intel: Delay testing for userptr until first use

Running __mmu_notifier_register() is surprisingly expensive, so let's
not do that unless we have to.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

diff --git a/intel/intel_bufmgr_gem.c b/intel/intel_bufmgr_gem.c
index 5a67f53..f5d6130 100644 (file)
--- a/intel/intel_bufmgr_gem.c
+++ b/intel/intel_bufmgr_gem.c
@@ -936,6 +936,71 @@ drm_intel_gem_bo_alloc_userptr(drm_intel_bufmgr *bufmgr,
        return &bo_gem->bo;
 }
 
+static bool
+has_userptr(drm_intel_bufmgr_gem *bufmgr_gem)
+{
+       int ret;
+       void *ptr;
+       long pgsz;
+       struct drm_i915_gem_userptr userptr;
+       struct drm_gem_close close_bo;
+
+       pgsz = sysconf(_SC_PAGESIZE);
+       assert(pgsz > 0);
+
+       ret = posix_memalign(&ptr, pgsz, pgsz);
+       if (ret) {
+               DBG("Failed to get a page (%ld) for userptr detection!\n",
+                       pgsz);
+               return false;
+       }
+
+       memclear(userptr);
+       userptr.user_ptr = (__u64)(unsigned long)ptr;
+       userptr.user_size = pgsz;
+
+retry:
+       ret = drmIoctl(bufmgr_gem->fd, DRM_IOCTL_I915_GEM_USERPTR, &userptr);
+       if (ret) {
+               if (errno == ENODEV && userptr.flags == 0) {
+                       userptr.flags = I915_USERPTR_UNSYNCHRONIZED;
+                       goto retry;
+               }
+               free(ptr);
+               return false;
+       }
+
+       memclear(close_bo);
+       close_bo.handle = userptr.handle;
+       ret = drmIoctl(bufmgr_gem->fd, DRM_IOCTL_GEM_CLOSE, &close_bo);
+       free(ptr);
+       if (ret) {
+               fprintf(stderr, "Failed to release test userptr object! (%d) "
+                               "i915 kernel driver may not be sane!\n", errno);
+               return false;
+       }
+
+       return true;
+}
+
+static drm_intel_bo *
+check_bo_alloc_userptr(drm_intel_bufmgr *bufmgr,
+                      const char *name,
+                      void *addr,
+                      uint32_t tiling_mode,
+                      uint32_t stride,
+                      unsigned long size,
+                      unsigned long flags)
+{
+       if (has_userptr((drm_intel_bufmgr_gem *)bufmgr))
+               bufmgr->bo_alloc_userptr = drm_intel_gem_bo_alloc_userptr;
+       else
+               bufmgr->bo_alloc_userptr = NULL;
+
+       return drm_intel_bo_alloc_userptr(bufmgr, name, addr,
+                                         tiling_mode, stride, size, flags);
+}
+
 /**
  * Returns a drm_intel_bo wrapping the given buffer object handle.
  *
@@ -3403,53 +3468,6 @@ drm_intel_bufmgr_gem_unref(drm_intel_bufmgr *bufmgr)
        }
 }
 
-static bool
-has_userptr(drm_intel_bufmgr_gem *bufmgr_gem)
-{
-       int ret;
-       void *ptr;
-       long pgsz;
-       struct drm_i915_gem_userptr userptr;
-       struct drm_gem_close close_bo;
-
-       pgsz = sysconf(_SC_PAGESIZE);
-       assert(pgsz > 0);
-
-       ret = posix_memalign(&ptr, pgsz, pgsz);
-       if (ret) {
-               DBG("Failed to get a page (%ld) for userptr detection!\n",
-                       pgsz);
-               return false;
-       }
-
-       memclear(userptr);
-       userptr.user_ptr = (__u64)(unsigned long)ptr;
-       userptr.user_size = pgsz;
-
-retry:
-       ret = drmIoctl(bufmgr_gem->fd, DRM_IOCTL_I915_GEM_USERPTR, &userptr);
-       if (ret) {
-               if (errno == ENODEV && userptr.flags == 0) {
-                       userptr.flags = I915_USERPTR_UNSYNCHRONIZED;
-                       goto retry;
-               }
-               free(ptr);
-               return false;
-       }
-
-       memclear(close_bo);
-       close_bo.handle = userptr.handle;
-       ret = drmIoctl(bufmgr_gem->fd, DRM_IOCTL_GEM_CLOSE, &close_bo);
-       free(ptr);
-       if (ret) {
-               fprintf(stderr, "Failed to release test userptr object! (%d) "
-                               "i915 kernel driver may not be sane!\n", errno);
-               return false;
-       }
-
-       return true;
-}
-
 /**
  * Initializes the GEM buffer manager, which uses the kernel to allocate, map,
  * and manage map buffer objections.
@@ -3554,9 +3572,7 @@ drm_intel_bufmgr_gem_init(int fd, int batch_size)
        ret = drmIoctl(bufmgr_gem->fd, DRM_IOCTL_I915_GETPARAM, &gp);
        bufmgr_gem->has_relaxed_fencing = ret == 0;
 
-       if (has_userptr(bufmgr_gem))
-               bufmgr_gem->bufmgr.bo_alloc_userptr =
-                       drm_intel_gem_bo_alloc_userptr;
+       bufmgr_gem->bufmgr.bo_alloc_userptr = check_bo_alloc_userptr;
 
        gp.param = I915_PARAM_HAS_WAIT_TIMEOUT;
        ret = drmIoctl(bufmgr_gem->fd, DRM_IOCTL_I915_GETPARAM, &gp);