diff options
author | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-08-05 17:04:01 -0300 |
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committer | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-08-05 17:04:01 -0300 |
commit | 57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch) | |
tree | 5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/powerpc/kernel/iommu.c |
Initial import
Diffstat (limited to 'arch/powerpc/kernel/iommu.c')
-rw-r--r-- | arch/powerpc/kernel/iommu.c | 1204 |
1 files changed, 1204 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c new file mode 100644 index 000000000..b054f33ab --- /dev/null +++ b/arch/powerpc/kernel/iommu.c @@ -0,0 +1,1204 @@ +/* + * 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 <linux/init.h> +#include <linux/types.h> +#include <linux/slab.h> +#include <linux/mm.h> +#include <linux/spinlock.h> +#include <linux/string.h> +#include <linux/dma-mapping.h> +#include <linux/bitmap.h> +#include <linux/iommu-helper.h> +#include <linux/crash_dump.h> +#include <linux/hash.h> +#include <linux/fault-inject.h> +#include <linux/pci.h> +#include <linux/iommu.h> +#include <linux/sched.h> +#include <asm/io.h> +#include <asm/prom.h> +#include <asm/iommu.h> +#include <asm/pci-bridge.h> +#include <asm/machdep.h> +#include <asm/kdump.h> +#include <asm/fadump.h> +#include <asm/vio.h> +#include <asm/tce.h> + +#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 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(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 = __this_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; + } + } + + if (dev) + boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1, + 1 << tbl->it_page_shift); + else + boundary_size = ALIGN(1UL << 32, 1 << tbl->it_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 >> 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 { + /* 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 << tbl->it_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(tbl), 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 >> 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; + + 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 ppc_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(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_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 << tbl->it_page_shift; + dma_addr |= (s->offset & ~IOMMU_PAGE_MASK(tbl)); + + 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(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 (ppc_md.tce_flush) + ppc_md.tce_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_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(tbl); + npages = iommu_num_pages(s->dma_address, s->dma_length, + IOMMU_PAGE_SIZE(tbl)); + __iommu_free(tbl, vaddr, npages); + s->dma_address = DMA_ERROR_CODE; + s->dma_length = 0; + } + if (s == outs) + break; + } + return 0; +} + + +void ppc_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(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 (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_KERNEL, 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 << 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; + } + + 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; + } + + /* + * In case we have reserved the first bit, we should not emit + * the warning below. + */ + if (tbl->it_offset == 0) + clear_bit(0, tbl->it_map); + +#ifdef CONFIG_IOMMU_API + if (tbl->it_group) { + iommu_group_put(tbl->it_group); + BUG_ON(tbl->it_group); + } +#endif + + /* 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(tbl)); + + if (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_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(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, + struct dma_attrs *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; + + 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 >> 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, 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 >> tbl->it_page_shift; + iommu_free(tbl, dma_handle, nio_pages); + size = PAGE_ALIGN(size); + free_pages((unsigned long)vaddr, get_order(size)); + } +} + +#ifdef CONFIG_IOMMU_API +/* + * SPAPR TCE API + */ +static void group_release(void *iommu_data) +{ + struct iommu_table *tbl = iommu_data; + tbl->it_group = NULL; +} + +void iommu_register_group(struct iommu_table *tbl, + 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; + } + tbl->it_group = grp; + iommu_group_set_iommudata(grp, tbl, 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 (ppc_md.tce_flush) + ppc_md.tce_flush(tbl); + + /* Make sure updates are seen by hardware */ + mb(); +} +EXPORT_SYMBOL_GPL(iommu_flush_tce); + +int iommu_tce_clear_param_check(struct iommu_table *tbl, + unsigned long ioba, unsigned long tce_value, + unsigned long npages) +{ + /* ppc_md.tce_free() does not support any value but 0 */ + if (tce_value) + return -EINVAL; + + if (ioba & ~IOMMU_PAGE_MASK(tbl)) + return -EINVAL; + + ioba >>= tbl->it_page_shift; + if (ioba < tbl->it_offset) + return -EINVAL; + + if ((ioba + npages) > (tbl->it_offset + tbl->it_size)) + return -EINVAL; + + return 0; +} +EXPORT_SYMBOL_GPL(iommu_tce_clear_param_check); + +int iommu_tce_put_param_check(struct iommu_table *tbl, + unsigned long ioba, unsigned long tce) +{ + if (!(tce & (TCE_PCI_WRITE | TCE_PCI_READ))) + return -EINVAL; + + if (tce & ~(IOMMU_PAGE_MASK(tbl) | TCE_PCI_WRITE | TCE_PCI_READ)) + return -EINVAL; + + if (ioba & ~IOMMU_PAGE_MASK(tbl)) + return -EINVAL; + + ioba >>= tbl->it_page_shift; + if (ioba < tbl->it_offset) + return -EINVAL; + + if ((ioba + 1) > (tbl->it_offset + tbl->it_size)) + return -EINVAL; + + return 0; +} +EXPORT_SYMBOL_GPL(iommu_tce_put_param_check); + +unsigned long iommu_clear_tce(struct iommu_table *tbl, unsigned long entry) +{ + unsigned long oldtce; + struct iommu_pool *pool = get_pool(tbl, entry); + + spin_lock(&(pool->lock)); + + oldtce = ppc_md.tce_get(tbl, entry); + if (oldtce & (TCE_PCI_WRITE | TCE_PCI_READ)) + ppc_md.tce_free(tbl, entry, 1); + else + oldtce = 0; + + spin_unlock(&(pool->lock)); + + return oldtce; +} +EXPORT_SYMBOL_GPL(iommu_clear_tce); + +int iommu_clear_tces_and_put_pages(struct iommu_table *tbl, + unsigned long entry, unsigned long pages) +{ + unsigned long oldtce; + struct page *page; + + for ( ; pages; --pages, ++entry) { + oldtce = iommu_clear_tce(tbl, entry); + if (!oldtce) + continue; + + page = pfn_to_page(oldtce >> PAGE_SHIFT); + WARN_ON(!page); + if (page) { + if (oldtce & TCE_PCI_WRITE) + SetPageDirty(page); + put_page(page); + } + } + + return 0; +} +EXPORT_SYMBOL_GPL(iommu_clear_tces_and_put_pages); + +/* + * hwaddr is a kernel virtual address here (0xc... bazillion), + * tce_build converts it to a physical address. + */ +int iommu_tce_build(struct iommu_table *tbl, unsigned long entry, + unsigned long hwaddr, enum dma_data_direction direction) +{ + int ret = -EBUSY; + unsigned long oldtce; + struct iommu_pool *pool = get_pool(tbl, entry); + + spin_lock(&(pool->lock)); + + oldtce = ppc_md.tce_get(tbl, entry); + /* Add new entry if it is not busy */ + if (!(oldtce & (TCE_PCI_WRITE | TCE_PCI_READ))) + ret = ppc_md.tce_build(tbl, entry, 1, hwaddr, direction, NULL); + + spin_unlock(&(pool->lock)); + + /* if (unlikely(ret)) + pr_err("iommu_tce: %s failed on hwaddr=%lx ioba=%lx kva=%lx ret=%d\n", + __func__, hwaddr, entry << tbl->it_page_shift, + hwaddr, ret); */ + + return ret; +} +EXPORT_SYMBOL_GPL(iommu_tce_build); + +int iommu_put_tce_user_mode(struct iommu_table *tbl, unsigned long entry, + unsigned long tce) +{ + int ret; + struct page *page = NULL; + unsigned long hwaddr, offset = tce & IOMMU_PAGE_MASK(tbl) & ~PAGE_MASK; + enum dma_data_direction direction = iommu_tce_direction(tce); + + ret = get_user_pages_fast(tce & PAGE_MASK, 1, + direction != DMA_TO_DEVICE, &page); + if (unlikely(ret != 1)) { + /* pr_err("iommu_tce: get_user_pages_fast failed tce=%lx ioba=%lx ret=%d\n", + tce, entry << tbl->it_page_shift, ret); */ + return -EFAULT; + } + hwaddr = (unsigned long) page_address(page) + offset; + + ret = iommu_tce_build(tbl, entry, hwaddr, direction); + if (ret) + put_page(page); + + if (ret < 0) + pr_err("iommu_tce: %s failed ioba=%lx, tce=%lx, ret=%d\n", + __func__, entry << tbl->it_page_shift, tce, ret); + + return ret; +} +EXPORT_SYMBOL_GPL(iommu_put_tce_user_mode); + +int iommu_take_ownership(struct iommu_table *tbl) +{ + unsigned long sz = (tbl->it_size + 7) >> 3; + + if (tbl->it_offset == 0) + clear_bit(0, tbl->it_map); + + if (!bitmap_empty(tbl->it_map, tbl->it_size)) { + pr_err("iommu_tce: it_map is not empty"); + return -EBUSY; + } + + memset(tbl->it_map, 0xff, sz); + iommu_clear_tces_and_put_pages(tbl, tbl->it_offset, tbl->it_size); + + /* + * Disable iommu bypass, otherwise the user can DMA to all of + * our physical memory via the bypass window instead of just + * the pages that has been explicitly mapped into the iommu + */ + if (tbl->set_bypass) + tbl->set_bypass(tbl, false); + + return 0; +} +EXPORT_SYMBOL_GPL(iommu_take_ownership); + +void iommu_release_ownership(struct iommu_table *tbl) +{ + unsigned long sz = (tbl->it_size + 7) >> 3; + + iommu_clear_tces_and_put_pages(tbl, tbl->it_offset, tbl->it_size); + memset(tbl->it_map, 0, sz); + + /* Restore bit#0 set by iommu_init_table() */ + if (tbl->it_offset == 0) + set_bit(0, tbl->it_map); + + /* The kernel owns the device now, we can restore the iommu bypass */ + if (tbl->set_bypass) + tbl->set_bypass(tbl, true); +} +EXPORT_SYMBOL_GPL(iommu_release_ownership); + +int iommu_add_device(struct device *dev) +{ + struct iommu_table *tbl; + + /* + * 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 (dev->iommu_group) { + pr_debug("%s: Skipping device %s with iommu group %d\n", + __func__, dev_name(dev), + iommu_group_id(dev->iommu_group)); + return -EBUSY; + } + + tbl = get_iommu_table_base(dev); + if (!tbl || !tbl->it_group) { + pr_debug("%s: Skipping device %s with no tbl\n", + __func__, dev_name(dev)); + return 0; + } + + pr_debug("%s: Adding %s to iommu group %d\n", + __func__, dev_name(dev), + iommu_group_id(tbl->it_group)); + + if (PAGE_SIZE < IOMMU_PAGE_SIZE(tbl)) { + pr_err("%s: Invalid IOMMU page size %lx (%lx) on %s\n", + __func__, IOMMU_PAGE_SIZE(tbl), + PAGE_SIZE, dev_name(dev)); + return -EINVAL; + } + + return iommu_group_add_device(tbl->it_group, dev); +} +EXPORT_SYMBOL_GPL(iommu_add_device); + +void iommu_del_device(struct device *dev) +{ + /* + * Some devices might not have IOMMU table and group + * and we needn't detach them from the associated + * IOMMU groups + */ + if (!dev->iommu_group) { + pr_debug("iommu_tce: skipping device %s with no tbl\n", + dev_name(dev)); + return; + } + + iommu_group_remove_device(dev); +} +EXPORT_SYMBOL_GPL(iommu_del_device); + +static int tce_iommu_bus_notifier(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct device *dev = data; + + switch (action) { + case BUS_NOTIFY_ADD_DEVICE: + return iommu_add_device(dev); + case BUS_NOTIFY_DEL_DEVICE: + if (dev->iommu_group) + iommu_del_device(dev); + return 0; + default: + return 0; + } +} + +static struct notifier_block tce_iommu_bus_nb = { + .notifier_call = tce_iommu_bus_notifier, +}; + +int __init tce_iommu_bus_notifier_init(void) +{ + bus_register_notifier(&pci_bus_type, &tce_iommu_bus_nb); + return 0; +} +#endif /* CONFIG_IOMMU_API */ |