sparc: Make sparc64 use scalable lib/iommu-common.c functions
authorSowmini Varadhan <sowmini.varadhan@oracle.com>
Thu, 9 Apr 2015 19:33:31 +0000 (15:33 -0400)
committerDavid S. Miller <davem@davemloft.net>
Sat, 18 Apr 2015 19:32:59 +0000 (12:32 -0700)
In iperf experiments running linux as the Tx side (TCP client) with
10 threads results in a severe performance drop when TSO is disabled,
indicating a weakness in the software that can be avoided by using
the scalable IOMMU arena DMA allocation.

Baseline numbers before this patch:
   with default settings (TSO enabled) :    9-9.5 Gbps
   Disable TSO using ethtool- drops badly:  2-3 Gbps.

After this patch, iperf client with 10 threads, can give a
throughput of at least 8.5 Gbps, even when TSO is disabled.

Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
arch/sparc/include/asm/iommu_64.h
arch/sparc/kernel/iommu.c
arch/sparc/kernel/iommu_common.h
arch/sparc/kernel/pci_sun4v.c

index 2b9321a..cd0d69f 100644 (file)
@@ -16,6 +16,7 @@
 #define IOPTE_WRITE   0x0000000000000002UL
 
 #define IOMMU_NUM_CTXS 4096
+#include <linux/iommu-common.h>
 
 struct iommu_arena {
        unsigned long   *map;
@@ -24,11 +25,10 @@ struct iommu_arena {
 };
 
 struct iommu {
+       struct iommu_map_table  tbl;
        spinlock_t              lock;
-       struct iommu_arena      arena;
-       void                    (*flush_all)(struct iommu *);
+       u32                     dma_addr_mask;
        iopte_t                 *page_table;
-       u32                     page_table_map_base;
        unsigned long           iommu_control;
        unsigned long           iommu_tsbbase;
        unsigned long           iommu_flush;
@@ -40,7 +40,6 @@ struct iommu {
        unsigned long           dummy_page_pa;
        unsigned long           ctx_lowest_free;
        DECLARE_BITMAP(ctx_bitmap, IOMMU_NUM_CTXS);
-       u32                     dma_addr_mask;
 };
 
 struct strbuf {
index bfa4d0c..5320689 100644 (file)
@@ -13,6 +13,7 @@
 #include <linux/errno.h>
 #include <linux/iommu-helper.h>
 #include <linux/bitmap.h>
+#include <linux/iommu-common.h>
 
 #ifdef CONFIG_PCI
 #include <linux/pci.h>
@@ -45,8 +46,9 @@
                               "i" (ASI_PHYS_BYPASS_EC_E))
 
 /* Must be invoked under the IOMMU lock. */
-static void iommu_flushall(struct iommu *iommu)
+static void iommu_flushall(struct iommu_map_table *iommu_map_table)
 {
+       struct iommu *iommu = container_of(iommu_map_table, struct iommu, tbl);
        if (iommu->iommu_flushinv) {
                iommu_write(iommu->iommu_flushinv, ~(u64)0);
        } else {
@@ -87,94 +89,6 @@ static inline void iopte_make_dummy(struct iommu *iommu, iopte_t *iopte)
        iopte_val(*iopte) = val;
 }
 
-/* Based almost entirely upon the ppc64 iommu allocator.  If you use the 'handle'
- * facility it must all be done in one pass while under the iommu lock.
- *
- * On sun4u platforms, we only flush the IOMMU once every time we've passed
- * over the entire page table doing allocations.  Therefore we only ever advance
- * the hint and cannot backtrack it.
- */
-unsigned long iommu_range_alloc(struct device *dev,
-                               struct iommu *iommu,
-                               unsigned long npages,
-                               unsigned long *handle)
-{
-       unsigned long n, end, start, limit, boundary_size;
-       struct iommu_arena *arena = &iommu->arena;
-       int pass = 0;
-
-       /* 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 (handle && *handle)
-               start = *handle;
-       else
-               start = arena->hint;
-
-       limit = arena->limit;
-
-       /* 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 beginning and flush.
-        */
-       if (start >= limit) {
-               start = 0;
-               if (iommu->flush_all)
-                       iommu->flush_all(iommu);
-       }
-
- again:
-
-       if (dev)
-               boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1,
-                                     1 << IO_PAGE_SHIFT);
-       else
-               boundary_size = ALIGN(1UL << 32, 1 << IO_PAGE_SHIFT);
-
-       n = iommu_area_alloc(arena->map, limit, start, npages,
-                            iommu->page_table_map_base >> IO_PAGE_SHIFT,
-                            boundary_size >> IO_PAGE_SHIFT, 0);
-       if (n == -1) {
-               if (likely(pass < 1)) {
-                       /* First failure, rescan from the beginning.  */
-                       start = 0;
-                       if (iommu->flush_all)
-                               iommu->flush_all(iommu);
-                       pass++;
-                       goto again;
-               } else {
-                       /* Second failure, give up */
-                       return DMA_ERROR_CODE;
-               }
-       }
-
-       end = n + npages;
-
-       arena->hint = end;
-
-       /* Update handle for SG allocations */
-       if (handle)
-               *handle = end;
-
-       return n;
-}
-
-void iommu_range_free(struct iommu *iommu, dma_addr_t dma_addr, unsigned long npages)
-{
-       struct iommu_arena *arena = &iommu->arena;
-       unsigned long entry;
-
-       entry = (dma_addr - iommu->page_table_map_base) >> IO_PAGE_SHIFT;
-
-       bitmap_clear(arena->map, entry, npages);
-}
-
 int iommu_table_init(struct iommu *iommu, int tsbsize,
                     u32 dma_offset, u32 dma_addr_mask,
                     int numa_node)
@@ -187,22 +101,20 @@ int iommu_table_init(struct iommu *iommu, int tsbsize,
        /* Setup initial software IOMMU state. */
        spin_lock_init(&iommu->lock);
        iommu->ctx_lowest_free = 1;
-       iommu->page_table_map_base = dma_offset;
+       iommu->tbl.table_map_base = dma_offset;
        iommu->dma_addr_mask = dma_addr_mask;
 
        /* Allocate and initialize the free area map.  */
        sz = num_tsb_entries / 8;
        sz = (sz + 7UL) & ~7UL;
-       iommu->arena.map = kmalloc_node(sz, GFP_KERNEL, numa_node);
-       if (!iommu->arena.map) {
-               printk(KERN_ERR "IOMMU: Error, kmalloc(arena.map) failed.\n");
+       iommu->tbl.map = kmalloc_node(sz, GFP_KERNEL, numa_node);
+       if (!iommu->tbl.map)
                return -ENOMEM;
-       }
-       memset(iommu->arena.map, 0, sz);
-       iommu->arena.limit = num_tsb_entries;
+       memset(iommu->tbl.map, 0, sz);
 
-       if (tlb_type != hypervisor)
-               iommu->flush_all = iommu_flushall;
+       iommu_tbl_pool_init(&iommu->tbl, num_tsb_entries, IO_PAGE_SHIFT,
+                           (tlb_type != hypervisor ? iommu_flushall : NULL),
+                           false, 1, false);
 
        /* Allocate and initialize the dummy page which we
         * set inactive IO PTEs to point to.
@@ -235,18 +147,20 @@ out_free_dummy_page:
        iommu->dummy_page = 0UL;
 
 out_free_map:
-       kfree(iommu->arena.map);
-       iommu->arena.map = NULL;
+       kfree(iommu->tbl.map);
+       iommu->tbl.map = NULL;
 
        return -ENOMEM;
 }
 
-static inline iopte_t *alloc_npages(struct device *dev, struct iommu *iommu,
+static inline iopte_t *alloc_npages(struct device *dev,
+                                   struct iommu *iommu,
                                    unsigned long npages)
 {
        unsigned long entry;
 
-       entry = iommu_range_alloc(dev, iommu, npages, NULL);
+       entry = iommu_tbl_range_alloc(dev, &iommu->tbl, npages, NULL,
+                                     (unsigned long)(-1), 0);
        if (unlikely(entry == DMA_ERROR_CODE))
                return NULL;
 
@@ -284,7 +198,7 @@ static void *dma_4u_alloc_coherent(struct device *dev, size_t size,
                                   dma_addr_t *dma_addrp, gfp_t gfp,
                                   struct dma_attrs *attrs)
 {
-       unsigned long flags, order, first_page;
+       unsigned long order, first_page;
        struct iommu *iommu;
        struct page *page;
        int npages, nid;
@@ -306,16 +220,14 @@ static void *dma_4u_alloc_coherent(struct device *dev, size_t size,
 
        iommu = dev->archdata.iommu;
 
-       spin_lock_irqsave(&iommu->lock, flags);
        iopte = alloc_npages(dev, iommu, size >> IO_PAGE_SHIFT);
-       spin_unlock_irqrestore(&iommu->lock, flags);
 
        if (unlikely(iopte == NULL)) {
                free_pages(first_page, order);
                return NULL;
        }
 
-       *dma_addrp = (iommu->page_table_map_base +
+       *dma_addrp = (iommu->tbl.table_map_base +
                      ((iopte - iommu->page_table) << IO_PAGE_SHIFT));
        ret = (void *) first_page;
        npages = size >> IO_PAGE_SHIFT;
@@ -336,16 +248,12 @@ static void dma_4u_free_coherent(struct device *dev, size_t size,
                                 struct dma_attrs *attrs)
 {
        struct iommu *iommu;
-       unsigned long flags, order, npages;
+       unsigned long order, npages;
 
        npages = IO_PAGE_ALIGN(size) >> IO_PAGE_SHIFT;
        iommu = dev->archdata.iommu;
 
-       spin_lock_irqsave(&iommu->lock, flags);
-
-       iommu_range_free(iommu, dvma, npages);
-
-       spin_unlock_irqrestore(&iommu->lock, flags);
+       iommu_tbl_range_free(&iommu->tbl, dvma, npages, DMA_ERROR_CODE);
 
        order = get_order(size);
        if (order < 10)
@@ -375,8 +283,8 @@ static dma_addr_t dma_4u_map_page(struct device *dev, struct page *page,
        npages = IO_PAGE_ALIGN(oaddr + sz) - (oaddr & IO_PAGE_MASK);
        npages >>= IO_PAGE_SHIFT;
 
-       spin_lock_irqsave(&iommu->lock, flags);
        base = alloc_npages(dev, iommu, npages);
+       spin_lock_irqsave(&iommu->lock, flags);
        ctx = 0;
        if (iommu->iommu_ctxflush)
                ctx = iommu_alloc_ctx(iommu);
@@ -385,7 +293,7 @@ static dma_addr_t dma_4u_map_page(struct device *dev, struct page *page,
        if (unlikely(!base))
                goto bad;
 
-       bus_addr = (iommu->page_table_map_base +
+       bus_addr = (iommu->tbl.table_map_base +
                    ((base - iommu->page_table) << IO_PAGE_SHIFT));
        ret = bus_addr | (oaddr & ~IO_PAGE_MASK);
        base_paddr = __pa(oaddr & IO_PAGE_MASK);
@@ -496,7 +404,7 @@ static void dma_4u_unmap_page(struct device *dev, dma_addr_t bus_addr,
        npages = IO_PAGE_ALIGN(bus_addr + sz) - (bus_addr & IO_PAGE_MASK);
        npages >>= IO_PAGE_SHIFT;
        base = iommu->page_table +
-               ((bus_addr - iommu->page_table_map_base) >> IO_PAGE_SHIFT);
+               ((bus_addr - iommu->tbl.table_map_base) >> IO_PAGE_SHIFT);
        bus_addr &= IO_PAGE_MASK;
 
        spin_lock_irqsave(&iommu->lock, flags);
@@ -515,11 +423,10 @@ static void dma_4u_unmap_page(struct device *dev, dma_addr_t bus_addr,
        for (i = 0; i < npages; i++)
                iopte_make_dummy(iommu, base + i);
 
-       iommu_range_free(iommu, bus_addr, npages);
-
        iommu_free_ctx(iommu, ctx);
-
        spin_unlock_irqrestore(&iommu->lock, flags);
+
+       iommu_tbl_range_free(&iommu->tbl, bus_addr, npages, DMA_ERROR_CODE);
 }
 
 static int dma_4u_map_sg(struct device *dev, struct scatterlist *sglist,
@@ -567,7 +474,7 @@ static int dma_4u_map_sg(struct device *dev, struct scatterlist *sglist,
        max_seg_size = dma_get_max_seg_size(dev);
        seg_boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1,
                                  IO_PAGE_SIZE) >> IO_PAGE_SHIFT;
-       base_shift = iommu->page_table_map_base >> IO_PAGE_SHIFT;
+       base_shift = iommu->tbl.table_map_base >> IO_PAGE_SHIFT;
        for_each_sg(sglist, s, nelems, i) {
                unsigned long paddr, npages, entry, out_entry = 0, slen;
                iopte_t *base;
@@ -581,7 +488,8 @@ static int dma_4u_map_sg(struct device *dev, struct scatterlist *sglist,
                /* Allocate iommu entries for that segment */
                paddr = (unsigned long) SG_ENT_PHYS_ADDRESS(s);
                npages = iommu_num_pages(paddr, slen, IO_PAGE_SIZE);
-               entry = iommu_range_alloc(dev, iommu, npages, &handle);
+               entry = iommu_tbl_range_alloc(dev, &iommu->tbl, npages,
+                                             &handle, (unsigned long)(-1), 0);
 
                /* Handle failure */
                if (unlikely(entry == DMA_ERROR_CODE)) {
@@ -594,7 +502,7 @@ static int dma_4u_map_sg(struct device *dev, struct scatterlist *sglist,
                base = iommu->page_table + entry;
 
                /* Convert entry to a dma_addr_t */
-               dma_addr = iommu->page_table_map_base +
+               dma_addr = iommu->tbl.table_map_base +
                        (entry << IO_PAGE_SHIFT);
                dma_addr |= (s->offset & ~IO_PAGE_MASK);
 
@@ -654,15 +562,17 @@ iommu_map_failed:
                        vaddr = s->dma_address & IO_PAGE_MASK;
                        npages = iommu_num_pages(s->dma_address, s->dma_length,
                                                 IO_PAGE_SIZE);
-                       iommu_range_free(iommu, vaddr, npages);
 
-                       entry = (vaddr - iommu->page_table_map_base)
+                       entry = (vaddr - iommu->tbl.table_map_base)
                                >> IO_PAGE_SHIFT;
                        base = iommu->page_table + entry;
 
                        for (j = 0; j < npages; j++)
                                iopte_make_dummy(iommu, base + j);
 
+                       iommu_tbl_range_free(&iommu->tbl, vaddr, npages,
+                                            DMA_ERROR_CODE);
+
                        s->dma_address = DMA_ERROR_CODE;
                        s->dma_length = 0;
                }
@@ -684,10 +594,11 @@ static unsigned long fetch_sg_ctx(struct iommu *iommu, struct scatterlist *sg)
        if (iommu->iommu_ctxflush) {
                iopte_t *base;
                u32 bus_addr;
+               struct iommu_map_table *tbl = &iommu->tbl;
 
                bus_addr = sg->dma_address & IO_PAGE_MASK;
                base = iommu->page_table +
-                       ((bus_addr - iommu->page_table_map_base) >> IO_PAGE_SHIFT);
+                       ((bus_addr - tbl->table_map_base) >> IO_PAGE_SHIFT);
 
                ctx = (iopte_val(*base) & IOPTE_CONTEXT) >> 47UL;
        }
@@ -723,9 +634,8 @@ static void dma_4u_unmap_sg(struct device *dev, struct scatterlist *sglist,
                if (!len)
                        break;
                npages = iommu_num_pages(dma_handle, len, IO_PAGE_SIZE);
-               iommu_range_free(iommu, dma_handle, npages);
 
-               entry = ((dma_handle - iommu->page_table_map_base)
+               entry = ((dma_handle - iommu->tbl.table_map_base)
                         >> IO_PAGE_SHIFT);
                base = iommu->page_table + entry;
 
@@ -737,6 +647,8 @@ static void dma_4u_unmap_sg(struct device *dev, struct scatterlist *sglist,
                for (i = 0; i < npages; i++)
                        iopte_make_dummy(iommu, base + i);
 
+               iommu_tbl_range_free(&iommu->tbl, dma_handle, npages,
+                                    DMA_ERROR_CODE);
                sg = sg_next(sg);
        }
 
@@ -770,9 +682,10 @@ static void dma_4u_sync_single_for_cpu(struct device *dev,
        if (iommu->iommu_ctxflush &&
            strbuf->strbuf_ctxflush) {
                iopte_t *iopte;
+               struct iommu_map_table *tbl = &iommu->tbl;
 
                iopte = iommu->page_table +
-                       ((bus_addr - iommu->page_table_map_base)>>IO_PAGE_SHIFT);
+                       ((bus_addr - tbl->table_map_base)>>IO_PAGE_SHIFT);
                ctx = (iopte_val(*iopte) & IOPTE_CONTEXT) >> 47UL;
        }
 
@@ -805,9 +718,10 @@ static void dma_4u_sync_sg_for_cpu(struct device *dev,
        if (iommu->iommu_ctxflush &&
            strbuf->strbuf_ctxflush) {
                iopte_t *iopte;
+               struct iommu_map_table *tbl = &iommu->tbl;
 
-               iopte = iommu->page_table +
-                       ((sglist[0].dma_address - iommu->page_table_map_base) >> IO_PAGE_SHIFT);
+               iopte = iommu->page_table + ((sglist[0].dma_address -
+                       tbl->table_map_base) >> IO_PAGE_SHIFT);
                ctx = (iopte_val(*iopte) & IOPTE_CONTEXT) >> 47UL;
        }
 
index 1ec0de4..f4be0d7 100644 (file)
@@ -48,12 +48,4 @@ static inline int is_span_boundary(unsigned long entry,
        return iommu_is_span_boundary(entry, nr, shift, boundary_size);
 }
 
-unsigned long iommu_range_alloc(struct device *dev,
-                               struct iommu *iommu,
-                               unsigned long npages,
-                               unsigned long *handle);
-void iommu_range_free(struct iommu *iommu,
-                     dma_addr_t dma_addr,
-                     unsigned long npages);
-
 #endif /* _IOMMU_COMMON_H */
index 47ddbd4..d2fe57d 100644 (file)
@@ -15,6 +15,7 @@
 #include <linux/export.h>
 #include <linux/log2.h>
 #include <linux/of_device.h>
+#include <linux/iommu-common.h>
 
 #include <asm/iommu.h>
 #include <asm/irq.h>
@@ -155,15 +156,13 @@ static void *dma_4v_alloc_coherent(struct device *dev, size_t size,
 
        iommu = dev->archdata.iommu;
 
-       spin_lock_irqsave(&iommu->lock, flags);
-       entry = iommu_range_alloc(dev, iommu, npages, NULL);
-       spin_unlock_irqrestore(&iommu->lock, flags);
+       entry = iommu_tbl_range_alloc(dev, &iommu->tbl, npages, NULL,
+                                     (unsigned long)(-1), 0);
 
        if (unlikely(entry == DMA_ERROR_CODE))
                goto range_alloc_fail;
 
-       *dma_addrp = (iommu->page_table_map_base +
-                     (entry << IO_PAGE_SHIFT));
+       *dma_addrp = (iommu->tbl.table_map_base + (entry << IO_PAGE_SHIFT));
        ret = (void *) first_page;
        first_page = __pa(first_page);
 
@@ -188,45 +187,46 @@ static void *dma_4v_alloc_coherent(struct device *dev, size_t size,
        return ret;
 
 iommu_map_fail:
-       /* Interrupts are disabled.  */
-       spin_lock(&iommu->lock);
-       iommu_range_free(iommu, *dma_addrp, npages);
-       spin_unlock_irqrestore(&iommu->lock, flags);
+       iommu_tbl_range_free(&iommu->tbl, *dma_addrp, npages, DMA_ERROR_CODE);
 
 range_alloc_fail:
        free_pages(first_page, order);
        return NULL;
 }
 
+static void dma_4v_iommu_demap(void *demap_arg, unsigned long entry,
+                              unsigned long npages)
+{
+       u32 devhandle = *(u32 *)demap_arg;
+       unsigned long num, flags;
+
+       local_irq_save(flags);
+       do {
+               num = pci_sun4v_iommu_demap(devhandle,
+                                           HV_PCI_TSBID(0, entry),
+                                           npages);
+
+               entry += num;
+               npages -= num;
+       } while (npages != 0);
+       local_irq_restore(flags);
+}
+
 static void dma_4v_free_coherent(struct device *dev, size_t size, void *cpu,
                                 dma_addr_t dvma, struct dma_attrs *attrs)
 {
        struct pci_pbm_info *pbm;
        struct iommu *iommu;
-       unsigned long flags, order, npages, entry;
+       unsigned long order, npages, entry;
        u32 devhandle;
 
        npages = IO_PAGE_ALIGN(size) >> IO_PAGE_SHIFT;
        iommu = dev->archdata.iommu;
        pbm = dev->archdata.host_controller;
        devhandle = pbm->devhandle;
-       entry = ((dvma - iommu->page_table_map_base) >> IO_PAGE_SHIFT);
-
-       spin_lock_irqsave(&iommu->lock, flags);
-
-       iommu_range_free(iommu, dvma, npages);
-
-       do {
-               unsigned long num;
-
-               num = pci_sun4v_iommu_demap(devhandle, HV_PCI_TSBID(0, entry),
-                                           npages);
-               entry += num;
-               npages -= num;
-       } while (npages != 0);
-
-       spin_unlock_irqrestore(&iommu->lock, flags);
-
+       entry = ((dvma - iommu->tbl.table_map_base) >> IO_PAGE_SHIFT);
+       dma_4v_iommu_demap(&devhandle, entry, npages);
+       iommu_tbl_range_free(&iommu->tbl, dvma, npages, DMA_ERROR_CODE);
        order = get_order(size);
        if (order < 10)
                free_pages((unsigned long)cpu, order);
@@ -253,15 +253,13 @@ static dma_addr_t dma_4v_map_page(struct device *dev, struct page *page,
        npages = IO_PAGE_ALIGN(oaddr + sz) - (oaddr & IO_PAGE_MASK);
        npages >>= IO_PAGE_SHIFT;
 
-       spin_lock_irqsave(&iommu->lock, flags);
-       entry = iommu_range_alloc(dev, iommu, npages, NULL);
-       spin_unlock_irqrestore(&iommu->lock, flags);
+       entry = iommu_tbl_range_alloc(dev, &iommu->tbl, npages, NULL,
+                                     (unsigned long)(-1), 0);
 
        if (unlikely(entry == DMA_ERROR_CODE))
                goto bad;
 
-       bus_addr = (iommu->page_table_map_base +
-                   (entry << IO_PAGE_SHIFT));
+       bus_addr = (iommu->tbl.table_map_base + (entry << IO_PAGE_SHIFT));
        ret = bus_addr | (oaddr & ~IO_PAGE_MASK);
        base_paddr = __pa(oaddr & IO_PAGE_MASK);
        prot = HV_PCI_MAP_ATTR_READ;
@@ -290,11 +288,7 @@ bad:
        return DMA_ERROR_CODE;
 
 iommu_map_fail:
-       /* Interrupts are disabled.  */
-       spin_lock(&iommu->lock);
-       iommu_range_free(iommu, bus_addr, npages);
-       spin_unlock_irqrestore(&iommu->lock, flags);
-
+       iommu_tbl_range_free(&iommu->tbl, bus_addr, npages, DMA_ERROR_CODE);
        return DMA_ERROR_CODE;
 }
 
@@ -304,7 +298,7 @@ static void dma_4v_unmap_page(struct device *dev, dma_addr_t bus_addr,
 {
        struct pci_pbm_info *pbm;
        struct iommu *iommu;
-       unsigned long flags, npages;
+       unsigned long npages;
        long entry;
        u32 devhandle;
 
@@ -321,22 +315,9 @@ static void dma_4v_unmap_page(struct device *dev, dma_addr_t bus_addr,
        npages = IO_PAGE_ALIGN(bus_addr + sz) - (bus_addr & IO_PAGE_MASK);
        npages >>= IO_PAGE_SHIFT;
        bus_addr &= IO_PAGE_MASK;
-
-       spin_lock_irqsave(&iommu->lock, flags);
-
-       iommu_range_free(iommu, bus_addr, npages);
-
-       entry = (bus_addr - iommu->page_table_map_base) >> IO_PAGE_SHIFT;
-       do {
-               unsigned long num;
-
-               num = pci_sun4v_iommu_demap(devhandle, HV_PCI_TSBID(0, entry),
-                                           npages);
-               entry += num;
-               npages -= num;
-       } while (npages != 0);
-
-       spin_unlock_irqrestore(&iommu->lock, flags);
+       entry = (bus_addr - iommu->tbl.table_map_base) >> IO_PAGE_SHIFT;
+       dma_4v_iommu_demap(&devhandle, entry, npages);
+       iommu_tbl_range_free(&iommu->tbl, bus_addr, npages, DMA_ERROR_CODE);
 }
 
 static int dma_4v_map_sg(struct device *dev, struct scatterlist *sglist,
@@ -371,14 +352,14 @@ static int dma_4v_map_sg(struct device *dev, struct scatterlist *sglist,
        /* Init first segment length for backout at failure */
        outs->dma_length = 0;
 
-       spin_lock_irqsave(&iommu->lock, flags);
+       local_irq_save(flags);
 
        iommu_batch_start(dev, prot, ~0UL);
 
        max_seg_size = dma_get_max_seg_size(dev);
        seg_boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1,
                                  IO_PAGE_SIZE) >> IO_PAGE_SHIFT;
-       base_shift = iommu->page_table_map_base >> IO_PAGE_SHIFT;
+       base_shift = iommu->tbl.table_map_base >> IO_PAGE_SHIFT;
        for_each_sg(sglist, s, nelems, i) {
                unsigned long paddr, npages, entry, out_entry = 0, slen;
 
@@ -391,7 +372,8 @@ static int dma_4v_map_sg(struct device *dev, struct scatterlist *sglist,
                /* Allocate iommu entries for that segment */
                paddr = (unsigned long) SG_ENT_PHYS_ADDRESS(s);
                npages = iommu_num_pages(paddr, slen, IO_PAGE_SIZE);
-               entry = iommu_range_alloc(dev, iommu, npages, &handle);
+               entry = iommu_tbl_range_alloc(dev, &iommu->tbl, npages,
+                                             &handle, (unsigned long)(-1), 0);
 
                /* Handle failure */
                if (unlikely(entry == DMA_ERROR_CODE)) {
@@ -404,8 +386,7 @@ static int dma_4v_map_sg(struct device *dev, struct scatterlist *sglist,
                iommu_batch_new_entry(entry);
 
                /* Convert entry to a dma_addr_t */
-               dma_addr = iommu->page_table_map_base +
-                       (entry << IO_PAGE_SHIFT);
+               dma_addr = iommu->tbl.table_map_base + (entry << IO_PAGE_SHIFT);
                dma_addr |= (s->offset & ~IO_PAGE_MASK);
 
                /* Insert into HW table */
@@ -451,7 +432,7 @@ static int dma_4v_map_sg(struct device *dev, struct scatterlist *sglist,
        if (unlikely(err < 0L))
                goto iommu_map_failed;
 
-       spin_unlock_irqrestore(&iommu->lock, flags);
+       local_irq_restore(flags);
 
        if (outcount < incount) {
                outs = sg_next(outs);
@@ -469,7 +450,8 @@ iommu_map_failed:
                        vaddr = s->dma_address & IO_PAGE_MASK;
                        npages = iommu_num_pages(s->dma_address, s->dma_length,
                                                 IO_PAGE_SIZE);
-                       iommu_range_free(iommu, vaddr, npages);
+                       iommu_tbl_range_free(&iommu->tbl, vaddr, npages,
+                                            DMA_ERROR_CODE);
                        /* XXX demap? XXX */
                        s->dma_address = DMA_ERROR_CODE;
                        s->dma_length = 0;
@@ -477,7 +459,7 @@ iommu_map_failed:
                if (s == outs)
                        break;
        }
-       spin_unlock_irqrestore(&iommu->lock, flags);
+       local_irq_restore(flags);
 
        return 0;
 }
@@ -489,7 +471,7 @@ static void dma_4v_unmap_sg(struct device *dev, struct scatterlist *sglist,
        struct pci_pbm_info *pbm;
        struct scatterlist *sg;
        struct iommu *iommu;
-       unsigned long flags;
+       unsigned long flags, entry;
        u32 devhandle;
 
        BUG_ON(direction == DMA_NONE);
@@ -498,33 +480,27 @@ static void dma_4v_unmap_sg(struct device *dev, struct scatterlist *sglist,
        pbm = dev->archdata.host_controller;
        devhandle = pbm->devhandle;
        
-       spin_lock_irqsave(&iommu->lock, flags);
+       local_irq_save(flags);
 
        sg = sglist;
        while (nelems--) {
                dma_addr_t dma_handle = sg->dma_address;
                unsigned int len = sg->dma_length;
-               unsigned long npages, entry;
+               unsigned long npages;
+               struct iommu_map_table *tbl = &iommu->tbl;
+               unsigned long shift = IO_PAGE_SHIFT;
 
                if (!len)
                        break;
                npages = iommu_num_pages(dma_handle, len, IO_PAGE_SIZE);
-               iommu_range_free(iommu, dma_handle, npages);
-
-               entry = ((dma_handle - iommu->page_table_map_base) >> IO_PAGE_SHIFT);
-               while (npages) {
-                       unsigned long num;
-
-                       num = pci_sun4v_iommu_demap(devhandle, HV_PCI_TSBID(0, entry),
-                                                   npages);
-                       entry += num;
-                       npages -= num;
-               }
-
+               entry = ((dma_handle - tbl->table_map_base) >> shift);
+               dma_4v_iommu_demap(&devhandle, entry, npages);
+               iommu_tbl_range_free(&iommu->tbl, dma_handle, npages,
+                                    DMA_ERROR_CODE);
                sg = sg_next(sg);
        }
 
-       spin_unlock_irqrestore(&iommu->lock, flags);
+       local_irq_restore(flags);
 }
 
 static struct dma_map_ops sun4v_dma_ops = {
@@ -550,30 +526,33 @@ static void pci_sun4v_scan_bus(struct pci_pbm_info *pbm, struct device *parent)
 }
 
 static unsigned long probe_existing_entries(struct pci_pbm_info *pbm,
-                                           struct iommu *iommu)
+                                           struct iommu_map_table *iommu)
 {
-       struct iommu_arena *arena = &iommu->arena;
-       unsigned long i, cnt = 0;
+       struct iommu_pool *pool;
+       unsigned long i, pool_nr, cnt = 0;
        u32 devhandle;
 
        devhandle = pbm->devhandle;
-       for (i = 0; i < arena->limit; i++) {
-               unsigned long ret, io_attrs, ra;
-
-               ret = pci_sun4v_iommu_getmap(devhandle,
-                                            HV_PCI_TSBID(0, i),
-                                            &io_attrs, &ra);
-               if (ret == HV_EOK) {
-                       if (page_in_phys_avail(ra)) {
-                               pci_sun4v_iommu_demap(devhandle,
-                                                     HV_PCI_TSBID(0, i), 1);
-                       } else {
-                               cnt++;
-                               __set_bit(i, arena->map);
+       for (pool_nr = 0; pool_nr < iommu->nr_pools; pool_nr++) {
+               pool = &(iommu->pools[pool_nr]);
+               for (i = pool->start; i <= pool->end; i++) {
+                       unsigned long ret, io_attrs, ra;
+
+                       ret = pci_sun4v_iommu_getmap(devhandle,
+                                                    HV_PCI_TSBID(0, i),
+                                                    &io_attrs, &ra);
+                       if (ret == HV_EOK) {
+                               if (page_in_phys_avail(ra)) {
+                                       pci_sun4v_iommu_demap(devhandle,
+                                                             HV_PCI_TSBID(0,
+                                                             i), 1);
+                               } else {
+                                       cnt++;
+                                       __set_bit(i, iommu->map);
+                               }
                        }
                }
        }
-
        return cnt;
 }
 
@@ -603,20 +582,22 @@ static int pci_sun4v_iommu_init(struct pci_pbm_info *pbm)
        /* Setup initial software IOMMU state. */
        spin_lock_init(&iommu->lock);
        iommu->ctx_lowest_free = 1;
-       iommu->page_table_map_base = dma_offset;
+       iommu->tbl.table_map_base = dma_offset;
        iommu->dma_addr_mask = dma_mask;
 
        /* Allocate and initialize the free area map.  */
        sz = (num_tsb_entries + 7) / 8;
        sz = (sz + 7UL) & ~7UL;
-       iommu->arena.map = kzalloc(sz, GFP_KERNEL);
-       if (!iommu->arena.map) {
+       iommu->tbl.map = kzalloc(sz, GFP_KERNEL);
+       if (!iommu->tbl.map) {
                printk(KERN_ERR PFX "Error, kmalloc(arena.map) failed.\n");
                return -ENOMEM;
        }
-       iommu->arena.limit = num_tsb_entries;
-
-       sz = probe_existing_entries(pbm, iommu);
+       iommu_tbl_pool_init(&iommu->tbl, num_tsb_entries, IO_PAGE_SHIFT,
+                           NULL, false /* no large_pool */,
+                           0 /* default npools */,
+                           false /* want span boundary checking */);
+       sz = probe_existing_entries(pbm, &iommu->tbl);
        if (sz)
                printk("%s: Imported %lu TSB entries from OBP\n",
                       pbm->name, sz);