| // 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 <asm/pci_dma.h> |
| |
| /* |
| * Physically contiguous memory regions can be mapped with 4 KiB alignment, |
| * we allow all page sizes that are an order of 4KiB (no special large page |
| * support so far). |
| */ |
| #define S390_IOMMU_PGSIZES (~0xFFFUL) |
| |
| 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 dma_table_lock; |
| spinlock_t list_lock; |
| }; |
| |
| struct s390_domain_device { |
| struct list_head list; |
| struct zpci_dev *zdev; |
| }; |
| |
| static struct s390_domain *to_s390_domain(struct iommu_domain *dom) |
| { |
| return container_of(dom, struct s390_domain, domain); |
| } |
| |
| static bool s390_iommu_capable(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; |
| } |
| |
| spin_lock_init(&s390_domain->dma_table_lock); |
| spin_lock_init(&s390_domain->list_lock); |
| INIT_LIST_HEAD(&s390_domain->devices); |
| |
| return &s390_domain->domain; |
| } |
| |
| static void s390_domain_free(struct iommu_domain *domain) |
| { |
| struct s390_domain *s390_domain = to_s390_domain(domain); |
| |
| dma_cleanup_tables(s390_domain->dma_table); |
| kfree(s390_domain); |
| } |
| |
| 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); |
| struct s390_domain_device *domain_device; |
| unsigned long flags; |
| int cc, rc; |
| |
| if (!zdev) |
| return -ENODEV; |
| |
| domain_device = kzalloc(sizeof(*domain_device), GFP_KERNEL); |
| if (!domain_device) |
| return -ENOMEM; |
| |
| if (zdev->dma_table) { |
| cc = zpci_dma_exit_device(zdev); |
| if (cc) { |
| rc = -EIO; |
| goto out_free; |
| } |
| } |
| |
| zdev->dma_table = s390_domain->dma_table; |
| cc = zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma, |
| virt_to_phys(zdev->dma_table)); |
| if (cc) { |
| rc = -EIO; |
| goto out_restore; |
| } |
| |
| spin_lock_irqsave(&s390_domain->list_lock, flags); |
| /* First device defines the DMA range limits */ |
| if (list_empty(&s390_domain->devices)) { |
| domain->geometry.aperture_start = zdev->start_dma; |
| domain->geometry.aperture_end = zdev->end_dma; |
| domain->geometry.force_aperture = true; |
| /* Allow only devices with identical DMA range limits */ |
| } else if (domain->geometry.aperture_start != zdev->start_dma || |
| domain->geometry.aperture_end != zdev->end_dma) { |
| rc = -EINVAL; |
| spin_unlock_irqrestore(&s390_domain->list_lock, flags); |
| goto out_restore; |
| } |
| domain_device->zdev = zdev; |
| zdev->s390_domain = s390_domain; |
| list_add(&domain_device->list, &s390_domain->devices); |
| spin_unlock_irqrestore(&s390_domain->list_lock, flags); |
| |
| return 0; |
| |
| out_restore: |
| zpci_dma_init_device(zdev); |
| out_free: |
| kfree(domain_device); |
| |
| return rc; |
| } |
| |
| static void s390_iommu_detach_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); |
| struct s390_domain_device *domain_device, *tmp; |
| unsigned long flags; |
| int found = 0; |
| |
| if (!zdev) |
| return; |
| |
| spin_lock_irqsave(&s390_domain->list_lock, flags); |
| list_for_each_entry_safe(domain_device, tmp, &s390_domain->devices, |
| list) { |
| if (domain_device->zdev == zdev) { |
| list_del(&domain_device->list); |
| kfree(domain_device); |
| found = 1; |
| break; |
| } |
| } |
| spin_unlock_irqrestore(&s390_domain->list_lock, flags); |
| |
| if (found) { |
| zdev->s390_domain = NULL; |
| zpci_unregister_ioat(zdev, 0); |
| zpci_dma_init_device(zdev); |
| } |
| } |
| |
| static struct iommu_device *s390_iommu_probe_device(struct device *dev) |
| { |
| struct zpci_dev *zdev = to_zpci_dev(dev); |
| |
| return &zdev->iommu_dev; |
| } |
| |
| static void s390_iommu_release_device(struct device *dev) |
| { |
| struct zpci_dev *zdev = to_zpci_dev(dev); |
| struct iommu_domain *domain; |
| |
| /* |
| * This is a workaround for a scenario where the IOMMU API common code |
| * "forgets" to call the detach_dev callback: After binding a device |
| * to vfio-pci and completing the VFIO_SET_IOMMU ioctl (which triggers |
| * the attach_dev), removing the device via |
| * "echo 1 > /sys/bus/pci/devices/.../remove" won't trigger detach_dev, |
| * only release_device will be called via the BUS_NOTIFY_REMOVED_DEVICE |
| * notifier. |
| * |
| * So let's call detach_dev from here if it hasn't been called before. |
| */ |
| if (zdev && zdev->s390_domain) { |
| domain = iommu_get_domain_for_dev(dev); |
| if (domain) |
| s390_iommu_detach_device(domain, dev); |
| } |
| } |
| |
| static int s390_iommu_update_trans(struct s390_domain *s390_domain, |
| phys_addr_t pa, dma_addr_t dma_addr, |
| size_t size, int flags) |
| { |
| struct s390_domain_device *domain_device; |
| phys_addr_t page_addr = pa & PAGE_MASK; |
| dma_addr_t start_dma_addr = dma_addr; |
| unsigned long irq_flags, nr_pages, i; |
| unsigned long *entry; |
| int rc = 0; |
| |
| if (dma_addr < s390_domain->domain.geometry.aperture_start || |
| dma_addr + size > s390_domain->domain.geometry.aperture_end) |
| return -EINVAL; |
| |
| nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT; |
| if (!nr_pages) |
| return 0; |
| |
| spin_lock_irqsave(&s390_domain->dma_table_lock, irq_flags); |
| for (i = 0; i < nr_pages; i++) { |
| entry = dma_walk_cpu_trans(s390_domain->dma_table, dma_addr); |
| if (!entry) { |
| rc = -ENOMEM; |
| goto undo_cpu_trans; |
| } |
| dma_update_cpu_trans(entry, page_addr, flags); |
| page_addr += PAGE_SIZE; |
| dma_addr += PAGE_SIZE; |
| } |
| |
| spin_lock(&s390_domain->list_lock); |
| list_for_each_entry(domain_device, &s390_domain->devices, list) { |
| rc = zpci_refresh_trans((u64) domain_device->zdev->fh << 32, |
| start_dma_addr, nr_pages * PAGE_SIZE); |
| if (rc) |
| break; |
| } |
| spin_unlock(&s390_domain->list_lock); |
| |
| undo_cpu_trans: |
| if (rc && ((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID)) { |
| flags = ZPCI_PTE_INVALID; |
| while (i-- > 0) { |
| page_addr -= PAGE_SIZE; |
| dma_addr -= PAGE_SIZE; |
| entry = dma_walk_cpu_trans(s390_domain->dma_table, |
| dma_addr); |
| if (!entry) |
| break; |
| dma_update_cpu_trans(entry, page_addr, flags); |
| } |
| } |
| spin_unlock_irqrestore(&s390_domain->dma_table_lock, irq_flags); |
| |
| return rc; |
| } |
| |
| static int s390_iommu_map(struct iommu_domain *domain, unsigned long iova, |
| phys_addr_t paddr, size_t size, int prot, gfp_t gfp) |
| { |
| struct s390_domain *s390_domain = to_s390_domain(domain); |
| int flags = ZPCI_PTE_VALID, rc = 0; |
| |
| if (!(prot & IOMMU_READ)) |
| return -EINVAL; |
| |
| if (!(prot & IOMMU_WRITE)) |
| flags |= ZPCI_TABLE_PROTECTED; |
| |
| rc = s390_iommu_update_trans(s390_domain, paddr, iova, |
| size, flags); |
| |
| 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 *sto, *pto, *rto, flags; |
| 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; |
| |
| spin_lock_irqsave(&s390_domain->dma_table_lock, flags); |
| if (rto && reg_entry_isvalid(rto[rtx])) { |
| sto = get_rt_sto(rto[rtx]); |
| if (sto && reg_entry_isvalid(sto[sx])) { |
| pto = get_st_pto(sto[sx]); |
| if (pto && pt_entry_isvalid(pto[px])) |
| phys = pto[px] & ZPCI_PTE_ADDR_MASK; |
| } |
| } |
| spin_unlock_irqrestore(&s390_domain->dma_table_lock, flags); |
| |
| return phys; |
| } |
| |
| static size_t s390_iommu_unmap(struct iommu_domain *domain, |
| unsigned long iova, size_t size, |
| struct iommu_iotlb_gather *gather) |
| { |
| struct s390_domain *s390_domain = to_s390_domain(domain); |
| int flags = ZPCI_PTE_INVALID; |
| phys_addr_t paddr; |
| int rc; |
| |
| paddr = s390_iommu_iova_to_phys(domain, iova); |
| if (!paddr) |
| return 0; |
| |
| rc = s390_iommu_update_trans(s390_domain, paddr, iova, |
| size, flags); |
| if (rc) |
| return 0; |
| |
| 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 = S390_IOMMU_PGSIZES, |
| .default_domain_ops = &(const struct iommu_domain_ops) { |
| .attach_dev = s390_iommu_attach_device, |
| .detach_dev = s390_iommu_detach_device, |
| .map = s390_iommu_map, |
| .unmap = s390_iommu_unmap, |
| .iova_to_phys = s390_iommu_iova_to_phys, |
| .free = s390_domain_free, |
| } |
| }; |
| |
| static int __init s390_iommu_init(void) |
| { |
| return bus_set_iommu(&pci_bus_type, &s390_iommu_ops); |
| } |
| subsys_initcall(s390_iommu_init); |