[PATCH 2/3] anv: Add new VK_MESA_query_timestamp extension to anv driver [v2]

[Keith Packard]

This extension adds a single function to query the current GPU
timestamp, just like glGetInteger64v(GL_TIMESTAMP, &timestamp). This
function is needed to complete the implementation of
GOOGLE_display_timing, which needs to be able to correlate GPU and CPU
timestamps.

v2:	Adopt Jason Ekstrand's coding conventions

	Declare variables at first use, eliminate extra whitespace between
	types and names. Wrap lines to 80 columns.

	Add extension to list in alphabetical order

	Suggested-by: Jason Ekstrand <jason.ekstrand at intel.com>

Signed-off-by: Keith Packard <keithp at keithp.com>
---
 src/intel/vulkan/anv_extensions.py |  1 +
 src/intel/vulkan/anv_gem.c         | 13 +++++++++++++
 src/intel/vulkan/anv_private.h     |  3 +++
 src/intel/vulkan/genX_query.c      | 15 +++++++++++++++
 4 files changed, 32 insertions(+)

diff --git a/src/intel/vulkan/anv_extensions.py b/src/intel/vulkan/anv_extensions.py
index 0f99f58ecb1..37bace23857 100644
--- a/src/intel/vulkan/anv_extensions.py
+++ b/src/intel/vulkan/anv_extensions.py
@@ -120,6 +120,7 @@ EXTENSIONS = [
               'device->has_context_priority'),
     Extension('VK_EXT_shader_viewport_index_layer',       1, True),
     Extension('VK_EXT_shader_stencil_export',             1, 'device->info.gen >= 9'),
+    Extension('VK_MESA_query_timestamp',                  1, True),
 ]
 
 class VkVersion:
diff --git a/src/intel/vulkan/anv_gem.c b/src/intel/vulkan/anv_gem.c
index 3ba6d198a8a..8a31940e7aa 100644
--- a/src/intel/vulkan/anv_gem.c
+++ b/src/intel/vulkan/anv_gem.c
@@ -423,6 +423,19 @@ anv_gem_fd_to_handle(struct anv_device *device, int fd)
    return args.handle;
 }
 
+int
+anv_gem_reg_read(struct anv_device *device, uint32_t offset, uint64_t *result)
+{
+   struct drm_i915_reg_read args = {
+      .offset = offset
+   };
+
+   int ret = anv_ioctl(device->fd, DRM_IOCTL_I915_REG_READ, &args);
+
+   *result = args.val;
+   return ret;
+}
+
 #ifndef SYNC_IOC_MAGIC
 /* duplicated from linux/sync_file.h to avoid build-time dependency
  * on new (v4.7) kernel headers.  Once distro's are mostly using
diff --git a/src/intel/vulkan/anv_private.h b/src/intel/vulkan/anv_private.h
index 510471da602..0fa2a46e333 100644
--- a/src/intel/vulkan/anv_private.h
+++ b/src/intel/vulkan/anv_private.h
@@ -76,6 +76,7 @@ struct gen_l3_config;
 #include <vulkan/vulkan_intel.h>
 #include <vulkan/vk_icd.h>
 #include <vulkan/vk_android_native_buffer.h>
+#include <vulkan/vk_mesa_query_timestamp.h>
 
 #include "anv_entrypoints.h"
 #include "anv_extensions.h"
@@ -1055,6 +1056,8 @@ int anv_gem_get_aperture(int fd, uint64_t *size);
 int anv_gem_gpu_get_reset_stats(struct anv_device *device,
                                 uint32_t *active, uint32_t *pending);
 int anv_gem_handle_to_fd(struct anv_device *device, uint32_t gem_handle);
+int anv_gem_reg_read(struct anv_device *device,
+                     uint32_t offset, uint64_t *result);
 uint32_t anv_gem_fd_to_handle(struct anv_device *device, int fd);
 int anv_gem_set_caching(struct anv_device *device, uint32_t gem_handle, uint32_t caching);
 int anv_gem_set_domain(struct anv_device *device, uint32_t gem_handle,
diff --git a/src/intel/vulkan/genX_query.c b/src/intel/vulkan/genX_query.c
index e35e9b85844..980c543460e 100644
--- a/src/intel/vulkan/genX_query.c
+++ b/src/intel/vulkan/genX_query.c
@@ -552,6 +552,21 @@ void genX(CmdWriteTimestamp)(
    }
 }
 
+VkResult genX(QueryCurrentTimestampMESA)(
+   VkDevice                                     _device,
+   uint64_t                                     *timestamp)
+{
+   ANV_FROM_HANDLE(anv_device, device, _device);
+   int  ret;
+
+   /* XXX older kernels don't support this interface. */
+   ret = anv_gem_reg_read(device, TIMESTAMP | 1, timestamp);
+
+   if (ret != 0)
+      return VK_ERROR_DEVICE_LOST;
+   return VK_SUCCESS;
+}
+
 #if GEN_GEN > 7 || GEN_IS_HASWELL
 
 static uint32_t
-- 
2.17.1