[PATCH 048/102] drm/amdkfd: Fix sdma_bitmap overflow issue

Alex Deucher alexdeucher at gmail.com
Mon Jul 15 21:23:43 UTC 2019


From: Oak Zeng <Oak.Zeng at amd.com>

In the original formula, when sdma queue number is 64,
the left shift overflows. Use an equivalence that won't
overflow.

Signed-off-by: Oak Zeng <Oak.Zeng at amd.com>
Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
---
 drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
index 587362bb912b..97ef55282c35 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
@@ -880,8 +880,8 @@ static int initialize_nocpsch(struct device_queue_manager *dqm)
 	}
 
 	dqm->vmid_bitmap = (1 << dqm->dev->vm_info.vmid_num_kfd) - 1;
-	dqm->sdma_bitmap = (1ULL << get_num_sdma_queues(dqm)) - 1;
-	dqm->xgmi_sdma_bitmap = (1ULL << get_num_xgmi_sdma_queues(dqm)) - 1;
+	dqm->sdma_bitmap = ~0ULL >> (64 - get_num_sdma_queues(dqm));
+	dqm->xgmi_sdma_bitmap = ~0ULL >> (64 - get_num_xgmi_sdma_queues(dqm));
 
 	return 0;
 }
@@ -1019,8 +1019,8 @@ static int initialize_cpsch(struct device_queue_manager *dqm)
 	dqm->sdma_queue_count = 0;
 	dqm->xgmi_sdma_queue_count = 0;
 	dqm->active_runlist = false;
-	dqm->sdma_bitmap = (1ULL << get_num_sdma_queues(dqm)) - 1;
-	dqm->xgmi_sdma_bitmap = (1ULL << get_num_xgmi_sdma_queues(dqm)) - 1;
+	dqm->sdma_bitmap = ~0ULL >> (64 - get_num_sdma_queues(dqm));
+	dqm->xgmi_sdma_bitmap = ~0ULL >> (64 - get_num_xgmi_sdma_queues(dqm));
 
 	INIT_WORK(&dqm->hw_exception_work, kfd_process_hw_exception);
 
-- 
2.20.1



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