The entire swiotlb aperture does not need to be contiguous.

Only individual aligned SEGSIZE blocks need to be contiguous.

Signed-off-by: Keir Fraser <keir@xensource.com>

diff --git a/linux-2.6-xen-sparse/arch/xen/i386/kernel/swiotlb.c b/linux-2.6-xen-sparse/arch/xen/i386/kernel/swiotlb.c
index 75afdc7e74f3fdac2804b385835610483845795f..db3881c840b05590d6b669e3b00c3588cce3e0ad 100644 (file)
--- a/linux-2.6-xen-sparse/arch/xen/i386/kernel/swiotlb.c
+++ b/linux-2.6-xen-sparse/arch/xen/i386/kernel/swiotlb.c
@@ -94,9 +94,6 @@ setup_io_tlb_npages(char *str)
                iotlb_nslabs = simple_strtoul(str, &str, 0) <<
                        (20 - IO_TLB_SHIFT);
                iotlb_nslabs = ALIGN(iotlb_nslabs, IO_TLB_SEGSIZE);
-               /* Round up to power of two (xen_create_contiguous_region). */
-               while (iotlb_nslabs & (iotlb_nslabs-1))
-                       iotlb_nslabs += iotlb_nslabs & ~(iotlb_nslabs-1);
        }
        if (*str == ',')
                ++str;
@@ -123,9 +120,6 @@ swiotlb_init_with_default_size (size_t default_size)
        if (!iotlb_nslabs) {
                iotlb_nslabs = (default_size >> IO_TLB_SHIFT);
                iotlb_nslabs = ALIGN(iotlb_nslabs, IO_TLB_SEGSIZE);
-               /* Round up to power of two (xen_create_contiguous_region). */
-               while (iotlb_nslabs & (iotlb_nslabs-1))
-                       iotlb_nslabs += iotlb_nslabs & ~(iotlb_nslabs-1);
        }
 
        bytes = iotlb_nslabs * (1UL << IO_TLB_SHIFT);
@@ -139,8 +133,10 @@ swiotlb_init_with_default_size (size_t default_size)
                      "Use dom0_mem Xen boot parameter to reserve\n"
                      "some DMA memory (e.g., dom0_mem=-128M).\n");
 
-       xen_create_contiguous_region(
-               (unsigned long)iotlb_virt_start, get_order(bytes));
+       for (i = 0; i < iotlb_nslabs; i += IO_TLB_SEGSIZE)
+               xen_create_contiguous_region(
+                       (unsigned long)iotlb_virt_start + (i << IO_TLB_SHIFT),
+                       get_order(IO_TLB_SEGSIZE << IO_TLB_SHIFT));
 
        iotlb_virt_end = iotlb_virt_start + bytes;