linux-kernel - [PATCH] i915: fix shift warning

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Date:   Wed, 30 Dec 2020 16:39:14 +0100
From:   Arnd Bergmann <arnd@...nel.org>
To:     Jani Nikula <jani.nikula@...ux.intel.com>,
        Joonas Lahtinen <joonas.lahtinen@...ux.intel.com>,
        Rodrigo Vivi <rodrigo.vivi@...el.com>,
        David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>
Cc:     Arnd Bergmann <arnd@...db.de>,
        Chris Wilson <chris@...is-wilson.co.uk>,
        Ville Syrjälä 
        <ville.syrjala@...ux.intel.com>,
        José Roberto de Souza <jose.souza@...el.com>,
        Matt Roper <matthew.d.roper@...el.com>,
        Daniele Ceraolo Spurio <daniele.ceraolospurio@...el.com>,
        intel-gfx@...ts.freedesktop.org, dri-devel@...ts.freedesktop.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH] i915: fix shift warning

From: Arnd Bergmann <arnd@...db.de>

Randconfig builds on 32-bit machines show lots of warnings for
the i915 driver for incorrect bit masks like:

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))

Since this is a 64-bit mask, use GENMASK_ULL instead of GENMASK.

Signed-off-by: Arnd Bergmann <arnd@...db.de>
---
 drivers/gpu/drm/i915/i915_drv.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 0a3ee4f9dc0a..ca32fa0d6a57 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1624,7 +1624,7 @@ tgl_revids_get(struct drm_i915_private *dev_priv)
 	unsigned int first__ = (first);					\
 	unsigned int count__ = (count);					\
 	((gt)->info.engine_mask &						\
-	 GENMASK(first__ + count__ - 1, first__)) >> first__;		\
+	 GENMASK_ULL(first__ + count__ - 1, first__)) >> first__;		\
 })
 #define VDBOX_MASK(gt) \
 	ENGINE_INSTANCES_MASK(gt, VCS0, I915_MAX_VCS)
-- 
2.29.2