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-rw-r--r--drivers/iommu/s390-iommu.c449
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 0000000000..fbf59a8db2
--- /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(&region->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(&region->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,
+ }
+};