[Intel-gfx] [PATCH v2 16/18] drm/i915: Check against correct user_size limit in 48b ppgtt mode

[Michel Thierry]

GTT is only 32b and its max value is 4GB. In order to allow objects
bigger than 4GB in 48b PPGTT, i915_gem_userptr_ioctl needs to check
against max 48b range (1ULL << 48).

Whenever possible, read the PPGTT's total instead of the GTT one, this
will be accurate in 32 and 48 bit modes.

v2: Use the default ctx to infer the ppgtt max size (Akash).

Cc: Akash Goel <akash.goel at intel.com>
Signed-off-by: Michel Thierry <michel.thierry at intel.com>
---
 drivers/gpu/drm/i915/i915_gem_userptr.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_userptr.c b/drivers/gpu/drm/i915/i915_gem_userptr.c
index 1f4e5a3..9783415 100644
--- a/drivers/gpu/drm/i915/i915_gem_userptr.c
+++ b/drivers/gpu/drm/i915/i915_gem_userptr.c
@@ -789,8 +789,10 @@ int
 i915_gem_userptr_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct drm_i915_file_private *file_priv = file->driver_priv;
 	struct drm_i915_gem_userptr *args = data;
 	struct drm_i915_gem_object *obj;
+	struct intel_context *ctx;
 	int ret;
 	u32 handle;
 
@@ -801,8 +803,14 @@ i915_gem_userptr_ioctl(struct drm_device *dev, void *data, struct drm_file *file
 	if (offset_in_page(args->user_ptr | args->user_size))
 		return -EINVAL;
 
-	if (args->user_size > dev_priv->gtt.base.total)
-		return -E2BIG;
+	ctx = i915_gem_context_get(file_priv, DEFAULT_CONTEXT_HANDLE);
+	if (ctx->ppgtt) {
+		if (args->user_size > ctx->ppgtt->base.total)
+			return -E2BIG;
+	} else {
+		if (args->user_size > dev_priv->gtt.base.total)
+			return -E2BIG;
+	}
 
 	if (!access_ok(args->flags & I915_USERPTR_READ_ONLY ? VERIFY_READ : VERIFY_WRITE,
 		       (char __user *)(unsigned long)args->user_ptr, args->user_size))
-- 
2.4.0