drm/i915: Mark a few functions as __must_check

... to benefit from the compiler checking that we remember to handle
and propagate errors.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

2 files changed, 58 insertions, 56 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index ee7df1d2b8c8..b6ca10ade426 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1093,11 +1093,11 @@ int i915_gem_init_object(struct drm_gem_object *obj);
 struct drm_i915_gem_object *i915_gem_alloc_object(struct drm_device *dev,
                                                   size_t size);
 void i915_gem_free_object(struct drm_gem_object *obj);
-int i915_gem_object_pin(struct drm_i915_gem_object *obj,
-                        uint32_t alignment,
-                        bool map_and_fenceable);
+int __must_check i915_gem_object_pin(struct drm_i915_gem_object *obj,
+                                     uint32_t alignment,
+                                     bool map_and_fenceable);
 void i915_gem_object_unpin(struct drm_i915_gem_object *obj);
-int i915_gem_object_unbind(struct drm_i915_gem_object *obj);
+int __must_check i915_gem_object_unbind(struct drm_i915_gem_object *obj);
 void i915_gem_release_mmap(struct drm_i915_gem_object *obj);
 void i915_gem_lastclose(struct drm_device *dev);
 
@@ -1110,37 +1110,42 @@ i915_seqno_passed(uint32_t seq1, uint32_t seq2)
         return (int32_t)(seq1 - seq2) >= 0;
 }
 
-int i915_gem_object_get_fence_reg(struct drm_i915_gem_object *obj,
-                                  bool interruptible);
-int i915_gem_object_put_fence_reg(struct drm_i915_gem_object *obj,
-                                  bool interruptible);
+int __must_check i915_gem_object_get_fence_reg(struct drm_i915_gem_object *obj,
+                                               bool interruptible);
+int __must_check i915_gem_object_put_fence_reg(struct drm_i915_gem_object *obj,
+                                               bool interruptible);
+
 void i915_gem_retire_requests(struct drm_device *dev);
 void i915_gem_reset(struct drm_device *dev);
 void i915_gem_clflush_object(struct drm_i915_gem_object *obj);
-int i915_gem_object_set_domain(struct drm_i915_gem_object *obj,
-                               uint32_t read_domains,
-                               uint32_t write_domain);
-int i915_gem_object_flush_gpu(struct drm_i915_gem_object *obj,
-                              bool interruptible);
-int i915_gem_init_ringbuffer(struct drm_device *dev);
+int __must_check i915_gem_object_set_domain(struct drm_i915_gem_object *obj,
+                                            uint32_t read_domains,
+                                            uint32_t write_domain);
+int __must_check i915_gem_object_flush_gpu(struct drm_i915_gem_object *obj,
+                                           bool interruptible);
+int __must_check i915_gem_init_ringbuffer(struct drm_device *dev);
 void i915_gem_cleanup_ringbuffer(struct drm_device *dev);
-int i915_gem_do_init(struct drm_device *dev, unsigned long start,
-                     unsigned long mappable_end, unsigned long end);
-int i915_gpu_idle(struct drm_device *dev);
-int i915_gem_idle(struct drm_device *dev);
-int i915_add_request(struct drm_device *dev,
-                     struct drm_file *file_priv,
-                     struct drm_i915_gem_request *request,
-                     struct intel_ring_buffer *ring);
-int i915_do_wait_request(struct drm_device *dev,
-                         uint32_t seqno,
-                         bool interruptible,
-                         struct intel_ring_buffer *ring);
+void i915_gem_do_init(struct drm_device *dev,
+                      unsigned long start,
+                      unsigned long mappable_end,
+                      unsigned long end);
+int __must_check i915_gpu_idle(struct drm_device *dev);
+int __must_check i915_gem_idle(struct drm_device *dev);
+int __must_check i915_add_request(struct drm_device *dev,
+                                  struct drm_file *file_priv,
+                                  struct drm_i915_gem_request *request,
+                                  struct intel_ring_buffer *ring);
+int __must_check i915_do_wait_request(struct drm_device *dev,
+                                      uint32_t seqno,
+                                      bool interruptible,
+                                      struct intel_ring_buffer *ring);
 int i915_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf);
-int i915_gem_object_set_to_gtt_domain(struct drm_i915_gem_object *obj,
-                                      int write);
-int i915_gem_object_set_to_display_plane(struct drm_i915_gem_object *obj,
-                                         struct intel_ring_buffer *pipelined);
+int __must_check
+i915_gem_object_set_to_gtt_domain(struct drm_i915_gem_object *obj,
+                                  bool write);
+int __must_check
+i915_gem_object_set_to_display_plane(struct drm_i915_gem_object *obj,
+                                     struct intel_ring_buffer *pipelined);
 int i915_gem_attach_phys_object(struct drm_device *dev,
                                 struct drm_i915_gem_object *obj,
                                 int id,
@@ -1152,14 +1157,16 @@ void i915_gem_release(struct drm_device *dev, struct drm_file *file);
 
 /* i915_gem_gtt.c */
 void i915_gem_restore_gtt_mappings(struct drm_device *dev);
-int i915_gem_gtt_bind_object(struct drm_i915_gem_object *obj);
+int __must_check i915_gem_gtt_bind_object(struct drm_i915_gem_object *obj);
 void i915_gem_gtt_unbind_object(struct drm_i915_gem_object *obj);
 
 /* i915_gem_evict.c */
-int i915_gem_evict_something(struct drm_device *dev, int min_size,
-                             unsigned alignment, bool mappable);
-int i915_gem_evict_everything(struct drm_device *dev, bool purgeable_only);
-int i915_gem_evict_inactive(struct drm_device *dev, bool purgeable_only);
+int __must_check i915_gem_evict_something(struct drm_device *dev, int min_size,
+                                          unsigned alignment, bool mappable);
+int __must_check i915_gem_evict_everything(struct drm_device *dev,
+                                           bool purgeable_only);
+int __must_check i915_gem_evict_inactive(struct drm_device *dev,
+                                         bool purgeable_only);
 
 /* i915_gem_tiling.c */
 void i915_gem_detect_bit_6_swizzle(struct drm_device *dev);
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 939c9e34ce96..f6167c55a649 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -215,27 +215,19 @@ i915_gem_object_is_inactive(struct drm_i915_gem_object *obj)
         return obj->gtt_space && !obj->active && obj->pin_count == 0;
 }
 
-int i915_gem_do_init(struct drm_device *dev,
-                     unsigned long start,
-                     unsigned long mappable_end,
-                     unsigned long end)
+void i915_gem_do_init(struct drm_device *dev,
+                      unsigned long start,
+                      unsigned long mappable_end,
+                      unsigned long end)
 {
         drm_i915_private_t *dev_priv = dev->dev_private;
 
-        if (start >= end ||
-            (start & (PAGE_SIZE - 1)) != 0 ||
-            (end & (PAGE_SIZE - 1)) != 0) {
-                return -EINVAL;
-        }
-
         drm_mm_init(&dev_priv->mm.gtt_space, start,
                     end - start);
 
         dev_priv->mm.gtt_total = end - start;
         dev_priv->mm.mappable_gtt_total = min(end, mappable_end) - start;
         dev_priv->mm.gtt_mappable_end = mappable_end;
-
-        return 0;
 }
 
 int
@@ -243,13 +235,16 @@ i915_gem_init_ioctl(struct drm_device *dev, void *data,
                     struct drm_file *file)
 {
         struct drm_i915_gem_init *args = data;
-        int ret;
+
+        if (args->gtt_start >= args->gtt_end ||
+            (args->gtt_end | args->gtt_start) & (PAGE_SIZE - 1))
+                return -EINVAL;
 
         mutex_lock(&dev->struct_mutex);
-        ret = i915_gem_do_init(dev, args->gtt_start, args->gtt_end, args->gtt_end);
+        i915_gem_do_init(dev, args->gtt_start, args->gtt_end, args->gtt_end);
         mutex_unlock(&dev->struct_mutex);
 
-        return ret;
+        return 0;
 }
 
 int
@@ -2949,7 +2944,7 @@ i915_gem_object_flush_cpu_write_domain(struct drm_i915_gem_object *obj)
  * flushes to occur.
  */
 int
-i915_gem_object_set_to_gtt_domain(struct drm_i915_gem_object *obj, int write)
+i915_gem_object_set_to_gtt_domain(struct drm_i915_gem_object *obj, bool write)
 {
         uint32_t old_write_domain, old_read_domains;
         int ret;
@@ -5177,8 +5172,8 @@ rescan:
                                  &dev_priv->mm.inactive_list,
                                  mm_list) {
                 if (i915_gem_object_is_purgeable(obj)) {
-                        i915_gem_object_unbind(obj);
-                        if (--nr_to_scan == 0)
+                        if (i915_gem_object_unbind(obj) == 0 &&
+                            --nr_to_scan == 0)
                                 break;
                 }
         }
@@ -5188,10 +5183,10 @@ rescan:
         list_for_each_entry_safe(obj, next,
                                  &dev_priv->mm.inactive_list,
                                  mm_list) {
-                if (nr_to_scan) {
-                        i915_gem_object_unbind(obj);
+                if (nr_to_scan &&
+                    i915_gem_object_unbind(obj) == 0)
                         nr_to_scan--;
-                } else
+                else
                         cnt++;
         }