1 files changed, 102 insertions, 0 deletions

diff --git a/arch/ia64/lib/swiotlb.c b/arch/ia64/lib/swiotlb.c
index a604efc7f6c9..48e5ff26eb1d 100644
--- a/arch/ia64/lib/swiotlb.c
+++ b/arch/ia64/lib/swiotlb.c
@@ -49,6 +49,15 @@
  */
 #define IO_TLB_SHIFT 11
 
+#define SLABS_PER_PAGE (1 << (PAGE_SHIFT - IO_TLB_SHIFT))
+
+/*
+ * Minimum IO TLB size to bother booting with.  Systems with mainly
+ * 64bit capable cards will only lightly use the swiotlb.  If we can't
+ * allocate a contiguous 1MB, we're probably in trouble anyway.
+ */
+#define IO_TLB_MIN_SLABS ((1<<20) >> IO_TLB_SHIFT)
+
 int swiotlb_force;
 
 /*
@@ -154,6 +163,99 @@ swiotlb_init (void)
         swiotlb_init_with_default_size(64 * (1<<20));   /* default to 64MB */
 }
 
+/*
+ * Systems with larger DMA zones (those that don't support ISA) can
+ * initialize the swiotlb later using the slab allocator if needed.
+ * This should be just like above, but with some error catching.
+ */
+int
+swiotlb_late_init_with_default_size (size_t default_size)
+{
+        unsigned long i, req_nslabs = io_tlb_nslabs;
+        unsigned int order;
+
+        if (!io_tlb_nslabs) {
+                io_tlb_nslabs = (default_size >> IO_TLB_SHIFT);
+                io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
+        }
+
+        /*
+         * Get IO TLB memory from the low pages
+         */
+        order = get_order(io_tlb_nslabs * (1 << IO_TLB_SHIFT));
+        io_tlb_nslabs = SLABS_PER_PAGE << order;
+
+        while ((SLABS_PER_PAGE << order) > IO_TLB_MIN_SLABS) {
+                io_tlb_start = (char *)__get_free_pages(GFP_DMA | __GFP_NOWARN,
+                                                        order);
+                if (io_tlb_start)
+                        break;
+                order--;
+        }
+
+        if (!io_tlb_start)
+                goto cleanup1;
+
+        if (order != get_order(io_tlb_nslabs * (1 << IO_TLB_SHIFT))) {
+                printk(KERN_WARNING "Warning: only able to allocate %ld MB "
+                       "for software IO TLB\n", (PAGE_SIZE << order) >> 20);
+                io_tlb_nslabs = SLABS_PER_PAGE << order;
+        }
+        io_tlb_end = io_tlb_start + io_tlb_nslabs * (1 << IO_TLB_SHIFT);
+        memset(io_tlb_start, 0, io_tlb_nslabs * (1 << IO_TLB_SHIFT));
+
+        /*
+         * Allocate and initialize the free list array.  This array is used
+         * to find contiguous free memory regions of size up to IO_TLB_SEGSIZE
+         * between io_tlb_start and io_tlb_end.
+         */
+        io_tlb_list = (unsigned int *)__get_free_pages(GFP_KERNEL,
+                                      get_order(io_tlb_nslabs * sizeof(int)));
+        if (!io_tlb_list)
+                goto cleanup2;
+
+        for (i = 0; i < io_tlb_nslabs; i++)
+                io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE);
+        io_tlb_index = 0;
+
+        io_tlb_orig_addr = (unsigned char **)__get_free_pages(GFP_KERNEL,
+                                   get_order(io_tlb_nslabs * sizeof(char *)));
+        if (!io_tlb_orig_addr)
+                goto cleanup3;
+
+        memset(io_tlb_orig_addr, 0, io_tlb_nslabs * sizeof(char *));
+
+        /*
+         * Get the overflow emergency buffer
+         */
+        io_tlb_overflow_buffer = (void *)__get_free_pages(GFP_DMA,
+                                                  get_order(io_tlb_overflow));
+        if (!io_tlb_overflow_buffer)
+                goto cleanup4;
+
+        printk(KERN_INFO "Placing %ldMB software IO TLB between 0x%lx - "
+               "0x%lx\n", (io_tlb_nslabs * (1 << IO_TLB_SHIFT)) >> 20,
+               virt_to_phys(io_tlb_start), virt_to_phys(io_tlb_end));
+
+        return 0;
+
+cleanup4:
+        free_pages((unsigned long)io_tlb_orig_addr, get_order(io_tlb_nslabs *
+                                                              sizeof(char *)));
+        io_tlb_orig_addr = NULL;
+cleanup3:
+        free_pages((unsigned long)io_tlb_list, get_order(io_tlb_nslabs *
+                                                         sizeof(int)));
+        io_tlb_list = NULL;
+        io_tlb_end = NULL;
+cleanup2:
+        free_pages((unsigned long)io_tlb_start, order);
+        io_tlb_start = NULL;
+cleanup1:
+        io_tlb_nslabs = req_nslabs;
+        return -ENOMEM;
+}
+
 static inline int
 address_needs_mapping(struct device *hwdev, dma_addr_t addr)
 {