1 files changed, 144 insertions, 134 deletions

diff --git a/arch/sparc64/kernel/pci_sun4v.c b/arch/sparc64/kernel/pci_sun4v.c
index 61baf8dc095e..ddca6c6c0b49 100644
--- a/arch/sparc64/kernel/pci_sun4v.c
+++ b/arch/sparc64/kernel/pci_sun4v.c
@@ -1,6 +1,6 @@
 /* pci_sun4v.c: SUN4V specific PCI controller support.
  *
- * Copyright (C) 2006, 2007 David S. Miller (davem@davemloft.net)
+ * Copyright (C) 2006, 2007, 2008 David S. Miller (davem@davemloft.net)
  */
 
 #include <linux/kernel.h>
@@ -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)
 {
@@ -113,54 +124,6 @@ static inline long iommu_batch_end(void)
         return iommu_batch_flush(p);
 }
 
-static long arena_alloc(struct iommu_arena *arena, unsigned long npages)
-{
-        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;
-                        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);
-}
-
 static void *dma_4v_alloc_coherent(struct device *dev, size_t size,
                                    dma_addr_t *dma_addrp, gfp_t gfp)
 {
@@ -185,11 +148,11 @@ static void *dma_4v_alloc_coherent(struct device *dev, size_t size,
         iommu = dev->archdata.iommu;
 
         spin_lock_irqsave(&iommu->lock, flags);
-        entry = arena_alloc(&iommu->arena, npages);
+        entry = iommu_range_alloc(dev, iommu, npages, NULL);
         spin_unlock_irqrestore(&iommu->lock, flags);
 
-        if (unlikely(entry < 0L))
-                goto arena_alloc_fail;
+        if (unlikely(entry == DMA_ERROR_CODE))
+                goto range_alloc_fail;
 
         *dma_addrp = (iommu->page_table_map_base +
                       (entry << IO_PAGE_SHIFT));
@@ -219,10 +182,10 @@ static void *dma_4v_alloc_coherent(struct device *dev, size_t size,
 iommu_map_fail:
         /* Interrupts are disabled.  */
         spin_lock(&iommu->lock);
-        arena_free(&iommu->arena, entry, npages);
+        iommu_range_free(iommu, *dma_addrp, npages);
         spin_unlock_irqrestore(&iommu->lock, flags);
 
-arena_alloc_fail:
+range_alloc_fail:
         free_pages(first_page, order);
         return NULL;
 }
@@ -243,7 +206,7 @@ static void dma_4v_free_coherent(struct device *dev, size_t size, void *cpu,
 
         spin_lock_irqsave(&iommu->lock, flags);
 
-        arena_free(&iommu->arena, entry, npages);
+        iommu_range_free(iommu, dvma, npages);
 
         do {
                 unsigned long num;
@@ -281,10 +244,10 @@ static dma_addr_t dma_4v_map_single(struct device *dev, void *ptr, size_t sz,
         npages >>= IO_PAGE_SHIFT;
 
         spin_lock_irqsave(&iommu->lock, flags);
-        entry = arena_alloc(&iommu->arena, npages);
+        entry = iommu_range_alloc(dev, iommu, npages, NULL);
         spin_unlock_irqrestore(&iommu->lock, flags);
 
-        if (unlikely(entry < 0L))
+        if (unlikely(entry == DMA_ERROR_CODE))
                 goto bad;
 
         bus_addr = (iommu->page_table_map_base +
@@ -319,7 +282,7 @@ bad:
 iommu_map_fail:
         /* Interrupts are disabled.  */
         spin_lock(&iommu->lock);
-        arena_free(&iommu->arena, entry, npages);
+        iommu_range_free(iommu, bus_addr, npages);
         spin_unlock_irqrestore(&iommu->lock, flags);
 
         return DMA_ERROR_CODE;
@@ -350,9 +313,9 @@ static void dma_4v_unmap_single(struct device *dev, dma_addr_t bus_addr,
 
         spin_lock_irqsave(&iommu->lock, flags);
 
-        entry = (bus_addr - iommu->page_table_map_base) >> IO_PAGE_SHIFT;
-        arena_free(&iommu->arena, entry, npages);
+        iommu_range_free(iommu, bus_addr, npages);
 
+        entry = (bus_addr - iommu->page_table_map_base) >> IO_PAGE_SHIFT;
         do {
                 unsigned long num;
 
@@ -368,88 +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;
-        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;
-        u32 dma_base;
-
-        /* 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 = arena_alloc(&iommu->arena, npages);
-        spin_unlock_irqrestore(&iommu->lock, flags);
+        outs = s = segstart = &sglist[0];
+        outcount = 1;
+        incount = nelems;
+        handle = 0;
 
-        if (unlikely(entry < 0L))
-                goto bad;
+        /* Init first segment length for backout at failure */
+        outs->dma_length = 0;
 
-        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);
-        arena_free(&iommu->arena, entry, 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;
@@ -458,39 +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);
 
-        arena_free(&iommu->arena, entry, 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);
 }