From a27bf2743cb80d3b36b5b43e8e2e702412c41668 Mon Sep 17 00:00:00 2001 From: Lu Baolu Date: Mon, 10 Jun 2024 16:55:35 +0800 Subject: iommu: Add iommu_paging_domain_alloc() interface Commit <17de3f5fdd35> ("iommu: Retire bus ops") removes iommu ops from bus. The iommu subsystem no longer relies on bus for operations. So the bus parameter in iommu_domain_alloc() is no longer relevant. Add a new interface named iommu_paging_domain_alloc(), which explicitly indicates the allocation of a paging domain for DMA managed by a kernel driver. The new interface takes a device pointer as its parameter, that better aligns with the current iommu subsystem. Signed-off-by: Lu Baolu Reviewed-by: Jason Gunthorpe Reviewed-by: Vasant Hegde Link: https://lore.kernel.org/r/20240610085555.88197-2-baolu.lu@linux.intel.com Signed-off-by: Will Deacon --- drivers/iommu/iommu.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'drivers/iommu/iommu.c') diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 9df7cc75c1bc..e03c71a34347 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -2016,6 +2016,10 @@ static int __iommu_domain_alloc_dev(struct device *dev, void *data) return 0; } +/* + * The iommu ops in bus has been retired. Do not use this interface in + * new drivers. + */ struct iommu_domain *iommu_domain_alloc(const struct bus_type *bus) { const struct iommu_ops *ops = NULL; @@ -2032,6 +2036,22 @@ struct iommu_domain *iommu_domain_alloc(const struct bus_type *bus) } EXPORT_SYMBOL_GPL(iommu_domain_alloc); +/** + * iommu_paging_domain_alloc() - Allocate a paging domain + * @dev: device for which the domain is allocated + * + * Allocate a paging domain which will be managed by a kernel driver. Return + * allocated domain if successful, or a ERR pointer for failure. + */ +struct iommu_domain *iommu_paging_domain_alloc(struct device *dev) +{ + if (!dev_has_iommu(dev)) + return ERR_PTR(-ENODEV); + + return __iommu_domain_alloc(dev_iommu_ops(dev), dev, IOMMU_DOMAIN_UNMANAGED); +} +EXPORT_SYMBOL_GPL(iommu_paging_domain_alloc); + void iommu_domain_free(struct iommu_domain *domain) { if (domain->type == IOMMU_DOMAIN_SVA) -- cgit