From 7423e01741dd6a5f1255f589145313f0fb1c8cbe Mon Sep 17 00:00:00 2001 From: Lu Baolu Date: Sat, 25 May 2019 13:41:22 +0800 Subject: [PATCH] iommu: Add API to request DMA domain for device Normally during iommu probing a device, a default doamin will be allocated and attached to the device. The domain type of the default domain is statically defined, which results in a situation where the allocated default domain isn't suitable for the device due to some limitations. We already have API iommu_request_dm_for_dev() to replace a DMA domain with an identity one. This adds iommu_request_dma_domain_for_dev() to request a dma domain if an allocated identity domain isn't suitable for the device in question. Signed-off-by: Lu Baolu Signed-off-by: Joerg Roedel --- drivers/iommu/iommu.c | 36 +++++++++++++++++++++++++----------- include/linux/iommu.h | 6 ++++++ 2 files changed, 31 insertions(+), 11 deletions(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 67ee6623f9b2..2fca04c3dbaf 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -1907,10 +1907,10 @@ struct iommu_resv_region *iommu_alloc_resv_region(phys_addr_t start, return region; } -/* Request that a device is direct mapped by the IOMMU */ -int iommu_request_dm_for_dev(struct device *dev) +static int +request_default_domain_for_dev(struct device *dev, unsigned long type) { - struct iommu_domain *dm_domain; + struct iommu_domain *domain; struct iommu_group *group; int ret; @@ -1923,8 +1923,7 @@ int iommu_request_dm_for_dev(struct device *dev) /* Check if the default domain is already direct mapped */ ret = 0; - if (group->default_domain && - group->default_domain->type == IOMMU_DOMAIN_IDENTITY) + if (group->default_domain && group->default_domain->type == type) goto out; /* Don't change mappings of existing devices */ @@ -1934,23 +1933,26 @@ int iommu_request_dm_for_dev(struct device *dev) /* Allocate a direct mapped domain */ ret = -ENOMEM; - dm_domain = __iommu_domain_alloc(dev->bus, IOMMU_DOMAIN_IDENTITY); - if (!dm_domain) + domain = __iommu_domain_alloc(dev->bus, type); + if (!domain) goto out; /* Attach the device to the domain */ - ret = __iommu_attach_group(dm_domain, group); + ret = __iommu_attach_group(domain, group); if (ret) { - iommu_domain_free(dm_domain); + iommu_domain_free(domain); goto out; } + iommu_group_create_direct_mappings(group, dev); + /* Make the direct mapped domain the default for this group */ if (group->default_domain) iommu_domain_free(group->default_domain); - group->default_domain = dm_domain; + group->default_domain = domain; - dev_info(dev, "Using iommu direct mapping\n"); + dev_info(dev, "Using iommu %s mapping\n", + type == IOMMU_DOMAIN_DMA ? "dma" : "direct"); ret = 0; out: @@ -1960,6 +1962,18 @@ out: return ret; } +/* Request that a device is direct mapped by the IOMMU */ +int iommu_request_dm_for_dev(struct device *dev) +{ + return request_default_domain_for_dev(dev, IOMMU_DOMAIN_IDENTITY); +} + +/* Request that a device can't be direct mapped by the IOMMU */ +int iommu_request_dma_domain_for_dev(struct device *dev) +{ + return request_default_domain_for_dev(dev, IOMMU_DOMAIN_DMA); +} + const struct iommu_ops *iommu_ops_from_fwnode(struct fwnode_handle *fwnode) { const struct iommu_ops *ops = NULL; diff --git a/include/linux/iommu.h b/include/linux/iommu.h index a815cf6f6f47..91af22a344e2 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -362,6 +362,7 @@ extern void iommu_set_fault_handler(struct iommu_domain *domain, extern void iommu_get_resv_regions(struct device *dev, struct list_head *list); extern void iommu_put_resv_regions(struct device *dev, struct list_head *list); extern int iommu_request_dm_for_dev(struct device *dev); +extern int iommu_request_dma_domain_for_dev(struct device *dev); extern struct iommu_resv_region * iommu_alloc_resv_region(phys_addr_t start, size_t length, int prot, enum iommu_resv_type type); @@ -626,6 +627,11 @@ static inline int iommu_request_dm_for_dev(struct device *dev) return -ENODEV; } +static inline int iommu_request_dma_domain_for_dev(struct device *dev) +{ + return -ENODEV; +} + static inline int iommu_attach_group(struct iommu_domain *domain, struct iommu_group *group) { -- 2.11.0