Messages in this thread Patch in this message |  | | From | Lu Baolu <> | Subject | [PATCH v5 08/12] iommu/sva: Use attach/detach_pasid_dev in SVA interfaces | Date | Mon, 2 May 2022 09:48:38 +0800 |
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The existing iommu SVA interfaces are implemented by calling the SVA specific iommu ops provided by the IOMMU drivers. There's no need for any SVA specific ops in iommu_ops vector anymore as we can achieve this through the generic attach/detach_dev_pasid domain ops.
This refactors the IOMMU SVA interfaces implementation by using the attach/detach_pasid_dev ops and align them with the concept of the iommu domain. Put the new SVA code in the sva related file in order to make it self-contained.
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> --- include/linux/iommu.h | 44 ++++---- drivers/iommu/iommu-sva-lib.c | 194 ++++++++++++++++++++++++++++++++++ drivers/iommu/iommu.c | 92 ---------------- 3 files changed, 217 insertions(+), 113 deletions(-)
diff --git a/include/linux/iommu.h b/include/linux/iommu.h index f582f434c513..c5a16b47cae8 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -683,12 +683,6 @@ int iommu_dev_enable_feature(struct device *dev, enum iommu_dev_features f); int iommu_dev_disable_feature(struct device *dev, enum iommu_dev_features f); bool iommu_dev_feature_enabled(struct device *dev, enum iommu_dev_features f); -struct iommu_sva *iommu_sva_bind_device(struct device *dev, - struct mm_struct *mm, - void *drvdata); -void iommu_sva_unbind_device(struct iommu_sva *handle); -u32 iommu_sva_get_pasid(struct iommu_sva *handle); - int iommu_device_use_default_domain(struct device *dev); void iommu_device_unuse_default_domain(struct device *dev); @@ -1030,21 +1024,6 @@ iommu_dev_disable_feature(struct device *dev, enum iommu_dev_features feat) return -ENODEV; } -static inline struct iommu_sva * -iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, void *drvdata) -{ - return NULL; -} - -static inline void iommu_sva_unbind_device(struct iommu_sva *handle) -{ -} - -static inline u32 iommu_sva_get_pasid(struct iommu_sva *handle) -{ - return IOMMU_PASID_INVALID; -} - static inline struct iommu_fwspec *dev_iommu_fwspec_get(struct device *dev) { return NULL; @@ -1086,6 +1065,29 @@ static inline void iommu_detach_device_pasid(struct iommu_domain *domain, } #endif /* CONFIG_IOMMU_API */ +#ifdef CONFIG_IOMMU_SVA +struct iommu_sva *iommu_sva_bind_device(struct device *dev, + struct mm_struct *mm, + void *drvdata); +void iommu_sva_unbind_device(struct iommu_sva *handle); +u32 iommu_sva_get_pasid(struct iommu_sva *handle); +#else /* CONFIG_IOMMU_SVA */ +static inline struct iommu_sva * +iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, void *drvdata) +{ + return NULL; +} + +static inline void iommu_sva_unbind_device(struct iommu_sva *handle) +{ +} + +static inline u32 iommu_sva_get_pasid(struct iommu_sva *handle) +{ + return IOMMU_PASID_INVALID; +} +#endif /* CONFIG_IOMMU_SVA */ + /** * iommu_map_sgtable - Map the given buffer to the IOMMU domain * @domain: The IOMMU domain to perform the mapping diff --git a/drivers/iommu/iommu-sva-lib.c b/drivers/iommu/iommu-sva-lib.c index d524a402be3b..0524659a4c0c 100644 --- a/drivers/iommu/iommu-sva-lib.c +++ b/drivers/iommu/iommu-sva-lib.c @@ -11,6 +11,7 @@ static DEFINE_MUTEX(iommu_sva_lock); static DECLARE_IOASID_SET(iommu_sva_pasid); +static DEFINE_XARRAY_ALLOC(iommu_sva_ioas_array); struct iommu_sva_ioas { struct mm_struct *mm; @@ -87,3 +88,196 @@ struct mm_struct *iommu_sva_find(ioasid_t pasid) return ioasid_find(&iommu_sva_pasid, pasid, __mmget_not_zero); } EXPORT_SYMBOL_GPL(iommu_sva_find); + +/* + * Get or put an ioas for a shared memory. + */ +static struct iommu_sva_ioas *iommu_sva_ioas_get(struct mm_struct *mm, + ioasid_t pasid) +{ + struct iommu_sva_ioas *ioas; + int ret; + + ioas = xa_load(&iommu_sva_ioas_array, pasid); + if (ioas) { + if (WARN_ON(ioas->mm != mm)) + return ERR_PTR(-EINVAL); + refcount_inc(&ioas->users); + return ioas; + } + + ioas = kzalloc(sizeof(*ioas), GFP_KERNEL); + if (!ioas) + return ERR_PTR(-ENOMEM); + + ioas->mm = mm; + ioas->pasid = pasid; + refcount_set(&ioas->users, 1); + INIT_LIST_HEAD(&ioas->bonds); + ret = xa_err(xa_store(&iommu_sva_ioas_array, pasid, ioas, GFP_KERNEL)); + if (ret) { + kfree(ioas); + return ERR_PTR(ret); + } + + mmgrab(mm); + + return ioas; +} + +static void iommu_sva_ioas_put(struct iommu_sva_ioas *ioas) +{ + if (refcount_dec_and_test(&ioas->users)) { + WARN_ON(!list_empty(&ioas->bonds)); + xa_erase(&iommu_sva_ioas_array, ioas->pasid); + mmdrop(ioas->mm); + kfree(ioas); + } +} + +/* + * IOMMU SVA driver-oriented interfaces + */ +static struct iommu_domain * +iommu_sva_alloc_domain(struct device *dev, struct iommu_sva_ioas *ioas) +{ + struct bus_type *bus = dev->bus; + struct iommu_domain *domain; + + if (!bus || !bus->iommu_ops) + return NULL; + + domain = bus->iommu_ops->domain_alloc(IOMMU_DOMAIN_SVA); + if (!domain) + return NULL; + + /* The caller must hold a reference to ioas. */ + domain->sva_ioas = ioas; + domain->type = IOMMU_DOMAIN_SVA; + + return domain; +} + +/** + * iommu_sva_bind_device() - Bind a process address space to a device + * @dev: the device + * @mm: the mm to bind, caller must hold a reference to it + * @drvdata: opaque data pointer to pass to bind callback + * + * Create a bond between device and address space, allowing the device to access + * the mm using the returned PASID. If a bond already exists between @device and + * @mm, it is returned and an additional reference is taken. Caller must call + * iommu_sva_unbind_device() to release each reference. + * + * iommu_dev_enable_feature(dev, IOMMU_DEV_FEAT_SVA) must be called first, to + * initialize the required SVA features. + * + * On error, returns an ERR_PTR value. + */ +struct iommu_sva * +iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, void *drvdata) +{ + int ret = -EINVAL; + struct iommu_sva *handle; + struct iommu_domain *domain; + struct iommu_sva_ioas *ioas; + + /* + * TODO: Remove the drvdata parameter after kernel PASID support is + * enabled for the idxd driver. + */ + if (drvdata) + return ERR_PTR(-EOPNOTSUPP); + + /* Allocate mm->pasid if necessary. */ + ret = iommu_sva_alloc_pasid(mm, 1, (1U << dev->iommu->pasid_bits) - 1); + if (ret) + return ERR_PTR(ret); + + mutex_lock(&iommu_sva_lock); + ioas = iommu_sva_ioas_get(mm, mm->pasid); + if (IS_ERR(ioas)) { + ret = PTR_ERR(ioas); + goto out_unlock; + } + + /* Search for an existing bond. */ + list_for_each_entry(handle, &ioas->bonds, node) { + if (handle->dev == dev) { + refcount_inc(&handle->users); + /* No new bond, drop the counter. */ + iommu_sva_ioas_put(ioas); + goto out_success; + } + } + + handle = kzalloc(sizeof(*handle), GFP_KERNEL); + if (!handle) { + ret = -ENOMEM; + goto out_put_ioas; + } + + /* The reference to ioas will be kept until domain free. */ + domain = iommu_sva_alloc_domain(dev, ioas); + if (!domain) { + ret = -ENODEV; + goto out_free_handle; + } + + ret = iommu_attach_device_pasid(domain, dev, mm->pasid); + if (ret) + goto out_free_domain; + + handle->dev = dev; + handle->domain = domain; + handle->sva_ioas = ioas; + refcount_set(&handle->users, 1); + list_add_tail(&handle->node, &ioas->bonds); + +out_success: + mutex_unlock(&iommu_sva_lock); + return handle; + +out_free_domain: + iommu_domain_free(domain); +out_free_handle: + kfree(handle); +out_put_ioas: + iommu_sva_ioas_put(ioas); +out_unlock: + mutex_unlock(&iommu_sva_lock); + return ERR_PTR(ret); +} +EXPORT_SYMBOL_GPL(iommu_sva_bind_device); + +/** + * iommu_sva_unbind_device() - Remove a bond created with iommu_sva_bind_device + * @handle: the handle returned by iommu_sva_bind_device() + * + * Put reference to a bond between device and address space. The device should + * not be issuing any more transaction for this PASID. All outstanding page + * requests for this PASID must have been flushed to the IOMMU. + */ +void iommu_sva_unbind_device(struct iommu_sva *handle) +{ + struct device *dev = handle->dev; + struct iommu_domain *domain = handle->domain; + struct iommu_sva_ioas *ioas = handle->sva_ioas; + + mutex_lock(&iommu_sva_lock); + if (refcount_dec_and_test(&handle->users)) { + list_del(&handle->node); + iommu_detach_device_pasid(domain, dev, ioas->pasid); + iommu_domain_free(domain); + iommu_sva_ioas_put(ioas); + kfree(handle); + } + mutex_unlock(&iommu_sva_lock); +} +EXPORT_SYMBOL_GPL(iommu_sva_unbind_device); + +u32 iommu_sva_get_pasid(struct iommu_sva *handle) +{ + return handle->sva_ioas->pasid; +} +EXPORT_SYMBOL_GPL(iommu_sva_get_pasid); diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 89c9d19ddb28..7cae631c1baa 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -2731,98 +2731,6 @@ bool iommu_dev_feature_enabled(struct device *dev, enum iommu_dev_features feat) } EXPORT_SYMBOL_GPL(iommu_dev_feature_enabled); -/** - * iommu_sva_bind_device() - Bind a process address space to a device - * @dev: the device - * @mm: the mm to bind, caller must hold a reference to it - * @drvdata: opaque data pointer to pass to bind callback - * - * Create a bond between device and address space, allowing the device to access - * the mm using the returned PASID. If a bond already exists between @device and - * @mm, it is returned and an additional reference is taken. Caller must call - * iommu_sva_unbind_device() to release each reference. - * - * iommu_dev_enable_feature(dev, IOMMU_DEV_FEAT_SVA) must be called first, to - * initialize the required SVA features. - * - * On error, returns an ERR_PTR value. - */ -struct iommu_sva * -iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, void *drvdata) -{ - struct iommu_group *group; - struct iommu_sva *handle = ERR_PTR(-EINVAL); - const struct iommu_ops *ops = dev_iommu_ops(dev); - - if (!ops->sva_bind) - return ERR_PTR(-ENODEV); - - group = iommu_group_get(dev); - if (!group) - return ERR_PTR(-ENODEV); - - /* Ensure device count and domain don't change while we're binding */ - mutex_lock(&group->mutex); - - /* - * To keep things simple, SVA currently doesn't support IOMMU groups - * with more than one device. Existing SVA-capable systems are not - * affected by the problems that required IOMMU groups (lack of ACS - * isolation, device ID aliasing and other hardware issues). - */ - if (iommu_group_device_count(group) != 1) - goto out_unlock; - - handle = ops->sva_bind(dev, mm, drvdata); - -out_unlock: - mutex_unlock(&group->mutex); - iommu_group_put(group); - - return handle; -} -EXPORT_SYMBOL_GPL(iommu_sva_bind_device); - -/** - * iommu_sva_unbind_device() - Remove a bond created with iommu_sva_bind_device - * @handle: the handle returned by iommu_sva_bind_device() - * - * Put reference to a bond between device and address space. The device should - * not be issuing any more transaction for this PASID. All outstanding page - * requests for this PASID must have been flushed to the IOMMU. - */ -void iommu_sva_unbind_device(struct iommu_sva *handle) -{ - struct iommu_group *group; - struct device *dev = handle->dev; - const struct iommu_ops *ops = dev_iommu_ops(dev); - - if (!ops->sva_unbind) - return; - - group = iommu_group_get(dev); - if (!group) - return; - - mutex_lock(&group->mutex); - ops->sva_unbind(handle); - mutex_unlock(&group->mutex); - - iommu_group_put(group); -} -EXPORT_SYMBOL_GPL(iommu_sva_unbind_device); - -u32 iommu_sva_get_pasid(struct iommu_sva *handle) -{ - const struct iommu_ops *ops = dev_iommu_ops(handle->dev); - - if (!ops->sva_get_pasid) - return IOMMU_PASID_INVALID; - - return ops->sva_get_pasid(handle); -} -EXPORT_SYMBOL_GPL(iommu_sva_get_pasid); - /* * Changes the default domain of an iommu group that has *only* one device * -- 2.25.1
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