asahi: add XML for multiple viewports

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/26614>

src/asahi/lib/agx_ppp.h

@@ -36,8 +36,15 @@ agx_ppp_update_size(struct AGX_PPP_HEADER *present)
    PPP_CASE(fragment_back_face_2, FRAGMENT_FACE_2);
    PPP_CASE(fragment_back_stencil, FRAGMENT_STENCIL);
    PPP_CASE(depth_bias_scissor, DEPTH_BIAS_SCISSOR);
-   PPP_CASE(region_clip, REGION_CLIP);
-   PPP_CASE(viewport, VIEWPORT);
+
+   if (present->region_clip)
+      size += present->viewport_count * AGX_REGION_CLIP_LENGTH;
+
+   if (present->viewport) {
+      size += AGX_VIEWPORT_CONTROL_LENGTH +
+              (present->viewport_count * AGX_VIEWPORT_LENGTH);
+   }
+
    PPP_CASE(w_clamp, W_CLAMP);
    PPP_CASE(output_select, OUTPUT_SELECT);
    PPP_CASE(varying_counts_32, VARYING_COUNTS);

src/asahi/lib/cmdbuf.xml

@@ -430,6 +430,7 @@
     <field name="Depth bias/scissor" size="1" start="8" type="bool"/>
     <field name="Region clip" size="1" start="10" type="bool"/>
     <field name="Viewport" size="1" start="11" type="bool"/>
+    <field name="Viewport count" size="4" start="12" type="uint" default="1" modifier="minus(1)"/>
     <field name="W clamp" size="1" start="16" type="bool"/>
     <field name="Output select" size="1" start="17" type="bool"/>
     <field name="Varying counts 32" size="1" start="18" type="bool"/>
@@ -445,7 +446,7 @@
   </struct>
 
   <!-- Acts like a scissor at 32x32 tile boundaries, ignored unless clip tile is set -->
-  <struct name="Region clip" size="12">
+  <struct name="Region clip" size="8">
     <field name="Max X" size="9" start="0" type="uint" modifier="minus(1)"/>
     <field name="Min X" size="9" start="16" type="uint"/>
     <field name="Enable" size="1" start="31" type="bool"/>
@@ -453,6 +454,11 @@
     <field name="Min Y" size="9" start="48" type="uint"/>
   </struct>
 
+  <struct name="Viewport control" size="4">
+     <!-- so far only seen zeroes, but it stands to reason this is meant as a
+          control word for the viewports -->
+  </struct>
+
   <!-- Used to convert clip space coordinates to NDC, does not clip -->
   <struct name="Viewport" size="24">
     <field name="Translate X" size="32" start="0:0" type="float"/>

src/asahi/lib/decode.c

@@ -517,8 +517,38 @@ agxdecode_record(uint64_t va, size_t size, bool verbose, decoder_params *params)
    PPP_PRINT(map, fragment_back_face_2, FRAGMENT_FACE_2, "Back face 2");
    PPP_PRINT(map, fragment_back_stencil, FRAGMENT_STENCIL, "Back stencil");
    PPP_PRINT(map, depth_bias_scissor, DEPTH_BIAS_SCISSOR, "Depth bias/scissor");
-   PPP_PRINT(map, region_clip, REGION_CLIP, "Region clip");
-   PPP_PRINT(map, viewport, VIEWPORT, "Viewport");
+
+   if (hdr.region_clip) {
+      if (((map + (AGX_REGION_CLIP_LENGTH * hdr.viewport_count)) >
+           (base + size))) {
+         fprintf(agxdecode_dump_stream, "Buffer overrun in PPP update\n");
+         return;
+      }
+
+      for (unsigned i = 0; i < hdr.viewport_count; ++i) {
+         DUMP_CL(REGION_CLIP, map, "Region clip");
+         map += AGX_REGION_CLIP_LENGTH;
+         fflush(agxdecode_dump_stream);
+      }
+   }
+
+   if (hdr.viewport) {
+      if (((map + AGX_VIEWPORT_CONTROL_LENGTH +
+            (AGX_VIEWPORT_LENGTH * hdr.viewport_count)) > (base + size))) {
+         fprintf(agxdecode_dump_stream, "Buffer overrun in PPP update\n");
+         return;
+      }
+
+      DUMP_CL(VIEWPORT_CONTROL, map, "Viewport control");
+      map += AGX_VIEWPORT_CONTROL_LENGTH;
+
+      for (unsigned i = 0; i < hdr.viewport_count; ++i) {
+         DUMP_CL(VIEWPORT, map, "Viewport");
+         map += AGX_VIEWPORT_LENGTH;
+         fflush(agxdecode_dump_stream);
+      }
+   }
+
    PPP_PRINT(map, w_clamp, W_CLAMP, "W clamp");
    PPP_PRINT(map, output_select, OUTPUT_SELECT, "Output select");
    PPP_PRINT(map, varying_counts_32, VARYING_COUNTS, "Varying counts 32");

src/gallium/drivers/asahi/agx_state.c

@@ -1040,6 +1040,7 @@ agx_upload_viewport_scissor(struct agx_pool *pool, struct agx_batch *batch,
                                   .depth_bias_scissor = true,
                                   .region_clip = true,
                                   .viewport = true,
+                                  .viewport_count = 1,
                                });
 
    agx_ppp_push(&ppp, DEPTH_BIAS_SCISSOR, cfg) {
@@ -1058,6 +1059,9 @@ agx_upload_viewport_scissor(struct agx_pool *pool, struct agx_batch *batch,
       cfg.max_y = DIV_ROUND_UP(MAX2(maxy, 1), 32);
    }
 
+   agx_ppp_push(&ppp, VIEWPORT_CONTROL, cfg)
+      ;
+
    agx_ppp_push(&ppp, VIEWPORT, cfg) {
       cfg.translate_x = vp->translate[0];
       cfg.translate_y = vp->translate[1];
@@ -2951,6 +2955,7 @@ agx_batch_init_state(struct agx_batch *batch)
                                           .occlusion_query_2 = true,
                                           .output_unknown = true,
                                           .varying_word_2 = true,
+                                          .viewport_count = 1, /* irrelevant */
                                        });
 
    /* clang-format off */
@@ -3139,6 +3144,7 @@ agx_encode_state(struct agx_batch *batch, uint8_t *out, bool is_lines,
          IS_DIRTY(FS) || varyings_dirty || IS_DIRTY(SAMPLE_MASK),
       .occlusion_query = IS_DIRTY(QUERY),
       .output_size = IS_DIRTY(VS_PROG),
+      .viewport_count = 1, /* irrelevant */
    };
 
    struct agx_ppp_update ppp = agx_new_ppp_update(pool, dirty);