drm/i915: Explicitly convert some macros to boolean values

Some IS_ and HAS_ macros can return any non-zero value for true.

One potential problem with that is that someone could assign
them to integers and be surprised with the result. Therefore it
is probably safer to do the conversion to 0/1 in the macros
themselves.

Luckily this does not seem to have an effect on code size.

Only one call site was getting bit by this and a patch for
that has been sent as "drm/i915/guc: Protect against HAS_GUC_*
returning true values other than one".

v2: Added some extra braces as suggested by checkpatch.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1467643823-9798-1-git-send-email-tvrtko.ursulin@linux.intel.com

drivers/gpu/drm/i915/i915_drv.h

@@ -2763,14 +2763,14 @@ struct drm_i915_cmd_table {
  * have their own (e.g. HAS_PCH_SPLIT for ILK+ display, IS_foo for particular
  * chips, etc.).
  */
-#define IS_GEN2(dev)	(INTEL_INFO(dev)->gen_mask & BIT(1))
-#define IS_GEN3(dev)	(INTEL_INFO(dev)->gen_mask & BIT(2))
-#define IS_GEN4(dev)	(INTEL_INFO(dev)->gen_mask & BIT(3))
-#define IS_GEN5(dev)	(INTEL_INFO(dev)->gen_mask & BIT(4))
-#define IS_GEN6(dev)	(INTEL_INFO(dev)->gen_mask & BIT(5))
-#define IS_GEN7(dev)	(INTEL_INFO(dev)->gen_mask & BIT(6))
-#define IS_GEN8(dev)	(INTEL_INFO(dev)->gen_mask & BIT(7))
-#define IS_GEN9(dev)	(INTEL_INFO(dev)->gen_mask & BIT(8))
+#define IS_GEN2(dev)	(!!(INTEL_INFO(dev)->gen_mask & BIT(1)))
+#define IS_GEN3(dev)	(!!(INTEL_INFO(dev)->gen_mask & BIT(2)))
+#define IS_GEN4(dev)	(!!(INTEL_INFO(dev)->gen_mask & BIT(3)))
+#define IS_GEN5(dev)	(!!(INTEL_INFO(dev)->gen_mask & BIT(4)))
+#define IS_GEN6(dev)	(!!(INTEL_INFO(dev)->gen_mask & BIT(5)))
+#define IS_GEN7(dev)	(!!(INTEL_INFO(dev)->gen_mask & BIT(6)))
+#define IS_GEN8(dev)	(!!(INTEL_INFO(dev)->gen_mask & BIT(7)))
+#define IS_GEN9(dev)	(!!(INTEL_INFO(dev)->gen_mask & BIT(8)))
 
 #define ENGINE_MASK(id)	BIT(id)
 #define RENDER_RING	ENGINE_MASK(RCS)
@@ -2781,7 +2781,7 @@ struct drm_i915_cmd_table {
 #define ALL_ENGINES	(~0)
 
 #define HAS_ENGINE(dev_priv, id) \
-	(INTEL_INFO(dev_priv)->ring_mask & ENGINE_MASK(id))
+	(!!(INTEL_INFO(dev_priv)->ring_mask & ENGINE_MASK(id)))
 
 #define HAS_BSD(dev_priv)	HAS_ENGINE(dev_priv, VCS)
 #define HAS_BSD2(dev_priv)	HAS_ENGINE(dev_priv, VCS2)
@@ -2790,7 +2790,7 @@ struct drm_i915_cmd_table {
 
 #define HAS_LLC(dev)		(INTEL_INFO(dev)->has_llc)
 #define HAS_SNOOP(dev)		(INTEL_INFO(dev)->has_snoop)
-#define HAS_EDRAM(dev)		(__I915__(dev)->edram_cap & EDRAM_ENABLED)
+#define HAS_EDRAM(dev)		(!!(__I915__(dev)->edram_cap & EDRAM_ENABLED))
 #define HAS_WT(dev)		((IS_HASWELL(dev) || IS_BROADWELL(dev)) && \
 				 HAS_EDRAM(dev))
 #define I915_NEED_GFX_HWS(dev)	(INTEL_INFO(dev)->need_gfx_hws)