Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

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,
+	}
+};