drm/i915/userptr: Probe existence of backing struct pages upon creation

[linux-2.6-microblaze.git] / drivers / gpu / drm / i915 / gem / i915_gem_userptr.c

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
index 56edfef..468a7a6 100644 (file)
--- a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
@@ -422,6 +422,34 @@ static const struct drm_i915_gem_object_ops i915_gem_userptr_ops = {
 
 #endif
 
+static int
+probe_range(struct mm_struct *mm, unsigned long addr, unsigned long len)
+{
+       const unsigned long end = addr + len;
+       struct vm_area_struct *vma;
+       int ret = -EFAULT;
+
+       mmap_read_lock(mm);
+       for (vma = find_vma(mm, addr); vma; vma = vma->vm_next) {
+               /* Check for holes, note that we also update the addr below */
+               if (vma->vm_start > addr)
+                       break;
+
+               if (vma->vm_flags & (VM_PFNMAP | VM_MIXEDMAP))
+                       break;
+
+               if (vma->vm_end >= end) {
+                       ret = 0;
+                       break;
+               }
+
+               addr = vma->vm_end;
+       }
+       mmap_read_unlock(mm);
+
+       return ret;
+}
+
 /*
  * Creates a new mm object that wraps some normal memory from the process
  * context - user memory.
@@ -477,7 +505,8 @@ i915_gem_userptr_ioctl(struct drm_device *dev,
        }
 
        if (args->flags & ~(I915_USERPTR_READ_ONLY |
-                           I915_USERPTR_UNSYNCHRONIZED))
+                           I915_USERPTR_UNSYNCHRONIZED |
+                           I915_USERPTR_PROBE))
                return -EINVAL;
 
        if (i915_gem_object_size_2big(args->user_size))
@@ -504,6 +533,16 @@ i915_gem_userptr_ioctl(struct drm_device *dev,
                        return -ENODEV;
        }
 
+       if (args->flags & I915_USERPTR_PROBE) {
+               /*
+                * Check that the range pointed to represents real struct
+                * pages and not iomappings (at this moment in time!)
+                */
+               ret = probe_range(current->mm, args->user_ptr, args->user_size);
+               if (ret)
+                       return ret;
+       }
+
 #ifdef CONFIG_MMU_NOTIFIER
        obj = i915_gem_object_alloc();
        if (obj == NULL)