Mesa (master): radv: make shader BOs read-only for the GPU

[Samuel Pitoiset]

Module: Mesa
Branch: master
Commit: a3c2a86757a3ca25453b7143f1c774c5f7fe499e
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=a3c2a86757a3ca25453b7143f1c774c5f7fe499e

Author: Samuel Pitoiset <samuel.pitoiset at gmail.com>
Date:   Thu Jan  4 15:19:47 2018 +0100

radv: make shader BOs read-only for the GPU

Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
Reviewed-by: Bas Nieuwenhuizen <bas at basnieuwenhuizen.nl>

---

 src/amd/vulkan/radv_device.c  | 2 ++
 src/amd/vulkan/radv_private.h | 1 +
 src/amd/vulkan/radv_shader.c  | 5 ++++-
 3 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/amd/vulkan/radv_device.c b/src/amd/vulkan/radv_device.c
index 5f78af624b..528d3539c9 100644
--- a/src/amd/vulkan/radv_device.c
+++ b/src/amd/vulkan/radv_device.c
@@ -263,6 +263,8 @@ radv_physical_device_init(struct radv_physical_device *device,
 	 */
 	device->has_clear_state = device->rad_info.chip_class >= CIK;
 
+	device->cpdma_prefetch_writes_memory = device->rad_info.chip_class <= VI;
+
 	radv_physical_device_init_mem_types(device);
 
 	result = radv_init_wsi(device);
diff --git a/src/amd/vulkan/radv_private.h b/src/amd/vulkan/radv_private.h
index 30ccbea176..f691c832bc 100644
--- a/src/amd/vulkan/radv_private.h
+++ b/src/amd/vulkan/radv_private.h
@@ -272,6 +272,7 @@ struct radv_physical_device {
 	bool has_rbplus; /* if RB+ register exist */
 	bool rbplus_allowed; /* if RB+ is allowed */
 	bool has_clear_state;
+	bool cpdma_prefetch_writes_memory;
 
 	/* This is the drivers on-disk cache used as a fallback as opposed to
 	 * the pipeline cache defined by apps.
diff --git a/src/amd/vulkan/radv_shader.c b/src/amd/vulkan/radv_shader.c
index 31879805ae..971d3abac9 100644
--- a/src/amd/vulkan/radv_shader.c
+++ b/src/amd/vulkan/radv_shader.c
@@ -330,7 +330,10 @@ radv_alloc_shader_memory(struct radv_device *device,
 
 	slab->size = 256 * 1024;
 	slab->bo = device->ws->buffer_create(device->ws, slab->size, 256,
-	                                     RADEON_DOMAIN_VRAM, RADEON_FLAG_NO_INTERPROCESS_SHARING);
+	                                     RADEON_DOMAIN_VRAM,
+					     RADEON_FLAG_NO_INTERPROCESS_SHARING |
+					     device->physical_device->cpdma_prefetch_writes_memory ?
+					             0 : RADEON_FLAG_READ_ONLY);
 	slab->ptr = (char*)device->ws->buffer_map(slab->bo);
 	list_inithead(&slab->shaders);