From d08c4e2327428d93f6d80ab0e7a79679f4c32906 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Wed, 21 Oct 2020 16:14:41 +0300 Subject: [PATCH] drm/i915: Fix potential overflows in ilk ips calculations MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit A bunch of the ips calculations require 64bit math. In particular 'corr' and 'corr2' look like they can overflow on 32bit systems. Switch to explicit u64 for those. Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20201021131443.25616-3-ville.syrjala@linux.intel.com Reviewed-by: Chris Wilson --- drivers/gpu/drm/i915/gt/intel_rps.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/intel_rps.c b/drivers/gpu/drm/i915/gt/intel_rps.c index e2d7ef5..0db565d 100644 --- a/drivers/gpu/drm/i915/gt/intel_rps.c +++ b/drivers/gpu/drm/i915/gt/intel_rps.c @@ -1281,8 +1281,9 @@ static unsigned long __ips_gfx_val(struct intel_ips *ips) { struct intel_rps *rps = container_of(ips, typeof(*rps), ips); struct intel_uncore *uncore = rps_to_uncore(rps); - unsigned long t, corr, state1, corr2, state2; + unsigned int t, state1, state2; u32 pxvid, ext_v; + u64 corr, corr2; lockdep_assert_held(&mchdev_lock); @@ -1303,11 +1304,10 @@ static unsigned long __ips_gfx_val(struct intel_ips *ips) else /* < 50 */ corr = t * 301 + 1004; - corr = corr * 150142 * state1 / 10000 - 78642; - corr /= 100000; - corr2 = corr * ips->corr; + corr = div_u64(corr * 150142 * state1, 10000) - 78642; + corr2 = div_u64(corr, 100000) * ips->corr; - state2 = corr2 * state1 / 10000; + state2 = div_u64(corr2 * state1, 10000); state2 /= 100; /* convert to mW */ __gen5_ips_update(ips); -- 2.7.4