* [Question] PCI ACS is broken for ARM SMMU v3? @ 2017-08-31 14:21 ` Zhou Wang 0 siblings, 0 replies; 10+ messages in thread From: Zhou Wang @ 2017-08-31 14:21 UTC (permalink / raw) To: Alex Williamson, Will Deacon; +Cc: linux-arm-kernel, Linux PCI, wangzhou1 Hi Will and Alex, pci_request_acs is called in drivers/iommu/arm-smmu-v3.c to set pci_acs_enable. PCI subsystem tries to enable ACS as below: pci_device_add --> pci_init_capabilities --> pci_enable_acs in ACPI PCI driver. However, ACPI PCI driver will be called before SMMU v3 driver, which will lead pci_enable_acs to return directly as pci_acs_enable is not set before SMMU v3 driver loading. I think this is a bug, what do you think about this problem? Best, Zhou ^ permalink raw reply [flat|nested] 10+ messages in thread
* [Question] PCI ACS is broken for ARM SMMU v3? @ 2017-08-31 14:21 ` Zhou Wang 0 siblings, 0 replies; 10+ messages in thread From: Zhou Wang @ 2017-08-31 14:21 UTC (permalink / raw) To: linux-arm-kernel Hi Will and Alex, pci_request_acs is called in drivers/iommu/arm-smmu-v3.c to set pci_acs_enable. PCI subsystem tries to enable ACS as below: pci_device_add --> pci_init_capabilities --> pci_enable_acs in ACPI PCI driver. However, ACPI PCI driver will be called before SMMU v3 driver, which will lead pci_enable_acs to return directly as pci_acs_enable is not set before SMMU v3 driver loading. I think this is a bug, what do you think about this problem? Best, Zhou ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [Question] PCI ACS is broken for ARM SMMU v3? 2017-08-31 14:21 ` Zhou Wang @ 2017-09-04 12:33 ` Zhou Wang -1 siblings, 0 replies; 10+ messages in thread From: Zhou Wang @ 2017-09-04 12:33 UTC (permalink / raw) To: Alex Williamson, Will Deacon, Lorenzo Pieralisi Cc: linux-arm-kernel, Linux PCI +to: Lorenzo On 2017/8/31 22:21, Zhou Wang wrote: > Hi Will and Alex, > > pci_request_acs is called in drivers/iommu/arm-smmu-v3.c to set pci_acs_enable. > > PCI subsystem tries to enable ACS as below: > > pci_device_add > --> pci_init_capabilities > --> pci_enable_acs > > in ACPI PCI driver. However, ACPI PCI driver will be called before SMMU v3 driver, > which will lead pci_enable_acs to return directly as pci_acs_enable is not set > before SMMU v3 driver loading. > > I think this is a bug, what do you think about this problem? > > Best, > Zhou > > > > > > . > ^ permalink raw reply [flat|nested] 10+ messages in thread
* [Question] PCI ACS is broken for ARM SMMU v3? @ 2017-09-04 12:33 ` Zhou Wang 0 siblings, 0 replies; 10+ messages in thread From: Zhou Wang @ 2017-09-04 12:33 UTC (permalink / raw) To: linux-arm-kernel +to: Lorenzo On 2017/8/31 22:21, Zhou Wang wrote: > Hi Will and Alex, > > pci_request_acs is called in drivers/iommu/arm-smmu-v3.c to set pci_acs_enable. > > PCI subsystem tries to enable ACS as below: > > pci_device_add > --> pci_init_capabilities > --> pci_enable_acs > > in ACPI PCI driver. However, ACPI PCI driver will be called before SMMU v3 driver, > which will lead pci_enable_acs to return directly as pci_acs_enable is not set > before SMMU v3 driver loading. > > I think this is a bug, what do you think about this problem? > > Best, > Zhou > > > > > > . > ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [Question] PCI ACS is broken for ARM SMMU v3? 2017-09-04 12:33 ` Zhou Wang @ 2017-09-04 15:59 ` Lorenzo Pieralisi -1 siblings, 0 replies; 10+ messages in thread From: Lorenzo Pieralisi @ 2017-09-04 15:59 UTC (permalink / raw) To: Zhou Wang; +Cc: Linux PCI, Alex Williamson, Will Deacon, linux-arm-kernel On Mon, Sep 04, 2017 at 08:33:22PM +0800, Zhou Wang wrote: > +to: Lorenzo > > On 2017/8/31 22:21, Zhou Wang wrote: > > Hi Will and Alex, > > > > pci_request_acs is called in drivers/iommu/arm-smmu-v3.c to set pci_acs_enable. > > > > PCI subsystem tries to enable ACS as below: > > > > pci_device_add > > --> pci_init_capabilities > > --> pci_enable_acs > > > > in ACPI PCI driver. However, ACPI PCI driver will be called before SMMU v3 driver, > > which will lead pci_enable_acs to return directly as pci_acs_enable is not set > > before SMMU v3 driver loading. > > > > I think this is a bug, what do you think about this problem? I think that it is a bug that affects OF/ACPI alike. One way of solving it is requesting ACS at IORT init following appropriate checks (ie mappings PCI->IOMMU - that would not solve the OF path though). I can put together a quick fix, the overall problem needs some thinking though. Lorenzo _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 10+ messages in thread
* [Question] PCI ACS is broken for ARM SMMU v3? @ 2017-09-04 15:59 ` Lorenzo Pieralisi 0 siblings, 0 replies; 10+ messages in thread From: Lorenzo Pieralisi @ 2017-09-04 15:59 UTC (permalink / raw) To: linux-arm-kernel On Mon, Sep 04, 2017 at 08:33:22PM +0800, Zhou Wang wrote: > +to: Lorenzo > > On 2017/8/31 22:21, Zhou Wang wrote: > > Hi Will and Alex, > > > > pci_request_acs is called in drivers/iommu/arm-smmu-v3.c to set pci_acs_enable. > > > > PCI subsystem tries to enable ACS as below: > > > > pci_device_add > > --> pci_init_capabilities > > --> pci_enable_acs > > > > in ACPI PCI driver. However, ACPI PCI driver will be called before SMMU v3 driver, > > which will lead pci_enable_acs to return directly as pci_acs_enable is not set > > before SMMU v3 driver loading. > > > > I think this is a bug, what do you think about this problem? I think that it is a bug that affects OF/ACPI alike. One way of solving it is requesting ACS at IORT init following appropriate checks (ie mappings PCI->IOMMU - that would not solve the OF path though). I can put together a quick fix, the overall problem needs some thinking though. Lorenzo ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [Question] PCI ACS is broken for ARM SMMU v3? 2017-09-04 15:59 ` Lorenzo Pieralisi @ 2017-09-05 12:47 ` Zhou Wang -1 siblings, 0 replies; 10+ messages in thread From: Zhou Wang @ 2017-09-05 12:47 UTC (permalink / raw) To: Lorenzo Pieralisi Cc: Alex Williamson, Will Deacon, linux-arm-kernel, Linux PCI On 2017/9/4 23:59, Lorenzo Pieralisi wrote: > On Mon, Sep 04, 2017 at 08:33:22PM +0800, Zhou Wang wrote: >> +to: Lorenzo >> >> On 2017/8/31 22:21, Zhou Wang wrote: >>> Hi Will and Alex, >>> >>> pci_request_acs is called in drivers/iommu/arm-smmu-v3.c to set pci_acs_enable. >>> >>> PCI subsystem tries to enable ACS as below: >>> >>> pci_device_add >>> --> pci_init_capabilities >>> --> pci_enable_acs >>> >>> in ACPI PCI driver. However, ACPI PCI driver will be called before SMMU v3 driver, >>> which will lead pci_enable_acs to return directly as pci_acs_enable is not set >>> before SMMU v3 driver loading. >>> >>> I think this is a bug, what do you think about this problem? > > I think that it is a bug that affects OF/ACPI alike. One way of solving Yes, DT also has this problem. > it is requesting ACS at IORT init following appropriate checks (ie > mappings PCI->IOMMU - that would not solve the OF path though). I can > put together a quick fix, the overall problem needs some thinking > though. I am not familiar with IORT init, but can we do it like: diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c index a3215ee..a6f1a21 100644 --- a/drivers/acpi/arm64/iort.c +++ b/drivers/acpi/arm64/iort.c @@ -1131,6 +1131,7 @@ static void __init iort_init_platform_devices(void) acpi_free_fwnode_static(fwnode); return; } + pci_request_acs(); } iort_node = ACPI_ADD_PTR(struct acpi_iort_node, iort_node, Best, Zhou > > Lorenzo > > . > ^ permalink raw reply related [flat|nested] 10+ messages in thread
* [Question] PCI ACS is broken for ARM SMMU v3? @ 2017-09-05 12:47 ` Zhou Wang 0 siblings, 0 replies; 10+ messages in thread From: Zhou Wang @ 2017-09-05 12:47 UTC (permalink / raw) To: linux-arm-kernel On 2017/9/4 23:59, Lorenzo Pieralisi wrote: > On Mon, Sep 04, 2017 at 08:33:22PM +0800, Zhou Wang wrote: >> +to: Lorenzo >> >> On 2017/8/31 22:21, Zhou Wang wrote: >>> Hi Will and Alex, >>> >>> pci_request_acs is called in drivers/iommu/arm-smmu-v3.c to set pci_acs_enable. >>> >>> PCI subsystem tries to enable ACS as below: >>> >>> pci_device_add >>> --> pci_init_capabilities >>> --> pci_enable_acs >>> >>> in ACPI PCI driver. However, ACPI PCI driver will be called before SMMU v3 driver, >>> which will lead pci_enable_acs to return directly as pci_acs_enable is not set >>> before SMMU v3 driver loading. >>> >>> I think this is a bug, what do you think about this problem? > > I think that it is a bug that affects OF/ACPI alike. One way of solving Yes, DT also has this problem. > it is requesting ACS at IORT init following appropriate checks (ie > mappings PCI->IOMMU - that would not solve the OF path though). I can > put together a quick fix, the overall problem needs some thinking > though. I am not familiar with IORT init, but can we do it like: diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c index a3215ee..a6f1a21 100644 --- a/drivers/acpi/arm64/iort.c +++ b/drivers/acpi/arm64/iort.c @@ -1131,6 +1131,7 @@ static void __init iort_init_platform_devices(void) acpi_free_fwnode_static(fwnode); return; } + pci_request_acs(); } iort_node = ACPI_ADD_PTR(struct acpi_iort_node, iort_node, Best, Zhou > > Lorenzo > > . > ^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [Question] PCI ACS is broken for ARM SMMU v3? 2017-09-05 12:47 ` Zhou Wang @ 2017-09-06 9:55 ` Lorenzo Pieralisi -1 siblings, 0 replies; 10+ messages in thread From: Lorenzo Pieralisi @ 2017-09-06 9:55 UTC (permalink / raw) To: Zhou Wang; +Cc: Linux PCI, Alex Williamson, Will Deacon, linux-arm-kernel On Tue, Sep 05, 2017 at 08:47:15PM +0800, Zhou Wang wrote: > On 2017/9/4 23:59, Lorenzo Pieralisi wrote: > > On Mon, Sep 04, 2017 at 08:33:22PM +0800, Zhou Wang wrote: > >> +to: Lorenzo > >> > >> On 2017/8/31 22:21, Zhou Wang wrote: > >>> Hi Will and Alex, > >>> > >>> pci_request_acs is called in drivers/iommu/arm-smmu-v3.c to set pci_acs_enable. > >>> > >>> PCI subsystem tries to enable ACS as below: > >>> > >>> pci_device_add > >>> --> pci_init_capabilities > >>> --> pci_enable_acs > >>> > >>> in ACPI PCI driver. However, ACPI PCI driver will be called before SMMU v3 driver, > >>> which will lead pci_enable_acs to return directly as pci_acs_enable is not set > >>> before SMMU v3 driver loading. > >>> > >>> I think this is a bug, what do you think about this problem? > > > > I think that it is a bug that affects OF/ACPI alike. One way of solving > > Yes, DT also has this problem. > > > it is requesting ACS at IORT init following appropriate checks (ie > > mappings PCI->IOMMU - that would not solve the OF path though). I can > > put together a quick fix, the overall problem needs some thinking > > though. > > I am not familiar with IORT init, but can we do it like: > > diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c > index a3215ee..a6f1a21 100644 > --- a/drivers/acpi/arm64/iort.c > +++ b/drivers/acpi/arm64/iort.c > @@ -1131,6 +1131,7 @@ static void __init iort_init_platform_devices(void) > acpi_free_fwnode_static(fwnode); > return; > } > + pci_request_acs(); > } > > iort_node = ACPI_ADD_PTR(struct acpi_iort_node, iort_node, > Yep, will send something similar shortly. Thanks, Lorenzo _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 10+ messages in thread
* [Question] PCI ACS is broken for ARM SMMU v3? @ 2017-09-06 9:55 ` Lorenzo Pieralisi 0 siblings, 0 replies; 10+ messages in thread From: Lorenzo Pieralisi @ 2017-09-06 9:55 UTC (permalink / raw) To: linux-arm-kernel On Tue, Sep 05, 2017 at 08:47:15PM +0800, Zhou Wang wrote: > On 2017/9/4 23:59, Lorenzo Pieralisi wrote: > > On Mon, Sep 04, 2017 at 08:33:22PM +0800, Zhou Wang wrote: > >> +to: Lorenzo > >> > >> On 2017/8/31 22:21, Zhou Wang wrote: > >>> Hi Will and Alex, > >>> > >>> pci_request_acs is called in drivers/iommu/arm-smmu-v3.c to set pci_acs_enable. > >>> > >>> PCI subsystem tries to enable ACS as below: > >>> > >>> pci_device_add > >>> --> pci_init_capabilities > >>> --> pci_enable_acs > >>> > >>> in ACPI PCI driver. However, ACPI PCI driver will be called before SMMU v3 driver, > >>> which will lead pci_enable_acs to return directly as pci_acs_enable is not set > >>> before SMMU v3 driver loading. > >>> > >>> I think this is a bug, what do you think about this problem? > > > > I think that it is a bug that affects OF/ACPI alike. One way of solving > > Yes, DT also has this problem. > > > it is requesting ACS at IORT init following appropriate checks (ie > > mappings PCI->IOMMU - that would not solve the OF path though). I can > > put together a quick fix, the overall problem needs some thinking > > though. > > I am not familiar with IORT init, but can we do it like: > > diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c > index a3215ee..a6f1a21 100644 > --- a/drivers/acpi/arm64/iort.c > +++ b/drivers/acpi/arm64/iort.c > @@ -1131,6 +1131,7 @@ static void __init iort_init_platform_devices(void) > acpi_free_fwnode_static(fwnode); > return; > } > + pci_request_acs(); > } > > iort_node = ACPI_ADD_PTR(struct acpi_iort_node, iort_node, > Yep, will send something similar shortly. Thanks, Lorenzo ^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2017-09-06 9:55 UTC | newest] Thread overview: 10+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2017-08-31 14:21 [Question] PCI ACS is broken for ARM SMMU v3? Zhou Wang 2017-08-31 14:21 ` Zhou Wang 2017-09-04 12:33 ` Zhou Wang 2017-09-04 12:33 ` Zhou Wang 2017-09-04 15:59 ` Lorenzo Pieralisi 2017-09-04 15:59 ` Lorenzo Pieralisi 2017-09-05 12:47 ` Zhou Wang 2017-09-05 12:47 ` Zhou Wang 2017-09-06 9:55 ` Lorenzo Pieralisi 2017-09-06 9:55 ` Lorenzo Pieralisi
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