Quoting Arnd Bergmann (2020-12-30 15:39:14)
From: Arnd Bergmann arnd@arndb.de
Randconfig builds on 32-bit machines show lots of warnings for the i915 driver for incorrect bit masks like:
mask is a u8.
VCS0 is 2, I915_MAX_VCS 4
(u8 & GENMASK(5, 2)) >> 2
drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c:2584:9: error: shift count >= width of type [-Werror,-Wshift-count-overflow] return hweight64(VDBOX_MASK(&i915->gt)); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/asm-generic/bitops/const_hweight.h:29:49: note: expanded from macro 'hweight64' #define hweight64(w) (__builtin_constant_p(w) ? __const_hweight64(w) : __arch_hweight64(w))
So it's upset by hweight64() on the unsigned long? So hweight_long?
Or use a cast, hweight8((intel_engine_mask_t)VDMASK())?
static __always_inline int engine_count(intel_engine_mask_t mask) { return sizeof(mask) == 1 ? hweight8(mask) : sizeof(mask) == 2 ? hweight16(mask) : sizeof(mask) == 4 ? hweight32(mask) : hweight64(mask); } -Chris