In amdgpu_seq64_alloc there is a possibility that two difference cores from two separate NODES can try to and could get the same free slot. So this fixes that race here using atomic test_and_set clear operations.
Signed-off-by: Sunil Khatri <[email protected]> --- drivers/gpu/drm/amd/amdgpu/amdgpu_seq64.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_seq64.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_seq64.c index a0b479d5fff1..f4be19223588 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_seq64.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_seq64.c @@ -175,11 +175,14 @@ int amdgpu_seq64_alloc(struct amdgpu_device *adev, u64 *va, { unsigned long bit_pos; - bit_pos = find_first_zero_bit(adev->seq64.used, adev->seq64.num_sem); - if (bit_pos >= adev->seq64.num_sem) - return -ENOSPC; + for (;;) { + bit_pos = find_first_zero_bit(adev->seq64.used, adev->seq64.num_sem); + if (bit_pos >= adev->seq64.num_sem) + return -ENOSPC; - __set_bit(bit_pos, adev->seq64.used); + if (!test_and_set_bit(bit_pos, adev->seq64.used)) + break; + } *va = bit_pos * sizeof(u64) + amdgpu_seq64_get_va_base(adev); @@ -205,7 +208,7 @@ void amdgpu_seq64_free(struct amdgpu_device *adev, u64 va) bit_pos = (va - amdgpu_seq64_get_va_base(adev)) / sizeof(u64); if (bit_pos < adev->seq64.num_sem) - __clear_bit(bit_pos, adev->seq64.used); + clear_bit(bit_pos, adev->seq64.used); } /** -- 2.34.1
