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authorSean Paul <seanpaul@chromium.org>2018-10-04 15:24:04 -0400
committerRob Clark <robdclark@gmail.com>2018-10-07 14:40:28 -0400
commitf926a2e1718edc28f59f1079ebb6832532810587 (patch)
tree12c10d41608dc20399d13c5cab357bf61b254c5e /drivers
parenta69c5ed25d71c6342fbc6a52fb09b679456394e3 (diff)
downloadlinux-f926a2e1718edc28f59f1079ebb6832532810587.tar.bz2
drm/msm: a5xx: Fix improper u64 division
This patch uses the proper do_div() macro to perform u64 division and guards against overflow if the result is too large for the unsigned long return type Fixes: de0a3d094de0 drm/msm: re-factor devfreq code Cc: Sharat Masetty <smasetty@codeaurora.org> Signed-off-by: Sean Paul <seanpaul@chromium.org> Signed-off-by: Rob Clark <robdclark@gmail.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/gpu/drm/msm/adreno/a5xx_gpu.c12
1 files changed, 7 insertions, 5 deletions
diff --git a/drivers/gpu/drm/msm/adreno/a5xx_gpu.c b/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
index 40b4f8a0ae6d..eabe9252ae1e 100644
--- a/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
@@ -1438,18 +1438,20 @@ static struct msm_ringbuffer *a5xx_active_ring(struct msm_gpu *gpu)
static unsigned long a5xx_gpu_busy(struct msm_gpu *gpu)
{
- u64 busy_cycles;
- unsigned long busy_time;
+ u64 busy_cycles, busy_time;
busy_cycles = gpu_read64(gpu, REG_A5XX_RBBM_PERFCTR_RBBM_0_LO,
REG_A5XX_RBBM_PERFCTR_RBBM_0_HI);
- busy_time = (busy_cycles - gpu->devfreq.busy_cycles) /
- (clk_get_rate(gpu->core_clk) / 1000000);
+ busy_time = (busy_cycles - gpu->devfreq.busy_cycles);
+ do_div(busy_time, (clk_get_rate(gpu->core_clk) / 1000000));
gpu->devfreq.busy_cycles = busy_cycles;
- return busy_time;
+ if (WARN_ON(busy_time > ~0LU))
+ return ~0LU;
+
+ return (unsigned long)busy_time;
}
static const struct adreno_gpu_funcs funcs = {