nvc0: replace use of explicit default_tsc with entry 0

This was used for implementing FBFETCH. However that uses TXF, which
doesn't do much with a TSC. The only important bit is that sRGB-decoding
works as expected, which we can achieve since all samplers we ever
generate enable sRGB-decoding. Always point to entry 0 in the TSC table,
and ensure that even before it ever gets initialized, the sRGB-decoding
enable bit is set.

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>

src/gallium/drivers/nouveau/nvc0/nvc0_context.c

@@ -478,6 +478,16 @@ nvc0_create(struct pipe_screen *pscreen, void *priv, unsigned ctxflags)
 
    util_dynarray_init(&nvc0->global_residents, NULL);
 
+   // Make sure that the first TSC entry has SRGB conversion bit set, since we
+   // use it as a fallback on Fermi for TXF, and on Kepler+ generations for
+   // FBFETCH handling (which also uses TXF).
+   //
+   // NOTE: Preliminary testing suggests that this isn't necessary at all at
+   // least on GM20x (untested on Kepler). However this is ~free, so no reason
+   // not to do it.
+   if (!screen->tsc.entries[0])
+      nvc0_upload_tsc0(nvc0);
+
    return pipe;
 
 out_err:

src/gallium/drivers/nouveau/nvc0/nvc0_context.h

@@ -365,6 +365,7 @@ bool nve4_validate_tsc(struct nvc0_context *nvc0, int s);
 void nvc0_validate_suf(struct nvc0_context *nvc0, int s);
 void nvc0_validate_textures(struct nvc0_context *);
 void nvc0_validate_samplers(struct nvc0_context *);
+void nvc0_upload_tsc0(struct nvc0_context *);
 void nve4_set_tex_handles(struct nvc0_context *);
 void nvc0_validate_surfaces(struct nvc0_context *);
 void nve4_set_surface_info(struct nouveau_pushbuf *,

src/gallium/drivers/nouveau/nvc0/nvc0_screen.c

@@ -628,7 +628,6 @@ nvc0_screen_destroy(struct pipe_screen *pscreen)
    nouveau_heap_destroy(&screen->lib_code);
    nouveau_heap_destroy(&screen->text_heap);
 
-   FREE(screen->default_tsc);
    FREE(screen->tic.entries);
 
    nouveau_object_del(&screen->eng3d);
@@ -1387,9 +1386,6 @@ nvc0_screen_create(struct nouveau_device *dev)
    if (!nvc0_blitter_create(screen))
       goto fail;
 
-   screen->default_tsc = CALLOC_STRUCT(nv50_tsc_entry);
-   screen->default_tsc->tsc[0] = G80_TSC_0_SRGB_CONVERSION;
-
    nouveau_fence_new(&screen->base, &screen->base.fence.current);
 
    return &screen->base;

src/gallium/drivers/nouveau/nvc0/nvc0_screen.h

@@ -89,8 +89,6 @@ struct nvc0_screen {
 
    struct nvc0_blitter *blitter;
 
-   struct nv50_tsc_entry *default_tsc;
-
    struct {
       void **entries;
       int next;

src/gallium/drivers/nouveau/nvc0/nvc0_state_validate.c

@@ -1,4 +1,4 @@
-
+#include "util/u_format.h"
 #include "util/u_framebuffer.h"
 #include "util/u_math.h"
 #include "util/u_viewport.h"
@@ -831,20 +831,6 @@ nvc0_validate_fbread(struct nvc0_context *nvc0)
       pipe_sampler_view_reference(&nvc0->fbtexture, NULL);
    nvc0->fbtexture = new_view;
 
-   if (screen->default_tsc->id < 0) {
-      struct nv50_tsc_entry *tsc = nv50_tsc_entry(screen->default_tsc);
-      tsc->id = nvc0_screen_tsc_alloc(screen, tsc);
-      nvc0->base.push_data(&nvc0->base, screen->txc, 65536 + tsc->id * 32,
-                           NV_VRAM_DOMAIN(&screen->base), 32, tsc->tsc);
-      screen->tsc.lock[tsc->id / 32] |= 1 << (tsc->id % 32);
-
-      IMMED_NVC0(push, NVC0_3D(TSC_FLUSH), 0);
-      if (screen->base.class_3d < NVE4_3D_CLASS) {
-         BEGIN_NVC0(push, NVC0_3D(BIND_TSC2(0)), 1);
-         PUSH_DATA (push, (tsc->id << 12) | 1);
-      }
-   }
-
    if (new_view) {
       struct nv50_tic_entry *tic = nv50_tic_entry(new_view);
       assert(tic->id < 0);
@@ -860,7 +846,7 @@ nvc0_validate_fbread(struct nvc0_context *nvc0)
          PUSH_DATA (push, screen->uniform_bo->offset + NVC0_CB_AUX_INFO(4));
          BEGIN_1IC0(push, NVC0_3D(CB_POS), 1 + 1);
          PUSH_DATA (push, NVC0_CB_AUX_FB_TEX_INFO);
-         PUSH_DATA (push, (screen->default_tsc->id << 20) | tic->id);
+         PUSH_DATA (push, (0 << 20) | tic->id);
       } else {
          BEGIN_NVC0(push, NVC0_3D(BIND_TIC2(0)), 1);
          PUSH_DATA (push, (tic->id << 9) | 1);

src/gallium/drivers/nouveau/nvc0/nvc0_tex.c

@@ -728,6 +728,18 @@ void nvc0_validate_samplers(struct nvc0_context *nvc0)
    nvc0->dirty_cp |= NVC0_NEW_CP_SAMPLERS;
 }
 
+void
+nvc0_upload_tsc0(struct nvc0_context *nvc0)
+{
+   struct nouveau_pushbuf *push = nvc0->base.pushbuf;
+   u32 data[8] = { G80_TSC_0_SRGB_CONVERSION };
+   nvc0->base.push_data(&nvc0->base, nvc0->screen->txc,
+                        65536 /*+ tsc->id * 32*/,
+                        NV_VRAM_DOMAIN(&nvc0->screen->base), 32, data);
+   BEGIN_NVC0(push, NVC0_3D(TSC_FLUSH), 1);
+   PUSH_DATA (push, 0);
+}
+
 /* Upload the "diagonal" entries for the possible texture sources ($t == $s).
  * At some point we might want to get a list of the combinations used by a
  * shader and fill in those entries instead of having it extract the handles.