Hi, On 12/16/18 6:38 AM, Liu, Yi L wrote:
From: Lu Baolu [mailto:[email protected]] Sent: Sunday, November 11, 2018 10:45 PM Subject: [RFC PATCH 1/5] iommu: Add APIs for IOMMU PASID managementThis adds APIs for IOMMU drivers and device drivers to manage the PASIDs used for DMA transfer and translation. It bases on I/O ASID allocator for PASID namespace management and relies on vendor specific IOMMU drivers for paravirtual PASIDs. Below APIs are added: * iommu_pasid_init(pasid) - Initialize a PASID consumer. The vendor specific IOMMU drivers are able to set the PASID range imposed by IOMMU hardware through a callback in iommu_ops. * iommu_pasid_exit(pasid) - The PASID consumer stops consuming any PASID. * iommu_pasid_alloc(pasid, min, max, private, *ioasid) - Allocate a PASID and associate a @private data with this PASID. The PASID value is stored in @ioaisd if returning success. * iommu_pasid_free(pasid, ioasid) - Free a PASID to the pool so that it could be consumed by others. This also adds below helpers to lookup or iterate PASID items associated with a consumer. * iommu_pasid_for_each(pasid, func, data) - Iterate PASID items of the consumer identified by @pasid, and call @func() against each item. An error returned from @func() will break the iteration. * iommu_pasid_find(pasid, ioasid) - Retrieve the private data associated with @ioasid. Cc: Ashok Raj <[email protected]> Cc: Jacob Pan <[email protected]> Cc: Kevin Tian <[email protected]> Cc: Jean-Philippe Brucker <[email protected]> Signed-off-by: Lu Baolu <[email protected]> --- drivers/iommu/Kconfig | 1 + drivers/iommu/iommu.c | 89 +++++++++++++++++++++++++++++++++++++++++++ include/linux/iommu.h | 73 +++++++++++++++++++++++++++++++++++ 3 files changed, 163 insertions(+) diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig index d9a25715650e..39f2bb76c7b8 100644 --- a/drivers/iommu/Kconfig +++ b/drivers/iommu/Kconfig @@ -1,6 +1,7 @@ # IOMMU_API always gets selected by whoever wants it. config IOMMU_API bool + select IOASID menuconfig IOMMU_SUPPORT bool "IOMMU Hardware Support" diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 0b7c96d1425e..570b244897bb 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -2082,3 +2082,92 @@ void iommu_detach_device_aux(struct iommu_domain *domain, struct device *dev) } } EXPORT_SYMBOL_GPL(iommu_detach_device_aux); + +/* + * APIs for PASID used by IOMMU and the device drivers which depend + * on IOMMU. + */ +struct iommu_pasid *iommu_pasid_init(struct bus_type *bus) {I'm thinking about if using struct iommu_domain here is better than struct bus_type. The major purpose is to pass iommu_ops in it and route into iommu-sublayer. iommu_domain may be better since some modules like vfio_iommu_type1 would use iommu_domain more than bus type.
But drivers might call this during initialization when it doesn't has any domain yet. Best regards, Lu Baolu
