sparc,sparc64: unify kernel/

o Move all files from sparc64/kernel/ to sparc/kernel
  - rename as appropriate
o Update sparc/Makefile to the changes
o Update sparc/kernel/Makefile to include the sparc64 files

NOTE: This commit changes link order on sparc64!

Link order had to change for either of sparc32 and sparc64.
And assuming sparc64 see more testing than sparc32 change link
order on sparc64 where issues will be caught faster.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 866 insertions, 0 deletions

diff --git a/arch/sparc/kernel/iommu.c b/arch/sparc/kernel/iommu.c
new file mode 100644
index 000000000000..1cc1995531e2
--- /dev/null
+++ b/arch/sparc/kernel/iommu.c
@@ -0,0 +1,866 @@
+/* iommu.c: Generic sparc64 IOMMU support.
+ *
+ * Copyright (C) 1999, 2007, 2008 David S. Miller (davem@davemloft.net)
+ * Copyright (C) 1999, 2000 Jakub Jelinek (jakub@redhat.com)
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/errno.h>
+#include <linux/iommu-helper.h>
+
+#ifdef CONFIG_PCI
+#include <linux/pci.h>
+#endif
+
+#include <asm/iommu.h>
+
+#include "iommu_common.h"
+
+#define STC_CTXMATCH_ADDR(STC, CTX)     \
+        ((STC)->strbuf_ctxmatch_base + ((CTX) << 3))
+#define STC_FLUSHFLAG_INIT(STC) \
+        (*((STC)->strbuf_flushflag) = 0UL)
+#define STC_FLUSHFLAG_SET(STC) \
+        (*((STC)->strbuf_flushflag) != 0UL)
+
+#define iommu_read(__reg) \
+({      u64 __ret; \
+        __asm__ __volatile__("ldxa [%1] %2, %0" \
+                             : "=r" (__ret) \
+                             : "r" (__reg), "i" (ASI_PHYS_BYPASS_EC_E) \
+                             : "memory"); \
+        __ret; \
+})
+#define iommu_write(__reg, __val) \
+        __asm__ __volatile__("stxa %0, [%1] %2" \
+                             : /* no outputs */ \
+                             : "r" (__val), "r" (__reg), \
+                               "i" (ASI_PHYS_BYPASS_EC_E))
+
+/* Must be invoked under the IOMMU lock. */
+static void iommu_flushall(struct iommu *iommu)
+{
+        if (iommu->iommu_flushinv) {
+                iommu_write(iommu->iommu_flushinv, ~(u64)0);
+        } else {
+                unsigned long tag;
+                int entry;
+
+                tag = iommu->iommu_tags;
+                for (entry = 0; entry < 16; entry++) {
+                        iommu_write(tag, 0);
+                        tag += 8;
+                }
+
+                /* Ensure completion of previous PIO writes. */
+                (void) iommu_read(iommu->write_complete_reg);
+        }
+}
+
+#define IOPTE_CONSISTENT(CTX) \
+        (IOPTE_VALID | IOPTE_CACHE | \
+         (((CTX) << 47) & IOPTE_CONTEXT))
+
+#define IOPTE_STREAMING(CTX) \
+        (IOPTE_CONSISTENT(CTX) | IOPTE_STBUF)
+
+/* Existing mappings are never marked invalid, instead they
+ * are pointed to a dummy page.
+ */
+#define IOPTE_IS_DUMMY(iommu, iopte)    \
+        ((iopte_val(*iopte) & IOPTE_PAGE) == (iommu)->dummy_page_pa)
+
+static inline void iopte_make_dummy(struct iommu *iommu, iopte_t *iopte)
+{
+        unsigned long val = iopte_val(*iopte);
+
+        val &= ~IOPTE_PAGE;
+        val |= iommu->dummy_page_pa;
+
+        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;
+
+        iommu_area_free(arena->map, entry, npages);
+}
+
+int iommu_table_init(struct iommu *iommu, int tsbsize,
+                     u32 dma_offset, u32 dma_addr_mask,
+                     int numa_node)
+{
+        unsigned long i, order, sz, num_tsb_entries;
+        struct page *page;
+
+        num_tsb_entries = tsbsize / sizeof(iopte_t);
+
+        /* Setup initial software IOMMU state. */
+        spin_lock_init(&iommu->lock);
+        iommu->ctx_lowest_free = 1;
+        iommu->page_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");
+                return -ENOMEM;
+        }
+        memset(iommu->arena.map, 0, sz);
+        iommu->arena.limit = num_tsb_entries;
+
+        if (tlb_type != hypervisor)
+                iommu->flush_all = iommu_flushall;
+
+        /* Allocate and initialize the dummy page which we
+         * set inactive IO PTEs to point to.
+         */
+        page = alloc_pages_node(numa_node, GFP_KERNEL, 0);
+        if (!page) {
+                printk(KERN_ERR "IOMMU: Error, gfp(dummy_page) failed.\n");
+                goto out_free_map;
+        }
+        iommu->dummy_page = (unsigned long) page_address(page);
+        memset((void *)iommu->dummy_page, 0, PAGE_SIZE);
+        iommu->dummy_page_pa = (unsigned long) __pa(iommu->dummy_page);
+
+        /* Now allocate and setup the IOMMU page table itself.  */
+        order = get_order(tsbsize);
+        page = alloc_pages_node(numa_node, GFP_KERNEL, order);
+        if (!page) {
+                printk(KERN_ERR "IOMMU: Error, gfp(tsb) failed.\n");
+                goto out_free_dummy_page;
+        }
+        iommu->page_table = (iopte_t *)page_address(page);
+
+        for (i = 0; i < num_tsb_entries; i++)
+                iopte_make_dummy(iommu, &iommu->page_table[i]);
+
+        return 0;
+
+out_free_dummy_page:
+        free_page(iommu->dummy_page);
+        iommu->dummy_page = 0UL;
+
+out_free_map:
+        kfree(iommu->arena.map);
+        iommu->arena.map = NULL;
+
+        return -ENOMEM;
+}
+
+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);
+        if (unlikely(entry == DMA_ERROR_CODE))
+                return NULL;
+
+        return iommu->page_table + entry;
+}
+
+static int iommu_alloc_ctx(struct iommu *iommu)
+{
+        int lowest = iommu->ctx_lowest_free;
+        int sz = IOMMU_NUM_CTXS - lowest;
+        int n = find_next_zero_bit(iommu->ctx_bitmap, sz, lowest);
+
+        if (unlikely(n == sz)) {
+                n = find_next_zero_bit(iommu->ctx_bitmap, lowest, 1);
+                if (unlikely(n == lowest)) {
+                        printk(KERN_WARNING "IOMMU: Ran out of contexts.\n");
+                        n = 0;
+                }
+        }
+        if (n)
+                __set_bit(n, iommu->ctx_bitmap);
+
+        return n;
+}
+
+static inline void iommu_free_ctx(struct iommu *iommu, int ctx)
+{
+        if (likely(ctx)) {
+                __clear_bit(ctx, iommu->ctx_bitmap);
+                if (ctx < iommu->ctx_lowest_free)
+                        iommu->ctx_lowest_free = ctx;
+        }
+}
+
+static void *dma_4u_alloc_coherent(struct device *dev, size_t size,
+                                   dma_addr_t *dma_addrp, gfp_t gfp)
+{
+        unsigned long flags, order, first_page;
+        struct iommu *iommu;
+        struct page *page;
+        int npages, nid;
+        iopte_t *iopte;
+        void *ret;
+
+        size = IO_PAGE_ALIGN(size);
+        order = get_order(size);
+        if (order >= 10)
+                return NULL;
+
+        nid = dev->archdata.numa_node;
+        page = alloc_pages_node(nid, gfp, order);
+        if (unlikely(!page))
+                return NULL;
+
+        first_page = (unsigned long) page_address(page);
+        memset((char *)first_page, 0, PAGE_SIZE << order);
+
+        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 +
+                      ((iopte - iommu->page_table) << IO_PAGE_SHIFT));
+        ret = (void *) first_page;
+        npages = size >> IO_PAGE_SHIFT;
+        first_page = __pa(first_page);
+        while (npages--) {
+                iopte_val(*iopte) = (IOPTE_CONSISTENT(0UL) |
+                                     IOPTE_WRITE |
+                                     (first_page & IOPTE_PAGE));
+                iopte++;
+                first_page += IO_PAGE_SIZE;
+        }
+
+        return ret;
+}
+
+static void dma_4u_free_coherent(struct device *dev, size_t size,
+                                 void *cpu, dma_addr_t dvma)
+{
+        struct iommu *iommu;
+        iopte_t *iopte;
+        unsigned long flags, order, npages;
+
+        npages = IO_PAGE_ALIGN(size) >> IO_PAGE_SHIFT;
+        iommu = dev->archdata.iommu;
+        iopte = iommu->page_table +
+                ((dvma - iommu->page_table_map_base) >> IO_PAGE_SHIFT);
+
+        spin_lock_irqsave(&iommu->lock, flags);
+
+        iommu_range_free(iommu, dvma, npages);
+
+        spin_unlock_irqrestore(&iommu->lock, flags);
+
+        order = get_order(size);
+        if (order < 10)
+                free_pages((unsigned long)cpu, order);
+}
+
+static dma_addr_t dma_4u_map_single(struct device *dev, void *ptr, size_t sz,
+                                    enum dma_data_direction direction)
+{
+        struct iommu *iommu;
+        struct strbuf *strbuf;
+        iopte_t *base;
+        unsigned long flags, npages, oaddr;
+        unsigned long i, base_paddr, ctx;
+        u32 bus_addr, ret;
+        unsigned long iopte_protection;
+
+        iommu = dev->archdata.iommu;
+        strbuf = dev->archdata.stc;
+
+        if (unlikely(direction == DMA_NONE))
+                goto bad_no_ctx;
+
+        oaddr = (unsigned long)ptr;
+        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);
+        ctx = 0;
+        if (iommu->iommu_ctxflush)
+                ctx = iommu_alloc_ctx(iommu);
+        spin_unlock_irqrestore(&iommu->lock, flags);
+
+        if (unlikely(!base))
+                goto bad;
+
+        bus_addr = (iommu->page_table_map_base +
+                    ((base - iommu->page_table) << IO_PAGE_SHIFT));
+        ret = bus_addr | (oaddr & ~IO_PAGE_MASK);
+        base_paddr = __pa(oaddr & IO_PAGE_MASK);
+        if (strbuf->strbuf_enabled)
+                iopte_protection = IOPTE_STREAMING(ctx);
+        else
+                iopte_protection = IOPTE_CONSISTENT(ctx);
+        if (direction != DMA_TO_DEVICE)
+                iopte_protection |= IOPTE_WRITE;
+
+        for (i = 0; i < npages; i++, base++, base_paddr += IO_PAGE_SIZE)
+                iopte_val(*base) = iopte_protection | base_paddr;
+
+        return ret;
+
+bad:
+        iommu_free_ctx(iommu, ctx);
+bad_no_ctx:
+        if (printk_ratelimit())
+                WARN_ON(1);
+        return DMA_ERROR_CODE;
+}
+
+static void strbuf_flush(struct strbuf *strbuf, struct iommu *iommu,
+                         u32 vaddr, unsigned long ctx, unsigned long npages,
+                         enum dma_data_direction direction)
+{
+        int limit;
+
+        if (strbuf->strbuf_ctxflush &&
+            iommu->iommu_ctxflush) {
+                unsigned long matchreg, flushreg;
+                u64 val;
+
+                flushreg = strbuf->strbuf_ctxflush;
+                matchreg = STC_CTXMATCH_ADDR(strbuf, ctx);
+
+                iommu_write(flushreg, ctx);
+                val = iommu_read(matchreg);
+                val &= 0xffff;
+                if (!val)
+                        goto do_flush_sync;
+
+                while (val) {
+                        if (val & 0x1)
+                                iommu_write(flushreg, ctx);
+                        val >>= 1;
+                }
+                val = iommu_read(matchreg);
+                if (unlikely(val)) {
+                        printk(KERN_WARNING "strbuf_flush: ctx flush "
+                               "timeout matchreg[%lx] ctx[%lx]\n",
+                               val, ctx);
+                        goto do_page_flush;
+                }
+        } else {
+                unsigned long i;
+
+        do_page_flush:
+                for (i = 0; i < npages; i++, vaddr += IO_PAGE_SIZE)
+                        iommu_write(strbuf->strbuf_pflush, vaddr);
+        }
+
+do_flush_sync:
+        /* If the device could not have possibly put dirty data into
+         * the streaming cache, no flush-flag synchronization needs
+         * to be performed.
+         */
+        if (direction == DMA_TO_DEVICE)
+                return;
+
+        STC_FLUSHFLAG_INIT(strbuf);
+        iommu_write(strbuf->strbuf_fsync, strbuf->strbuf_flushflag_pa);
+        (void) iommu_read(iommu->write_complete_reg);
+
+        limit = 100000;
+        while (!STC_FLUSHFLAG_SET(strbuf)) {
+                limit--;
+                if (!limit)
+                        break;
+                udelay(1);
+                rmb();
+        }
+        if (!limit)
+                printk(KERN_WARNING "strbuf_flush: flushflag timeout "
+                       "vaddr[%08x] ctx[%lx] npages[%ld]\n",
+                       vaddr, ctx, npages);
+}
+
+static void dma_4u_unmap_single(struct device *dev, dma_addr_t bus_addr,
+                                size_t sz, enum dma_data_direction direction)
+{
+        struct iommu *iommu;
+        struct strbuf *strbuf;
+        iopte_t *base;
+        unsigned long flags, npages, ctx, i;
+
+        if (unlikely(direction == DMA_NONE)) {
+                if (printk_ratelimit())
+                        WARN_ON(1);
+                return;
+        }
+
+        iommu = dev->archdata.iommu;
+        strbuf = dev->archdata.stc;
+
+        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 &= IO_PAGE_MASK;
+
+        spin_lock_irqsave(&iommu->lock, flags);
+
+        /* Record the context, if any. */
+        ctx = 0;
+        if (iommu->iommu_ctxflush)
+                ctx = (iopte_val(*base) & IOPTE_CONTEXT) >> 47UL;
+
+        /* Step 1: Kick data out of streaming buffers if necessary. */
+        if (strbuf->strbuf_enabled)
+                strbuf_flush(strbuf, iommu, bus_addr, ctx,
+                             npages, direction);
+
+        /* Step 2: Clear out TSB entries. */
+        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);
+}
+
+static int dma_4u_map_sg(struct device *dev, struct scatterlist *sglist,
+                         int nelems, enum dma_data_direction direction)
+{
+        struct scatterlist *s, *outs, *segstart;
+        unsigned long flags, handle, prot, ctx;
+        dma_addr_t dma_next = 0, dma_addr;
+        unsigned int max_seg_size;
+        unsigned long seg_boundary_size;
+        int outcount, incount, i;
+        struct strbuf *strbuf;
+        struct iommu *iommu;
+        unsigned long base_shift;
+
+        BUG_ON(direction == DMA_NONE);
+
+        iommu = dev->archdata.iommu;
+        strbuf = dev->archdata.stc;
+        if (nelems == 0 || !iommu)
+                return 0;
+
+        spin_lock_irqsave(&iommu->lock, flags);
+
+        ctx = 0;
+        if (iommu->iommu_ctxflush)
+                ctx = iommu_alloc_ctx(iommu);
+
+        if (strbuf->strbuf_enabled)
+                prot = IOPTE_STREAMING(ctx);
+        else
+                prot = IOPTE_CONSISTENT(ctx);
+        if (direction != DMA_TO_DEVICE)
+                prot |= IOPTE_WRITE;
+
+        outs = s = segstart = &sglist[0];
+        outcount = 1;
+        incount = nelems;
+        handle = 0;
+
+        /* Init first segment length for backout at failure */
+        outs->dma_length = 0;
+
+        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;
+        for_each_sg(sglist, s, nelems, i) {
+                unsigned long paddr, npages, entry, out_entry = 0, slen;
+                iopte_t *base;
+
+                slen = s->length;
+                /* Sanity check */
+                if (slen == 0) {
+                        dma_next = 0;
+                        continue;
+                }
+                /* 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);
+
+                /* Handle failure */
+                if (unlikely(entry == DMA_ERROR_CODE)) {
+                        if (printk_ratelimit())
+                                printk(KERN_INFO "iommu_alloc failed, iommu %p paddr %lx"
+                                       " npages %lx\n", iommu, paddr, npages);
+                        goto iommu_map_failed;
+                }
+
+                base = iommu->page_table + entry;
+
+                /* Convert entry to a dma_addr_t */
+                dma_addr = iommu->page_table_map_base +
+                        (entry << IO_PAGE_SHIFT);
+                dma_addr |= (s->offset & ~IO_PAGE_MASK);
+
+                /* Insert into HW table */
+                paddr &= IO_PAGE_MASK;
+                while (npages--) {
+                        iopte_val(*base) = prot | paddr;
+                        base++;
+                        paddr += IO_PAGE_SIZE;
+                }
+
+                /* If we are in an open segment, try merging */
+                if (segstart != s) {
+                        /* We cannot merge if:
+                         * - allocated dma_addr isn't contiguous to previous allocation
+                         */
+                        if ((dma_addr != dma_next) ||
+                            (outs->dma_length + s->length > max_seg_size) ||
+                            (is_span_boundary(out_entry, base_shift,
+                                              seg_boundary_size, outs, s))) {
+                                /* Can't merge: create a new segment */
+                                segstart = s;
+                                outcount++;
+                                outs = sg_next(outs);
+                        } else {
+                                outs->dma_length += s->length;
+                        }
+                }
+
+                if (segstart == s) {
+                        /* This is a new segment, fill entries */
+                        outs->dma_address = dma_addr;
+                        outs->dma_length = slen;
+                        out_entry = entry;
+                }
+
+                /* Calculate next page pointer for contiguous check */
+                dma_next = dma_addr + slen;
+        }
+
+        spin_unlock_irqrestore(&iommu->lock, flags);
+
+        if (outcount < incount) {
+                outs = sg_next(outs);
+                outs->dma_address = DMA_ERROR_CODE;
+                outs->dma_length = 0;
+        }
+
+        return outcount;
+
+iommu_map_failed:
+        for_each_sg(sglist, s, nelems, i) {
+                if (s->dma_length != 0) {
+                        unsigned long vaddr, npages, entry, j;
+                        iopte_t *base;
+
+                        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)
+                                >> IO_PAGE_SHIFT;
+                        base = iommu->page_table + entry;
+
+                        for (j = 0; j < npages; j++)
+                                iopte_make_dummy(iommu, base + j);
+
+                        s->dma_address = DMA_ERROR_CODE;
+                        s->dma_length = 0;
+                }
+                if (s == outs)
+                        break;
+        }
+        spin_unlock_irqrestore(&iommu->lock, flags);
+
+        return 0;
+}
+
+/* If contexts are being used, they are the same in all of the mappings
+ * we make for a particular SG.
+ */
+static unsigned long fetch_sg_ctx(struct iommu *iommu, struct scatterlist *sg)
+{
+        unsigned long ctx = 0;
+
+        if (iommu->iommu_ctxflush) {
+                iopte_t *base;
+                u32 bus_addr;
+
+                bus_addr = sg->dma_address & IO_PAGE_MASK;
+                base = iommu->page_table +
+                        ((bus_addr - iommu->page_table_map_base) >> IO_PAGE_SHIFT);
+
+                ctx = (iopte_val(*base) & IOPTE_CONTEXT) >> 47UL;
+        }
+        return ctx;
+}
+
+static void dma_4u_unmap_sg(struct device *dev, struct scatterlist *sglist,
+                            int nelems, enum dma_data_direction direction)
+{
+        unsigned long flags, ctx;
+        struct scatterlist *sg;
+        struct strbuf *strbuf;
+        struct iommu *iommu;
+
+        BUG_ON(direction == DMA_NONE);
+
+        iommu = dev->archdata.iommu;
+        strbuf = dev->archdata.stc;
+
+        ctx = fetch_sg_ctx(iommu, sglist);
+
+        spin_lock_irqsave(&iommu->lock, flags);
+
+        sg = sglist;
+        while (nelems--) {
+                dma_addr_t dma_handle = sg->dma_address;
+                unsigned int len = sg->dma_length;
+                unsigned long npages, entry;
+                iopte_t *base;
+                int i;
+
+                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);
+                base = iommu->page_table + entry;
+
+                dma_handle &= IO_PAGE_MASK;
+                if (strbuf->strbuf_enabled)
+                        strbuf_flush(strbuf, iommu, dma_handle, ctx,
+                                     npages, direction);
+
+                for (i = 0; i < npages; i++)
+                        iopte_make_dummy(iommu, base + i);
+
+                sg = sg_next(sg);
+        }
+
+        iommu_free_ctx(iommu, ctx);
+
+        spin_unlock_irqrestore(&iommu->lock, flags);
+}
+
+static void dma_4u_sync_single_for_cpu(struct device *dev,
+                                       dma_addr_t bus_addr, size_t sz,
+                                       enum dma_data_direction direction)
+{
+        struct iommu *iommu;
+        struct strbuf *strbuf;
+        unsigned long flags, ctx, npages;
+
+        iommu = dev->archdata.iommu;
+        strbuf = dev->archdata.stc;
+
+        if (!strbuf->strbuf_enabled)
+                return;
+
+        spin_lock_irqsave(&iommu->lock, flags);
+
+        npages = IO_PAGE_ALIGN(bus_addr + sz) - (bus_addr & IO_PAGE_MASK);
+        npages >>= IO_PAGE_SHIFT;
+        bus_addr &= IO_PAGE_MASK;
+
+        /* Step 1: Record the context, if any. */
+        ctx = 0;
+        if (iommu->iommu_ctxflush &&
+            strbuf->strbuf_ctxflush) {
+                iopte_t *iopte;
+
+                iopte = iommu->page_table +
+                        ((bus_addr - iommu->page_table_map_base)>>IO_PAGE_SHIFT);
+                ctx = (iopte_val(*iopte) & IOPTE_CONTEXT) >> 47UL;
+        }
+
+        /* Step 2: Kick data out of streaming buffers. */
+        strbuf_flush(strbuf, iommu, bus_addr, ctx, npages, direction);
+
+        spin_unlock_irqrestore(&iommu->lock, flags);
+}
+
+static void dma_4u_sync_sg_for_cpu(struct device *dev,
+                                   struct scatterlist *sglist, int nelems,
+                                   enum dma_data_direction direction)
+{
+        struct iommu *iommu;
+        struct strbuf *strbuf;
+        unsigned long flags, ctx, npages, i;
+        struct scatterlist *sg, *sgprv;
+        u32 bus_addr;
+
+        iommu = dev->archdata.iommu;
+        strbuf = dev->archdata.stc;
+
+        if (!strbuf->strbuf_enabled)
+                return;
+
+        spin_lock_irqsave(&iommu->lock, flags);
+
+        /* Step 1: Record the context, if any. */
+        ctx = 0;
+        if (iommu->iommu_ctxflush &&
+            strbuf->strbuf_ctxflush) {
+                iopte_t *iopte;
+
+                iopte = iommu->page_table +
+                        ((sglist[0].dma_address - iommu->page_table_map_base) >> IO_PAGE_SHIFT);
+                ctx = (iopte_val(*iopte) & IOPTE_CONTEXT) >> 47UL;
+        }
+
+        /* Step 2: Kick data out of streaming buffers. */
+        bus_addr = sglist[0].dma_address & IO_PAGE_MASK;
+        sgprv = NULL;
+        for_each_sg(sglist, sg, nelems, i) {
+                if (sg->dma_length == 0)
+                        break;
+                sgprv = sg;
+        }
+
+        npages = (IO_PAGE_ALIGN(sgprv->dma_address + sgprv->dma_length)
+                  - bus_addr) >> IO_PAGE_SHIFT;
+        strbuf_flush(strbuf, iommu, bus_addr, ctx, npages, direction);
+
+        spin_unlock_irqrestore(&iommu->lock, flags);
+}
+
+static const struct dma_ops sun4u_dma_ops = {
+        .alloc_coherent         = dma_4u_alloc_coherent,
+        .free_coherent          = dma_4u_free_coherent,
+        .map_single             = dma_4u_map_single,
+        .unmap_single           = dma_4u_unmap_single,
+        .map_sg                 = dma_4u_map_sg,
+        .unmap_sg               = dma_4u_unmap_sg,
+        .sync_single_for_cpu    = dma_4u_sync_single_for_cpu,
+        .sync_sg_for_cpu        = dma_4u_sync_sg_for_cpu,
+};
+
+const struct dma_ops *dma_ops = &sun4u_dma_ops;
+EXPORT_SYMBOL(dma_ops);
+
+int dma_supported(struct device *dev, u64 device_mask)
+{
+        struct iommu *iommu = dev->archdata.iommu;
+        u64 dma_addr_mask = iommu->dma_addr_mask;
+
+        if (device_mask >= (1UL << 32UL))
+                return 0;
+
+        if ((device_mask & dma_addr_mask) == dma_addr_mask)
+                return 1;
+
+#ifdef CONFIG_PCI
+        if (dev->bus == &pci_bus_type)
+                return pci_dma_supported(to_pci_dev(dev), device_mask);
+#endif
+
+        return 0;
+}
+EXPORT_SYMBOL(dma_supported);
+
+int dma_set_mask(struct device *dev, u64 dma_mask)
+{
+#ifdef CONFIG_PCI
+        if (dev->bus == &pci_bus_type)
+                return pci_set_dma_mask(to_pci_dev(dev), dma_mask);
+#endif
+        return -EINVAL;
+}
+EXPORT_SYMBOL(dma_set_mask);