From 064a57d7ddfc46ada02b477b91c478001b03bfa3 Mon Sep 17 00:00:00 2001 From: Jacob Pan Date: Sat, 16 May 2020 14:20:54 +0800 Subject: [PATCH] iommu/vt-d: Replace intel SVM APIs with generic SVA APIs This patch is an initial step to replace Intel SVM code with the following IOMMU SVA ops: intel_svm_bind_mm() => iommu_sva_bind_device() intel_svm_unbind_mm() => iommu_sva_unbind_device() intel_svm_is_pasid_valid() => iommu_sva_get_pasid() The features below will continue to work but are not included in this patch in that they are handled mostly within the IOMMU subsystem. - IO page fault - mmu notifier Consolidation of the above will come after merging generic IOMMU sva code[1]. There should not be any changes needed for SVA users such as accelerator device drivers during this time. [1] http://jpbrucker.net/sva/ Signed-off-by: Jacob Pan Signed-off-by: Lu Baolu Link: https://lore.kernel.org/r/20200516062101.29541-12-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel --- drivers/iommu/intel-iommu.c | 3 + drivers/iommu/intel-svm.c | 124 ++++++++++++++++++++---------------- include/linux/intel-iommu.h | 6 ++ include/linux/intel-svm.h | 86 ------------------------- 4 files changed, 78 insertions(+), 141 deletions(-) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index ed7de7420b3c..7d28ef2e6fe2 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -6071,6 +6071,9 @@ const struct iommu_ops intel_iommu_ops = { .cache_invalidate = intel_iommu_sva_invalidate, .sva_bind_gpasid = intel_svm_bind_gpasid, .sva_unbind_gpasid = intel_svm_unbind_gpasid, + .sva_bind = intel_svm_bind, + .sva_unbind = intel_svm_unbind, + .sva_get_pasid = intel_svm_get_pasid, #endif }; diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c index 75a1ba4439f7..8b66bf45477e 100644 --- a/drivers/iommu/intel-svm.c +++ b/drivers/iommu/intel-svm.c @@ -426,13 +426,15 @@ out: return ret; } -int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_ops *ops) +/* Caller must hold pasid_mutex, mm reference */ +static int +intel_svm_bind_mm(struct device *dev, int flags, struct svm_dev_ops *ops, + struct mm_struct *mm, struct intel_svm_dev **sd) { struct intel_iommu *iommu = intel_svm_device_to_iommu(dev); struct device_domain_info *info; struct intel_svm_dev *sdev; struct intel_svm *svm = NULL; - struct mm_struct *mm = NULL; int pasid_max; int ret; @@ -449,16 +451,15 @@ int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_ } else pasid_max = 1 << 20; + /* Bind supervisor PASID shuld have mm = NULL */ if (flags & SVM_FLAG_SUPERVISOR_MODE) { - if (!ecap_srs(iommu->ecap)) + if (!ecap_srs(iommu->ecap) || mm) { + pr_err("Supervisor PASID with user provided mm.\n"); return -EINVAL; - } else if (pasid) { - mm = get_task_mm(current); - BUG_ON(!mm); + } } - mutex_lock(&pasid_mutex); - if (pasid && !(flags & SVM_FLAG_PRIVATE_PASID)) { + if (!(flags & SVM_FLAG_PRIVATE_PASID)) { struct intel_svm *t; list_for_each_entry(t, &global_svm_list, list) { @@ -496,9 +497,7 @@ int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_ sdev->dev = dev; ret = intel_iommu_enable_pasid(iommu, dev); - if (ret || !pasid) { - /* If they don't actually want to assign a PASID, this is - * just an enabling check/preparation. */ + if (ret) { kfree(sdev); goto out; } @@ -597,18 +596,17 @@ int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_ } } list_add_rcu(&sdev->list, &svm->devs); - - success: - *pasid = svm->pasid; +success: + sdev->pasid = svm->pasid; + sdev->sva.dev = dev; + if (sd) + *sd = sdev; ret = 0; out: - mutex_unlock(&pasid_mutex); - if (mm) - mmput(mm); return ret; } -EXPORT_SYMBOL_GPL(intel_svm_bind_mm); +/* Caller must hold pasid_mutex */ int intel_svm_unbind_mm(struct device *dev, int pasid) { struct intel_svm_dev *sdev; @@ -616,7 +614,6 @@ int intel_svm_unbind_mm(struct device *dev, int pasid) struct intel_svm *svm; int ret = -EINVAL; - mutex_lock(&pasid_mutex); iommu = intel_svm_device_to_iommu(dev); if (!iommu) goto out; @@ -662,45 +659,9 @@ int intel_svm_unbind_mm(struct device *dev, int pasid) break; } out: - mutex_unlock(&pasid_mutex); return ret; } -EXPORT_SYMBOL_GPL(intel_svm_unbind_mm); - -int intel_svm_is_pasid_valid(struct device *dev, int pasid) -{ - struct intel_iommu *iommu; - struct intel_svm *svm; - int ret = -EINVAL; - - mutex_lock(&pasid_mutex); - iommu = intel_svm_device_to_iommu(dev); - if (!iommu) - goto out; - - svm = ioasid_find(NULL, pasid, NULL); - if (!svm) - goto out; - - if (IS_ERR(svm)) { - ret = PTR_ERR(svm); - goto out; - } - /* init_mm is used in this case */ - if (!svm->mm) - ret = 1; - else if (atomic_read(&svm->mm->mm_users) > 0) - ret = 1; - else - ret = 0; - - out: - mutex_unlock(&pasid_mutex); - - return ret; -} -EXPORT_SYMBOL_GPL(intel_svm_is_pasid_valid); /* Page request queue descriptor */ struct page_req_dsc { @@ -894,3 +855,56 @@ static irqreturn_t prq_event_thread(int irq, void *d) return IRQ_RETVAL(handled); } + +#define to_intel_svm_dev(handle) container_of(handle, struct intel_svm_dev, sva) +struct iommu_sva * +intel_svm_bind(struct device *dev, struct mm_struct *mm, void *drvdata) +{ + struct iommu_sva *sva = ERR_PTR(-EINVAL); + struct intel_svm_dev *sdev = NULL; + int flags = 0; + int ret; + + /* + * TODO: Consolidate with generic iommu-sva bind after it is merged. + * It will require shared SVM data structures, i.e. combine io_mm + * and intel_svm etc. + */ + if (drvdata) + flags = *(int *)drvdata; + mutex_lock(&pasid_mutex); + ret = intel_svm_bind_mm(dev, flags, NULL, mm, &sdev); + if (ret) + sva = ERR_PTR(ret); + else if (sdev) + sva = &sdev->sva; + else + WARN(!sdev, "SVM bind succeeded with no sdev!\n"); + + mutex_unlock(&pasid_mutex); + + return sva; +} + +void intel_svm_unbind(struct iommu_sva *sva) +{ + struct intel_svm_dev *sdev; + + mutex_lock(&pasid_mutex); + sdev = to_intel_svm_dev(sva); + intel_svm_unbind_mm(sdev->dev, sdev->pasid); + mutex_unlock(&pasid_mutex); +} + +int intel_svm_get_pasid(struct iommu_sva *sva) +{ + struct intel_svm_dev *sdev; + int pasid; + + mutex_lock(&pasid_mutex); + sdev = to_intel_svm_dev(sva); + pasid = sdev->pasid; + mutex_unlock(&pasid_mutex); + + return pasid; +} diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h index caa179e806fc..42245e1e1b48 100644 --- a/include/linux/intel-iommu.h +++ b/include/linux/intel-iommu.h @@ -723,6 +723,10 @@ extern int intel_svm_finish_prq(struct intel_iommu *iommu); int intel_svm_bind_gpasid(struct iommu_domain *domain, struct device *dev, struct iommu_gpasid_bind_data *data); int intel_svm_unbind_gpasid(struct device *dev, int pasid); +struct iommu_sva *intel_svm_bind(struct device *dev, struct mm_struct *mm, + void *drvdata); +void intel_svm_unbind(struct iommu_sva *handle); +int intel_svm_get_pasid(struct iommu_sva *handle); struct svm_dev_ops; struct intel_svm_dev { @@ -730,6 +734,8 @@ struct intel_svm_dev { struct rcu_head rcu; struct device *dev; struct svm_dev_ops *ops; + struct iommu_sva sva; + int pasid; int users; u16 did; u16 dev_iotlb:1; diff --git a/include/linux/intel-svm.h b/include/linux/intel-svm.h index 1b47ca46373e..c9e7e601950d 100644 --- a/include/linux/intel-svm.h +++ b/include/linux/intel-svm.h @@ -21,7 +21,6 @@ struct svm_dev_ops { #define SVM_REQ_EXEC (1<<1) #define SVM_REQ_PRIV (1<<0) - /* * The SVM_FLAG_PRIVATE_PASID flag requests a PASID which is *not* the "main" * PASID for the current process. Even if a PASID already exists, a new one @@ -57,89 +56,4 @@ struct svm_dev_ops { */ #define SVM_FLAG_GUEST_PASID (1<<3) -#ifdef CONFIG_INTEL_IOMMU_SVM - -/** - * intel_svm_bind_mm() - Bind the current process to a PASID - * @dev: Device to be granted access - * @pasid: Address for allocated PASID - * @flags: Flags. Later for requesting supervisor mode, etc. - * @ops: Callbacks to device driver - * - * This function attempts to enable PASID support for the given device. - * If the @pasid argument is non-%NULL, a PASID is allocated for access - * to the MM of the current process. - * - * By using a %NULL value for the @pasid argument, this function can - * be used to simply validate that PASID support is available for the - * given device — i.e. that it is behind an IOMMU which has the - * requisite support, and is enabled. - * - * Page faults are handled transparently by the IOMMU code, and there - * should be no need for the device driver to be involved. If a page - * fault cannot be handled (i.e. is an invalid address rather than - * just needs paging in), then the page request will be completed by - * the core IOMMU code with appropriate status, and the device itself - * can then report the resulting fault to its driver via whatever - * mechanism is appropriate. - * - * Multiple calls from the same process may result in the same PASID - * being re-used. A reference count is kept. - */ -extern int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, - struct svm_dev_ops *ops); - -/** - * intel_svm_unbind_mm() - Unbind a specified PASID - * @dev: Device for which PASID was allocated - * @pasid: PASID value to be unbound - * - * This function allows a PASID to be retired when the device no - * longer requires access to the address space of a given process. - * - * If the use count for the PASID in question reaches zero, the - * PASID is revoked and may no longer be used by hardware. - * - * Device drivers are required to ensure that no access (including - * page requests) is currently outstanding for the PASID in question, - * before calling this function. - */ -extern int intel_svm_unbind_mm(struct device *dev, int pasid); - -/** - * intel_svm_is_pasid_valid() - check if pasid is valid - * @dev: Device for which PASID was allocated - * @pasid: PASID value to be checked - * - * This function checks if the specified pasid is still valid. A - * valid pasid means the backing mm is still having a valid user. - * For kernel callers init_mm is always valid. for other mm, if mm->mm_users - * is non-zero, it is valid. - * - * returns -EINVAL if invalid pasid, 0 if pasid ref count is invalid - * 1 if pasid is valid. - */ -extern int intel_svm_is_pasid_valid(struct device *dev, int pasid); - -#else /* CONFIG_INTEL_IOMMU_SVM */ - -static inline int intel_svm_bind_mm(struct device *dev, int *pasid, - int flags, struct svm_dev_ops *ops) -{ - return -ENOSYS; -} - -static inline int intel_svm_unbind_mm(struct device *dev, int pasid) -{ - BUG(); -} - -static inline int intel_svm_is_pasid_valid(struct device *dev, int pasid) -{ - return -EINVAL; -} -#endif /* CONFIG_INTEL_IOMMU_SVM */ - -#define intel_svm_available(dev) (!intel_svm_bind_mm((dev), NULL, 0, NULL)) - #endif /* __INTEL_SVM_H__ */