/* * 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. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define DBG(...) 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 IS_ERR(dir) ? PTR_ERR(dir) : 0; } 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(fail_iommu, S_IRUGO|S_IWUSR, fail_iommu_show, fail_iommu_store); 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; } static struct notifier_block fail_iommu_bus_notifier = { .notifier_call = fail_iommu_bus_notify }; static int __init fail_iommu_setup(void) { #ifdef CONFIG_PCI bus_register_notifier(&pci_bus_type, &fail_iommu_bus_notifier); #endif #ifdef CONFIG_IBMVIO bus_register_notifier(&vio_bus_type, &fail_iommu_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 boundary_size; unsigned long flags; unsigned int pool_nr; struct iommu_pool *pool; align_mask = 0xffffffffffffffffl >> (64 - align_order); /* 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_ERROR_CODE; } if (should_fail_iommu(dev)) return DMA_ERROR_CODE; /* * We don't need to disable preemption here because any CPU can * safely use any IOMMU pool. */ pool_nr = __raw_get_cpu_var(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; } } if (dev) boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1, 1 << IOMMU_PAGE_SHIFT); else boundary_size = ALIGN(1UL << 32, 1 << IOMMU_PAGE_SHIFT); /* 4GB boundary for iseries_hv_alloc and iseries_hv_map */ n = iommu_area_alloc(tbl->it_map, limit, start, npages, tbl->it_offset, boundary_size >> IOMMU_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 { /* Give up */ spin_unlock_irqrestore(&(pool->lock), flags); return DMA_ERROR_CODE; } } 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, struct dma_attrs *attrs) { unsigned long entry; dma_addr_t ret = DMA_ERROR_CODE; int build_fail; entry = iommu_range_alloc(dev, tbl, npages, NULL, mask, align_order); if (unlikely(entry == DMA_ERROR_CODE)) return DMA_ERROR_CODE; entry += tbl->it_offset; /* Offset into real TCE table */ ret = entry << IOMMU_PAGE_SHIFT; /* Set the return dma address */ /* Put the TCEs in the HW table */ build_fail = ppc_md.tce_build(tbl, entry, npages, (unsigned long)page & IOMMU_PAGE_MASK, direction, attrs); /* ppc_md.tce_build() only returns non-zero for transient errors. * Clean up the table bitmap in this case and return * DMA_ERROR_CODE. For all other errors the functionality is * not altered. */ if (unlikely(build_fail)) { __iommu_free(tbl, ret, npages); return DMA_ERROR_CODE; } /* Flush/invalidate TLB caches if necessary */ if (ppc_md.tce_flush) ppc_md.tce_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 >> IOMMU_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 >> IOMMU_PAGE_SHIFT; free_entry = entry - tbl->it_offset; pool = get_pool(tbl, free_entry); if (!iommu_free_check(tbl, dma_addr, npages)) return; ppc_md.tce_free(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 (ppc_md.tce_flush) ppc_md.tce_flush(tbl); } int iommu_map_sg(struct device *dev, struct iommu_table *tbl, struct scatterlist *sglist, int nelems, unsigned long mask, enum dma_data_direction direction, struct dma_attrs *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 0; 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); align = 0; if (IOMMU_PAGE_SHIFT < PAGE_SHIFT && slen >= PAGE_SIZE && (vaddr & ~PAGE_MASK) == 0) align = PAGE_SHIFT - IOMMU_PAGE_SHIFT; entry = iommu_range_alloc(dev, tbl, npages, &handle, mask >> IOMMU_PAGE_SHIFT, align); DBG(" - vaddr: %lx, size: %lx\n", vaddr, slen); /* Handle failure */ if (unlikely(entry == DMA_ERROR_CODE)) { if (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 << IOMMU_PAGE_SHIFT; dma_addr |= (s->offset & ~IOMMU_PAGE_MASK); DBG(" - %lu pages, entry: %lx, dma_addr: %lx\n", npages, entry, dma_addr); /* Insert into HW table */ build_fail = ppc_md.tce_build(tbl, entry, npages, vaddr & IOMMU_PAGE_MASK, 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 (ppc_md.tce_flush) ppc_md.tce_flush(tbl); DBG("mapped %d elements:\n", outcount); /* For the sake of 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_address = DMA_ERROR_CODE; 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; npages = iommu_num_pages(s->dma_address, s->dma_length, IOMMU_PAGE_SIZE); __iommu_free(tbl, vaddr, npages); s->dma_address = DMA_ERROR_CODE; s->dma_length = 0; } if (s == outs) break; } return 0; } void iommu_unmap_sg(struct iommu_table *tbl, struct scatterlist *sglist, int nelems, enum dma_data_direction direction, struct dma_attrs *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); __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 (ppc_md.tce_flush) ppc_md.tce_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 */ ppc_md.tce_free(tbl, tbl->it_offset, tbl->it_size); return; } #ifdef CONFIG_CRASH_DUMP if (ppc_md.tce_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 = ppc_md.tce_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 } /* * 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 sz; static int welcomed = 0; struct page *page; unsigned int i; struct iommu_pool *p; /* number of bytes needed for the bitmap */ sz = BITS_TO_LONGS(tbl->it_size) * sizeof(unsigned long); page = alloc_pages_node(nid, GFP_ATOMIC, get_order(sz)); if (!page) panic("iommu_init_table: Can't allocate %ld bytes\n", sz); tbl->it_map = page_address(page); memset(tbl->it_map, 0, sz); /* * 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); /* We only split the IOMMU table if we have 1GB or more of space */ if ((tbl->it_size << IOMMU_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; } return tbl; } void iommu_free_table(struct iommu_table *tbl, const char *node_name) { unsigned long bitmap_sz; unsigned int order; if (!tbl || !tbl->it_map) { printk(KERN_ERR "%s: expected TCE map for %s\n", __func__, node_name); return; } /* verify that table contains no entries */ if (!bitmap_empty(tbl->it_map, tbl->it_size)) pr_warn("%s: Unexpected TCEs for %s\n", __func__, node_name); /* calculate bitmap size in bytes */ bitmap_sz = BITS_TO_LONGS(tbl->it_size) * sizeof(unsigned long); /* free bitmap */ order = get_order(bitmap_sz); free_pages((unsigned long) tbl->it_map, order); /* free table */ kfree(tbl); } /* 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, struct dma_attrs *attrs) { dma_addr_t dma_handle = DMA_ERROR_CODE; void *vaddr; unsigned long uaddr; unsigned int npages, align; BUG_ON(direction == DMA_NONE); vaddr = page_address(page) + offset; uaddr = (unsigned long)vaddr; npages = iommu_num_pages(uaddr, size, IOMMU_PAGE_SIZE); if (tbl) { align = 0; if (IOMMU_PAGE_SHIFT < PAGE_SHIFT && size >= PAGE_SIZE && ((unsigned long)vaddr & ~PAGE_MASK) == 0) align = PAGE_SHIFT - IOMMU_PAGE_SHIFT; dma_handle = iommu_alloc(dev, tbl, vaddr, npages, direction, mask >> IOMMU_PAGE_SHIFT, align, attrs); if (dma_handle == DMA_ERROR_CODE) { if (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); } return dma_handle; } void iommu_unmap_page(struct iommu_table *tbl, dma_addr_t dma_handle, size_t size, enum dma_data_direction direction, struct dma_attrs *attrs) { unsigned int npages; BUG_ON(direction == DMA_NONE); if (tbl) { npages = iommu_num_pages(dma_handle, size, IOMMU_PAGE_SIZE); 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; 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 = size >> IOMMU_PAGE_SHIFT; io_order = get_iommu_order(size); mapping = iommu_alloc(dev, tbl, ret, nio_pages, DMA_BIDIRECTIONAL, mask >> IOMMU_PAGE_SHIFT, io_order, NULL); if (mapping == DMA_ERROR_CODE) { free_pages((unsigned long)ret, order); return NULL; } *dma_handle = mapping; 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 = size >> IOMMU_PAGE_SHIFT; iommu_free(tbl, dma_handle, nio_pages); size = PAGE_ALIGN(size); free_pages((unsigned long)vaddr, get_order(size)); } }