Messages in this thread | | | Subject | Re: [PATCH 1/2] irqdomain: add empty irq_domain_check_msi_remap | From | Mian Yousaf Kaukab <> | Date | Thu, 2 Mar 2017 14:31:37 +0100 |
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On 03/02/2017 02:12 PM, Auger Eric wrote: > Hi Yousaf, > > On 02/03/2017 13:23, Mian Yousaf Kaukab wrote: >> On 03/02/2017 11:24 AM, Auger Eric wrote: >>> Hi Mian Yousaf, >>> >>> On 02/03/2017 11:01, Mian Yousaf Kaukab wrote: >>>> Fix following build error for s390: >>>> drivers/vfio/vfio_iommu_type1.c: In function >>>> 'vfio_iommu_type1_attach_group': >>>> drivers/vfio/vfio_iommu_type1.c:1290:25: error: implicit declaration >>>> of function 'irq_domain_check_msi_remap' >>>> >>>> Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@suse.com> >>>> --- >>>> include/linux/irqdomain.h | 4 ++++ >>>> 1 file changed, 4 insertions(+) >>>> >>>> diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h >>>> index 188eced6813e..137817b08cdc 100644 >>>> --- a/include/linux/irqdomain.h >>>> +++ b/include/linux/irqdomain.h >>>> @@ -524,6 +524,10 @@ static inline struct irq_domain >>>> *irq_find_matching_fwnode( >>>> { >>>> return NULL; >>>> } >>>> +static inline bool irq_domain_check_msi_remap(void) >>>> +{ >>>> + return true; >>> By default you should rather return false, reporting there is no MSI >>> remapping capability on irq domain side. Besides thank you for the fix. >> I choose to return true based on the function header comments of >> irq_domain_check_msi_remap. It says >> >> "Return: false if any MSI irq domain does not support IRQ remapping, >> true otherwise (including if there is no MSI irq domain)" >> >> So function should return true in case of no MSI irq domain. Have I miss >> understood this? > This behavior is indeed mandated on ARM - where MSI are translated by > the smmu - to allow safe device assignment if there is no MSI domain, > ie. in this situation there is no risk an assigned device writes into an > MSI doorbell. > > As the function is not implemented at all in your case, personally I > would rather be defensive though and return false. You were not able to > check the capability. OK Agree. I will send an update as soon as a decision is made on 2/2.
BR, Yousaf
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