Messages in this thread | | | Subject | Re: [PATCH 4/4] iommu/arm-smmu-v3: Remove cmpxchg() in arm_smmu_cmdq_issue_cmdlist() | From | John Garry <> | Date | Tue, 23 Jun 2020 11:19:47 +0100 |
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On 23/06/2020 10:35, Rikard Falkeborn wrote: > > I'd say that GENMASK_INPUT_CHECK() should be able to handle a l=0 and > h=unsigned value, so I doubt this warn. > > Using GENMASK((int)cmdq->q.llq.max_n_shift, 0) resolves it, but it > looks > like GENMASK_INPUT_CHECK() could be improved. > > > Indeed it could, it is fixed in -next.
ok, thanks for the pointer, but I still see this on today's -next with this patch:
make W=1 drivers/iommu/arm-smmu-v3.o
In file included from ./include/linux/bits.h:23:0, from ./include/linux/ioport.h:15, from ./include/linux/acpi.h:12, from drivers/iommu/arm-smmu-v3.c:12: drivers/iommu/arm-smmu-v3.c: In function ‘arm_smmu_cmdq_issue_cmdlist’: ./include/linux/bits.h:27:7: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] (l) > (h), 0))) ^ ./include/linux/build_bug.h:16:62: note: in definition of macro ‘BUILD_BUG_ON_ZERO’ #define BUILD_BUG_ON_ZERO(e) ((int)(sizeof(struct { int:(-!!(e)); }))) ^ ./include/linux/bits.h:40:3: note: in expansion of macro ‘GENMASK_INPUT_CHECK’ (GENMASK_INPUT_CHECK(h, l) + __GENMASK(h, l)) ^~~~~~~~~~~~~~~~~~~ drivers/iommu/arm-smmu-v3.c:1404:18: note: in expansion of macro ‘GENMASK’ u32 prod_mask = GENMASK(cmdq->q.llq.max_n_shift, 0);
That's gcc 7.5.0 .
Cheers, John
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