1 files changed, 218 insertions, 159 deletions

diff --git a/drivers/iommu/s390-iommu.c b/drivers/iommu/s390-iommu.c
index 3c071782f6f1..ed33c6cce083 100644
--- a/drivers/iommu/s390-iommu.c
+++ b/drivers/iommu/s390-iommu.c
@@ -10,28 +10,18 @@
 #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>
 
-/*
- * 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;
+	struct rcu_head		rcu;
 };
 
 static struct s390_domain *to_s390_domain(struct iommu_domain *dom)
@@ -67,119 +57,125 @@ static struct iommu_domain *s390_domain_alloc(unsigned domain_type)
 		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->dma_table_lock);
 	spin_lock_init(&s390_domain->list_lock);
-	INIT_LIST_HEAD(&s390_domain->devices);
+	INIT_LIST_HEAD_RCU(&s390_domain->devices);
 
 	return &s390_domain->domain;
 }
 
-static void s390_domain_free(struct iommu_domain *domain)
+static void s390_iommu_rcu_free_domain(struct rcu_head *head)
 {
-	struct s390_domain *s390_domain = to_s390_domain(domain);
+	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);
-	struct s390_domain_device *domain_device;
 	unsigned long flags;
-	int cc, rc;
+	u8 status;
+	int cc;
 
 	if (!zdev)
 		return -ENODEV;
 
-	domain_device = kzalloc(sizeof(*domain_device), GFP_KERNEL);
-	if (!domain_device)
-		return -ENOMEM;
-
-	if (zdev->dma_table && !zdev->s390_domain) {
-		cc = zpci_dma_exit_device(zdev);
-		if (cc) {
-			rc = -EIO;
-			goto out_free;
-		}
-	}
+	if (WARN_ON(domain->geometry.aperture_start > zdev->end_dma ||
+		domain->geometry.aperture_end < zdev->start_dma))
+		return -EINVAL;
 
 	if (zdev->s390_domain)
-		zpci_unregister_ioat(zdev, 0);
+		__s390_iommu_detach_device(zdev);
+	else if (zdev->dma_table)
+		zpci_dma_exit_device(zdev);
 
-	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;
-	}
+				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;
 
-	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->dma_table = s390_domain->dma_table;
 	zdev->s390_domain = s390_domain;
-	list_add(&domain_device->list, &s390_domain->devices);
+
+	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;
-
-out_restore:
-	if (!zdev->s390_domain) {
-		zpci_dma_init_device(zdev);
-	} else {
-		zdev->dma_table = zdev->s390_domain->dma_table;
-		zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma,
-				   virt_to_phys(zdev->dma_table));
-	}
-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;
+	WARN_ON(zdev->s390_domain != to_s390_domain(domain));
 
-	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;
-		}
+	__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);
 	}
-	spin_unlock_irqrestore(&s390_domain->list_lock, flags);
 
-	if (found && (zdev->s390_domain == s390_domain)) {
-		zdev->s390_domain = NULL;
-		zpci_unregister_ioat(zdev, 0);
-		zpci_dma_init_device(zdev);
+	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);
 	}
 }
 
@@ -192,55 +188,88 @@ static struct iommu_device *s390_iommu_probe_device(struct device *dev)
 
 	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);
-	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.
+	 * 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 && zdev->s390_domain) {
-		domain = iommu_get_domain_for_dev(dev);
-		if (domain)
-			s390_iommu_detach_device(domain, dev);
+	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 int s390_iommu_update_trans(struct s390_domain *s390_domain,
-				   phys_addr_t pa, dma_addr_t dma_addr,
-				   size_t size, int flags)
+static void s390_iommu_iotlb_sync(struct iommu_domain *domain,
+				  struct iommu_iotlb_gather *gather)
 {
-	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;
+	struct s390_domain *s390_domain = to_s390_domain(domain);
+	size_t size = gather->end - gather->start + 1;
+	struct zpci_dev *zdev;
 
-	if (dma_addr < s390_domain->domain.geometry.aperture_start ||
-	    dma_addr + size > s390_domain->domain.geometry.aperture_end)
-		return -EINVAL;
+	/* If gather was never added to there is nothing to flush */
+	if (!gather->end)
+		return;
 
-	nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
-	if (!nr_pages)
-		return 0;
+	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;
 
-	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) {
+		if (unlikely(!entry)) {
 			rc = -ENOMEM;
 			goto undo_cpu_trans;
 		}
@@ -249,47 +278,70 @@ static int s390_iommu_update_trans(struct s390_domain *s390_domain,
 		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)
+	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);
 	}
-	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);
+	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;
 	}
-	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)
+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_update_trans(s390_domain, paddr, iova,
-				     size, flags);
+	rc = s390_iommu_validate_trans(s390_domain, paddr, iova,
+				       pgcount, flags);
+	if (!rc)
+		*mapped = size;
 
 	return rc;
 }
@@ -298,7 +350,8 @@ 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 long *rto, *sto, *pto;
+	unsigned long ste, pte, rte;
 	unsigned int rtx, sx, px;
 	phys_addr_t phys = 0;
 
@@ -311,38 +364,40 @@ static phys_addr_t s390_iommu_iova_to_phys(struct iommu_domain *domain,
 	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;
+	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;
 		}
 	}
-	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)
+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);
-	int flags = ZPCI_PTE_INVALID;
-	phys_addr_t paddr;
+	size_t size = pgcount << __ffs(pgsize);
 	int rc;
 
-	paddr = s390_iommu_iova_to_phys(domain, iova);
-	if (!paddr)
+	if (WARN_ON(iova < s390_domain->domain.geometry.aperture_start ||
+	    (iova + size - 1) > s390_domain->domain.geometry.aperture_end))
 		return 0;
 
-	rc = s390_iommu_update_trans(s390_domain, paddr, iova,
-				     size, flags);
+	rc = s390_iommu_invalidate_trans(s390_domain, iova, pgcount);
 	if (rc)
 		return 0;
 
+	iommu_iotlb_gather_add_range(gather, iova, size);
+
 	return size;
 }
 
@@ -380,12 +435,16 @@ static const struct iommu_ops s390_iommu_ops = {
 	.probe_device = s390_iommu_probe_device,
 	.release_device = s390_iommu_release_device,
 	.device_group = generic_device_group,
-	.pgsize_bitmap = S390_IOMMU_PGSIZES,
+	.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		= s390_iommu_map,
-		.unmap		= s390_iommu_unmap,
+		.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,
 	}