drm/i915: Allow optimized platform checks
If we store the platform as a bitmask, and convert the
IS_PLATFORM macro to use it, we allow the compiler to
merge the IS_PLATFORM(a) || IS_PLATFORM(b) || ... checks
into a single conditional.
As a secondary benefit this saves almost 1k of text:
text data bss dec hex filename
-1460254 60014 3656 1523924 1740d4 drivers/gpu/drm/i915/i915.ko
+1459260 60026 3656 1522942 173cfe drivers/gpu/drm/i915/i915.ko
v2: Removed the infamous -1.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170927164138.15474-1-tvrtko.ursulin@linux.intel.com
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 7056bb2..59ac919 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -870,6 +870,10 @@ static int i915_driver_init_early(struct drm_i915_private *dev_priv,
memcpy(device_info, match_info, sizeof(*device_info));
device_info->device_id = dev_priv->drm.pdev->device;
+ BUILD_BUG_ON(INTEL_MAX_PLATFORMS >
+ sizeof(device_info->platform_mask) * BITS_PER_BYTE);
+ device_info->platform_mask = BIT(device_info->platform);
+
BUG_ON(device_info->gen > sizeof(device_info->gen_mask) * BITS_PER_BYTE);
device_info->gen_mask = BIT(device_info->gen - 1);