From: Jani Nikula Date: Fri, 24 May 2019 18:52:53 +0000 (+0300) Subject: drm/i915: make REG_BIT() and REG_GENMASK() work with variables X-Git-Tag: v5.15~5407^2~21^2~617 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=591d4dc4729004e98509efd1d23b8d8bf0111182;p=platform%2Fkernel%2Flinux-starfive.git drm/i915: make REG_BIT() and REG_GENMASK() work with variables REG_BIT() and REG_GENMASK() were intended to work with both constant expressions and otherwise, with the former having extra compile time checks for the bit ranges. Incredibly, the result of __builtin_constant_p() is not an integer constant expression when given a non-constant expression, leading to errors in BUILD_BUG_ON_ZERO(). Replace __builtin_constant_p() with the __is_constexpr() magic spell. Reported-by: Ville Syrjala Reviewed-by: Chris Wilson Signed-off-by: Jani Nikula Link: https://patchwork.freedesktop.org/patch/msgid/20190524185253.1088-1-jani.nikula@intel.com --- diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index 49dce04dd688..019c48748dc9 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -126,7 +126,7 @@ */ #define REG_BIT(__n) \ ((u32)(BIT(__n) + \ - BUILD_BUG_ON_ZERO(__builtin_constant_p(__n) && \ + BUILD_BUG_ON_ZERO(__is_constexpr(__n) && \ ((__n) < 0 || (__n) > 31)))) /** @@ -140,8 +140,8 @@ */ #define REG_GENMASK(__high, __low) \ ((u32)(GENMASK(__high, __low) + \ - BUILD_BUG_ON_ZERO(__builtin_constant_p(__high) && \ - __builtin_constant_p(__low) && \ + BUILD_BUG_ON_ZERO(__is_constexpr(__high) && \ + __is_constexpr(__low) && \ ((__low) < 0 || (__high) > 31 || (__low) > (__high))))) /*