radv: Implement VK_AMD_shader_info

This allows an app to query shader statistics and get a disassembly of
a shader. RenderDoc git has support for it, so this allows you to view
shader disassembly from a capture.

When this extension is enabled on a device (or when tracing), we now
disable pipeline caching, since we don't get the shader debug info when
we retrieve cached shaders.

v2: Improvements to resource usage reporting
v3: Disassembly string must be null terminated (string_buffer's length
    does not include the terminator)
v4: Fixed LDS reporting. (Bas)

Signed-off-by: Alex Smith <asmith@feralinteractive.com>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>

src/amd/vulkan/radv_device.c

@@ -944,10 +944,15 @@ VkResult radv_CreateDevice(
 	VkResult result;
 	struct radv_device *device;
 
+	bool keep_shader_info = false;
+
 	for (uint32_t i = 0; i < pCreateInfo->enabledExtensionCount; i++) {
 		const char *ext_name = pCreateInfo->ppEnabledExtensionNames[i];
 		if (!radv_physical_device_extension_supported(physical_device, ext_name))
 			return vk_error(VK_ERROR_EXTENSION_NOT_PRESENT);
+
+		if (strcmp(ext_name, VK_AMD_SHADER_INFO_EXTENSION_NAME) == 0)
+			keep_shader_info = true;
 	}
 
 	/* Check enabled features */
@@ -1041,10 +1046,14 @@ VkResult radv_CreateDevice(
 		device->physical_device->rad_info.max_se >= 2;
 
 	if (getenv("RADV_TRACE_FILE")) {
+		keep_shader_info = true;
+
 		if (!radv_init_trace(device))
 			goto fail;
 	}
 
+	device->keep_shader_info = keep_shader_info;
+
 	result = radv_device_init_meta(device);
 	if (result != VK_SUCCESS)
 		goto fail;

src/amd/vulkan/radv_extensions.py

@@ -81,6 +81,7 @@ EXTENSIONS = [
     Extension('VK_EXT_global_priority',                   1, 'device->rad_info.has_ctx_priority'),
     Extension('VK_AMD_draw_indirect_count',               1, True),
     Extension('VK_AMD_rasterization_order',               1, 'device->rad_info.chip_class >= VI && device->rad_info.max_se >= 2'),
+    Extension('VK_AMD_shader_info',                       1, True),
 ]
 
 class VkVersion:

src/amd/vulkan/radv_pipeline.c

@@ -1942,7 +1942,7 @@ void radv_create_shaders(struct radv_pipeline *pipeline,
 
 	for (int i = 0; i < MESA_SHADER_STAGES; ++i) {
 		free(codes[i]);
-		if (modules[i] && !pipeline->device->trace_bo)
+		if (modules[i] && !pipeline->device->keep_shader_info)
 			ralloc_free(nir[i]);
 	}
 

src/amd/vulkan/radv_pipeline_cache.c

@@ -62,9 +62,11 @@ radv_pipeline_cache_init(struct radv_pipeline_cache *cache,
 	cache->hash_table = malloc(byte_size);
 
 	/* We don't consider allocation failure fatal, we just start with a 0-sized
-	 * cache. */
+	 * cache. Disable caching when we want to keep shader debug info, since
+	 * we don't get the debug info on cached shaders. */
 	if (cache->hash_table == NULL ||
-	    (device->instance->debug_flags & RADV_DEBUG_NO_CACHE))
+	    (device->instance->debug_flags & RADV_DEBUG_NO_CACHE) ||
+	    device->keep_shader_info)
 		cache->table_size = 0;
 	else
 		memset(cache->hash_table, 0, byte_size);
@@ -186,8 +188,11 @@ radv_create_shader_variants_from_pipeline_cache(struct radv_device *device,
 	entry = radv_pipeline_cache_search_unlocked(cache, sha1);
 
 	if (!entry) {
+		/* Again, don't cache when we want debug info, since this isn't
+		 * present in the cache. */
 		if (!device->physical_device->disk_cache ||
-		    (device->instance->debug_flags & RADV_DEBUG_NO_CACHE)) {
+		    (device->instance->debug_flags & RADV_DEBUG_NO_CACHE) ||
+		    device->keep_shader_info) {
 			pthread_mutex_unlock(&cache->mutex);
 			return false;
 		}

src/amd/vulkan/radv_private.h

@@ -563,6 +563,9 @@ struct radv_device {
 	struct radeon_winsys_bo                      *trace_bo;
 	uint32_t                                     *trace_id_ptr;
 
+	/* Whether to keep shader debug info, for tracing or VK_AMD_shader_info */
+	bool                                         keep_shader_info;
+
 	struct radv_physical_device                  *physical_device;
 
 	/* Backup in-memory cache to be used if the app doesn't provide one */

src/amd/vulkan/radv_shader.c

@@ -46,6 +46,8 @@
 #include "util/debug.h"
 #include "ac_exp_param.h"
 
+#include "util/string_buffer.h"
+
 static const struct nir_shader_compiler_options nir_options = {
 	.vertex_id_zero_based = true,
 	.lower_scmp = true,
@@ -471,7 +473,7 @@ shader_variant_create(struct radv_device *device,
 	free(binary.relocs);
 	variant->ref_count = 1;
 
-	if (device->trace_bo) {
+	if (device->keep_shader_info) {
 		variant->disasm_string = binary.disasm_string;
 		if (!gs_copy_shader && !module->nir) {
 			variant->nir = *shaders;
@@ -593,11 +595,20 @@ radv_get_shader_name(struct radv_shader_variant *var, gl_shader_stage stage)
 	};
 }
 
-void
-radv_shader_dump_stats(struct radv_device *device,
-		       struct radv_shader_variant *variant,
-		       gl_shader_stage stage,
-		       FILE *file)
+static uint32_t
+get_total_sgprs(struct radv_device *device)
+{
+	if (device->physical_device->rad_info.chip_class >= VI)
+		return 800;
+	else
+		return 512;
+}
+
+static void
+generate_shader_stats(struct radv_device *device,
+		      struct radv_shader_variant *variant,
+		      gl_shader_stage stage,
+		      struct _mesa_string_buffer *buf)
 {
 	unsigned lds_increment = device->physical_device->rad_info.chip_class >= CIK ? 512 : 256;
 	struct ac_shader_config *conf;
@@ -623,12 +634,8 @@ radv_shader_dump_stats(struct radv_device *device,
 				     lds_increment);
 	}
 
-	if (conf->num_sgprs) {
-		if (device->physical_device->rad_info.chip_class >= VI)
-			max_simd_waves = MIN2(max_simd_waves, 800 / conf->num_sgprs);
-		else
-			max_simd_waves = MIN2(max_simd_waves, 512 / conf->num_sgprs);
-	}
+	if (conf->num_sgprs)
+		max_simd_waves = MIN2(max_simd_waves, get_total_sgprs(device) / conf->num_sgprs);
 
 	if (conf->num_vgprs)
 		max_simd_waves = MIN2(max_simd_waves, 256 / conf->num_vgprs);
@@ -639,27 +646,138 @@ radv_shader_dump_stats(struct radv_device *device,
 	if (lds_per_wave)
 		max_simd_waves = MIN2(max_simd_waves, 16384 / lds_per_wave);
 
+	if (stage == MESA_SHADER_FRAGMENT) {
+		_mesa_string_buffer_printf(buf, "*** SHADER CONFIG ***\n"
+					   "SPI_PS_INPUT_ADDR = 0x%04x\n"
+					   "SPI_PS_INPUT_ENA  = 0x%04x\n",
+					   conf->spi_ps_input_addr, conf->spi_ps_input_ena);
+	}
+
+	_mesa_string_buffer_printf(buf, "*** SHADER STATS ***\n"
+				   "SGPRS: %d\n"
+				   "VGPRS: %d\n"
+				   "Spilled SGPRs: %d\n"
+				   "Spilled VGPRs: %d\n"
+				   "Code Size: %d bytes\n"
+				   "LDS: %d blocks\n"
+				   "Scratch: %d bytes per wave\n"
+				   "Max Waves: %d\n"
+				   "********************\n\n\n",
+				   conf->num_sgprs, conf->num_vgprs,
+				   conf->spilled_sgprs, conf->spilled_vgprs, variant->code_size,
+				   conf->lds_size, conf->scratch_bytes_per_wave,
+				   max_simd_waves);
+}
+
+void
+radv_shader_dump_stats(struct radv_device *device,
+		       struct radv_shader_variant *variant,
+		       gl_shader_stage stage,
+		       FILE *file)
+{
+	struct _mesa_string_buffer *buf = _mesa_string_buffer_create(NULL, 256);
+
+	generate_shader_stats(device, variant, stage, buf);
+
 	fprintf(file, "\n%s:\n", radv_get_shader_name(variant, stage));
+	fprintf(file, buf->buf);
 
-	if (stage == MESA_SHADER_FRAGMENT) {
-		fprintf(file, "*** SHADER CONFIG ***\n"
-			"SPI_PS_INPUT_ADDR = 0x%04x\n"
-			"SPI_PS_INPUT_ENA  = 0x%04x\n",
-			conf->spi_ps_input_addr, conf->spi_ps_input_ena);
+	_mesa_string_buffer_destroy(buf);
+}
+
+VkResult
+radv_GetShaderInfoAMD(VkDevice _device,
+		      VkPipeline _pipeline,
+		      VkShaderStageFlagBits shaderStage,
+		      VkShaderInfoTypeAMD infoType,
+		      size_t* pInfoSize,
+		      void* pInfo)
+{
+	RADV_FROM_HANDLE(radv_device, device, _device);
+	RADV_FROM_HANDLE(radv_pipeline, pipeline, _pipeline);
+	gl_shader_stage stage = vk_to_mesa_shader_stage(shaderStage);
+	struct radv_shader_variant *variant = pipeline->shaders[stage];
+	struct _mesa_string_buffer *buf;
+	VkResult result = VK_SUCCESS;
+
+	/* Spec doesn't indicate what to do if the stage is invalid, so just
+	 * return no info for this. */
+	if (!variant)
+		return VK_ERROR_FEATURE_NOT_PRESENT;
+
+	switch (infoType) {
+	case VK_SHADER_INFO_TYPE_STATISTICS_AMD:
+		if (!pInfo) {
+			*pInfoSize = sizeof(VkShaderStatisticsInfoAMD);
+		} else {
+			unsigned lds_multiplier = device->physical_device->rad_info.chip_class >= CIK ? 512 : 256;
+			struct ac_shader_config *conf = &variant->config;
+
+			VkShaderStatisticsInfoAMD statistics = {};
+			statistics.shaderStageMask = shaderStage;
+			statistics.numPhysicalVgprs = 256;
+			statistics.numPhysicalSgprs = get_total_sgprs(device);
+			statistics.numAvailableSgprs = statistics.numPhysicalSgprs;
+
+			if (stage == MESA_SHADER_COMPUTE) {
+				unsigned *local_size = variant->nir->info.cs.local_size;
+				unsigned workgroup_size = local_size[0] * local_size[1] * local_size[2];
+
+				statistics.numAvailableVgprs = statistics.numPhysicalVgprs /
+							       ceil(workgroup_size / statistics.numPhysicalVgprs);
+
+				statistics.computeWorkGroupSize[0] = local_size[0];
+				statistics.computeWorkGroupSize[1] = local_size[1];
+				statistics.computeWorkGroupSize[2] = local_size[2];
+			} else {
+				statistics.numAvailableVgprs = statistics.numPhysicalVgprs;
+			}
+
+			statistics.resourceUsage.numUsedVgprs = conf->num_vgprs;
+			statistics.resourceUsage.numUsedSgprs = conf->num_sgprs;
+			statistics.resourceUsage.ldsSizePerLocalWorkGroup = 32768;
+			statistics.resourceUsage.ldsUsageSizeInBytes = conf->lds_size * lds_multiplier;
+			statistics.resourceUsage.scratchMemUsageInBytes = conf->scratch_bytes_per_wave;
+
+			size_t size = *pInfoSize;
+			*pInfoSize = sizeof(statistics);
+
+			memcpy(pInfo, &statistics, MIN2(size, *pInfoSize));
+
+			if (size < *pInfoSize)
+				result = VK_INCOMPLETE;
+		}
+
+		break;
+	case VK_SHADER_INFO_TYPE_DISASSEMBLY_AMD:
+		buf = _mesa_string_buffer_create(NULL, 1024);
+
+		_mesa_string_buffer_printf(buf, "%s:\n", radv_get_shader_name(variant, stage));
+		_mesa_string_buffer_printf(buf, "%s\n\n", variant->disasm_string);
+		generate_shader_stats(device, variant, stage, buf);
+
+		/* Need to include the null terminator. */
+		size_t length = buf->length + 1;
+
+		if (!pInfo) {
+			*pInfoSize = length;
+		} else {
+			size_t size = *pInfoSize;
+			*pInfoSize = length;
+
+			memcpy(pInfo, buf->buf, MIN2(size, length));
+
+			if (size < length)
+				result = VK_INCOMPLETE;
+		}
+
+		_mesa_string_buffer_destroy(buf);
+		break;
+	default:
+		/* VK_SHADER_INFO_TYPE_BINARY_AMD unimplemented for now. */
+		result = VK_ERROR_FEATURE_NOT_PRESENT;
+		break;
 	}
 
-	fprintf(file, "*** SHADER STATS ***\n"
-		"SGPRS: %d\n"
-		"VGPRS: %d\n"
-		"Spilled SGPRs: %d\n"
-		"Spilled VGPRs: %d\n"
-		"Code Size: %d bytes\n"
-		"LDS: %d blocks\n"
-		"Scratch: %d bytes per wave\n"
-		"Max Waves: %d\n"
-		"********************\n\n\n",
-		conf->num_sgprs, conf->num_vgprs,
-		conf->spilled_sgprs, conf->spilled_vgprs, variant->code_size,
-		conf->lds_size, conf->scratch_bytes_per_wave,
-		max_simd_waves);
+	return result;
 }