From df31b298477e65a01deff0af352be3a61524d930 Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Wed, 13 Sep 2023 10:43:34 -0300 Subject: iommu: Add iommu_ops->identity_domain This allows a driver to set a global static to an IDENTITY domain and the core code will automatically use it whenever an IDENTITY domain is requested. By making it always available it means the IDENTITY can be used in error handling paths to force the iommu driver into a known state. Devices implementing global static identity domains should avoid failing their attach_dev ops. To make global static domains simpler allow drivers to omit their free function and update the iommufd selftest. Convert rockchip to use the new mechanism. Tested-by: Steven Price Tested-by: Marek Szyprowski Tested-by: Nicolin Chen Reviewed-by: Lu Baolu Reviewed-by: Jerry Snitselaar Signed-off-by: Jason Gunthorpe Link: https://lore.kernel.org/r/1-v8-81230027b2fa+9d-iommu_all_defdom_jgg@nvidia.com Signed-off-by: Joerg Roedel --- drivers/iommu/iommu.c | 6 +++++- drivers/iommu/iommufd/selftest.c | 5 ----- drivers/iommu/rockchip-iommu.c | 9 +-------- include/linux/iommu.h | 3 +++ 4 files changed, 9 insertions(+), 14 deletions(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 3bfc56df4f78..33bd11070907 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -1978,6 +1978,9 @@ static struct iommu_domain *__iommu_domain_alloc(const struct bus_type *bus, if (bus == NULL || bus->iommu_ops == NULL) return NULL; + if (alloc_type == IOMMU_DOMAIN_IDENTITY && bus->iommu_ops->identity_domain) + return bus->iommu_ops->identity_domain; + domain = bus->iommu_ops->domain_alloc(alloc_type); if (!domain) return NULL; @@ -2011,7 +2014,8 @@ void iommu_domain_free(struct iommu_domain *domain) if (domain->type == IOMMU_DOMAIN_SVA) mmdrop(domain->mm); iommu_put_dma_cookie(domain); - domain->ops->free(domain); + if (domain->ops->free) + domain->ops->free(domain); } EXPORT_SYMBOL_GPL(iommu_domain_free); diff --git a/drivers/iommu/iommufd/selftest.c b/drivers/iommu/iommufd/selftest.c index 56506d5753f1..d48a202a7c3b 100644 --- a/drivers/iommu/iommufd/selftest.c +++ b/drivers/iommu/iommufd/selftest.c @@ -111,10 +111,6 @@ struct selftest_obj { }; }; -static void mock_domain_blocking_free(struct iommu_domain *domain) -{ -} - static int mock_domain_nop_attach(struct iommu_domain *domain, struct device *dev) { @@ -122,7 +118,6 @@ static int mock_domain_nop_attach(struct iommu_domain *domain, } static const struct iommu_domain_ops mock_blocking_ops = { - .free = mock_domain_blocking_free, .attach_dev = mock_domain_nop_attach, }; diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c index 8ff69fbf9f65..033678f2f8b3 100644 --- a/drivers/iommu/rockchip-iommu.c +++ b/drivers/iommu/rockchip-iommu.c @@ -989,13 +989,8 @@ static int rk_iommu_identity_attach(struct iommu_domain *identity_domain, return 0; } -static void rk_iommu_identity_free(struct iommu_domain *domain) -{ -} - static struct iommu_domain_ops rk_identity_ops = { .attach_dev = rk_iommu_identity_attach, - .free = rk_iommu_identity_free, }; static struct iommu_domain rk_identity_domain = { @@ -1059,9 +1054,6 @@ static struct iommu_domain *rk_iommu_domain_alloc(unsigned type) { struct rk_iommu_domain *rk_domain; - if (type == IOMMU_DOMAIN_IDENTITY) - return &rk_identity_domain; - if (type != IOMMU_DOMAIN_UNMANAGED && type != IOMMU_DOMAIN_DMA) return NULL; @@ -1186,6 +1178,7 @@ static int rk_iommu_of_xlate(struct device *dev, } static const struct iommu_ops rk_iommu_ops = { + .identity_domain = &rk_identity_domain, .domain_alloc = rk_iommu_domain_alloc, .probe_device = rk_iommu_probe_device, .release_device = rk_iommu_release_device, diff --git a/include/linux/iommu.h b/include/linux/iommu.h index c50a769d569a..d0920b2a9f1c 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -260,6 +260,8 @@ struct iommu_iotlb_gather { * will be blocked by the hardware. * @pgsize_bitmap: bitmap of all possible supported page sizes * @owner: Driver module providing these ops + * @identity_domain: An always available, always attachable identity + * translation. */ struct iommu_ops { bool (*capable)(struct device *dev, enum iommu_cap); @@ -294,6 +296,7 @@ struct iommu_ops { const struct iommu_domain_ops *default_domain_ops; unsigned long pgsize_bitmap; struct module *owner; + struct iommu_domain *identity_domain; }; /** -- cgit