[Mesa-dev] [PATCH 4/6] i965: Implement interface to edit binding table entries

[Abdiel Janulgue]

Unlike normal software binding tables where the driver has to manually
generate and fill a binding table array which are then uploaded to the
hardware, the resource streamer instead presents the driver with an option
to fill out slots for individual binding table indices. The hardware
accumulates the state for these combined edits which it then automatically
flushes to a binding table pool when the binding table pointer state
command is invoked.

v2: Clarify binding table edit bit aligment (Topi).
v3: Make comments and function names more clearer (Ken).

Reviewed-by: Kenneth Graunke <kenneth at whitecape.org>
Signed-off-by: Abdiel Janulgue <abdiel.janulgue at linux.intel.com>
---
 src/mesa/drivers/dri/i965/brw_binding_tables.c | 55 ++++++++++++++++++++++++++
 src/mesa/drivers/dri/i965/brw_state.h          |  9 +++++
 2 files changed, 64 insertions(+)

diff --git a/src/mesa/drivers/dri/i965/brw_binding_tables.c b/src/mesa/drivers/dri/i965/brw_binding_tables.c
index 6bc540f..a0bc2f3 100644
--- a/src/mesa/drivers/dri/i965/brw_binding_tables.c
+++ b/src/mesa/drivers/dri/i965/brw_binding_tables.c
@@ -44,6 +44,12 @@
 #include "brw_state.h"
 #include "intel_batchbuffer.h"
 
+static const GLuint stage_to_bt_edit[MESA_SHADER_FRAGMENT + 1] = {
+   _3DSTATE_BINDING_TABLE_EDIT_VS,
+   _3DSTATE_BINDING_TABLE_EDIT_GS,
+   _3DSTATE_BINDING_TABLE_EDIT_PS,
+};
+
 /**
  * Upload a shader stage's binding table as indirect state.
  *
@@ -171,6 +177,55 @@ const struct brw_tracked_state brw_gs_binding_table = {
 };
 
 /**
+ * Edit a single entry in a hardware-generated binding table
+ */
+void
+gen7_edit_hw_binding_table_entry(struct brw_context *brw,
+                                 gl_shader_stage stage,
+                                 uint32_t index,
+                                 uint32_t surf_offset)
+{
+   assert(stage <= MESA_SHADER_FRAGMENT);
+
+   uint32_t dw2 = SET_FIELD(index, BRW_BINDING_TABLE_INDEX) |
+      (brw->gen >= 8 ? GEN8_SURFACE_STATE_EDIT(surf_offset) :
+       HSW_SURFACE_STATE_EDIT(surf_offset));
+
+   BEGIN_BATCH(3);
+   OUT_BATCH(stage_to_bt_edit[stage] << 16 | (3 - 2));
+   OUT_BATCH(BRW_BINDING_TABLE_EDIT_TARGET_ALL);
+   OUT_BATCH(dw2);
+   ADVANCE_BATCH();
+}
+
+/**
+ * Upload a whole hardware binding table for the given stage.
+ *
+ * Takes an array of surface offsets and the number of binding table
+ * entries.
+ */
+void
+gen7_update_binding_table_from_array(struct brw_context *brw,
+                                     gl_shader_stage stage,
+                                     const uint32_t* binding_table,
+                                     int num_surfaces)
+{
+   uint32_t dw2 = 0;
+   assert(stage <= MESA_SHADER_FRAGMENT);
+
+   BEGIN_BATCH(num_surfaces + 2);
+   OUT_BATCH(stage_to_bt_edit[stage] << 16 | num_surfaces);
+   OUT_BATCH(BRW_BINDING_TABLE_EDIT_TARGET_ALL);
+   for (int i = 0; i < num_surfaces; i++) {
+      dw2 = SET_FIELD(i, BRW_BINDING_TABLE_INDEX) |
+         (brw->gen >= 8 ? GEN8_SURFACE_STATE_EDIT(binding_table[i]) :
+          HSW_SURFACE_STATE_EDIT(binding_table[i]));
+      OUT_BATCH(dw2);
+   }
+   ADVANCE_BATCH();
+}
+
+/**
  * Hardware-generated binding tables for the resource streamer
  */
 void
diff --git a/src/mesa/drivers/dri/i965/brw_state.h b/src/mesa/drivers/dri/i965/brw_state.h
index f8ef98f..2eff1b5 100644
--- a/src/mesa/drivers/dri/i965/brw_state.h
+++ b/src/mesa/drivers/dri/i965/brw_state.h
@@ -374,6 +374,15 @@ gen7_upload_constant_state(struct brw_context *brw,
                            bool active, unsigned opcode);
 
 void gen7_rs_control(struct brw_context *brw, int enable);
+
+void gen7_edit_hw_binding_table_entry(struct brw_context *brw,
+                                      gl_shader_stage stage,
+                                      uint32_t index,
+                                      uint32_t surf_offset);
+void gen7_update_binding_table_from_array(struct brw_context *brw,
+                                          gl_shader_stage stage,
+                                          const uint32_t* binding_table,
+                                          int num_surfaces);
 void gen7_enable_hw_binding_tables(struct brw_context *brw);
 void gen7_disable_hw_binding_tables(struct brw_context *brw);
 void gen7_reset_hw_bt_pool_offsets(struct brw_context *brw);
-- 
1.9.1