Merge ../torvalds-2.6/

[pandora-kernel.git] / arch / ia64 / mm / init.c

diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c
index 65f9958..1281c60 100644 (file)
--- a/arch/ia64/mm/init.c
+++ b/arch/ia64/mm/init.c
@@ -382,13 +382,22 @@ ia64_mmu_init (void *my_cpu_data)
 
        if (impl_va_bits < 51 || impl_va_bits > 61)
                panic("CPU has bogus IMPL_VA_MSB value of %lu!\n", impl_va_bits - 1);
+       /*
+        * mapped_space_bits - PAGE_SHIFT is the total number of ptes we need,
+        * which must fit into "vmlpt_bits - pte_bits" slots. Second half of
+        * the test makes sure that our mapped space doesn't overlap the
+        * unimplemented hole in the middle of the region.
+        */
+       if ((mapped_space_bits - PAGE_SHIFT > vmlpt_bits - pte_bits) ||
+           (mapped_space_bits > impl_va_bits - 1))
+               panic("Cannot build a big enough virtual-linear page table"
+                     " to cover mapped address space.\n"
+                     " Try using a smaller page size.\n");
+
 
        /* place the VMLPT at the end of each page-table mapped region: */
        pta = POW2(61) - POW2(vmlpt_bits);
 
-       if (POW2(mapped_space_bits) >= pta)
-               panic("mm/init: overlap between virtually mapped linear page table and "
-                     "mapped kernel space!");
        /*
         * Set the (virtually mapped linear) page table address.  Bit
         * 8 selects between the short and long format, bits 2-7 the