[PATCH] [v2] i915: fix shift warning

[PATCH] [v2] i915: fix shift warning

[Arnd Bergmann]

From: Arnd Bergmann <arnd@arndb.de>

Randconfig builds on 32-bit machines show lots of warnings for
the i915 driver for passing a 32-bit value into __const_hweight64():

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))

Change it to hweight_long() to avoid the warning.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index bcc80f428172..43164a0b0023 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -2581,7 +2581,7 @@ static int eb_submit(struct i915_execbuffer *eb, struct i915_vma *batch)
 
 static int num_vcs_engines(const struct drm_i915_private *i915)
 {
-	return hweight64(VDBOX_MASK(&i915->gt));
+	return hweight_long(VDBOX_MASK(&i915->gt));
 }
 
 /*
-- 
2.29.2

Re: [PATCH] [v2] i915: fix shift warning

[Chris Wilson]

Quoting Arnd Bergmann (2021-01-03 13:51:44)
> From: Arnd Bergmann <arnd@arndb.de>
> 
> Randconfig builds on 32-bit machines show lots of warnings for
> the i915 driver for passing a 32-bit value into __const_hweight64():
> 
> 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))
> 
> Change it to hweight_long() to avoid the warning.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by:: Chris Wilson <chris@chris-wilson.co.uk>
-Chris