diff options
Diffstat (limited to 'arch/s390/pci/pci_dma.c')
| -rw-r--r-- | arch/s390/pci/pci_dma.c | 510 |
1 files changed, 510 insertions, 0 deletions
diff --git a/arch/s390/pci/pci_dma.c b/arch/s390/pci/pci_dma.c new file mode 100644 index 00000000000..a547419907c --- /dev/null +++ b/arch/s390/pci/pci_dma.c @@ -0,0 +1,510 @@ +/* + * 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/pci.h> +#include <asm/pci_dma.h> + +static struct kmem_cache *dma_region_table_cache; +static struct kmem_cache *dma_page_table_cache; + +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) { + dev_err(&zdev->pdev->dev, "Missing DMA table\n"); + 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; + } + + /* + * rpcit is not required to establish new translations when previously + * invalid translation-table entries are validated, however it is + * required when altering previously valid entries. + */ + if (!zdev->tlb_refresh && + ((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID)) + /* + * TODO: also need to check that the old entry is indeed INVALID + * and not only for one page but for the whole range... + * -> now we WARN_ON in that case but with lazy unmap that + * needs to be redone! + */ + goto no_refresh; + rc = rpcit_instr((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 = 0x1000000; + + 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; + + spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags); + offset = __dma_alloc_iommu(zdev, zdev->next_bit, size); + if (offset == -1) + offset = __dma_alloc_iommu(zdev, 0, size); + + if (offset != -1) { + zdev->next_bit = offset + size; + if (zdev->next_bit >= zdev->iommu_pages) + zdev->next_bit = 0; + } + 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); + if (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(container_of(dev, struct 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; + + WARN_ON_ONCE(offset > PAGE_SIZE); + + /* 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) { + dev_err(dev, "(dma_addr: 0x%16.16LX + size: 0x%16.16lx) > end_dma: 0x%16.16Lx\n", + 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, (atomic64_t *) &zdev->fmb->mapped_pages); + return dma_addr + offset; + } + +out_free: + dma_free_iommu(zdev, iommu_page_index, nr_pages); +out_err: + dev_err(dev, "Failed to map addr: %lx\n", 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(container_of(dev, struct 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)) + dev_err(dev, "Failed to unmap addr: %Lx\n", dma_addr); + + atomic64_add(npages, (atomic64_t *) &zdev->fmb->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(container_of(dev, struct 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; + + atomic64_add(size / PAGE_SIZE, (atomic64_t *) &zdev->fmb->allocated_pages); + 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; + } + + 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) +{ + s390_dma_unmap_pages(dev, dma_handle, PAGE_ALIGN(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) +{ + unsigned int bitmap_order; + 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; + bitmap_order = get_order(zdev->iommu_pages / 8); + pr_info("iommu_size: 0x%lx iommu_pages: 0x%lx bitmap_order: %i\n", + zdev->iommu_size, zdev->iommu_pages, bitmap_order); + + zdev->iommu_bitmap = (void *) __get_free_pages(GFP_KERNEL | __GFP_ZERO, + bitmap_order); + 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); + free_pages((unsigned long) zdev->iommu_bitmap, + get_order(zdev->iommu_pages / 8)); + 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); |