Re: [RFC 1/3] iommu/arm-smmu: Add support to opt-in to stalling

2017-01-30 Thread Rob Clark
On Thu, Jan 12, 2017 at 10:17 AM, Will Deacon wrote: > On Wed, Jan 11, 2017 at 03:59:30PM -0500, Rob Clark wrote: >> On Wed, Jan 11, 2017 at 4:36 AM, Will Deacon wrote: >> > On Tue, Jan 10, 2017 at 02:20:13PM -0500, Rob Clark wrote: >> >> On Tue, Jan 10, 2017 at 12:52 PM, Will Deacon wrote: >> >

Re: [RFC 1/3] iommu/arm-smmu: Add support to opt-in to stalling

2017-01-12 Thread Will Deacon
On Wed, Jan 11, 2017 at 03:59:30PM -0500, Rob Clark wrote: > On Wed, Jan 11, 2017 at 4:36 AM, Will Deacon wrote: > > On Tue, Jan 10, 2017 at 02:20:13PM -0500, Rob Clark wrote: > >> On Tue, Jan 10, 2017 at 12:52 PM, Will Deacon wrote: > >> > On Fri, Jan 06, 2017 at 11:26:49AM -0500, Rob Clark wrot

Re: [RFC 1/3] iommu/arm-smmu: Add support to opt-in to stalling

2017-01-11 Thread Rob Clark
On Wed, Jan 11, 2017 at 4:36 AM, Will Deacon wrote: > On Tue, Jan 10, 2017 at 02:20:13PM -0500, Rob Clark wrote: >> On Tue, Jan 10, 2017 at 12:52 PM, Will Deacon wrote: >> > On Fri, Jan 06, 2017 at 11:26:49AM -0500, Rob Clark wrote: >> >> Hmm, well we install the fault handler on the iommu_domain

Re: [RFC 1/3] iommu/arm-smmu: Add support to opt-in to stalling

2017-01-11 Thread Will Deacon
On Tue, Jan 10, 2017 at 02:20:13PM -0500, Rob Clark wrote: > On Tue, Jan 10, 2017 at 12:52 PM, Will Deacon wrote: > > On Fri, Jan 06, 2017 at 11:26:49AM -0500, Rob Clark wrote: > >> Hmm, well we install the fault handler on the iommu_domain.. perhaps > >> maybe a combo of dts property (or decidin

Re: [RFC 1/3] iommu/arm-smmu: Add support to opt-in to stalling

2017-01-10 Thread Rob Clark
On Tue, Jan 10, 2017 at 12:52 PM, Will Deacon wrote: > Hi Rob, > > On Fri, Jan 06, 2017 at 11:26:49AM -0500, Rob Clark wrote: >> On Thu, Jan 5, 2017 at 10:49 AM, Will Deacon wrote: >> > On Thu, Jan 05, 2017 at 10:27:27AM -0500, Rob Clark wrote: >> >> I'm not sure if the better solution then would

Re: [RFC 1/3] iommu/arm-smmu: Add support to opt-in to stalling

2017-01-10 Thread Will Deacon
Hi Rob, On Fri, Jan 06, 2017 at 11:26:49AM -0500, Rob Clark wrote: > On Thu, Jan 5, 2017 at 10:49 AM, Will Deacon wrote: > > On Thu, Jan 05, 2017 at 10:27:27AM -0500, Rob Clark wrote: > >> I'm not sure if the better solution then would be to have two fault > >> callbacks, one immediately from the

Re: [RFC 1/3] iommu/arm-smmu: Add support to opt-in to stalling

2017-01-06 Thread Rob Clark
On Thu, Jan 5, 2017 at 12:25 PM, Will Deacon wrote: >> That's still got to be a per-master property, not a SMMU property, I >> think. To illustrate: >> >> [A] [B] [C] >>| |_| >> __|__|___ >> | TBU || TBU | >> |_| SMMU |_| >> |__|

Re: [RFC 1/3] iommu/arm-smmu: Add support to opt-in to stalling

2017-01-06 Thread Rob Clark
On Thu, Jan 5, 2017 at 10:49 AM, Will Deacon wrote: > On Thu, Jan 05, 2017 at 10:27:27AM -0500, Rob Clark wrote: >> On Thu, Jan 5, 2017 at 6:55 AM, Will Deacon wrote: >> > On Tue, Jan 03, 2017 at 04:30:54PM -0500, Rob Clark wrote: >> >> TODO maybe we want two options, one to enable stalling, and

Re: [RFC 1/3] iommu/arm-smmu: Add support to opt-in to stalling

2017-01-05 Thread Will Deacon
On Thu, Jan 05, 2017 at 05:03:30PM +, Robin Murphy wrote: > On 05/01/17 16:07, Will Deacon wrote: > > On Thu, Jan 05, 2017 at 03:32:50PM +, Robin Murphy wrote: > >> I think this needs to be some kind of "arm,smmu-stall-safe" property > >> placed on individual master device nodes (mad idea:

Re: [RFC 1/3] iommu/arm-smmu: Add support to opt-in to stalling

2017-01-05 Thread Robin Murphy
On 05/01/17 16:07, Will Deacon wrote: > On Thu, Jan 05, 2017 at 03:32:50PM +, Robin Murphy wrote: >> On 05/01/17 14:47, Will Deacon wrote: >>> On Thu, Jan 05, 2017 at 02:07:31PM +, Mark Rutland wrote: Ok. It would be good to elaborate on what "stalling is useable" means in the pro

Re: [RFC 1/3] iommu/arm-smmu: Add support to opt-in to stalling

2017-01-05 Thread Will Deacon
On Thu, Jan 05, 2017 at 03:32:50PM +, Robin Murphy wrote: > On 05/01/17 14:47, Will Deacon wrote: > > On Thu, Jan 05, 2017 at 02:07:31PM +, Mark Rutland wrote: > >> Ok. It would be good to elaborate on what "stalling is useable" means in > >> the property description. i.e. what specificallt

Re: [RFC 1/3] iommu/arm-smmu: Add support to opt-in to stalling

2017-01-05 Thread Will Deacon
On Thu, Jan 05, 2017 at 10:27:27AM -0500, Rob Clark wrote: > On Thu, Jan 5, 2017 at 6:55 AM, Will Deacon wrote: > > On Tue, Jan 03, 2017 at 04:30:54PM -0500, Rob Clark wrote: > >> TODO maybe we want two options, one to enable stalling, and 2nd to punt > >> handling to wq? I haven't needed to use

Re: [RFC 1/3] iommu/arm-smmu: Add support to opt-in to stalling

2017-01-05 Thread Robin Murphy
On 05/01/17 14:47, Will Deacon wrote: > On Thu, Jan 05, 2017 at 02:07:31PM +, Mark Rutland wrote: >> On Thu, Jan 05, 2017 at 02:00:05PM +, Will Deacon wrote: >>> On Thu, Jan 05, 2017 at 12:08:57PM +, Mark Rutland wrote: On Thu, Jan 05, 2017 at 11:55:29AM +, Will Deacon wrote: >

Re: [RFC 1/3] iommu/arm-smmu: Add support to opt-in to stalling

2017-01-05 Thread Rob Clark
On Thu, Jan 5, 2017 at 6:55 AM, Will Deacon wrote: > On Tue, Jan 03, 2017 at 04:30:54PM -0500, Rob Clark wrote: >> TODO maybe we want two options, one to enable stalling, and 2nd to punt >> handling to wq? I haven't needed to use mm APIs from fault handler yet >> (although it is something that I

Re: [RFC 1/3] iommu/arm-smmu: Add support to opt-in to stalling

2017-01-05 Thread Will Deacon
On Thu, Jan 05, 2017 at 02:07:31PM +, Mark Rutland wrote: > On Thu, Jan 05, 2017 at 02:00:05PM +, Will Deacon wrote: > > On Thu, Jan 05, 2017 at 12:08:57PM +, Mark Rutland wrote: > > > On Thu, Jan 05, 2017 at 11:55:29AM +, Will Deacon wrote: > > > > On Tue, Jan 03, 2017 at 04:30:54P

Re: [RFC 1/3] iommu/arm-smmu: Add support to opt-in to stalling

2017-01-05 Thread Mark Rutland
On Thu, Jan 05, 2017 at 02:00:05PM +, Will Deacon wrote: > On Thu, Jan 05, 2017 at 12:08:57PM +, Mark Rutland wrote: > > On Thu, Jan 05, 2017 at 11:55:29AM +, Will Deacon wrote: > > > On Tue, Jan 03, 2017 at 04:30:54PM -0500, Rob Clark wrote: > > > > diff --git a/Documentation/devicetre

Re: [RFC 1/3] iommu/arm-smmu: Add support to opt-in to stalling

2017-01-05 Thread Will Deacon
On Thu, Jan 05, 2017 at 12:08:57PM +, Mark Rutland wrote: > On Thu, Jan 05, 2017 at 11:55:29AM +, Will Deacon wrote: > > On Tue, Jan 03, 2017 at 04:30:54PM -0500, Rob Clark wrote: > > > diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu.txt > > > b/Documentation/devicetree/bindi

Re: [RFC 1/3] iommu/arm-smmu: Add support to opt-in to stalling

2017-01-05 Thread Mark Rutland
On Thu, Jan 05, 2017 at 11:55:29AM +, Will Deacon wrote: > On Tue, Jan 03, 2017 at 04:30:54PM -0500, Rob Clark wrote: > > TODO maybe we want two options, one to enable stalling, and 2nd to punt > > handling to wq? I haven't needed to use mm APIs from fault handler yet > > (although it is somet

Re: [RFC 1/3] iommu/arm-smmu: Add support to opt-in to stalling

2017-01-05 Thread Will Deacon
On Tue, Jan 03, 2017 at 04:30:54PM -0500, Rob Clark wrote: > TODO maybe we want two options, one to enable stalling, and 2nd to punt > handling to wq? I haven't needed to use mm APIs from fault handler yet > (although it is something that I think we'll want some day). Perhaps > stalling support i

[RFC 1/3] iommu/arm-smmu: Add support to opt-in to stalling

2017-01-03 Thread Rob Clark
TODO maybe we want two options, one to enable stalling, and 2nd to punt handling to wq? I haven't needed to use mm APIs from fault handler yet (although it is something that I think we'll want some day). Perhaps stalling support is limited to just letting driver dump some extra debugging informat