| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * IOMMU API for s390 PCI devices |
| * |
| * Copyright IBM Corp. 2015 |
| * Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com> |
| */ |
| |
| #include <linux/pci.h> |
| #include <linux/iommu.h> |
| #include <linux/iommu-helper.h> |
| #include <linux/sizes.h> |
| #include <linux/rculist.h> |
| #include <linux/rcupdate.h> |
| #include <asm/pci_dma.h> |
| |
| static const struct iommu_ops s390_iommu_ops; |
| |
| struct s390_domain { |
| struct iommu_domain domain; |
| struct list_head devices; |
| unsigned long *dma_table; |
| spinlock_t list_lock; |
| struct rcu_head rcu; |
| }; |
| |
| static struct s390_domain *to_s390_domain(struct iommu_domain *dom) |
| { |
| return container_of(dom, struct s390_domain, domain); |
| } |
| |
| static bool s390_iommu_capable(struct device *dev, enum iommu_cap cap) |
| { |
| switch (cap) { |
| case IOMMU_CAP_CACHE_COHERENCY: |
| return true; |
| case IOMMU_CAP_INTR_REMAP: |
| return true; |
| default: |
| return false; |
| } |
| } |
| |
| static struct iommu_domain *s390_domain_alloc(unsigned domain_type) |
| { |
| struct s390_domain *s390_domain; |
| |
| if (domain_type != IOMMU_DOMAIN_UNMANAGED) |
| return NULL; |
| |
| s390_domain = kzalloc(sizeof(*s390_domain), GFP_KERNEL); |
| if (!s390_domain) |
| return NULL; |
| |
| s390_domain->dma_table = dma_alloc_cpu_table(); |
| if (!s390_domain->dma_table) { |
| kfree(s390_domain); |
| return NULL; |
| } |
| s390_domain->domain.geometry.force_aperture = true; |
| s390_domain->domain.geometry.aperture_start = 0; |
| s390_domain->domain.geometry.aperture_end = ZPCI_TABLE_SIZE_RT - 1; |
| |
| spin_lock_init(&s390_domain->list_lock); |
| INIT_LIST_HEAD_RCU(&s390_domain->devices); |
| |
| return &s390_domain->domain; |
| } |
| |
| static void s390_iommu_rcu_free_domain(struct rcu_head *head) |
| { |
| struct s390_domain *s390_domain = container_of(head, struct s390_domain, rcu); |
| |
| dma_cleanup_tables(s390_domain->dma_table); |
| kfree(s390_domain); |
| } |
| |
| static void s390_domain_free(struct iommu_domain *domain) |
| { |
| struct s390_domain *s390_domain = to_s390_domain(domain); |
| |
| rcu_read_lock(); |
| WARN_ON(!list_empty(&s390_domain->devices)); |
| rcu_read_unlock(); |
| |
| call_rcu(&s390_domain->rcu, s390_iommu_rcu_free_domain); |
| } |
| |
| static void __s390_iommu_detach_device(struct zpci_dev *zdev) |
| { |
| struct s390_domain *s390_domain = zdev->s390_domain; |
| unsigned long flags; |
| |
| if (!s390_domain) |
| return; |
| |
| spin_lock_irqsave(&s390_domain->list_lock, flags); |
| list_del_rcu(&zdev->iommu_list); |
| spin_unlock_irqrestore(&s390_domain->list_lock, flags); |
| |
| zpci_unregister_ioat(zdev, 0); |
| zdev->s390_domain = NULL; |
| zdev->dma_table = NULL; |
| } |
| |
| static int s390_iommu_attach_device(struct iommu_domain *domain, |
| struct device *dev) |
| { |
| struct s390_domain *s390_domain = to_s390_domain(domain); |
| struct zpci_dev *zdev = to_zpci_dev(dev); |
| unsigned long flags; |
| u8 status; |
| int cc; |
| |
| if (!zdev) |
| return -ENODEV; |
| |
| if (WARN_ON(domain->geometry.aperture_start > zdev->end_dma || |
| domain->geometry.aperture_end < zdev->start_dma)) |
| return -EINVAL; |
| |
| if (zdev->s390_domain) |
| __s390_iommu_detach_device(zdev); |
| else if (zdev->dma_table) |
| zpci_dma_exit_device(zdev); |
| |
| cc = zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma, |
| virt_to_phys(s390_domain->dma_table), &status); |
| /* |
| * If the device is undergoing error recovery the reset code |
| * will re-establish the new domain. |
| */ |
| if (cc && status != ZPCI_PCI_ST_FUNC_NOT_AVAIL) |
| return -EIO; |
| zdev->dma_table = s390_domain->dma_table; |
| |
| zdev->dma_table = s390_domain->dma_table; |
| zdev->s390_domain = s390_domain; |
| |
| spin_lock_irqsave(&s390_domain->list_lock, flags); |
| list_add_rcu(&zdev->iommu_list, &s390_domain->devices); |
| spin_unlock_irqrestore(&s390_domain->list_lock, flags); |
| |
| return 0; |
| } |
| |
| static void s390_iommu_detach_device(struct iommu_domain *domain, |
| struct device *dev) |
| { |
| struct zpci_dev *zdev = to_zpci_dev(dev); |
| |
| WARN_ON(zdev->s390_domain != to_s390_domain(domain)); |
| |
| __s390_iommu_detach_device(zdev); |
| zpci_dma_init_device(zdev); |
| } |
| |
| static void s390_iommu_get_resv_regions(struct device *dev, |
| struct list_head *list) |
| { |
| struct zpci_dev *zdev = to_zpci_dev(dev); |
| struct iommu_resv_region *region; |
| |
| if (zdev->start_dma) { |
| region = iommu_alloc_resv_region(0, zdev->start_dma, 0, |
| IOMMU_RESV_RESERVED, GFP_KERNEL); |
| if (!region) |
| return; |
| list_add_tail(®ion->list, list); |
| } |
| |
| if (zdev->end_dma < ZPCI_TABLE_SIZE_RT - 1) { |
| region = iommu_alloc_resv_region(zdev->end_dma + 1, |
| ZPCI_TABLE_SIZE_RT - zdev->end_dma - 1, |
| 0, IOMMU_RESV_RESERVED, GFP_KERNEL); |
| if (!region) |
| return; |
| list_add_tail(®ion->list, list); |
| } |
| } |
| |
| static struct iommu_device *s390_iommu_probe_device(struct device *dev) |
| { |
| struct zpci_dev *zdev; |
| |
| if (!dev_is_pci(dev)) |
| return ERR_PTR(-ENODEV); |
| |
| zdev = to_zpci_dev(dev); |
| |
| if (zdev->start_dma > zdev->end_dma || |
| zdev->start_dma > ZPCI_TABLE_SIZE_RT - 1) |
| return ERR_PTR(-EINVAL); |
| |
| if (zdev->end_dma > ZPCI_TABLE_SIZE_RT - 1) |
| zdev->end_dma = ZPCI_TABLE_SIZE_RT - 1; |
| |
| return &zdev->iommu_dev; |
| } |
| |
| static void s390_iommu_release_device(struct device *dev) |
| { |
| struct zpci_dev *zdev = to_zpci_dev(dev); |
| |
| /* |
| * release_device is expected to detach any domain currently attached |
| * to the device, but keep it attached to other devices in the group. |
| */ |
| if (zdev) |
| __s390_iommu_detach_device(zdev); |
| } |
| |
| static void s390_iommu_flush_iotlb_all(struct iommu_domain *domain) |
| { |
| struct s390_domain *s390_domain = to_s390_domain(domain); |
| struct zpci_dev *zdev; |
| |
| rcu_read_lock(); |
| list_for_each_entry_rcu(zdev, &s390_domain->devices, iommu_list) { |
| zpci_refresh_trans((u64)zdev->fh << 32, zdev->start_dma, |
| zdev->end_dma - zdev->start_dma + 1); |
| } |
| rcu_read_unlock(); |
| } |
| |
| static void s390_iommu_iotlb_sync(struct iommu_domain *domain, |
| struct iommu_iotlb_gather *gather) |
| { |
| struct s390_domain *s390_domain = to_s390_domain(domain); |
| size_t size = gather->end - gather->start + 1; |
| struct zpci_dev *zdev; |
| |
| /* If gather was never added to there is nothing to flush */ |
| if (!gather->end) |
| return; |
| |
| rcu_read_lock(); |
| list_for_each_entry_rcu(zdev, &s390_domain->devices, iommu_list) { |
| zpci_refresh_trans((u64)zdev->fh << 32, gather->start, |
| size); |
| } |
| rcu_read_unlock(); |
| } |
| |
| static void s390_iommu_iotlb_sync_map(struct iommu_domain *domain, |
| unsigned long iova, size_t size) |
| { |
| struct s390_domain *s390_domain = to_s390_domain(domain); |
| struct zpci_dev *zdev; |
| |
| rcu_read_lock(); |
| list_for_each_entry_rcu(zdev, &s390_domain->devices, iommu_list) { |
| if (!zdev->tlb_refresh) |
| continue; |
| zpci_refresh_trans((u64)zdev->fh << 32, |
| iova, size); |
| } |
| rcu_read_unlock(); |
| } |
| |
| static int s390_iommu_validate_trans(struct s390_domain *s390_domain, |
| phys_addr_t pa, dma_addr_t dma_addr, |
| unsigned long nr_pages, int flags) |
| { |
| phys_addr_t page_addr = pa & PAGE_MASK; |
| unsigned long *entry; |
| unsigned long i; |
| int rc; |
| |
| for (i = 0; i < nr_pages; i++) { |
| entry = dma_walk_cpu_trans(s390_domain->dma_table, dma_addr); |
| if (unlikely(!entry)) { |
| rc = -ENOMEM; |
| goto undo_cpu_trans; |
| } |
| dma_update_cpu_trans(entry, page_addr, flags); |
| page_addr += PAGE_SIZE; |
| dma_addr += PAGE_SIZE; |
| } |
| |
| return 0; |
| |
| undo_cpu_trans: |
| while (i-- > 0) { |
| dma_addr -= PAGE_SIZE; |
| entry = dma_walk_cpu_trans(s390_domain->dma_table, |
| dma_addr); |
| if (!entry) |
| break; |
| dma_update_cpu_trans(entry, 0, ZPCI_PTE_INVALID); |
| } |
| |
| return rc; |
| } |
| |
| static int s390_iommu_invalidate_trans(struct s390_domain *s390_domain, |
| dma_addr_t dma_addr, unsigned long nr_pages) |
| { |
| unsigned long *entry; |
| unsigned long i; |
| int rc = 0; |
| |
| for (i = 0; i < nr_pages; i++) { |
| entry = dma_walk_cpu_trans(s390_domain->dma_table, dma_addr); |
| if (unlikely(!entry)) { |
| rc = -EINVAL; |
| break; |
| } |
| dma_update_cpu_trans(entry, 0, ZPCI_PTE_INVALID); |
| dma_addr += PAGE_SIZE; |
| } |
| |
| return rc; |
| } |
| |
| static int s390_iommu_map_pages(struct iommu_domain *domain, |
| unsigned long iova, phys_addr_t paddr, |
| size_t pgsize, size_t pgcount, |
| int prot, gfp_t gfp, size_t *mapped) |
| { |
| struct s390_domain *s390_domain = to_s390_domain(domain); |
| size_t size = pgcount << __ffs(pgsize); |
| int flags = ZPCI_PTE_VALID, rc = 0; |
| |
| if (pgsize != SZ_4K) |
| return -EINVAL; |
| |
| if (iova < s390_domain->domain.geometry.aperture_start || |
| (iova + size - 1) > s390_domain->domain.geometry.aperture_end) |
| return -EINVAL; |
| |
| if (!IS_ALIGNED(iova | paddr, pgsize)) |
| return -EINVAL; |
| |
| if (!(prot & IOMMU_READ)) |
| return -EINVAL; |
| |
| if (!(prot & IOMMU_WRITE)) |
| flags |= ZPCI_TABLE_PROTECTED; |
| |
| rc = s390_iommu_validate_trans(s390_domain, paddr, iova, |
| pgcount, flags); |
| if (!rc) |
| *mapped = size; |
| |
| return rc; |
| } |
| |
| static phys_addr_t s390_iommu_iova_to_phys(struct iommu_domain *domain, |
| dma_addr_t iova) |
| { |
| struct s390_domain *s390_domain = to_s390_domain(domain); |
| unsigned long *rto, *sto, *pto; |
| unsigned long ste, pte, rte; |
| unsigned int rtx, sx, px; |
| phys_addr_t phys = 0; |
| |
| if (iova < domain->geometry.aperture_start || |
| iova > domain->geometry.aperture_end) |
| return 0; |
| |
| rtx = calc_rtx(iova); |
| sx = calc_sx(iova); |
| px = calc_px(iova); |
| rto = s390_domain->dma_table; |
| |
| rte = READ_ONCE(rto[rtx]); |
| if (reg_entry_isvalid(rte)) { |
| sto = get_rt_sto(rte); |
| ste = READ_ONCE(sto[sx]); |
| if (reg_entry_isvalid(ste)) { |
| pto = get_st_pto(ste); |
| pte = READ_ONCE(pto[px]); |
| if (pt_entry_isvalid(pte)) |
| phys = pte & ZPCI_PTE_ADDR_MASK; |
| } |
| } |
| |
| return phys; |
| } |
| |
| static size_t s390_iommu_unmap_pages(struct iommu_domain *domain, |
| unsigned long iova, |
| size_t pgsize, size_t pgcount, |
| struct iommu_iotlb_gather *gather) |
| { |
| struct s390_domain *s390_domain = to_s390_domain(domain); |
| size_t size = pgcount << __ffs(pgsize); |
| int rc; |
| |
| if (WARN_ON(iova < s390_domain->domain.geometry.aperture_start || |
| (iova + size - 1) > s390_domain->domain.geometry.aperture_end)) |
| return 0; |
| |
| rc = s390_iommu_invalidate_trans(s390_domain, iova, pgcount); |
| if (rc) |
| return 0; |
| |
| iommu_iotlb_gather_add_range(gather, iova, size); |
| |
| return size; |
| } |
| |
| int zpci_init_iommu(struct zpci_dev *zdev) |
| { |
| int rc = 0; |
| |
| rc = iommu_device_sysfs_add(&zdev->iommu_dev, NULL, NULL, |
| "s390-iommu.%08x", zdev->fid); |
| if (rc) |
| goto out_err; |
| |
| rc = iommu_device_register(&zdev->iommu_dev, &s390_iommu_ops, NULL); |
| if (rc) |
| goto out_sysfs; |
| |
| return 0; |
| |
| out_sysfs: |
| iommu_device_sysfs_remove(&zdev->iommu_dev); |
| |
| out_err: |
| return rc; |
| } |
| |
| void zpci_destroy_iommu(struct zpci_dev *zdev) |
| { |
| iommu_device_unregister(&zdev->iommu_dev); |
| iommu_device_sysfs_remove(&zdev->iommu_dev); |
| } |
| |
| static const struct iommu_ops s390_iommu_ops = { |
| .capable = s390_iommu_capable, |
| .domain_alloc = s390_domain_alloc, |
| .probe_device = s390_iommu_probe_device, |
| .release_device = s390_iommu_release_device, |
| .device_group = generic_device_group, |
| .pgsize_bitmap = SZ_4K, |
| .get_resv_regions = s390_iommu_get_resv_regions, |
| .default_domain_ops = &(const struct iommu_domain_ops) { |
| .attach_dev = s390_iommu_attach_device, |
| .detach_dev = s390_iommu_detach_device, |
| .map_pages = s390_iommu_map_pages, |
| .unmap_pages = s390_iommu_unmap_pages, |
| .flush_iotlb_all = s390_iommu_flush_iotlb_all, |
| .iotlb_sync = s390_iommu_iotlb_sync, |
| .iotlb_sync_map = s390_iommu_iotlb_sync_map, |
| .iova_to_phys = s390_iommu_iova_to_phys, |
| .free = s390_domain_free, |
| } |
| }; |