[Mesa-dev] [PATCH 3/3] anv: Disable constant buffer 0 being relative.

[Rafael Antognolli]

If we are on gen8+ and have context isolation support, just make that
constant buffer address be absolute, so we can use it for push UBOs too.
---
 src/intel/vulkan/anv_device.c  |  5 ++++-
 src/intel/vulkan/anv_private.h |  1 +
 src/intel/vulkan/genX_state.c  | 27 +++++++++++++++++++++++++++
 3 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/src/intel/vulkan/anv_device.c b/src/intel/vulkan/anv_device.c
index d1637f097e8..002b05f15f8 100644
--- a/src/intel/vulkan/anv_device.c
+++ b/src/intel/vulkan/anv_device.c
@@ -430,7 +430,8 @@ anv_physical_device_init(struct anv_physical_device *device,
    device->compiler->shader_debug_log = compiler_debug_log;
    device->compiler->shader_perf_log = compiler_perf_log;
    device->compiler->supports_pull_constants = false;
-   device->compiler->constant_buffer_0_is_relative = true;
+   device->compiler->constant_buffer_0_is_relative =
+      device->info.gen < 8 || !device->has_context_isolation;
 
    isl_device_init(&device->isl_dev, &device->info, swizzled);
 
@@ -1519,6 +1520,8 @@ VkResult anv_CreateDevice(
    device->chipset_id = physical_device->chipset_id;
    device->no_hw = physical_device->no_hw;
    device->lost = false;
+   device->constant_buffer_0_is_relative =
+      physical_device->compiler->constant_buffer_0_is_relative;
 
    if (pAllocator)
       device->alloc = *pAllocator;
diff --git a/src/intel/vulkan/anv_private.h b/src/intel/vulkan/anv_private.h
index 6af2a0bd3f3..d7297da6f57 100644
--- a/src/intel/vulkan/anv_private.h
+++ b/src/intel/vulkan/anv_private.h
@@ -983,6 +983,7 @@ struct anv_device {
     pthread_mutex_t                             mutex;
     pthread_cond_t                              queue_submit;
     bool                                        lost;
+    bool                                        constant_buffer_0_is_relative;
 };
 
 static inline struct anv_state_pool *
diff --git a/src/intel/vulkan/genX_state.c b/src/intel/vulkan/genX_state.c
index c6e54046910..46e020c8134 100644
--- a/src/intel/vulkan/genX_state.c
+++ b/src/intel/vulkan/genX_state.c
@@ -169,6 +169,33 @@ genX(init_device_state)(struct anv_device *device)
    gen10_emit_wa_lri_to_cache_mode_zero(&batch);
 #endif
 
+   /* Set the "CONSTANT_BUFFER Address Offset Disable" bit, so
+    * 3DSTATE_CONSTANT_XS buffer 0 is an absolute address.
+    *
+    * This is only safe on kernels with context isolation support.
+    */
+   if (GEN_GEN >= 8 &&
+       !device->constant_buffer_0_is_relative) {
+      UNUSED uint32_t tmp_reg;
+#if GEN_GEN >= 9
+      anv_pack_struct(&tmp_reg, GENX(CS_DEBUG_MODE2),
+                      .CONSTANT_BUFFERAddressOffsetDisable = true,
+                      .CONSTANT_BUFFERAddressOffsetDisableMask = true);
+      anv_batch_emit(&batch, GENX(MI_LOAD_REGISTER_IMM), lri) {
+         lri.RegisterOffset = GENX(CS_DEBUG_MODE2_num);
+         lri.DataDWord      = tmp_reg;
+      }
+#elif GEN_GEN == 8
+      anv_pack_struct(&tmp_reg, GENX(INSTPM),
+                      .CONSTANT_BUFFERAddressOffsetDisable = true,
+                      .CONSTANT_BUFFERAddressOffsetDisableMask = true);
+      anv_batch_emit(&batch, GENX(MI_LOAD_REGISTER_IMM), lri) {
+         lri.RegisterOffset = GENX(INSTPM_num);
+         lri.DataDWord      = tmp_reg;
+      }
+#endif
+   }
+
    anv_batch_emit(&batch, GENX(MI_BATCH_BUFFER_END), bbe);
 
    assert(batch.next <= batch.end);
-- 
2.14.3