// SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright (C) 2001 Mike Corrigan & Dave Engebretsen, IBM Corporation * * Rewrite, cleanup, new allocation schemes, virtual merging: * Copyright (C) 2004 Olof Johansson, IBM Corporation * and Ben. Herrenschmidt, IBM Corporation * * Dynamic DMA mapping support, bus-independent parts. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define DBG(...) #ifdef CONFIG_IOMMU_DEBUGFS static int iommu_debugfs_weight_get(void *data, u64 *val) { struct iommu_table *tbl = data; *val = bitmap_weight(tbl->it_map, tbl->it_size); return 0; } DEFINE_DEBUGFS_ATTRIBUTE(iommu_debugfs_fops_weight, iommu_debugfs_weight_get, NULL, "%llu\n"); static void iommu_debugfs_add(struct iommu_table *tbl) { char name[10]; struct dentry *liobn_entry; sprintf(name, "%08lx", tbl->it_index); liobn_entry = debugfs_create_dir(name, iommu_debugfs_dir); debugfs_create_file_unsafe("weight", 0400, liobn_entry, tbl, &iommu_debugfs_fops_weight); debugfs_create_ulong("it_size", 0400, liobn_entry, &tbl->it_size); debugfs_create_ulong("it_page_shift", 0400, liobn_entry, &tbl->it_page_shift); debugfs_create_ulong("it_reserved_start", 0400, liobn_entry, &tbl->it_reserved_start); debugfs_create_ulong("it_reserved_end", 0400, liobn_entry, &tbl->it_reserved_end); debugfs_create_ulong("it_indirect_levels", 0400, liobn_entry, &tbl->it_indirect_levels); debugfs_create_ulong("it_level_size", 0400, liobn_entry, &tbl->it_level_size); } static void iommu_debugfs_del(struct iommu_table *tbl) { char name[10]; sprintf(name, "%08lx", tbl->it_index); debugfs_lookup_and_remove(name, iommu_debugfs_dir); } #else static void iommu_debugfs_add(struct iommu_table *tbl){} static void iommu_debugfs_del(struct iommu_table *tbl){} #endif static int novmerge; static void __iommu_free(struct iommu_table *, dma_addr_t, unsigned int); static int __init setup_iommu(char *str) { if (!strcmp(str, "novmerge")) novmerge = 1; else if (!strcmp(str, "vmerge")) novmerge = 0; return 1; } __setup("iommu=", setup_iommu); static DEFINE_PER_CPU(unsigned int, iommu_pool_hash); /* * We precalculate the hash to avoid doing it on every allocation. * * The hash is important to spread CPUs across all the pools. For example, * on a POWER7 with 4 way SMT we want interrupts on the primary threads and * with 4 pools all primary threads would map to the same pool. */ static int __init setup_iommu_pool_hash(void) { unsigned int i; for_each_possible_cpu(i) per_cpu(iommu_pool_hash, i) = hash_32(i, IOMMU_POOL_HASHBITS); return 0; } subsys_initcall(setup_iommu_pool_hash); #ifdef CONFIG_FAIL_IOMMU static DECLARE_FAULT_ATTR(fail_iommu); static int __init setup_fail_iommu(char *str) { return setup_fault_attr(&fail_iommu, str); } __setup("fail_iommu=", setup_fail_iommu); static bool should_fail_iommu(struct device *dev) { return dev->archdata.fail_iommu && should_fail(&fail_iommu, 1); } static int __init fail_iommu_debugfs(void) { struct dentry *dir = fault_create_debugfs_attr("fail_iommu", NULL, &fail_iommu); return PTR_ERR_OR_ZERO(dir); } late_initcall(fail_iommu_debugfs); static ssize_t fail_iommu_show(struct device *dev, struct device_attribute *attr, char *buf) { return sprintf(buf, "%d\n", dev->archdata.fail_iommu); } static ssize_t fail_iommu_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { int i; if (count > 0 && sscanf(buf, "%d", &i) > 0) dev->archdata.fail_iommu = (i == 0) ? 0 : 1; return count; } static DEVICE_ATTR_RW(fail_iommu); static int fail_iommu_bus_notify(struct notifier_block *nb, unsigned long action, void *data) { struct device *dev = data; if (action == BUS_NOTIFY_ADD_DEVICE) { if (device_create_file(dev, &dev_attr_fail_iommu)) pr_warn("Unable to create IOMMU fault injection sysfs " "entries\n"); } else if (action == BUS_NOTIFY_DEL_DEVICE) { device_remove_file(dev, &dev_attr_fail_iommu); } return 0; } /* * PCI and VIO buses need separate notifier_block structs, since they're linked * list nodes. Sharing a notifier_block would mean that any notifiers later * registered for PCI buses would also get called by VIO buses and vice versa. */ static struct notifier_block fail_iommu_pci_bus_notifier = { .notifier_call = fail_iommu_bus_notify }; #ifdef CONFIG_IBMVIO static struct notifier_block fail_iommu_vio_bus_notifier = { .notifier_call = fail_iommu_bus_notify }; #endif static int __init fail_iommu_setup(void) { #ifdef CONFIG_PCI bus_register_notifier(&pci_bus_type, &fail_iommu_pci_bus_notifier); #endif #ifdef CONFIG_IBMVIO bus_register_notifier(&vio_bus_type, &fail_iommu_vio_bus_notifier); #endif return 0; } /* * Must execute after PCI and VIO subsystem have initialised but before * devices are probed. */ arch_initcall(fail_iommu_setup); #else static inline bool should_fail_iommu(struct device *dev) { return false; } #endif static unsigned long iommu_range_alloc(struct device *dev, struct iommu_table *tbl, unsigned long npages, unsigned long *handle, unsigned long mask, unsigned int align_order) { unsigned long n, end, start; unsigned long limit; int largealloc = npages > 15; int pass = 0; unsigned long align_mask; unsigned long flags; unsigned int pool_nr; struct iommu_pool *pool; align_mask = (1ull << align_order) - 1; /* This allocator was derived from x86_64's bit string search */ /* Sanity check */ if (unlikely(npages == 0)) { if (printk_ratelimit()) WARN_ON(1); return DMA_MAPPING_ERROR; } if (should_fail_iommu(dev)) return DMA_MAPPING_ERROR; /* * We don't need to disable preemption here because any CPU can * safely use any IOMMU pool. */ pool_nr = raw_cpu_read(iommu_pool_hash) & (tbl->nr_pools - 1); if (largealloc) pool = &(tbl->large_pool); else pool = &(tbl->pools[pool_nr]); spin_lock_irqsave(&(pool->lock), flags); again: if ((pass == 0) && handle && *handle && (*handle >= pool->start) && (*handle < pool->end)) start = *handle; else start = pool->hint; limit = pool->end; /* The case below can happen if we have a small segment appended * to a large, or when the previous alloc was at the very end of * the available space. If so, go back to the initial start. */ if (start >= limit) start = pool->start; if (limit + tbl->it_offset > mask) { limit = mask - tbl->it_offset + 1; /* If we're constrained on address range, first try * at the masked hint to avoid O(n) search complexity, * but on second pass, start at 0 in pool 0. */ if ((start & mask) >= limit || pass > 0) { spin_unlock(&(pool->lock)); pool = &(tbl->pools[0]); spin_lock(&(pool->lock)); start = pool->start; } else { start &= mask; } } n = iommu_area_alloc(tbl->it_map, limit, start, npages, tbl->it_offset, dma_get_seg_boundary_nr_pages(dev, tbl->it_page_shift), align_mask); if (n == -1) { if (likely(pass == 0)) { /* First try the pool from the start */ pool->hint = pool->start; pass++; goto again; } else if (pass <= tbl->nr_pools) { /* Now try scanning all the other pools */ spin_unlock(&(pool->lock)); pool_nr = (pool_nr + 1) & (tbl->nr_pools - 1); pool = &tbl->pools[pool_nr]; spin_lock(&(pool->lock)); pool->hint = pool->start; pass++; goto again; } else if (pass == tbl->nr_pools + 1) { /* Last resort: try largepool */ spin_unlock(&pool->lock); pool = &tbl->large_pool; spin_lock(&pool->lock); pool->hint = pool->start; pass++; goto again; } else { /* Give up */ spin_unlock_irqrestore(&(pool->lock), flags); return DMA_MAPPING_ERROR; } } end = n + npages; /* Bump the hint to a new block for small allocs. */ if (largealloc) { /* Don't bump to new block to avoid fragmentation */ pool->hint = end; } else { /* Overflow will be taken care of at the next allocation */ pool->hint = (end + tbl->it_blocksize - 1) & ~(tbl->it_blocksize - 1); } /* Update handle for SG allocations */ if (handle) *handle = end; spin_unlock_irqrestore(&(pool->lock), flags); return n; } static dma_addr_t iommu_alloc(struct device *dev, struct iommu_table *tbl, void *page, unsigned int npages, enum dma_data_direction direction, unsigned long mask, unsigned int align_order, unsigned long attrs) { unsigned long entry; dma_addr_t ret = DMA_MAPPING_ERROR; int build_fail; entry = iommu_range_alloc(dev, tbl, npages, NULL, mask, align_order); if (unlikely(entry == DMA_MAPPING_ERROR)) return DMA_MAPPING_ERROR; entry += tbl->it_offset; /* Offset into real TCE table */ ret = entry << tbl->it_page_shift; /* Set the return dma address */ /* Put the TCEs in the HW table */ build_fail = tbl->it_ops->set(tbl, entry, npages, (unsigned long)page & IOMMU_PAGE_MASK(tbl), direction, attrs); /* tbl->it_ops->set() only returns non-zero for transient errors. * Clean up the table bitmap in this case and return * DMA_MAPPING_ERROR. For all other errors the functionality is * not altered. */ if (unlikely(build_fail)) { __iommu_free(tbl, ret, npages); return DMA_MAPPING_ERROR; } /* Flush/invalidate TLB caches if necessary */ if (tbl->it_ops->flush) tbl->it_ops->flush(tbl); /* Make sure updates are seen by hardware */ mb(); return ret; } static bool iommu_free_check(struct iommu_table *tbl, dma_addr_t dma_addr, unsigned int npages) { unsigned long entry, free_entry; entry = dma_addr >> tbl->it_page_shift; free_entry = entry - tbl->it_offset; if (((free_entry + npages) > tbl->it_size) || (entry < tbl->it_offset)) { if (printk_ratelimit()) { printk(KERN_INFO "iommu_free: invalid entry\n"); printk(KERN_INFO "\tentry = 0x%lx\n", entry); printk(KERN_INFO "\tdma_addr = 0x%llx\n", (u64)dma_addr); printk(KERN_INFO "\tTable = 0x%llx\n", (u64)tbl); printk(KERN_INFO "\tbus# = 0x%llx\n", (u64)tbl->it_busno); printk(KERN_INFO "\tsize = 0x%llx\n", (u64)tbl->it_size); printk(KERN_INFO "\tstartOff = 0x%llx\n", (u64)tbl->it_offset); printk(KERN_INFO "\tindex = 0x%llx\n", (u64)tbl->it_index); WARN_ON(1); } return false; } return true; } static struct iommu_pool *get_pool(struct iommu_table *tbl, unsigned long entry) { struct iommu_pool *p; unsigned long largepool_start = tbl->large_pool.start; /* The large pool is the last pool at the top of the table */ if (entry >= largepool_start) { p = &tbl->large_pool; } else { unsigned int pool_nr = entry / tbl->poolsize; BUG_ON(pool_nr > tbl->nr_pools); p = &tbl->pools[pool_nr]; } return p; } static void __iommu_free(struct iommu_table *tbl, dma_addr_t dma_addr, unsigned int npages) { unsigned long entry, free_entry; unsigned long flags; struct iommu_pool *pool; entry = dma_addr >> tbl->it_page_shift; free_entry = entry - tbl->it_offset; pool = get_pool(tbl, free_entry); if (!iommu_free_check(tbl, dma_addr, npages)) return; tbl->it_ops->clear(tbl, entry, npages); spin_lock_irqsave(&(pool->lock), flags); bitmap_clear(tbl->it_map, free_entry, npages); spin_unlock_irqrestore(&(pool->lock), flags); } static void iommu_free(struct iommu_table *tbl, dma_addr_t dma_addr, unsigned int npages) { __iommu_free(tbl, dma_addr, npages); /* Make sure TLB cache is flushed if the HW needs it. We do * not do an mb() here on purpose, it is not needed on any of * the current platforms. */ if (tbl->it_ops->flush) tbl->it_ops->flush(tbl); } int ppc_iommu_map_sg(struct device *dev, struct iommu_table *tbl, struct scatterlist *sglist, int nelems, unsigned long mask, enum dma_data_direction direction, unsigned long attrs) { dma_addr_t dma_next = 0, dma_addr; struct scatterlist *s, *outs, *segstart; int outcount, incount, i, build_fail = 0; unsigned int align; unsigned long handle; unsigned int max_seg_size; BUG_ON(direction == DMA_NONE); if ((nelems == 0) || !tbl) return -EINVAL; outs = s = segstart = &sglist[0]; outcount = 1; incount = nelems; handle = 0; /* Init first segment length for backout at failure */ outs->dma_length = 0; DBG("sg mapping %d elements:\n", nelems); max_seg_size = dma_get_max_seg_size(dev); for_each_sg(sglist, s, nelems, i) { unsigned long vaddr, npages, entry, slen; slen = s->length; /* Sanity check */ if (slen == 0) { dma_next = 0; continue; } /* Allocate iommu entries for that segment */ vaddr = (unsigned long) sg_virt(s); npages = iommu_num_pages(vaddr, slen, IOMMU_PAGE_SIZE(tbl)); align = 0; if (tbl->it_page_shift < PAGE_SHIFT && slen >= PAGE_SIZE && (vaddr & ~PAGE_MASK) == 0) align = PAGE_SHIFT - tbl->it_page_shift; entry = iommu_range_alloc(dev, tbl, npages, &handle, mask >> tbl->it_page_shift, align); DBG(" - vaddr: %lx, size: %lx\n", vaddr, slen); /* Handle failure */ if (unlikely(entry == DMA_MAPPING_ERROR)) { if (!(attrs & DMA_ATTR_NO_WARN) && printk_ratelimit()) dev_info(dev, "iommu_alloc failed, tbl %p " "vaddr %lx npages %lu\n", tbl, vaddr, npages); goto failure; } /* Convert entry to a dma_addr_t */ entry += tbl->it_offset; dma_addr = entry << tbl->it_page_shift; dma_addr |= (vaddr & ~IOMMU_PAGE_MASK(tbl)); DBG(" - %lu pages, entry: %lx, dma_addr: %lx\n", npages, entry, dma_addr); /* Insert into HW table */ build_fail = tbl->it_ops->set(tbl, entry, npages, vaddr & IOMMU_PAGE_MASK(tbl), direction, attrs); if(unlikely(build_fail)) goto failure; /* If we are in an open segment, try merging */ if (segstart != s) { DBG(" - trying merge...\n"); /* We cannot merge if: * - allocated dma_addr isn't contiguous to previous allocation */ if (novmerge || (dma_addr != dma_next) || (outs->dma_length + s->length > max_seg_size)) { /* Can't merge: create a new segment */ segstart = s; outcount++; outs = sg_next(outs); DBG(" can't merge, new segment.\n"); } else { outs->dma_length += s->length; DBG(" merged, new len: %ux\n", outs->dma_length); } } if (segstart == s) { /* This is a new segment, fill entries */ DBG(" - filling new segment.\n"); outs->dma_address = dma_addr; outs->dma_length = slen; } /* Calculate next page pointer for contiguous check */ dma_next = dma_addr + slen; DBG(" - dma next is: %lx\n", dma_next); } /* Flush/invalidate TLB caches if necessary */ if (tbl->it_ops->flush) tbl->it_ops->flush(tbl); DBG("mapped %d elements:\n", outcount); /* For the sake of ppc_iommu_unmap_sg, we clear out the length in the * next entry of the sglist if we didn't fill the list completely */ if (outcount < incount) { outs = sg_next(outs); outs->dma_length = 0; } /* Make sure updates are seen by hardware */ mb(); return outcount; failure: for_each_sg(sglist, s, nelems, i) { if (s->dma_length != 0) { unsigned long vaddr, npages; vaddr = s->dma_address & IOMMU_PAGE_MASK(tbl); npages = iommu_num_pages(s->dma_address, s->dma_length, IOMMU_PAGE_SIZE(tbl)); __iommu_free(tbl, vaddr, npages); s->dma_length = 0; } if (s == outs) break; } return -EIO; } void ppc_iommu_unmap_sg(struct iommu_table *tbl, struct scatterlist *sglist, int nelems, enum dma_data_direction direction, unsigned long attrs) { struct scatterlist *sg; BUG_ON(direction == DMA_NONE); if (!tbl) return; sg = sglist; while (nelems--) { unsigned int npages; dma_addr_t dma_handle = sg->dma_address; if (sg->dma_length == 0) break; npages = iommu_num_pages(dma_handle, sg->dma_length, IOMMU_PAGE_SIZE(tbl)); __iommu_free(tbl, dma_handle, npages); sg = sg_next(sg); } /* Flush/invalidate TLBs if necessary. As for iommu_free(), we * do not do an mb() here, the affected platforms do not need it * when freeing. */ if (tbl->it_ops->flush) tbl->it_ops->flush(tbl); } static void iommu_table_clear(struct iommu_table *tbl) { /* * In case of firmware assisted dump system goes through clean * reboot process at the time of system crash. Hence it's safe to * clear the TCE entries if firmware assisted dump is active. */ if (!is_kdump_kernel() || is_fadump_active()) { /* Clear the table in case firmware left allocations in it */ tbl->it_ops->clear(tbl, tbl->it_offset, tbl->it_size); return; } #ifdef CONFIG_CRASH_DUMP if (tbl->it_ops->get) { unsigned long index, tceval, tcecount = 0; /* Reserve the existing mappings left by the first kernel. */ for (index = 0; index < tbl->it_size; index++) { tceval = tbl->it_ops->get(tbl, index + tbl->it_offset); /* * Freed TCE entry contains 0x7fffffffffffffff on JS20 */ if (tceval && (tceval != 0x7fffffffffffffffUL)) { __set_bit(index, tbl->it_map); tcecount++; } } if ((tbl->it_size - tcecount) < KDUMP_MIN_TCE_ENTRIES) { printk(KERN_WARNING "TCE table is full; freeing "); printk(KERN_WARNING "%d entries for the kdump boot\n", KDUMP_MIN_TCE_ENTRIES); for (index = tbl->it_size - KDUMP_MIN_TCE_ENTRIES; index < tbl->it_size; index++) __clear_bit(index, tbl->it_map); } } #endif } static void iommu_table_reserve_pages(struct iommu_table *tbl, unsigned long res_start, unsigned long res_end) { int i; WARN_ON_ONCE(res_end < res_start); /* * Reserve page 0 so it will not be used for any mappings. * This avoids buggy drivers that consider page 0 to be invalid * to crash the machine or even lose data. */ if (tbl->it_offset == 0) set_bit(0, tbl->it_map); if (res_start < tbl->it_offset) res_start = tbl->it_offset; if (res_end > (tbl->it_offset + tbl->it_size)) res_end = tbl->it_offset + tbl->it_size; /* Check if res_start..res_end is a valid range in the table */ if (res_start >= res_end) { tbl->it_reserved_start = tbl->it_offset; tbl->it_reserved_end = tbl->it_offset; return; } tbl->it_reserved_start = res_start; tbl->it_reserved_end = res_end; for (i = tbl->it_reserved_start; i < tbl->it_reserved_end; ++i) set_bit(i - tbl->it_offset, tbl->it_map); } /* * Build a iommu_table structure. This contains a bit map which * is used to manage allocation of the tce space. */ struct iommu_table *iommu_init_table(struct iommu_table *tbl, int nid, unsigned long res_start, unsigned long res_end) { unsigned long sz; static int welcomed = 0; unsigned int i; struct iommu_pool *p; BUG_ON(!tbl->it_ops); /* number of bytes needed for the bitmap */ sz = BITS_TO_LONGS(tbl->it_size) * sizeof(unsigned long); tbl->it_map = vzalloc_node(sz, nid); if (!tbl->it_map) { pr_err("%s: Can't allocate %ld bytes\n", __func__, sz); return NULL; } iommu_table_reserve_pages(tbl, res_start, res_end); /* We only split the IOMMU table if we have 1GB or more of space */ if ((tbl->it_size << tbl->it_page_shift) >= (1UL * 1024 * 1024 * 1024)) tbl->nr_pools = IOMMU_NR_POOLS; else tbl->nr_pools = 1; /* We reserve the top 1/4 of the table for large allocations */ tbl->poolsize = (tbl->it_size * 3 / 4) / tbl->nr_pools; for (i = 0; i < tbl->nr_pools; i++) { p = &tbl->pools[i]; spin_lock_init(&(p->lock)); p->start = tbl->poolsize * i; p->hint = p->start; p->end = p->start + tbl->poolsize; } p = &tbl->large_pool; spin_lock_init(&(p->lock)); p->start = tbl->poolsize * i; p->hint = p->start; p->end = tbl->it_size; iommu_table_clear(tbl); if (!welcomed) { printk(KERN_INFO "IOMMU table initialized, virtual merging %s\n", novmerge ? "disabled" : "enabled"); welcomed = 1; } iommu_debugfs_add(tbl); return tbl; } bool iommu_table_in_use(struct iommu_table *tbl) { unsigned long start = 0, end; /* ignore reserved bit0 */ if (tbl->it_offset == 0) start = 1; /* Simple case with no reserved MMIO32 region */ if (!tbl->it_reserved_start && !tbl->it_reserved_end) return find_next_bit(tbl->it_map, tbl->it_size, start) != tbl->it_size; end = tbl->it_reserved_start - tbl->it_offset; if (find_next_bit(tbl->it_map, end, start) != end) return true; start = tbl->it_reserved_end - tbl->it_offset; end = tbl->it_size; return find_next_bit(tbl->it_map, end, start) != end; } static void iommu_table_free(struct kref *kref) { struct iommu_table *tbl; tbl = container_of(kref, struct iommu_table, it_kref); if (tbl->it_ops->free) tbl->it_ops->free(tbl); if (!tbl->it_map) { kfree(tbl); return; } iommu_debugfs_del(tbl); /* verify that table contains no entries */ if (iommu_table_in_use(tbl)) pr_warn("%s: Unexpected TCEs\n", __func__); /* free bitmap */ vfree(tbl->it_map); /* free table */ kfree(tbl); } struct iommu_table *iommu_tce_table_get(struct iommu_table *tbl) { if (kref_get_unless_zero(&tbl->it_kref)) return tbl; return NULL; } EXPORT_SYMBOL_GPL(iommu_tce_table_get); int iommu_tce_table_put(struct iommu_table *tbl) { if (WARN_ON(!tbl)) return 0; return kref_put(&tbl->it_kref, iommu_table_free); } EXPORT_SYMBOL_GPL(iommu_tce_table_put); /* Creates TCEs for a user provided buffer. The user buffer must be * contiguous real kernel storage (not vmalloc). The address passed here * comprises a page address and offset into that page. The dma_addr_t * returned will point to the same byte within the page as was passed in. */ dma_addr_t iommu_map_page(struct device *dev, struct iommu_table *tbl, struct page *page, unsigned long offset, size_t size, unsigned long mask, enum dma_data_direction direction, unsigned long attrs) { dma_addr_t dma_handle = DMA_MAPPING_ERROR; void *vaddr; unsigned long uaddr; unsigned int npages, align; BUG_ON(direction == DMA_NONE); vaddr = page_address(page) + offset; uaddr = (unsigned long)vaddr; if (tbl) { npages = iommu_num_pages(uaddr, size, IOMMU_PAGE_SIZE(tbl)); align = 0; if (tbl->it_page_shift < PAGE_SHIFT && size >= PAGE_SIZE && ((unsigned long)vaddr & ~PAGE_MASK) == 0) align = PAGE_SHIFT - tbl->it_page_shift; dma_handle = iommu_alloc(dev, tbl, vaddr, npages, direction, mask >> tbl->it_page_shift, align, attrs); if (dma_handle == DMA_MAPPING_ERROR) { if (!(attrs & DMA_ATTR_NO_WARN) && printk_ratelimit()) { dev_info(dev, "iommu_alloc failed, tbl %p " "vaddr %p npages %d\n", tbl, vaddr, npages); } } else dma_handle |= (uaddr & ~IOMMU_PAGE_MASK(tbl)); } return dma_handle; } void iommu_unmap_page(struct iommu_table *tbl, dma_addr_t dma_handle, size_t size, enum dma_data_direction direction, unsigned long attrs) { unsigned int npages; BUG_ON(direction == DMA_NONE); if (tbl) { npages = iommu_num_pages(dma_handle, size, IOMMU_PAGE_SIZE(tbl)); iommu_free(tbl, dma_handle, npages); } } /* Allocates a contiguous real buffer and creates mappings over it. * Returns the virtual address of the buffer and sets dma_handle * to the dma address (mapping) of the first page. */ void *iommu_alloc_coherent(struct device *dev, struct iommu_table *tbl, size_t size, dma_addr_t *dma_handle, unsigned long mask, gfp_t flag, int node) { void *ret = NULL; dma_addr_t mapping; unsigned int order; unsigned int nio_pages, io_order; struct page *page; int tcesize = (1 << tbl->it_page_shift); size = PAGE_ALIGN(size); order = get_order(size); /* * Client asked for way too much space. This is checked later * anyway. It is easier to debug here for the drivers than in * the tce tables. */ if (order >= IOMAP_MAX_ORDER) { dev_info(dev, "iommu_alloc_consistent size too large: 0x%lx\n", size); return NULL; } if (!tbl) return NULL; /* Alloc enough pages (and possibly more) */ page = alloc_pages_node(node, flag, order); if (!page) return NULL; ret = page_address(page); memset(ret, 0, size); /* Set up tces to cover the allocated range */ nio_pages = IOMMU_PAGE_ALIGN(size, tbl) >> tbl->it_page_shift; io_order = get_iommu_order(size, tbl); mapping = iommu_alloc(dev, tbl, ret, nio_pages, DMA_BIDIRECTIONAL, mask >> tbl->it_page_shift, io_order, 0); if (mapping == DMA_MAPPING_ERROR) { free_pages((unsigned long)ret, order); return NULL; } *dma_handle = mapping | ((u64)ret & (tcesize - 1)); return ret; } void iommu_free_coherent(struct iommu_table *tbl, size_t size, void *vaddr, dma_addr_t dma_handle) { if (tbl) { unsigned int nio_pages; size = PAGE_ALIGN(size); nio_pages = IOMMU_PAGE_ALIGN(size, tbl) >> tbl->it_page_shift; iommu_free(tbl, dma_handle, nio_pages); size = PAGE_ALIGN(size); free_pages((unsigned long)vaddr, get_order(size)); } } unsigned long iommu_direction_to_tce_perm(enum dma_data_direction dir) { switch (dir) { case DMA_BIDIRECTIONAL: return TCE_PCI_READ | TCE_PCI_WRITE; case DMA_FROM_DEVICE: return TCE_PCI_WRITE; case DMA_TO_DEVICE: return TCE_PCI_READ; default: return 0; } } EXPORT_SYMBOL_GPL(iommu_direction_to_tce_perm); #ifdef CONFIG_IOMMU_API /* * SPAPR TCE API */ static void group_release(void *iommu_data) { struct iommu_table_group *table_group = iommu_data; table_group->group = NULL; } void iommu_register_group(struct iommu_table_group *table_group, int pci_domain_number, unsigned long pe_num) { struct iommu_group *grp; char *name; grp = iommu_group_alloc(); if (IS_ERR(grp)) { pr_warn("powerpc iommu api: cannot create new group, err=%ld\n", PTR_ERR(grp)); return; } table_group->group = grp; iommu_group_set_iommudata(grp, table_group, group_release); name = kasprintf(GFP_KERNEL, "domain%d-pe%lx", pci_domain_number, pe_num); if (!name) return; iommu_group_set_name(grp, name); kfree(name); } enum dma_data_direction iommu_tce_direction(unsigned long tce) { if ((tce & TCE_PCI_READ) && (tce & TCE_PCI_WRITE)) return DMA_BIDIRECTIONAL; else if (tce & TCE_PCI_READ) return DMA_TO_DEVICE; else if (tce & TCE_PCI_WRITE) return DMA_FROM_DEVICE; else return DMA_NONE; } EXPORT_SYMBOL_GPL(iommu_tce_direction); void iommu_flush_tce(struct iommu_table *tbl) { /* Flush/invalidate TLB caches if necessary */ if (tbl->it_ops->flush) tbl->it_ops->flush(tbl); /* Make sure updates are seen by hardware */ mb(); } EXPORT_SYMBOL_GPL(iommu_flush_tce); int iommu_tce_check_ioba(unsigned long page_shift, unsigned long offset, unsigned long size, unsigned long ioba, unsigned long npages) { unsigned long mask = (1UL << page_shift) - 1; if (ioba & mask) return -EINVAL; ioba >>= page_shift; if (ioba < offset) return -EINVAL; if ((ioba + 1) > (offset + size)) return -EINVAL; return 0; } EXPORT_SYMBOL_GPL(iommu_tce_check_ioba); int iommu_tce_check_gpa(unsigned long page_shift, unsigned long gpa) { unsigned long mask = (1UL << page_shift) - 1; if (gpa & mask) return -EINVAL; return 0; } EXPORT_SYMBOL_GPL(iommu_tce_check_gpa); extern long iommu_tce_xchg_no_kill(struct mm_struct *mm, struct iommu_table *tbl, unsigned long entry, unsigned long *hpa, enum dma_data_direction *direction) { long ret; unsigned long size = 0; ret = tbl->it_ops->xchg_no_kill(tbl, entry, hpa, direction); if (!ret && ((*direction == DMA_FROM_DEVICE) || (*direction == DMA_BIDIRECTIONAL)) && !mm_iommu_is_devmem(mm, *hpa, tbl->it_page_shift, &size)) SetPageDirty(pfn_to_page(*hpa >> PAGE_SHIFT)); return ret; } EXPORT_SYMBOL_GPL(iommu_tce_xchg_no_kill); void iommu_tce_kill(struct iommu_table *tbl, unsigned long entry, unsigned long pages) { if (tbl->it_ops->tce_kill) tbl->it_ops->tce_kill(tbl, entry, pages); } EXPORT_SYMBOL_GPL(iommu_tce_kill); #if defined(CONFIG_PPC_PSERIES) || defined(CONFIG_PPC_POWERNV) static int iommu_take_ownership(struct iommu_table *tbl) { unsigned long flags, i, sz = (tbl->it_size + 7) >> 3; int ret = 0; /* * VFIO does not control TCE entries allocation and the guest * can write new TCEs on top of existing ones so iommu_tce_build() * must be able to release old pages. This functionality * requires exchange() callback defined so if it is not * implemented, we disallow taking ownership over the table. */ if (!tbl->it_ops->xchg_no_kill) return -EINVAL; spin_lock_irqsave(&tbl->large_pool.lock, flags); for (i = 0; i < tbl->nr_pools; i++) spin_lock_nest_lock(&tbl->pools[i].lock, &tbl->large_pool.lock); if (iommu_table_in_use(tbl)) { pr_err("iommu_tce: it_map is not empty"); ret = -EBUSY; } else { memset(tbl->it_map, 0xff, sz); } for (i = 0; i < tbl->nr_pools; i++) spin_unlock(&tbl->pools[i].lock); spin_unlock_irqrestore(&tbl->large_pool.lock, flags); return ret; } static void iommu_release_ownership(struct iommu_table *tbl) { unsigned long flags, i, sz = (tbl->it_size + 7) >> 3; spin_lock_irqsave(&tbl->large_pool.lock, flags); for (i = 0; i < tbl->nr_pools; i++) spin_lock_nest_lock(&tbl->pools[i].lock, &tbl->large_pool.lock); memset(tbl->it_map, 0, sz); iommu_table_reserve_pages(tbl, tbl->it_reserved_start, tbl->it_reserved_end); for (i = 0; i < tbl->nr_pools; i++) spin_unlock(&tbl->pools[i].lock); spin_unlock_irqrestore(&tbl->large_pool.lock, flags); } #endif int iommu_add_device(struct iommu_table_group *table_group, struct device *dev) { /* * The sysfs entries should be populated before * binding IOMMU group. If sysfs entries isn't * ready, we simply bail. */ if (!device_is_registered(dev)) return -ENOENT; if (device_iommu_mapped(dev)) { pr_debug("%s: Skipping device %s with iommu group %d\n", __func__, dev_name(dev), iommu_group_id(dev->iommu_group)); return -EBUSY; } pr_debug("%s: Adding %s to iommu group %d\n", __func__, dev_name(dev), iommu_group_id(table_group->group)); /* * This is still not adding devices via the IOMMU bus notifier because * of pcibios_init() from arch/powerpc/kernel/pci_64.c which calls * pcibios_scan_phb() first (and this guy adds devices and triggers * the notifier) and only then it calls pci_bus_add_devices() which * configures DMA for buses which also creates PEs and IOMMU groups. */ return iommu_probe_device(dev); } EXPORT_SYMBOL_GPL(iommu_add_device); #if defined(CONFIG_PPC_PSERIES) || defined(CONFIG_PPC_POWERNV) /* * A simple iommu_table_group_ops which only allows reusing the existing * iommu_table. This handles VFIO for POWER7 or the nested KVM. * The ops does not allow creating windows and only allows reusing the existing * one if it matches table_group->tce32_start/tce32_size/page_shift. */ static unsigned long spapr_tce_get_table_size(__u32 page_shift, __u64 window_size, __u32 levels) { unsigned long size; if (levels > 1) return ~0U; size = window_size >> (page_shift - 3); return size; } static long spapr_tce_create_table(struct iommu_table_group *table_group, int num, __u32 page_shift, __u64 window_size, __u32 levels, struct iommu_table **ptbl) { struct iommu_table *tbl = table_group->tables[0]; if (num > 0) return -EPERM; if (tbl->it_page_shift != page_shift || tbl->it_size != (window_size >> page_shift) || tbl->it_indirect_levels != levels - 1) return -EINVAL; *ptbl = iommu_tce_table_get(tbl); return 0; } static long spapr_tce_set_window(struct iommu_table_group *table_group, int num, struct iommu_table *tbl) { return tbl == table_group->tables[num] ? 0 : -EPERM; } static long spapr_tce_unset_window(struct iommu_table_group *table_group, int num) { return 0; } static long spapr_tce_take_ownership(struct iommu_table_group *table_group) { int i, j, rc = 0; for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) { struct iommu_table *tbl = table_group->tables[i]; if (!tbl || !tbl->it_map) continue; rc = iommu_take_ownership(tbl); if (!rc) continue; for (j = 0; j < i; ++j) iommu_release_ownership(table_group->tables[j]); return rc; } return 0; } static void spapr_tce_release_ownership(struct iommu_table_group *table_group) { int i; for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) { struct iommu_table *tbl = table_group->tables[i]; if (!tbl) continue; iommu_table_clear(tbl); if (tbl->it_map) iommu_release_ownership(tbl); } } struct iommu_table_group_ops spapr_tce_table_group_ops = { .get_table_size = spapr_tce_get_table_size, .create_table = spapr_tce_create_table, .set_window = spapr_tce_set_window, .unset_window = spapr_tce_unset_window, .take_ownership = spapr_tce_take_ownership, .release_ownership = spapr_tce_release_ownership, }; /* * A simple iommu_ops to allow less cruft in generic VFIO code. */ static int spapr_tce_blocking_iommu_attach_dev(struct iommu_domain *dom, struct device *dev) { struct iommu_group *grp = iommu_group_get(dev); struct iommu_table_group *table_group; int ret = -EINVAL; if (!grp) return -ENODEV; table_group = iommu_group_get_iommudata(grp); ret = table_group->ops->take_ownership(table_group); iommu_group_put(grp); return ret; } static void spapr_tce_blocking_iommu_set_platform_dma(struct device *dev) { struct iommu_group *grp = iommu_group_get(dev); struct iommu_table_group *table_group; table_group = iommu_group_get_iommudata(grp); table_group->ops->release_ownership(table_group); } static const struct iommu_domain_ops spapr_tce_blocking_domain_ops = { .attach_dev = spapr_tce_blocking_iommu_attach_dev, }; static bool spapr_tce_iommu_capable(struct device *dev, enum iommu_cap cap) { switch (cap) { case IOMMU_CAP_CACHE_COHERENCY: return true; default: break; } return false; } static struct iommu_domain *spapr_tce_iommu_domain_alloc(unsigned int type) { struct iommu_domain *dom; if (type != IOMMU_DOMAIN_BLOCKED) return NULL; dom = kzalloc(sizeof(*dom), GFP_KERNEL); if (!dom) return NULL; dom->ops = &spapr_tce_blocking_domain_ops; return dom; } static struct iommu_device *spapr_tce_iommu_probe_device(struct device *dev) { struct pci_dev *pdev; struct pci_controller *hose; if (!dev_is_pci(dev)) return ERR_PTR(-ENODEV); pdev = to_pci_dev(dev); hose = pdev->bus->sysdata; return &hose->iommu; } static void spapr_tce_iommu_release_device(struct device *dev) { } static struct iommu_group *spapr_tce_iommu_device_group(struct device *dev) { struct pci_controller *hose; struct pci_dev *pdev; pdev = to_pci_dev(dev); hose = pdev->bus->sysdata; if (!hose->controller_ops.device_group) return ERR_PTR(-ENOENT); return hose->controller_ops.device_group(hose, pdev); } static const struct iommu_ops spapr_tce_iommu_ops = { .capable = spapr_tce_iommu_capable, .domain_alloc = spapr_tce_iommu_domain_alloc, .probe_device = spapr_tce_iommu_probe_device, .release_device = spapr_tce_iommu_release_device, .device_group = spapr_tce_iommu_device_group, .set_platform_dma_ops = spapr_tce_blocking_iommu_set_platform_dma, }; static struct attribute *spapr_tce_iommu_attrs[] = { NULL, }; static struct attribute_group spapr_tce_iommu_group = { .name = "spapr-tce-iommu", .attrs = spapr_tce_iommu_attrs, }; static const struct attribute_group *spapr_tce_iommu_groups[] = { &spapr_tce_iommu_group, NULL, }; void ppc_iommu_register_device(struct pci_controller *phb) { iommu_device_sysfs_add(&phb->iommu, phb->parent, spapr_tce_iommu_groups, "iommu-phb%04x", phb->global_number); iommu_device_register(&phb->iommu, &spapr_tce_iommu_ops, phb->parent); } void ppc_iommu_unregister_device(struct pci_controller *phb) { iommu_device_unregister(&phb->iommu); iommu_device_sysfs_remove(&phb->iommu); } /* * This registers IOMMU devices of PHBs. This needs to happen * after core_initcall(iommu_init) + postcore_initcall(pci_driver_init) and * before subsys_initcall(iommu_subsys_init). */ static int __init spapr_tce_setup_phb_iommus_initcall(void) { struct pci_controller *hose; list_for_each_entry(hose, &hose_list, list_node) { ppc_iommu_register_device(hose); } return 0; } postcore_initcall_sync(spapr_tce_setup_phb_iommus_initcall); #endif #endif /* CONFIG_IOMMU_API */