From 2d7514152b1c82c81a363f8a171237567ebb7e66 Mon Sep 17 00:00:00 2001 From: Tvrtko Ursulin Date: Fri, 3 Nov 2017 09:05:38 +0000 Subject: [PATCH] drm/i915: Warn in debug builds of incorrect usages of ptr_pack_bits Git-commit: 2d7514152b1c82c81a363f8a171237567ebb7e66 Patch-mainline: v4.16-rc1 References: FATE#322643 bsc#1055900 GEM_BUG_ON if the packed bits do not fit into the specified width. V2: Avoid using the macro argument twice. V3: Drop unnecessary braces. (Joonas) Signed-off-by: Tvrtko Ursulin Reviewed-by: Chris Wilson (v1) Reviewed-by: Joonas Lahtinen Link: https://patchwork.freedesktop.org/patch/msgid/20171103090538.14474-1-tvrtko.ursulin@linux.intel.com Acked-by: Takashi Iwai --- drivers/gpu/drm/i915/i915_utils.h | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/drivers/gpu/drm/i915/i915_utils.h +++ b/drivers/gpu/drm/i915/i915_utils.h @@ -83,8 +83,11 @@ (typeof(ptr))(__v & -BIT(n)); \ }) -#define ptr_pack_bits(ptr, bits, n) \ - ((typeof(ptr))((unsigned long)(ptr) | (bits))) +#define ptr_pack_bits(ptr, bits, n) ({ \ + unsigned long __bits = (bits); \ + GEM_BUG_ON(__bits & -BIT(n)); \ + ((typeof(ptr))((unsigned long)(ptr) | __bits)); \ +}) #define page_mask_bits(ptr) ptr_mask_bits(ptr, PAGE_SHIFT) #define page_unmask_bits(ptr) ptr_unmask_bits(ptr, PAGE_SHIFT)