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);