From d7416ebc1966a28b81b250d61d1894a9ef29ea7e Mon Sep 17 00:00:00 2001
From: Faith Ekstrand <faith.ekstrand@collabora.com>
Date: Thu, 14 Aug 2025 16:18:26 -0400
Subject: [PATCH] intel/gem: Add an intel_gem_supports_dma_buf_sync_file()
 helper

Acked-by: Daniel Stone <daniels@collabora.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/36783>
---
 src/intel/common/i915/intel_gem.c | 55 +++++++++++++++++++++++++++++++
 src/intel/common/i915/intel_gem.h |  1 +
 2 files changed, 56 insertions(+)

diff --git a/src/intel/common/i915/intel_gem.c b/src/intel/common/i915/intel_gem.c
index 75c3cd5c6e4..5ea2cacd754 100644
--- a/src/intel/common/i915/intel_gem.c
+++ b/src/intel/common/i915/intel_gem.c
@@ -27,6 +27,9 @@
 #include "i915/intel_engine.h"
 
 #include "drm-uapi/i915_drm.h"
+#include "drm-uapi/dma-buf.h"
+
+#include <fcntl.h>
 
 bool
 i915_gem_create_context(int fd, uint32_t *context_id)
@@ -309,3 +312,55 @@ i915_gem_can_render_on_fd(int fd)
    int val;
    return intel_gem_get_param(fd, I915_PARAM_CHIPSET_ID, &val) && val > 0;
 }
+
+bool
+i915_gem_supports_dma_buf_sync_file(int fd)
+{
+   uint32_t handle = 0;
+   int err = 0, dma_buf_fd = -1;
+
+   struct drm_i915_gem_create gem_create = {
+      .size = 64 << 10,
+   };
+   if (intel_ioctl(fd, DRM_IOCTL_I915_GEM_CREATE, &gem_create))
+      return false;
+
+   handle = gem_create.handle;
+
+   struct drm_prime_handle handle_to_fd = {
+      .handle = handle,
+      .flags = DRM_CLOEXEC | DRM_RDWR,
+   };
+   err = intel_ioctl(fd, DRM_IOCTL_PRIME_HANDLE_TO_FD, &handle_to_fd);
+   if (err)
+      goto fail;
+
+   dma_buf_fd = handle_to_fd.fd;
+
+   struct dma_buf_export_sync_file export = {
+      .flags = DMA_BUF_SYNC_RW,
+      .fd = -1,
+   };
+   err = intel_ioctl(dma_buf_fd, DMA_BUF_IOCTL_EXPORT_SYNC_FILE, &export);
+   if (err)
+      goto fail;
+
+   struct dma_buf_import_sync_file import = {
+      .flags = DMA_BUF_SYNC_RW,
+      .fd = export.fd,
+   };
+   err = intel_ioctl(dma_buf_fd, DMA_BUF_IOCTL_IMPORT_SYNC_FILE, &import);
+   close(export.fd);
+
+fail:
+   if (dma_buf_fd >= 0)
+      close(dma_buf_fd);
+
+   if (handle != 0) {
+      struct drm_gem_close gem_close = { .handle = handle };
+      err = intel_ioctl(fd, DRM_IOCTL_GEM_CLOSE, &gem_close);
+      assert(err == 0);
+   }
+
+   return !err;
+}
diff --git a/src/intel/common/i915/intel_gem.h b/src/intel/common/i915/intel_gem.h
index cb82e38c17a..a2af62bb21d 100644
--- a/src/intel/common/i915/intel_gem.h
+++ b/src/intel/common/i915/intel_gem.h
@@ -50,6 +50,7 @@ i915_gem_create_context_ext(int fd,
 bool i915_gem_supports_protected_context(int fd);
 bool i915_gem_get_param(int fd, uint32_t param, int *value);
 bool i915_gem_can_render_on_fd(int fd);
+bool i915_gem_supports_dma_buf_sync_file(int fd);
 
 /**
  * A wrapper around DRM_IOCTL_I915_QUERY