * 2;
-
    rsc->lrz_height = lrz_height;
    rsc->lrz_width = lrz_pitch;
    rsc->lrz_pitch = lrz_pitch;
-   rsc->lrz = fd_bo_new(screen->dev, size, FD_BO_NOMAP, "lrz");
+
+   unsigned lrz_size = lrz_pitch * lrz_height * 2;
+
+   unsigned nblocksx = DIV_ROUND_UP(DIV_ROUND_UP(width0, 8), 16);
+   unsigned nblocksy = DIV_ROUND_UP(DIV_ROUND_UP(height0, 8), 4);
+
+   /* Fast-clear buffer is 1bit/block */
+   unsigned lrz_fc_size = DIV_ROUND_UP(nblocksx * nblocksy, 8);
+
+   /* Fast-clear buffer cannot be larger than 512 bytes on A6XX and 1024 bytes
+    * on A7XX (HW limitation)
+    */
+   bool has_lrz_fc = screen->info->a6xx.enable_lrz_fast_clear &&
+                     lrz_fc_size <= fd_lrzfc_layout<CHIP>::FC_SIZE;
+
+   /* Allocate a LRZ fast-clear buffer even if we aren't using FC, if the
+    * hw is re-using this buffer for direction tracking
+    */
+   if (has_lrz_fc || screen->info->a6xx.has_lrz_dir_tracking) {
+      rsc->lrz_fc_offset = lrz_size;
+      lrz_size += sizeof(fd_lrzfc_layout<CHIP>);
+   }
+
+   rsc->lrz = fd_bo_new(screen->dev, lrz_size, FD_BO_NOMAP, "lrz");
 }
 
 static uint32_t
 fd6_setup_slices(struct fd_resource *rsc)
 {
    struct pipe_resource *prsc = &rsc->b.b;
+   struct fd_screen *screen = fd_screen(prsc->screen);
 
    if (!FD_DBG(NOLRZ) && has_depth(prsc->format) && !is_z32(prsc->format))
-      setup_lrz(rsc);
+      FD_CALLX(screen->info, setup_lrz)(rsc);
 
    if (rsc->layout.ubwc && !ok_ubwc_format(prsc->screen, prsc->format))
       rsc->layout.ubwc = false;

src/gallium/drivers/freedreno/freedreno_resource.h

@@ -168,6 +168,7 @@ struct fd_resource {
    uint16_t lrz_width; // for lrz clear, does this differ from lrz_pitch?
    uint16_t lrz_height;
    uint16_t lrz_pitch;
+   uint16_t lrz_fc_offset;
    struct fd_bo *lrz;
 };