[SPARC64]: Fix conflicts in SBUS/PCI/EBUS/ISA DMA handling.

Fully unify all of the DMA ops so that subordinate bus types to
the DMA operation providers (such as ebus, isa, of_device) can
work transparently.

Basically, we just make sure that for every system device we
create, the dev->archdata 'iommu' and 'stc' fields are filled
in.

Then we have two platform variants of the DMA ops, one for SUN4U which
actually programs the real hardware, and one for SUN4V which makes
hypervisor calls.

This also fixes the crashes in parport_pc on sparc64, reported by
Meelis Roos.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 809 insertions, 0 deletions

diff --git a/arch/sparc64/kernel/iommu.c b/arch/sparc64/kernel/iommu.c
new file mode 100644
index 000000000000..b35a62167e9c
--- /dev/null
+++ b/arch/sparc64/kernel/iommu.c
@@ -0,0 +1,809 @@
+/* iommu.c: Generic sparc64 IOMMU support.
+ *
+ * Copyright (C) 1999, 2007 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>
+
+#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 largely upon the ppc64 iommu allocator.  */
+static long arena_alloc(struct iommu *iommu, unsigned long npages)
+{
+        struct iommu_arena *arena = &iommu->arena;
+        unsigned long n, i, start, end, limit;
+        int pass;
+
+        limit = arena->limit;
+        start = arena->hint;
+        pass = 0;
+
+again:
+        n = find_next_zero_bit(arena->map, limit, start);
+        end = n + npages;
+        if (unlikely(end >= limit)) {
+                if (likely(pass < 1)) {
+                        limit = start;
+                        start = 0;
+                        __iommu_flushall(iommu);
+                        pass++;
+                        goto again;
+                } else {
+                        /* Scanned the whole thing, give up. */
+                        return -1;
+                }
+        }
+
+        for (i = n; i < end; i++) {
+                if (test_bit(i, arena->map)) {
+                        start = i + 1;
+                        goto again;
+                }
+        }
+
+        for (i = n; i < end; i++)
+                __set_bit(i, arena->map);
+
+        arena->hint = end;
+
+        return n;
+}
+
+static void arena_free(struct iommu_arena *arena, unsigned long base, unsigned long npages)
+{
+        unsigned long i;
+
+        for (i = base; i < (base + npages); i++)
+                __clear_bit(i, arena->map);
+}
+
+int iommu_table_init(struct iommu *iommu, int tsbsize,
+                     u32 dma_offset, u32 dma_addr_mask)
+{
+        unsigned long i, tsbbase, order, sz, num_tsb_entries;
+
+        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 = kzalloc(sz, GFP_KERNEL);
+        if (!iommu->arena.map) {
+                printk(KERN_ERR "IOMMU: Error, kmalloc(arena.map) failed.\n");
+                return -ENOMEM;
+        }
+        iommu->arena.limit = num_tsb_entries;
+
+        /* Allocate and initialize the dummy page which we
+         * set inactive IO PTEs to point to.
+         */
+        iommu->dummy_page = __get_free_pages(GFP_KERNEL, 0);
+        if (!iommu->dummy_page) {
+                printk(KERN_ERR "IOMMU: Error, gfp(dummy_page) failed.\n");
+                goto out_free_map;
+        }
+        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);
+        tsbbase = __get_free_pages(GFP_KERNEL, order);
+        if (!tsbbase) {
+                printk(KERN_ERR "IOMMU: Error, gfp(tsb) failed.\n");
+                goto out_free_dummy_page;
+        }
+        iommu->page_table = (iopte_t *)tsbbase;
+
+        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 iommu *iommu, unsigned long npages)
+{
+        long entry;
+
+        entry = arena_alloc(iommu, npages);
+        if (unlikely(entry < 0))
+                return NULL;
+
+        return iommu->page_table + entry;
+}
+
+static inline void free_npages(struct iommu *iommu, dma_addr_t base, unsigned long npages)
+{
+        arena_free(&iommu->arena, base >> IO_PAGE_SHIFT, npages);
+}
+
+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)
+{
+        struct iommu *iommu;
+        iopte_t *iopte;
+        unsigned long flags, order, first_page;
+        void *ret;
+        int npages;
+
+        size = IO_PAGE_ALIGN(size);
+        order = get_order(size);
+        if (order >= 10)
+                return NULL;
+
+        first_page = __get_free_pages(gfp, order);
+        if (first_page == 0UL)
+                return NULL;
+        memset((char *)first_page, 0, PAGE_SIZE << order);
+
+        iommu = dev->archdata.iommu;
+
+        spin_lock_irqsave(&iommu->lock, flags);
+        iopte = alloc_npages(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);
+
+        free_npages(iommu, dvma - iommu->page_table_map_base, 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(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);
+
+        free_npages(iommu, bus_addr - iommu->page_table_map_base, npages);
+
+        iommu_free_ctx(iommu, ctx);
+
+        spin_unlock_irqrestore(&iommu->lock, flags);
+}
+
+#define SG_ENT_PHYS_ADDRESS(SG) \
+        (__pa(page_address((SG)->page)) + (SG)->offset)
+
+static inline void fill_sg(iopte_t *iopte, struct scatterlist *sg,
+                           int nused, int nelems,
+                           unsigned long iopte_protection)
+{
+        struct scatterlist *dma_sg = sg;
+        struct scatterlist *sg_end = sg + nelems;
+        int i;
+
+        for (i = 0; i < nused; i++) {
+                unsigned long pteval = ~0UL;
+                u32 dma_npages;
+
+                dma_npages = ((dma_sg->dma_address & (IO_PAGE_SIZE - 1UL)) +
+                              dma_sg->dma_length +
+                              ((IO_PAGE_SIZE - 1UL))) >> IO_PAGE_SHIFT;
+                do {
+                        unsigned long offset;
+                        signed int len;
+
+                        /* If we are here, we know we have at least one
+                         * more page to map.  So walk forward until we
+                         * hit a page crossing, and begin creating new
+                         * mappings from that spot.
+                         */
+                        for (;;) {
+                                unsigned long tmp;
+
+                                tmp = SG_ENT_PHYS_ADDRESS(sg);
+                                len = sg->length;
+                                if (((tmp ^ pteval) >> IO_PAGE_SHIFT) != 0UL) {
+                                        pteval = tmp & IO_PAGE_MASK;
+                                        offset = tmp & (IO_PAGE_SIZE - 1UL);
+                                        break;
+                                }
+                                if (((tmp ^ (tmp + len - 1UL)) >> IO_PAGE_SHIFT) != 0UL) {
+                                        pteval = (tmp + IO_PAGE_SIZE) & IO_PAGE_MASK;
+                                        offset = 0UL;
+                                        len -= (IO_PAGE_SIZE - (tmp & (IO_PAGE_SIZE - 1UL)));
+                                        break;
+                                }
+                                sg++;
+                        }
+
+                        pteval = iopte_protection | (pteval & IOPTE_PAGE);
+                        while (len > 0) {
+                                *iopte++ = __iopte(pteval);
+                                pteval += IO_PAGE_SIZE;
+                                len -= (IO_PAGE_SIZE - offset);
+                                offset = 0;
+                                dma_npages--;
+                        }
+
+                        pteval = (pteval & IOPTE_PAGE) + len;
+                        sg++;
+
+                        /* Skip over any tail mappings we've fully mapped,
+                         * adjusting pteval along the way.  Stop when we
+                         * detect a page crossing event.
+                         */
+                        while (sg < sg_end &&
+                               (pteval << (64 - IO_PAGE_SHIFT)) != 0UL &&
+                               (pteval == SG_ENT_PHYS_ADDRESS(sg)) &&
+                               ((pteval ^
+                                 (SG_ENT_PHYS_ADDRESS(sg) + sg->length - 1UL)) >> IO_PAGE_SHIFT) == 0UL) {
+                                pteval += sg->length;
+                                sg++;
+                        }
+                        if ((pteval << (64 - IO_PAGE_SHIFT)) == 0UL)
+                                pteval = ~0UL;
+                } while (dma_npages != 0);
+                dma_sg++;
+        }
+}
+
+static int dma_4u_map_sg(struct device *dev, struct scatterlist *sglist,
+                         int nelems, enum dma_data_direction direction)
+{
+        struct iommu *iommu;
+        struct strbuf *strbuf;
+        unsigned long flags, ctx, npages, iopte_protection;
+        iopte_t *base;
+        u32 dma_base;
+        struct scatterlist *sgtmp;
+        int used;
+
+        /* Fast path single entry scatterlists. */
+        if (nelems == 1) {
+                sglist->dma_address =
+                        dma_4u_map_single(dev,
+                                          (page_address(sglist->page) +
+                                           sglist->offset),
+                                          sglist->length, direction);
+                if (unlikely(sglist->dma_address == DMA_ERROR_CODE))
+                        return 0;
+                sglist->dma_length = sglist->length;
+                return 1;
+        }
+
+        iommu = dev->archdata.iommu;
+        strbuf = dev->archdata.stc;
+
+        if (unlikely(direction == DMA_NONE))
+                goto bad_no_ctx;
+
+        /* Step 1: Prepare scatter list. */
+
+        npages = prepare_sg(sglist, nelems);
+
+        /* Step 2: Allocate a cluster and context, if necessary. */
+
+        spin_lock_irqsave(&iommu->lock, flags);
+
+        base = alloc_npages(iommu, npages);
+        ctx = 0;
+        if (iommu->iommu_ctxflush)
+                ctx = iommu_alloc_ctx(iommu);
+
+        spin_unlock_irqrestore(&iommu->lock, flags);
+
+        if (base == NULL)
+                goto bad;
+
+        dma_base = iommu->page_table_map_base +
+                ((base - iommu->page_table) << IO_PAGE_SHIFT);
+
+        /* Step 3: Normalize DMA addresses. */
+        used = nelems;
+
+        sgtmp = sglist;
+        while (used && sgtmp->dma_length) {
+                sgtmp->dma_address += dma_base;
+                sgtmp++;
+                used--;
+        }
+        used = nelems - used;
+
+        /* Step 4: Create the mappings. */
+        if (strbuf->strbuf_enabled)
+                iopte_protection = IOPTE_STREAMING(ctx);
+        else
+                iopte_protection = IOPTE_CONSISTENT(ctx);
+        if (direction != DMA_TO_DEVICE)
+                iopte_protection |= IOPTE_WRITE;
+
+        fill_sg(base, sglist, used, nelems, iopte_protection);
+
+#ifdef VERIFY_SG
+        verify_sglist(sglist, nelems, base, npages);
+#endif
+
+        return used;
+
+bad:
+        iommu_free_ctx(iommu, ctx);
+bad_no_ctx:
+        if (printk_ratelimit())
+                WARN_ON(1);
+        return 0;
+}
+
+static void dma_4u_unmap_sg(struct device *dev, struct scatterlist *sglist,
+                            int nelems, enum dma_data_direction direction)
+{
+        struct iommu *iommu;
+        struct strbuf *strbuf;
+        iopte_t *base;
+        unsigned long flags, ctx, i, npages;
+        u32 bus_addr;
+
+        if (unlikely(direction == DMA_NONE)) {
+                if (printk_ratelimit())
+                        WARN_ON(1);
+        }
+
+        iommu = dev->archdata.iommu;
+        strbuf = dev->archdata.stc;
+
+        bus_addr = sglist->dma_address & IO_PAGE_MASK;
+
+        for (i = 1; i < nelems; i++)
+                if (sglist[i].dma_length == 0)
+                        break;
+        i--;
+        npages = (IO_PAGE_ALIGN(sglist[i].dma_address + sglist[i].dma_length) -
+                  bus_addr) >> IO_PAGE_SHIFT;
+
+        base = iommu->page_table +
+                ((bus_addr - iommu->page_table_map_base) >> IO_PAGE_SHIFT);
+
+        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 the TSB entries. */
+        for (i = 0; i < npages; i++)
+                iopte_make_dummy(iommu, base + i);
+
+        free_npages(iommu, bus_addr - iommu->page_table_map_base, npages);
+
+        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;
+        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;
+        for(i = 1; i < nelems; i++)
+                if (!sglist[i].dma_length)
+                        break;
+        i--;
+        npages = (IO_PAGE_ALIGN(sglist[i].dma_address + sglist[i].dma_length)
+                  - bus_addr) >> IO_PAGE_SHIFT;
+        strbuf_flush(strbuf, iommu, bus_addr, ctx, npages, direction);
+
+        spin_unlock_irqrestore(&iommu->lock, flags);
+}
+
+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);