diff options
Diffstat (limited to 'drivers/iommu/iommu-sva-lib.c')
| -rw-r--r-- | drivers/iommu/iommu-sva-lib.c | 240 |
1 files changed, 0 insertions, 240 deletions
diff --git a/drivers/iommu/iommu-sva-lib.c b/drivers/iommu/iommu-sva-lib.c deleted file mode 100644 index 089fd61ff453..000000000000 --- a/drivers/iommu/iommu-sva-lib.c +++ /dev/null @@ -1,240 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * Helpers for IOMMU drivers implementing SVA - */ -#include <linux/mutex.h> -#include <linux/sched/mm.h> -#include <linux/iommu.h> - -#include "iommu-sva-lib.h" - -static DEFINE_MUTEX(iommu_sva_lock); -static DECLARE_IOASID_SET(iommu_sva_pasid); - -/** - * iommu_sva_alloc_pasid - Allocate a PASID for the mm - * @mm: the mm - * @min: minimum PASID value (inclusive) - * @max: maximum PASID value (inclusive) - * - * Try to allocate a PASID for this mm, or take a reference to the existing one - * provided it fits within the [@min, @max] range. On success the PASID is - * available in mm->pasid and will be available for the lifetime of the mm. - * - * Returns 0 on success and < 0 on error. - */ -int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max) -{ - int ret = 0; - ioasid_t pasid; - - if (min == INVALID_IOASID || max == INVALID_IOASID || - min == 0 || max < min) - return -EINVAL; - - mutex_lock(&iommu_sva_lock); - /* Is a PASID already associated with this mm? */ - if (pasid_valid(mm->pasid)) { - if (mm->pasid < min || mm->pasid >= max) - ret = -EOVERFLOW; - goto out; - } - - pasid = ioasid_alloc(&iommu_sva_pasid, min, max, mm); - if (!pasid_valid(pasid)) - ret = -ENOMEM; - else - mm_pasid_set(mm, pasid); -out: - mutex_unlock(&iommu_sva_lock); - return ret; -} -EXPORT_SYMBOL_GPL(iommu_sva_alloc_pasid); - -/* ioasid_find getter() requires a void * argument */ -static bool __mmget_not_zero(void *mm) -{ - return mmget_not_zero(mm); -} - -/** - * iommu_sva_find() - Find mm associated to the given PASID - * @pasid: Process Address Space ID assigned to the mm - * - * On success a reference to the mm is taken, and must be released with mmput(). - * - * Returns the mm corresponding to this PASID, or an error if not found. - */ -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); - -/** - * 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 mm_users - * - * Create a bond between device and address space, allowing the device to - * access the mm using the PASID returned by iommu_sva_get_pasid(). If a - * bond already exists between @device and @mm, an additional internal - * 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) -{ - struct iommu_domain *domain; - struct iommu_sva *handle; - ioasid_t max_pasids; - int ret; - - max_pasids = dev->iommu->max_pasids; - if (!max_pasids) - return ERR_PTR(-EOPNOTSUPP); - - /* Allocate mm->pasid if necessary. */ - ret = iommu_sva_alloc_pasid(mm, 1, max_pasids - 1); - if (ret) - return ERR_PTR(ret); - - handle = kzalloc(sizeof(*handle), GFP_KERNEL); - if (!handle) - return ERR_PTR(-ENOMEM); - - mutex_lock(&iommu_sva_lock); - /* Search for an existing domain. */ - domain = iommu_get_domain_for_dev_pasid(dev, mm->pasid, - IOMMU_DOMAIN_SVA); - if (IS_ERR(domain)) { - ret = PTR_ERR(domain); - goto out_unlock; - } - - if (domain) { - domain->users++; - goto out; - } - - /* Allocate a new domain and set it on device pasid. */ - domain = iommu_sva_domain_alloc(dev, mm); - if (!domain) { - ret = -ENOMEM; - goto out_unlock; - } - - ret = iommu_attach_device_pasid(domain, dev, mm->pasid); - if (ret) - goto out_free_domain; - domain->users = 1; -out: - mutex_unlock(&iommu_sva_lock); - handle->dev = dev; - handle->domain = domain; - - return handle; - -out_free_domain: - iommu_domain_free(domain); -out_unlock: - mutex_unlock(&iommu_sva_lock); - kfree(handle); - - 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 iommu_domain *domain = handle->domain; - ioasid_t pasid = domain->mm->pasid; - struct device *dev = handle->dev; - - mutex_lock(&iommu_sva_lock); - if (--domain->users == 0) { - iommu_detach_device_pasid(domain, dev, pasid); - iommu_domain_free(domain); - } - mutex_unlock(&iommu_sva_lock); - kfree(handle); -} -EXPORT_SYMBOL_GPL(iommu_sva_unbind_device); - -u32 iommu_sva_get_pasid(struct iommu_sva *handle) -{ - struct iommu_domain *domain = handle->domain; - - return domain->mm->pasid; -} -EXPORT_SYMBOL_GPL(iommu_sva_get_pasid); - -/* - * I/O page fault handler for SVA - */ -enum iommu_page_response_code -iommu_sva_handle_iopf(struct iommu_fault *fault, void *data) -{ - vm_fault_t ret; - struct vm_area_struct *vma; - struct mm_struct *mm = data; - unsigned int access_flags = 0; - unsigned int fault_flags = FAULT_FLAG_REMOTE; - struct iommu_fault_page_request *prm = &fault->prm; - enum iommu_page_response_code status = IOMMU_PAGE_RESP_INVALID; - - if (!(prm->flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID)) - return status; - - if (!mmget_not_zero(mm)) - return status; - - mmap_read_lock(mm); - - vma = find_extend_vma(mm, prm->addr); - if (!vma) - /* Unmapped area */ - goto out_put_mm; - - if (prm->perm & IOMMU_FAULT_PERM_READ) - access_flags |= VM_READ; - - if (prm->perm & IOMMU_FAULT_PERM_WRITE) { - access_flags |= VM_WRITE; - fault_flags |= FAULT_FLAG_WRITE; - } - - if (prm->perm & IOMMU_FAULT_PERM_EXEC) { - access_flags |= VM_EXEC; - fault_flags |= FAULT_FLAG_INSTRUCTION; - } - - if (!(prm->perm & IOMMU_FAULT_PERM_PRIV)) - fault_flags |= FAULT_FLAG_USER; - - if (access_flags & ~vma->vm_flags) - /* Access fault */ - goto out_put_mm; - - ret = handle_mm_fault(vma, prm->addr, fault_flags, NULL); - status = ret & VM_FAULT_ERROR ? IOMMU_PAGE_RESP_INVALID : - IOMMU_PAGE_RESP_SUCCESS; - -out_put_mm: - mmap_read_unlock(mm); - mmput(mm); - - return status; -} |