--- /dev/null
+/*
+ * 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-mapping.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);
+}
+
+static 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 | ZPCI_TABLE_PROTECTED;
+ 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 | ZPCI_TABLE_PROTECTED;
+ 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;
+}
+
+static 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];
+}
+
+static void dma_update_cpu_trans(struct zpci_dev *zdev, void *page_addr,
+ dma_addr_t dma_addr, int flags)
+{
+ unsigned long *entry;
+
+ entry = dma_walk_cpu_trans(zdev->dma_table, dma_addr);
+ if (!entry) {
+ WARN_ON_ONCE(1);
+ return;
+ }
+
+ if (flags & ZPCI_PTE_INVALID) {
+ invalidate_pt_entry(entry);
+ return;
+ } 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);
+ dma_addr_t start_dma_addr = dma_addr;
+ unsigned long irq_flags;
+ int i, rc = 0;
+
+ if (!nr_pages)
+ return -EINVAL;
+
+ spin_lock_irqsave(&zdev->dma_table_lock, irq_flags);
+ if (!zdev->dma_table)
+ goto no_refresh;
+
+ for (i = 0; i < nr_pages; i++) {
+ dma_update_cpu_trans(zdev, page_addr, dma_addr, flags);
+ page_addr += PAGE_SIZE;
+ dma_addr += PAGE_SIZE;
+ }
+
+ /*
+ * With zdev->tlb_refresh == 0, rpcit is not required to establish new
+ * translations when previously invalid translation-table entries are
+ * validated. With lazy unmap, it also 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 (!zdev->tlb_refresh &&
+ (!s390_iommu_strict ||
+ ((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID)))
+ goto no_refresh;
+
+ rc = zpci_refresh_trans((u64) zdev->fh << 32, start_dma_addr,
+ nr_pages * PAGE_SIZE);
+
+no_refresh:
+ spin_unlock_irqrestore(&zdev->dma_table_lock, irq_flags);
+ return rc;
+}
+
+static 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);
+}
+
+static void dma_cleanup_tables(struct zpci_dev *zdev)
+{
+ unsigned long *table;
+ int rtx;
+
+ if (!zdev || !zdev->dma_table)
+ return;
+
+ table = zdev->dma_table;
+ 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);
+ zdev->dma_table = NULL;
+}
+
+static unsigned long __dma_alloc_iommu(struct zpci_dev *zdev,
+ unsigned long start, int size)
+{
+ unsigned long boundary_size;
+
+ boundary_size = ALIGN(dma_get_seg_boundary(&zdev->pdev->dev) + 1,
+ PAGE_SIZE) >> PAGE_SHIFT;
+ return iommu_area_alloc(zdev->iommu_bitmap, zdev->iommu_pages,
+ start, size, 0, boundary_size, 0);
+}
+
+static unsigned long dma_alloc_iommu(struct zpci_dev *zdev, int size)
+{
+ unsigned long offset, flags;
+ int wrap = 0;
+
+ spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags);
+ offset = __dma_alloc_iommu(zdev, zdev->next_bit, size);
+ if (offset == -1) {
+ /* wrap-around */
+ offset = __dma_alloc_iommu(zdev, 0, size);
+ wrap = 1;
+ }
+
+ if (offset != -1) {
+ zdev->next_bit = offset + size;
+ if (!zdev->tlb_refresh && !s390_iommu_strict && wrap)
+ /* global flush after wrap-around with lazy unmap */
+ zpci_refresh_global(zdev);
+ }
+ spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
+ return offset;
+}
+
+static void dma_free_iommu(struct zpci_dev *zdev, unsigned long offset, int size)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags);
+ if (!zdev->iommu_bitmap)
+ goto out;
+ bitmap_clear(zdev->iommu_bitmap, offset, size);
+ /*
+ * Lazy flush for unmap: need to move next_bit to avoid address re-use
+ * until wrap-around.
+ */
+ if (!s390_iommu_strict && offset >= zdev->next_bit)
+ zdev->next_bit = offset + size;
+out:
+ spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
+}
+
+int dma_set_mask(struct device *dev, u64 mask)
+{
+ if (!dev->dma_mask || !dma_supported(dev, mask))
+ return -EIO;
+
+ *dev->dma_mask = mask;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(dma_set_mask);
+
+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,
+ struct dma_attrs *attrs)
+{
+ struct zpci_dev *zdev = get_zdev(to_pci_dev(dev));
+ unsigned long nr_pages, iommu_page_index;
+ unsigned long pa = page_to_phys(page) + offset;
+ int flags = ZPCI_PTE_VALID;
+ dma_addr_t dma_addr;
+
+ /* This rounds up number of pages based on size and offset */
+ nr_pages = iommu_num_pages(pa, size, PAGE_SIZE);
+ iommu_page_index = dma_alloc_iommu(zdev, nr_pages);
+ if (iommu_page_index == -1)
+ goto out_err;
+
+ /* Use rounded up size */
+ size = nr_pages * PAGE_SIZE;
+
+ dma_addr = zdev->start_dma + iommu_page_index * PAGE_SIZE;
+ if (dma_addr + size > zdev->end_dma)
+ goto out_free;
+
+ if (direction == DMA_NONE || direction == DMA_TO_DEVICE)
+ flags |= ZPCI_TABLE_PROTECTED;
+
+ if (!dma_update_trans(zdev, pa, dma_addr, size, flags)) {
+ atomic64_add(nr_pages, &zdev->mapped_pages);
+ return dma_addr + (offset & ~PAGE_MASK);
+ }
+
+out_free:
+ dma_free_iommu(zdev, iommu_page_index, nr_pages);
+out_err:
+ zpci_err("map error:\n");
+ zpci_err_hex(&pa, sizeof(pa));
+ return DMA_ERROR_CODE;
+}
+
+static void s390_dma_unmap_pages(struct device *dev, dma_addr_t dma_addr,
+ size_t size, enum dma_data_direction direction,
+ struct dma_attrs *attrs)
+{
+ struct zpci_dev *zdev = get_zdev(to_pci_dev(dev));
+ unsigned long iommu_page_index;
+ int npages;
+
+ npages = iommu_num_pages(dma_addr, size, PAGE_SIZE);
+ dma_addr = dma_addr & PAGE_MASK;
+ if (dma_update_trans(zdev, 0, dma_addr, npages * PAGE_SIZE,
+ ZPCI_TABLE_PROTECTED | ZPCI_PTE_INVALID)) {
+ zpci_err("unmap error:\n");
+ zpci_err_hex(&dma_addr, sizeof(dma_addr));
+ }
+
+ atomic64_add(npages, &zdev->unmapped_pages);
+ iommu_page_index = (dma_addr - zdev->start_dma) >> PAGE_SHIFT;
+ dma_free_iommu(zdev, iommu_page_index, npages);
+}
+
+static void *s390_dma_alloc(struct device *dev, size_t size,
+ dma_addr_t *dma_handle, gfp_t flag,
+ struct dma_attrs *attrs)
+{
+ struct zpci_dev *zdev = get_zdev(to_pci_dev(dev));
+ struct page *page;
+ unsigned long pa;
+ dma_addr_t map;
+
+ size = PAGE_ALIGN(size);
+ page = alloc_pages(flag, get_order(size));
+ if (!page)
+ return NULL;
+
+ pa = page_to_phys(page);
+ memset((void *) pa, 0, size);
+
+ map = s390_dma_map_pages(dev, page, pa % PAGE_SIZE,
+ size, DMA_BIDIRECTIONAL, NULL);
+ 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,
+ struct dma_attrs *attrs)
+{
+ struct zpci_dev *zdev = get_zdev(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, NULL);
+ free_pages((unsigned long) pa, get_order(size));
+}
+
+static int s390_dma_map_sg(struct device *dev, struct scatterlist *sg,
+ int nr_elements, enum dma_data_direction dir,
+ struct dma_attrs *attrs)
+{
+ int mapped_elements = 0;
+ struct scatterlist *s;
+ int i;
+
+ for_each_sg(sg, s, nr_elements, i) {
+ struct page *page = sg_page(s);
+ s->dma_address = s390_dma_map_pages(dev, page, s->offset,
+ s->length, dir, NULL);
+ if (!dma_mapping_error(dev, s->dma_address)) {
+ s->dma_length = s->length;
+ mapped_elements++;
+ } else
+ goto unmap;
+ }
+out:
+ return mapped_elements;
+
+unmap:
+ for_each_sg(sg, s, mapped_elements, i) {
+ if (s->dma_address)
+ s390_dma_unmap_pages(dev, s->dma_address, s->dma_length,
+ dir, NULL);
+ s->dma_address = 0;
+ s->dma_length = 0;
+ }
+ mapped_elements = 0;
+ goto out;
+}
+
+static void s390_dma_unmap_sg(struct device *dev, struct scatterlist *sg,
+ int nr_elements, enum dma_data_direction dir,
+ struct dma_attrs *attrs)
+{
+ struct scatterlist *s;
+ int i;
+
+ for_each_sg(sg, s, nr_elements, i) {
+ s390_dma_unmap_pages(dev, s->dma_address, s->dma_length, dir, NULL);
+ s->dma_address = 0;
+ s->dma_length = 0;
+ }
+}
+
+int zpci_dma_init_device(struct zpci_dev *zdev)
+{
+ int rc;
+
+ 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_clean;
+ }
+
+ zdev->iommu_size = (unsigned long) high_memory - PAGE_OFFSET;
+ zdev->iommu_pages = zdev->iommu_size >> PAGE_SHIFT;
+ zdev->iommu_bitmap = vzalloc(zdev->iommu_pages / 8);
+ if (!zdev->iommu_bitmap) {
+ rc = -ENOMEM;
+ goto out_reg;
+ }
+
+ rc = zpci_register_ioat(zdev,
+ 0,
+ zdev->start_dma + PAGE_OFFSET,
+ zdev->start_dma + zdev->iommu_size - 1,
+ (u64) zdev->dma_table);
+ if (rc)
+ goto out_reg;
+ return 0;
+
+out_reg:
+ dma_free_cpu_table(zdev->dma_table);
+out_clean:
+ return rc;
+}
+
+void zpci_dma_exit_device(struct zpci_dev *zdev)
+{
+ zpci_unregister_ioat(zdev, 0);
+ dma_cleanup_tables(zdev);
+ vfree(zdev->iommu_bitmap);
+ zdev->iommu_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);
+}
+
+#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
+
+static int __init dma_debug_do_init(void)
+{
+ dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
+ return 0;
+}
+fs_initcall(dma_debug_do_init);
+
+struct dma_map_ops s390_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,
+ /* if we support direct DMA this must be conditional */
+ .is_phys = 0,
+ /* dma_supported is unconditionally true without a callback */
+};
+EXPORT_SYMBOL_GPL(s390_dma_ops);
+
+static int __init s390_iommu_setup(char *str)
+{
+ if (!strncmp(str, "strict", 6))
+ s390_iommu_strict = 1;
+ return 0;
+}
+
+__setup("s390_iommu=", s390_iommu_setup);
Code Review / kvmfornfv.git / blobdiff