2 files changed, 290 insertions, 147 deletions

diff --git a/arch/sparc64/kernel/iommu.c b/arch/sparc64/kernel/iommu.c
index 90a5907080a1..d3276ebcfb47 100644
--- a/arch/sparc64/kernel/iommu.c
+++ b/arch/sparc64/kernel/iommu.c
@@ -512,124 +512,209 @@ static void dma_4u_unmap_single(struct device *dev, dma_addr_t bus_addr,
 static int dma_4u_map_sg(struct device *dev, struct scatterlist *sglist,
                          int nelems, enum dma_data_direction direction)
 {
-        unsigned long flags, ctx, i, npages, iopte_protection;
-        struct scatterlist *sg;
+        struct scatterlist *s, *outs, *segstart;
+        unsigned long flags, handle, prot, ctx;
+        dma_addr_t dma_next = 0, dma_addr;
+        unsigned int max_seg_size;
+        int outcount, incount, i;
         struct strbuf *strbuf;
         struct iommu *iommu;
-        iopte_t *base;
-        u32 dma_base;
-
-        /* Fast path single entry scatterlists. */
-        if (nelems == 1) {
-                sglist->dma_address =
-                        dma_4u_map_single(dev, sg_virt(sglist),
-                                          sglist->length, direction);
-                if (unlikely(sglist->dma_address == DMA_ERROR_CODE))
-                        return 0;
-                sglist->dma_length = sglist->length;
-                return 1;
-        }
+
+        BUG_ON(direction == DMA_NONE);
 
         iommu = dev->archdata.iommu;
         strbuf = dev->archdata.stc;
-
-        if (unlikely(direction == DMA_NONE))
-                goto bad_no_ctx;
-
-        npages = calc_npages(sglist, nelems);
+        if (nelems == 0 || !iommu)
+                return 0;
 
         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 (base == NULL)
-                goto bad;
-
-        dma_base = iommu->page_table_map_base +
-                ((base - iommu->page_table) << IO_PAGE_SHIFT);
-
         if (strbuf->strbuf_enabled)
-                iopte_protection = IOPTE_STREAMING(ctx);
+                prot = IOPTE_STREAMING(ctx);
         else
-                iopte_protection = IOPTE_CONSISTENT(ctx);
+                prot = IOPTE_CONSISTENT(ctx);
         if (direction != DMA_TO_DEVICE)
-                iopte_protection |= IOPTE_WRITE;
-
-        for_each_sg(sglist, sg, nelems, i) {
-                unsigned long paddr = SG_ENT_PHYS_ADDRESS(sg);
-                unsigned long slen = sg->length;
-                unsigned long this_npages;
+                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);
+        for_each_sg(sglist, s, nelems, i) {
+                unsigned long paddr, npages, entry, 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);
+                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;
+                }
 
-                this_npages = iommu_num_pages(paddr, slen);
+                base = iommu->page_table + entry;
 
-                sg->dma_address = dma_base | (paddr & ~IO_PAGE_MASK);
-                sg->dma_length = slen;
+                /* 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 (this_npages--) {
-                        iopte_val(*base) = iopte_protection | paddr;
-
+                while (npages--) {
+                        iopte_val(*base) = prot | paddr;
                         base++;
                         paddr += IO_PAGE_SIZE;
-                        dma_base += 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)) {
+                                /* 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;
+                }
+
+                /* Calculate next page pointer for contiguous check */
+                dma_next = dma_addr + slen;
         }
 
-        return nelems;
+        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, i;
+                        iopte_t *base;
+
+                        vaddr = s->dma_address & IO_PAGE_MASK;
+                        npages = iommu_num_pages(s->dma_address, s->dma_length);
+                        iommu_range_free(iommu, vaddr, npages);
+
+                        entry = (vaddr - iommu->page_table_map_base)
+                                >> IO_PAGE_SHIFT;
+                        base = iommu->page_table + entry;
+
+                        for (i = 0; i < npages; i++)
+                                iopte_make_dummy(iommu, base + i);
+
+                        s->dma_address = DMA_ERROR_CODE;
+                        s->dma_length = 0;
+                }
+                if (s == outs)
+                        break;
+        }
+        spin_unlock_irqrestore(&iommu->lock, flags);
 
-bad:
-        iommu_free_ctx(iommu, ctx);
-bad_no_ctx:
-        if (printk_ratelimit())
-                WARN_ON(1);
         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, i, npages;
+        unsigned long flags, ctx;
+        struct scatterlist *sg;
         struct strbuf *strbuf;
         struct iommu *iommu;
-        iopte_t *base;
-        u32 bus_addr;
 
-        if (unlikely(direction == DMA_NONE)) {
-                if (printk_ratelimit())
-                        WARN_ON(1);
-        }
+        BUG_ON(direction == DMA_NONE);
 
         iommu = dev->archdata.iommu;
         strbuf = dev->archdata.stc;
 
-        bus_addr = sglist->dma_address & IO_PAGE_MASK;
+        ctx = fetch_sg_ctx(iommu, sglist);
 
-        npages = calc_npages(sglist, nelems);
+        spin_lock_irqsave(&iommu->lock, flags);
 
-        base = iommu->page_table +
-                ((bus_addr - iommu->page_table_map_base) >> IO_PAGE_SHIFT);
+        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;
 
-        spin_lock_irqsave(&iommu->lock, flags);
+                if (!len)
+                        break;
+                npages = iommu_num_pages(dma_handle, len);
+                iommu_range_free(iommu, dma_handle, npages);
 
-        /* Record the context, if any. */
-        ctx = 0;
-        if (iommu->iommu_ctxflush)
-                ctx = (iopte_val(*base) & IOPTE_CONTEXT) >> 47UL;
+                entry = ((dma_handle - iommu->page_table_map_base)
+                         >> IO_PAGE_SHIFT);
+                base = iommu->page_table + entry;
 
-        /* Step 1: Kick data out of streaming buffers if necessary. */
-        if (strbuf->strbuf_enabled)
-                strbuf_flush(strbuf, iommu, bus_addr, ctx, npages, direction);
+                dma_handle &= IO_PAGE_MASK;
+                if (strbuf->strbuf_enabled)
+                        strbuf_flush(strbuf, iommu, dma_handle, ctx,
+                                     npages, direction);
 
-        /* Step 2: Clear out the TSB entries. */
-        for (i = 0; i < npages; i++)
-                iopte_make_dummy(iommu, base + i);
+                for (i = 0; i < npages; i++)
+                        iopte_make_dummy(iommu, base + i);
 
-        iommu_range_free(iommu, bus_addr, npages);
+                sg = sg_next(sg);
+        }
 
         iommu_free_ctx(iommu, ctx);
 
diff --git a/arch/sparc64/kernel/pci_sun4v.c b/arch/sparc64/kernel/pci_sun4v.c
index c8b6199a5dc4..ddca6c6c0b49 100644
--- a/arch/sparc64/kernel/pci_sun4v.c
+++ b/arch/sparc64/kernel/pci_sun4v.c
@@ -89,6 +89,17 @@ static long iommu_batch_flush(struct iommu_batch *p)
         return 0;
 }
 
+static inline void iommu_batch_new_entry(unsigned long entry)
+{
+        struct iommu_batch *p = &__get_cpu_var(iommu_batch);
+
+        if (p->entry + p->npages == entry)
+                return;
+        if (p->entry != ~0UL)
+                iommu_batch_flush(p);
+        p->entry = entry;
+}
+
 /* Interrupts must be disabled.  */
 static inline long iommu_batch_add(u64 phys_page)
 {
@@ -320,88 +331,131 @@ static void dma_4v_unmap_single(struct device *dev, dma_addr_t bus_addr,
 static int dma_4v_map_sg(struct device *dev, struct scatterlist *sglist,
                          int nelems, enum dma_data_direction direction)
 {
-        unsigned long flags, npages, i, prot;
-        u32 dma_base, orig_dma_base;
-        struct scatterlist *sg;
+        struct scatterlist *s, *outs, *segstart;
+        unsigned long flags, handle, prot;
+        dma_addr_t dma_next = 0, dma_addr;
+        unsigned int max_seg_size;
+        int outcount, incount, i;
         struct iommu *iommu;
-        long entry, err;
-
-        /* Fast path single entry scatterlists. */
-        if (nelems == 1) {
-                sglist->dma_address =
-                        dma_4v_map_single(dev, sg_virt(sglist),
-                                          sglist->length, direction);
-                if (unlikely(sglist->dma_address == DMA_ERROR_CODE))
-                        return 0;
-                sglist->dma_length = sglist->length;
-                return 1;
-        }
+        long err;
+
+        BUG_ON(direction == DMA_NONE);
 
         iommu = dev->archdata.iommu;
+        if (nelems == 0 || !iommu)
+                return 0;
         
-        if (unlikely(direction == DMA_NONE))
-                goto bad;
-
-        npages = calc_npages(sglist, nelems);
+        prot = HV_PCI_MAP_ATTR_READ;
+        if (direction != DMA_TO_DEVICE)
+                prot |= HV_PCI_MAP_ATTR_WRITE;
 
-        spin_lock_irqsave(&iommu->lock, flags);
-        entry = iommu_range_alloc(dev, iommu, npages, NULL);
-        spin_unlock_irqrestore(&iommu->lock, flags);
+        outs = s = segstart = &sglist[0];
+        outcount = 1;
+        incount = nelems;
+        handle = 0;
 
-        if (unlikely(entry == DMA_ERROR_CODE))
-                goto bad;
+        /* Init first segment length for backout at failure */
+        outs->dma_length = 0;
 
-        orig_dma_base = dma_base = iommu->page_table_map_base +
-                (entry << IO_PAGE_SHIFT);
+        spin_lock_irqsave(&iommu->lock, flags);
 
-        prot = HV_PCI_MAP_ATTR_READ;
-        if (direction != DMA_TO_DEVICE)
-                prot |= HV_PCI_MAP_ATTR_WRITE;
+        iommu_batch_start(dev, prot, ~0UL);
 
-        local_irq_save(flags);
+        max_seg_size = dma_get_max_seg_size(dev);
+        for_each_sg(sglist, s, nelems, i) {
+                unsigned long paddr, npages, entry, slen;
 
-        iommu_batch_start(dev, prot, entry);
+                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);
+                entry = iommu_range_alloc(dev, iommu, npages, &handle);
 
-        for_each_sg(sglist, sg, nelems, i) {
-                unsigned long paddr = SG_ENT_PHYS_ADDRESS(sg);
-                unsigned long slen = sg->length;
-                unsigned long this_npages;
+                /* 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;
+                }
 
-                this_npages = iommu_num_pages(paddr, slen);
+                iommu_batch_new_entry(entry);
 
-                sg->dma_address = dma_base | (paddr & ~IO_PAGE_MASK);
-                sg->dma_length = slen;
+                /* 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 (this_npages--) {
+                while (npages--) {
                         err = iommu_batch_add(paddr);
-                        if (unlikely(err < 0L)) {
-                                local_irq_restore(flags);
+                        if (unlikely(err < 0L))
                                 goto iommu_map_failed;
+                        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)) {
+                                /* Can't merge: create a new segment */
+                                segstart = s;
+                                outcount++;
+                                outs = sg_next(outs);
+                        } else {
+                                outs->dma_length += s->length;
                         }
+                }
 
-                        paddr += IO_PAGE_SIZE;
-                        dma_base += IO_PAGE_SIZE;
+                if (segstart == s) {
+                        /* This is a new segment, fill entries */
+                        outs->dma_address = dma_addr;
+                        outs->dma_length = slen;
                 }
+
+                /* Calculate next page pointer for contiguous check */
+                dma_next = dma_addr + slen;
         }
 
         err = iommu_batch_end();
 
-        local_irq_restore(flags);
-
         if (unlikely(err < 0L))
                 goto iommu_map_failed;
 
-        return nelems;
+        spin_unlock_irqrestore(&iommu->lock, flags);
 
-bad:
-        if (printk_ratelimit())
-                WARN_ON(1);
-        return 0;
+        if (outcount < incount) {
+                outs = sg_next(outs);
+                outs->dma_address = DMA_ERROR_CODE;
+                outs->dma_length = 0;
+        }
+
+        return outcount;
 
 iommu_map_failed:
-        spin_lock_irqsave(&iommu->lock, flags);
-        iommu_range_free(iommu, orig_dma_base, npages);
+        for_each_sg(sglist, s, nelems, i) {
+                if (s->dma_length != 0) {
+                        unsigned long vaddr, npages;
+
+                        vaddr = s->dma_address & IO_PAGE_MASK;
+                        npages = iommu_num_pages(s->dma_address, s->dma_length);
+                        iommu_range_free(iommu, vaddr, npages);
+                        /* XXX demap? XXX */
+                        s->dma_address = DMA_ERROR_CODE;
+                        s->dma_length = 0;
+                }
+                if (s == outs)
+                        break;
+        }
         spin_unlock_irqrestore(&iommu->lock, flags);
 
         return 0;
@@ -410,39 +464,43 @@ iommu_map_failed:
 static void dma_4v_unmap_sg(struct device *dev, struct scatterlist *sglist,
                             int nelems, enum dma_data_direction direction)
 {
-        unsigned long flags, npages;
         struct pci_pbm_info *pbm;
-        u32 devhandle, bus_addr;
+        struct scatterlist *sg;
         struct iommu *iommu;
-        long entry;
+        unsigned long flags;
+        u32 devhandle;
 
-        if (unlikely(direction == DMA_NONE)) {
-                if (printk_ratelimit())
-                        WARN_ON(1);
-        }
+        BUG_ON(direction == DMA_NONE);
 
         iommu = dev->archdata.iommu;
         pbm = dev->archdata.host_controller;
         devhandle = pbm->devhandle;
         
-        bus_addr = sglist->dma_address & IO_PAGE_MASK;
-
-        npages = calc_npages(sglist, nelems);
-
-        entry = ((bus_addr - iommu->page_table_map_base) >> IO_PAGE_SHIFT);
-
         spin_lock_irqsave(&iommu->lock, flags);
 
-        iommu_range_free(iommu, bus_addr, npages);
-
-        do {
-                unsigned long num;
+        sg = sglist;
+        while (nelems--) {
+                dma_addr_t dma_handle = sg->dma_address;
+                unsigned int len = sg->dma_length;
+                unsigned long npages, entry;
+
+                if (!len)
+                        break;
+                npages = iommu_num_pages(dma_handle, len);
+                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;
+                }
 
-                num = pci_sun4v_iommu_demap(devhandle, HV_PCI_TSBID(0, entry),
-                                            npages);
-                entry += num;
-                npages -= num;
-        } while (npages != 0);
+                sg = sg_next(sg);
+        }
 
         spin_unlock_irqrestore(&iommu->lock, flags);
 }