diff options
Diffstat (limited to 'arch/powerpc/kernel/iommu.c')
| -rw-r--r-- | arch/powerpc/kernel/iommu.c | 1417 |
1 files changed, 1417 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c new file mode 100644 index 0000000000..14251bc521 --- /dev/null +++ b/arch/powerpc/kernel/iommu.c @@ -0,0 +1,1417 @@ +// 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 <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 <linux/debugfs.h> +#include <asm/io.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> +#include <asm/mmu_context.h> +#include <asm/ppc-pci.h> + +#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(-EPERM); + + 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, +}; + +/* + * 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) { + iommu_device_sysfs_add(&hose->iommu, hose->parent, + spapr_tce_iommu_groups, "iommu-phb%04x", + hose->global_number); + iommu_device_register(&hose->iommu, &spapr_tce_iommu_ops, + hose->parent); + } + return 0; +} +postcore_initcall_sync(spapr_tce_setup_phb_iommus_initcall); +#endif + +#endif /* CONFIG_IOMMU_API */ |