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Groups > linux.kernel > #1686477
| From | Rob Clark <robdclark@gmail.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH V4 3/6] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device |
| Date | 2017-07-13 14:00 +0200 |
| Message-ID | <u2KWK-58b-23@gated-at.bofh.it> (permalink) |
| References | <u0bqp-2sh-5@gated-at.bofh.it> <u0bqp-2sh-13@gated-at.bofh.it> <u2yLU-5QV-17@gated-at.bofh.it> <u2EHD-1nz-1@gated-at.bofh.it> <u2F10-1tT-7@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Thu, Jul 13, 2017 at 1:35 AM, Sricharan R <sricharan@codeaurora.org> wrote:
> Hi Vivek,
>
> On 7/13/2017 10:43 AM, Vivek Gautam wrote:
>> Hi Stephen,
>>
>>
>> On 07/13/2017 04:24 AM, Stephen Boyd wrote:
>>> On 07/06, Vivek Gautam wrote:
>>>> @@ -1231,12 +1237,18 @@ static int arm_smmu_map(struct iommu_domain *domain, unsigned long iova,
>>>> static size_t arm_smmu_unmap(struct iommu_domain *domain, unsigned long iova,
>>>> size_t size)
>>>> {
>>>> - struct io_pgtable_ops *ops = to_smmu_domain(domain)->pgtbl_ops;
>>>> + struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
>>>> + struct io_pgtable_ops *ops = smmu_domain->pgtbl_ops;
>>>> + size_t ret;
>>>> if (!ops)
>>>> return 0;
>>>> - return ops->unmap(ops, iova, size);
>>>> + pm_runtime_get_sync(smmu_domain->smmu->dev);
>>> Can these map/unmap ops be called from an atomic context? I seem
>>> to recall that being a problem before.
>>
>> That's something which was dropped in the following patch merged in master:
>> 523d7423e21b iommu/arm-smmu: Remove io-pgtable spinlock
>>
>> Looks like we don't need locks here anymore?
>
> Apart from the locking, wonder why a explicit pm_runtime is needed
> from unmap. Somehow looks like some path in the master using that
> should have enabled the pm ?
>
Yes, there are a bunch of scenarios where unmap can happen with
disabled master (but not in atomic context). On the gpu side we
opportunistically keep a buffer mapping until the buffer is freed
(which can happen after gpu is disabled). Likewise, v4l2 won't unmap
an exported dmabuf while some other driver holds a reference to it
(which can be dropped when the v4l2 device is suspended).
Since unmap triggers tbl flush which touches iommu regs, the iommu
driver *definitely* needs a pm_runtime_get_sync().
BR,
-R
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[PATCH V4 0/6] iommu/arm-smmu: Add runtime pm/sleep support Vivek Gautam <vivek.gautam@codeaurora.org> - 2017-07-06 11:40 +0200
[PATCH V4 2/6] iommu/arm-smmu: Add pm_runtime/sleep ops Vivek Gautam <vivek.gautam@codeaurora.org> - 2017-07-06 11:40 +0200
Re: [PATCH V4 2/6] iommu/arm-smmu: Add pm_runtime/sleep ops Stephen Boyd <sboyd@codeaurora.org> - 2017-07-13 01:00 +0200
Re: [PATCH V4 2/6] iommu/arm-smmu: Add pm_runtime/sleep ops Stephen Boyd <sboyd@codeaurora.org> - 2017-07-13 01:10 +0200
Re: [PATCH V4 2/6] iommu/arm-smmu: Add pm_runtime/sleep ops Vivek Gautam <vivek.gautam@codeaurora.org> - 2017-07-13 06:00 +0200
[PATCH V4 3/6] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device Vivek Gautam <vivek.gautam@codeaurora.org> - 2017-07-06 11:40 +0200
Re: [PATCH V4 3/6] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device Stephen Boyd <sboyd@codeaurora.org> - 2017-07-13 01:00 +0200
Re: [PATCH V4 3/6] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device Vivek Gautam <vivek.gautam@codeaurora.org> - 2017-07-13 07:20 +0200
Re: [PATCH V4 3/6] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device Sricharan R <sricharan@codeaurora.org> - 2017-07-13 07:40 +0200
Re: [PATCH V4 3/6] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device Rob Clark <robdclark@gmail.com> - 2017-07-13 14:00 +0200
Re: [PATCH V4 3/6] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device Marek Szyprowski <m.szyprowski@samsung.com> - 2017-07-13 14:10 +0200
Re: [PATCH V4 3/6] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device Rob Clark <robdclark@gmail.com> - 2017-07-13 14:20 +0200
Re: [PATCH V4 3/6] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device Marek Szyprowski <m.szyprowski@samsung.com> - 2017-07-13 14:30 +0200
Re: [PATCH V4 3/6] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device Sricharan R <sricharan@codeaurora.org> - 2017-07-13 16:00 +0200
Re: [PATCH V4 3/6] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device Rob Clark <robdclark@gmail.com> - 2017-07-13 17:00 +0200
Re: [PATCH V4 3/6] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device Will Deacon <will.deacon@arm.com> - 2017-07-14 19:10 +0200
Re: [PATCH V4 3/6] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device Rob Clark <robdclark@gmail.com> - 2017-07-14 19:50 +0200
Re: [PATCH V4 3/6] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device Will Deacon <will.deacon@arm.com> - 2017-07-14 20:10 +0200
Re: [PATCH V4 3/6] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device Rob Clark <robdclark@gmail.com> - 2017-07-14 20:30 +0200
Re: [PATCH V4 3/6] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device Will Deacon <will.deacon@arm.com> - 2017-07-14 21:10 +0200
Re: [PATCH V4 3/6] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device Rob Clark <robdclark@gmail.com> - 2017-07-14 21:40 +0200
Re: [PATCH V4 3/6] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device Sricharan R <sricharan@codeaurora.org> - 2017-07-17 13:50 +0200
Re: [PATCH V4 3/6] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device Sricharan R <sricharan@codeaurora.org> - 2017-07-17 14:30 +0200
Re: [PATCH V4 3/6] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device Will Deacon <will.deacon@arm.com> - 2017-07-14 21:40 +0200
Re: [PATCH V4 3/6] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device Rob Clark <robdclark@gmail.com> - 2017-07-14 21:40 +0200
Re: [PATCH V4 3/6] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device Vivek Gautam <vivek.gautam@codeaurora.org> - 2017-07-13 16:00 +0200
Re: [PATCH V4 3/6] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device Vivek Gautam <vivek.gautam@codeaurora.org> - 2017-07-13 16:10 +0200
Re: [PATCH V4 3/6] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device Stephen Boyd <sboyd@codeaurora.org> - 2017-07-13 08:50 +0200
Re: [PATCH V4 3/6] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device Robin Murphy <robin.murphy@arm.com> - 2017-07-13 12:00 +0200
Re: [PATCH V4 3/6] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device Rob Clark <robdclark@gmail.com> - 2017-07-13 14:00 +0200
[PATCH V4 4/6] iommu/arm-smmu: Add the device_link between masters and smmu Vivek Gautam <vivek.gautam@codeaurora.org> - 2017-07-06 11:40 +0200
Re: [PATCH V4 4/6] iommu/arm-smmu: Add the device_link between masters and smmu Stephen Boyd <sboyd@codeaurora.org> - 2017-07-13 01:00 +0200
Re: [PATCH V4 4/6] iommu/arm-smmu: Add the device_link between masters and smmu Vivek Gautam <vivek.gautam@codeaurora.org> - 2017-07-13 06:00 +0200
[PATCH V4 5/6] iommu/arm-smmu: Add support for MMU40x/500 clocks Vivek Gautam <vivek.gautam@codeaurora.org> - 2017-07-06 11:40 +0200
Re: [PATCH V4 5/6] iommu/arm-smmu: Add support for MMU40x/500 clocks Rob Herring <robh@kernel.org> - 2017-07-10 05:40 +0200
Re: [PATCH V4 5/6] iommu/arm-smmu: Add support for MMU40x/500 clocks Vivek Gautam <vivek.gautam@codeaurora.org> - 2017-07-11 07:20 +0200
[PATCH V4 6/6] iommu/arm-smmu: Add support for qcom,msm8996-smmu-v2 clocks Vivek Gautam <vivek.gautam@codeaurora.org> - 2017-07-06 11:40 +0200
Re: [PATCH V4 6/6] iommu/arm-smmu: Add support for qcom,msm8996-smmu-v2 clocks Rob Herring <robh@kernel.org> - 2017-07-10 05:50 +0200
Re: [PATCH V4 6/6] iommu/arm-smmu: Add support for qcom,msm8996-smmu-v2 clocks Vivek Gautam <vivek.gautam@codeaurora.org> - 2017-07-10 08:50 +0200
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