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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
commit5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch)
treea94efe259b9009378be6d90eb30d2b019d95c194 /arch/s390/pci/pci_dma.c
parentInitial commit. (diff)
downloadlinux-upstream.tar.xz
linux-upstream.zip
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/s390/pci/pci_dma.c')
-rw-r--r--arch/s390/pci/pci_dma.c695
1 files changed, 695 insertions, 0 deletions
diff --git a/arch/s390/pci/pci_dma.c b/arch/s390/pci/pci_dma.c
new file mode 100644
index 000000000..f6690a700
--- /dev/null
+++ b/arch/s390/pci/pci_dma.c
@@ -0,0 +1,695 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright IBM Corp. 2012
+ *
+ * Author(s):
+ * Jan Glauber <jang@linux.vnet.ibm.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/export.h>
+#include <linux/iommu-helper.h>
+#include <linux/dma-map-ops.h>
+#include <linux/vmalloc.h>
+#include <linux/pci.h>
+#include <asm/pci_dma.h>
+
+static struct kmem_cache *dma_region_table_cache;
+static struct kmem_cache *dma_page_table_cache;
+static int s390_iommu_strict;
+
+static int zpci_refresh_global(struct zpci_dev *zdev)
+{
+ return zpci_refresh_trans((u64) zdev->fh << 32, zdev->start_dma,
+ zdev->iommu_pages * PAGE_SIZE);
+}
+
+unsigned long *dma_alloc_cpu_table(void)
+{
+ unsigned long *table, *entry;
+
+ table = kmem_cache_alloc(dma_region_table_cache, GFP_ATOMIC);
+ if (!table)
+ return NULL;
+
+ for (entry = table; entry < table + ZPCI_TABLE_ENTRIES; entry++)
+ *entry = ZPCI_TABLE_INVALID;
+ return table;
+}
+
+static void dma_free_cpu_table(void *table)
+{
+ kmem_cache_free(dma_region_table_cache, table);
+}
+
+static unsigned long *dma_alloc_page_table(void)
+{
+ unsigned long *table, *entry;
+
+ table = kmem_cache_alloc(dma_page_table_cache, GFP_ATOMIC);
+ if (!table)
+ return NULL;
+
+ for (entry = table; entry < table + ZPCI_PT_ENTRIES; entry++)
+ *entry = ZPCI_PTE_INVALID;
+ return table;
+}
+
+static void dma_free_page_table(void *table)
+{
+ kmem_cache_free(dma_page_table_cache, table);
+}
+
+static unsigned long *dma_get_seg_table_origin(unsigned long *entry)
+{
+ unsigned long *sto;
+
+ if (reg_entry_isvalid(*entry))
+ sto = get_rt_sto(*entry);
+ else {
+ sto = dma_alloc_cpu_table();
+ if (!sto)
+ return NULL;
+
+ set_rt_sto(entry, sto);
+ validate_rt_entry(entry);
+ entry_clr_protected(entry);
+ }
+ return sto;
+}
+
+static unsigned long *dma_get_page_table_origin(unsigned long *entry)
+{
+ unsigned long *pto;
+
+ if (reg_entry_isvalid(*entry))
+ pto = get_st_pto(*entry);
+ else {
+ pto = dma_alloc_page_table();
+ if (!pto)
+ return NULL;
+ set_st_pto(entry, pto);
+ validate_st_entry(entry);
+ entry_clr_protected(entry);
+ }
+ return pto;
+}
+
+unsigned long *dma_walk_cpu_trans(unsigned long *rto, dma_addr_t dma_addr)
+{
+ unsigned long *sto, *pto;
+ unsigned int rtx, sx, px;
+
+ rtx = calc_rtx(dma_addr);
+ sto = dma_get_seg_table_origin(&rto[rtx]);
+ if (!sto)
+ return NULL;
+
+ sx = calc_sx(dma_addr);
+ pto = dma_get_page_table_origin(&sto[sx]);
+ if (!pto)
+ return NULL;
+
+ px = calc_px(dma_addr);
+ return &pto[px];
+}
+
+void dma_update_cpu_trans(unsigned long *entry, void *page_addr, int flags)
+{
+ if (flags & ZPCI_PTE_INVALID) {
+ invalidate_pt_entry(entry);
+ } else {
+ set_pt_pfaa(entry, page_addr);
+ validate_pt_entry(entry);
+ }
+
+ if (flags & ZPCI_TABLE_PROTECTED)
+ entry_set_protected(entry);
+ else
+ entry_clr_protected(entry);
+}
+
+static int __dma_update_trans(struct zpci_dev *zdev, unsigned long pa,
+ dma_addr_t dma_addr, size_t size, int flags)
+{
+ unsigned int nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
+ u8 *page_addr = (u8 *) (pa & PAGE_MASK);
+ unsigned long irq_flags;
+ unsigned long *entry;
+ int i, rc = 0;
+
+ if (!nr_pages)
+ return -EINVAL;
+
+ spin_lock_irqsave(&zdev->dma_table_lock, irq_flags);
+ if (!zdev->dma_table) {
+ rc = -EINVAL;
+ goto out_unlock;
+ }
+
+ for (i = 0; i < nr_pages; i++) {
+ entry = dma_walk_cpu_trans(zdev->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;
+ }
+
+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(zdev->dma_table, dma_addr);
+ if (!entry)
+ break;
+ dma_update_cpu_trans(entry, page_addr, flags);
+ }
+ }
+out_unlock:
+ spin_unlock_irqrestore(&zdev->dma_table_lock, irq_flags);
+ return rc;
+}
+
+static int __dma_purge_tlb(struct zpci_dev *zdev, dma_addr_t dma_addr,
+ size_t size, int flags)
+{
+ unsigned long irqflags;
+ int ret;
+
+ /*
+ * With zdev->tlb_refresh == 0, rpcit is not required to establish new
+ * translations when previously invalid translation-table entries are
+ * validated. With lazy unmap, rpcit is skipped for previously valid
+ * entries, but a global rpcit is then required before any address can
+ * be re-used, i.e. after each iommu bitmap wrap-around.
+ */
+ if ((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID) {
+ if (!zdev->tlb_refresh)
+ return 0;
+ } else {
+ if (!s390_iommu_strict)
+ return 0;
+ }
+
+ ret = zpci_refresh_trans((u64) zdev->fh << 32, dma_addr,
+ PAGE_ALIGN(size));
+ if (ret == -ENOMEM && !s390_iommu_strict) {
+ /* enable the hypervisor to free some resources */
+ if (zpci_refresh_global(zdev))
+ goto out;
+
+ spin_lock_irqsave(&zdev->iommu_bitmap_lock, irqflags);
+ bitmap_andnot(zdev->iommu_bitmap, zdev->iommu_bitmap,
+ zdev->lazy_bitmap, zdev->iommu_pages);
+ bitmap_zero(zdev->lazy_bitmap, zdev->iommu_pages);
+ spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, irqflags);
+ ret = 0;
+ }
+out:
+ return ret;
+}
+
+static int dma_update_trans(struct zpci_dev *zdev, unsigned long pa,
+ dma_addr_t dma_addr, size_t size, int flags)
+{
+ int rc;
+
+ rc = __dma_update_trans(zdev, pa, dma_addr, size, flags);
+ if (rc)
+ return rc;
+
+ rc = __dma_purge_tlb(zdev, dma_addr, size, flags);
+ if (rc && ((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID))
+ __dma_update_trans(zdev, pa, dma_addr, size, ZPCI_PTE_INVALID);
+
+ return rc;
+}
+
+void dma_free_seg_table(unsigned long entry)
+{
+ unsigned long *sto = get_rt_sto(entry);
+ int sx;
+
+ for (sx = 0; sx < ZPCI_TABLE_ENTRIES; sx++)
+ if (reg_entry_isvalid(sto[sx]))
+ dma_free_page_table(get_st_pto(sto[sx]));
+
+ dma_free_cpu_table(sto);
+}
+
+void dma_cleanup_tables(unsigned long *table)
+{
+ int rtx;
+
+ if (!table)
+ return;
+
+ for (rtx = 0; rtx < ZPCI_TABLE_ENTRIES; rtx++)
+ if (reg_entry_isvalid(table[rtx]))
+ dma_free_seg_table(table[rtx]);
+
+ dma_free_cpu_table(table);
+}
+
+static unsigned long __dma_alloc_iommu(struct device *dev,
+ unsigned long start, int size)
+{
+ struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
+
+ return iommu_area_alloc(zdev->iommu_bitmap, zdev->iommu_pages,
+ start, size, zdev->start_dma >> PAGE_SHIFT,
+ dma_get_seg_boundary_nr_pages(dev, PAGE_SHIFT),
+ 0);
+}
+
+static dma_addr_t dma_alloc_address(struct device *dev, int size)
+{
+ struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
+ unsigned long offset, flags;
+
+ spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags);
+ offset = __dma_alloc_iommu(dev, zdev->next_bit, size);
+ if (offset == -1) {
+ if (!s390_iommu_strict) {
+ /* global flush before DMA addresses are reused */
+ if (zpci_refresh_global(zdev))
+ goto out_error;
+
+ bitmap_andnot(zdev->iommu_bitmap, zdev->iommu_bitmap,
+ zdev->lazy_bitmap, zdev->iommu_pages);
+ bitmap_zero(zdev->lazy_bitmap, zdev->iommu_pages);
+ }
+ /* wrap-around */
+ offset = __dma_alloc_iommu(dev, 0, size);
+ if (offset == -1)
+ goto out_error;
+ }
+ zdev->next_bit = offset + size;
+ spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
+
+ return zdev->start_dma + offset * PAGE_SIZE;
+
+out_error:
+ spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
+ return DMA_MAPPING_ERROR;
+}
+
+static void dma_free_address(struct device *dev, dma_addr_t dma_addr, int size)
+{
+ struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
+ unsigned long flags, offset;
+
+ offset = (dma_addr - zdev->start_dma) >> PAGE_SHIFT;
+
+ spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags);
+ if (!zdev->iommu_bitmap)
+ goto out;
+
+ if (s390_iommu_strict)
+ bitmap_clear(zdev->iommu_bitmap, offset, size);
+ else
+ bitmap_set(zdev->lazy_bitmap, offset, size);
+
+out:
+ spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
+}
+
+static inline void zpci_err_dma(unsigned long rc, unsigned long addr)
+{
+ struct {
+ unsigned long rc;
+ unsigned long addr;
+ } __packed data = {rc, addr};
+
+ zpci_err_hex(&data, sizeof(data));
+}
+
+static dma_addr_t s390_dma_map_pages(struct device *dev, struct page *page,
+ unsigned long offset, size_t size,
+ enum dma_data_direction direction,
+ unsigned long attrs)
+{
+ struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
+ unsigned long pa = page_to_phys(page) + offset;
+ int flags = ZPCI_PTE_VALID;
+ unsigned long nr_pages;
+ dma_addr_t dma_addr;
+ int ret;
+
+ /* This rounds up number of pages based on size and offset */
+ nr_pages = iommu_num_pages(pa, size, PAGE_SIZE);
+ dma_addr = dma_alloc_address(dev, nr_pages);
+ if (dma_addr == DMA_MAPPING_ERROR) {
+ ret = -ENOSPC;
+ goto out_err;
+ }
+
+ /* Use rounded up size */
+ size = nr_pages * PAGE_SIZE;
+
+ if (direction == DMA_NONE || direction == DMA_TO_DEVICE)
+ flags |= ZPCI_TABLE_PROTECTED;
+
+ ret = dma_update_trans(zdev, pa, dma_addr, size, flags);
+ if (ret)
+ goto out_free;
+
+ atomic64_add(nr_pages, &zdev->mapped_pages);
+ return dma_addr + (offset & ~PAGE_MASK);
+
+out_free:
+ dma_free_address(dev, dma_addr, nr_pages);
+out_err:
+ zpci_err("map error:\n");
+ zpci_err_dma(ret, pa);
+ return DMA_MAPPING_ERROR;
+}
+
+static void s390_dma_unmap_pages(struct device *dev, dma_addr_t dma_addr,
+ size_t size, enum dma_data_direction direction,
+ unsigned long attrs)
+{
+ struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
+ int npages, ret;
+
+ npages = iommu_num_pages(dma_addr, size, PAGE_SIZE);
+ dma_addr = dma_addr & PAGE_MASK;
+ ret = dma_update_trans(zdev, 0, dma_addr, npages * PAGE_SIZE,
+ ZPCI_PTE_INVALID);
+ if (ret) {
+ zpci_err("unmap error:\n");
+ zpci_err_dma(ret, dma_addr);
+ return;
+ }
+
+ atomic64_add(npages, &zdev->unmapped_pages);
+ dma_free_address(dev, dma_addr, npages);
+}
+
+static void *s390_dma_alloc(struct device *dev, size_t size,
+ dma_addr_t *dma_handle, gfp_t flag,
+ unsigned long attrs)
+{
+ struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
+ struct page *page;
+ unsigned long pa;
+ dma_addr_t map;
+
+ size = PAGE_ALIGN(size);
+ page = alloc_pages(flag | __GFP_ZERO, get_order(size));
+ if (!page)
+ return NULL;
+
+ pa = page_to_phys(page);
+ map = s390_dma_map_pages(dev, page, 0, size, DMA_BIDIRECTIONAL, 0);
+ if (dma_mapping_error(dev, map)) {
+ free_pages(pa, get_order(size));
+ return NULL;
+ }
+
+ atomic64_add(size / PAGE_SIZE, &zdev->allocated_pages);
+ if (dma_handle)
+ *dma_handle = map;
+ return (void *) pa;
+}
+
+static void s390_dma_free(struct device *dev, size_t size,
+ void *pa, dma_addr_t dma_handle,
+ unsigned long attrs)
+{
+ struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
+
+ size = PAGE_ALIGN(size);
+ atomic64_sub(size / PAGE_SIZE, &zdev->allocated_pages);
+ s390_dma_unmap_pages(dev, dma_handle, size, DMA_BIDIRECTIONAL, 0);
+ free_pages((unsigned long) pa, get_order(size));
+}
+
+/* Map a segment into a contiguous dma address area */
+static int __s390_dma_map_sg(struct device *dev, struct scatterlist *sg,
+ size_t size, dma_addr_t *handle,
+ enum dma_data_direction dir)
+{
+ unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
+ struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
+ dma_addr_t dma_addr_base, dma_addr;
+ int flags = ZPCI_PTE_VALID;
+ struct scatterlist *s;
+ unsigned long pa = 0;
+ int ret;
+
+ dma_addr_base = dma_alloc_address(dev, nr_pages);
+ if (dma_addr_base == DMA_MAPPING_ERROR)
+ return -ENOMEM;
+
+ dma_addr = dma_addr_base;
+ if (dir == DMA_NONE || dir == DMA_TO_DEVICE)
+ flags |= ZPCI_TABLE_PROTECTED;
+
+ for (s = sg; dma_addr < dma_addr_base + size; s = sg_next(s)) {
+ pa = page_to_phys(sg_page(s));
+ ret = __dma_update_trans(zdev, pa, dma_addr,
+ s->offset + s->length, flags);
+ if (ret)
+ goto unmap;
+
+ dma_addr += s->offset + s->length;
+ }
+ ret = __dma_purge_tlb(zdev, dma_addr_base, size, flags);
+ if (ret)
+ goto unmap;
+
+ *handle = dma_addr_base;
+ atomic64_add(nr_pages, &zdev->mapped_pages);
+
+ return ret;
+
+unmap:
+ dma_update_trans(zdev, 0, dma_addr_base, dma_addr - dma_addr_base,
+ ZPCI_PTE_INVALID);
+ dma_free_address(dev, dma_addr_base, nr_pages);
+ zpci_err("map error:\n");
+ zpci_err_dma(ret, pa);
+ return ret;
+}
+
+static int s390_dma_map_sg(struct device *dev, struct scatterlist *sg,
+ int nr_elements, enum dma_data_direction dir,
+ unsigned long attrs)
+{
+ struct scatterlist *s = sg, *start = sg, *dma = sg;
+ unsigned int max = dma_get_max_seg_size(dev);
+ unsigned int size = s->offset + s->length;
+ unsigned int offset = s->offset;
+ int count = 0, i;
+
+ for (i = 1; i < nr_elements; i++) {
+ s = sg_next(s);
+
+ s->dma_address = DMA_MAPPING_ERROR;
+ s->dma_length = 0;
+
+ if (s->offset || (size & ~PAGE_MASK) ||
+ size + s->length > max) {
+ if (__s390_dma_map_sg(dev, start, size,
+ &dma->dma_address, dir))
+ goto unmap;
+
+ dma->dma_address += offset;
+ dma->dma_length = size - offset;
+
+ size = offset = s->offset;
+ start = s;
+ dma = sg_next(dma);
+ count++;
+ }
+ size += s->length;
+ }
+ if (__s390_dma_map_sg(dev, start, size, &dma->dma_address, dir))
+ goto unmap;
+
+ dma->dma_address += offset;
+ dma->dma_length = size - offset;
+
+ return count + 1;
+unmap:
+ for_each_sg(sg, s, count, i)
+ s390_dma_unmap_pages(dev, sg_dma_address(s), sg_dma_len(s),
+ dir, attrs);
+
+ return 0;
+}
+
+static void s390_dma_unmap_sg(struct device *dev, struct scatterlist *sg,
+ int nr_elements, enum dma_data_direction dir,
+ unsigned long attrs)
+{
+ struct scatterlist *s;
+ int i;
+
+ for_each_sg(sg, s, nr_elements, i) {
+ if (s->dma_length)
+ s390_dma_unmap_pages(dev, s->dma_address, s->dma_length,
+ dir, attrs);
+ s->dma_address = 0;
+ s->dma_length = 0;
+ }
+}
+
+static unsigned long *bitmap_vzalloc(size_t bits, gfp_t flags)
+{
+ size_t n = BITS_TO_LONGS(bits);
+ size_t bytes;
+
+ if (unlikely(check_mul_overflow(n, sizeof(unsigned long), &bytes)))
+ return NULL;
+
+ return vzalloc(bytes);
+}
+
+int zpci_dma_init_device(struct zpci_dev *zdev)
+{
+ int rc;
+
+ /*
+ * At this point, if the device is part of an IOMMU domain, this would
+ * be a strong hint towards a bug in the IOMMU API (common) code and/or
+ * simultaneous access via IOMMU and DMA API. So let's issue a warning.
+ */
+ WARN_ON(zdev->s390_domain);
+
+ spin_lock_init(&zdev->iommu_bitmap_lock);
+ spin_lock_init(&zdev->dma_table_lock);
+
+ zdev->dma_table = dma_alloc_cpu_table();
+ if (!zdev->dma_table) {
+ rc = -ENOMEM;
+ goto out;
+ }
+
+ /*
+ * Restrict the iommu bitmap size to the minimum of the following:
+ * - main memory size
+ * - 3-level pagetable address limit minus start_dma offset
+ * - DMA address range allowed by the hardware (clp query pci fn)
+ *
+ * Also set zdev->end_dma to the actual end address of the usable
+ * range, instead of the theoretical maximum as reported by hardware.
+ */
+ zdev->start_dma = PAGE_ALIGN(zdev->start_dma);
+ zdev->iommu_size = min3((u64) high_memory,
+ ZPCI_TABLE_SIZE_RT - zdev->start_dma,
+ zdev->end_dma - zdev->start_dma + 1);
+ zdev->end_dma = zdev->start_dma + zdev->iommu_size - 1;
+ zdev->iommu_pages = zdev->iommu_size >> PAGE_SHIFT;
+ zdev->iommu_bitmap = bitmap_vzalloc(zdev->iommu_pages, GFP_KERNEL);
+ if (!zdev->iommu_bitmap) {
+ rc = -ENOMEM;
+ goto free_dma_table;
+ }
+ if (!s390_iommu_strict) {
+ zdev->lazy_bitmap = bitmap_vzalloc(zdev->iommu_pages, GFP_KERNEL);
+ if (!zdev->lazy_bitmap) {
+ rc = -ENOMEM;
+ goto free_bitmap;
+ }
+
+ }
+ rc = zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma,
+ (u64) zdev->dma_table);
+ if (rc)
+ goto free_bitmap;
+
+ return 0;
+free_bitmap:
+ vfree(zdev->iommu_bitmap);
+ zdev->iommu_bitmap = NULL;
+ vfree(zdev->lazy_bitmap);
+ zdev->lazy_bitmap = NULL;
+free_dma_table:
+ dma_free_cpu_table(zdev->dma_table);
+ zdev->dma_table = NULL;
+out:
+ return rc;
+}
+
+void zpci_dma_exit_device(struct zpci_dev *zdev)
+{
+ /*
+ * At this point, if the device is part of an IOMMU domain, this would
+ * be a strong hint towards a bug in the IOMMU API (common) code and/or
+ * simultaneous access via IOMMU and DMA API. So let's issue a warning.
+ */
+ WARN_ON(zdev->s390_domain);
+
+ if (zpci_unregister_ioat(zdev, 0))
+ return;
+
+ dma_cleanup_tables(zdev->dma_table);
+ zdev->dma_table = NULL;
+ vfree(zdev->iommu_bitmap);
+ zdev->iommu_bitmap = NULL;
+ vfree(zdev->lazy_bitmap);
+ zdev->lazy_bitmap = NULL;
+
+ zdev->next_bit = 0;
+}
+
+static int __init dma_alloc_cpu_table_caches(void)
+{
+ dma_region_table_cache = kmem_cache_create("PCI_DMA_region_tables",
+ ZPCI_TABLE_SIZE, ZPCI_TABLE_ALIGN,
+ 0, NULL);
+ if (!dma_region_table_cache)
+ return -ENOMEM;
+
+ dma_page_table_cache = kmem_cache_create("PCI_DMA_page_tables",
+ ZPCI_PT_SIZE, ZPCI_PT_ALIGN,
+ 0, NULL);
+ if (!dma_page_table_cache) {
+ kmem_cache_destroy(dma_region_table_cache);
+ return -ENOMEM;
+ }
+ return 0;
+}
+
+int __init zpci_dma_init(void)
+{
+ return dma_alloc_cpu_table_caches();
+}
+
+void zpci_dma_exit(void)
+{
+ kmem_cache_destroy(dma_page_table_cache);
+ kmem_cache_destroy(dma_region_table_cache);
+}
+
+const struct dma_map_ops s390_pci_dma_ops = {
+ .alloc = s390_dma_alloc,
+ .free = s390_dma_free,
+ .map_sg = s390_dma_map_sg,
+ .unmap_sg = s390_dma_unmap_sg,
+ .map_page = s390_dma_map_pages,
+ .unmap_page = s390_dma_unmap_pages,
+ .mmap = dma_common_mmap,
+ .get_sgtable = dma_common_get_sgtable,
+ .alloc_pages = dma_common_alloc_pages,
+ .free_pages = dma_common_free_pages,
+ /* dma_supported is unconditionally true without a callback */
+};
+EXPORT_SYMBOL_GPL(s390_pci_dma_ops);
+
+static int __init s390_iommu_setup(char *str)
+{
+ if (!strcmp(str, "strict"))
+ s390_iommu_strict = 1;
+ return 1;
+}
+
+__setup("s390_iommu=", s390_iommu_setup);