diff options
Diffstat (limited to 'drivers/iommu/s390-iommu.c')
| -rw-r--r-- | drivers/iommu/s390-iommu.c | 449 |
1 files changed, 449 insertions, 0 deletions
diff --git a/drivers/iommu/s390-iommu.c b/drivers/iommu/s390-iommu.c new file mode 100644 index 000000000..fbf59a8db --- /dev/null +++ b/drivers/iommu/s390-iommu.c @@ -0,0 +1,449 @@ +// 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; + 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(GFP_KERNEL); + 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_set_platform_dma(struct device *dev) +{ + struct zpci_dev *zdev = to_zpci_dev(dev); + + __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, + gfp_t gfp) +{ + 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, + gfp); + 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, gfp); + 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, + GFP_ATOMIC); + 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, gfp); + 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, + .set_platform_dma_ops = s390_iommu_set_platform_dma, + .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, + .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, + } +}; |