powerpc/mm: vmalloc abstraction in preparation for radix

The vmalloc range differs between hash and radix config. Hence make
VMALLOC_START and related constants a variable which will be runtime
initialized depending on whether hash or radix mode is active.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
[mpe: Fix missing init of ioremap_bot in pgtable_64.c for ppc64e]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/mm/pgtable_64.c b/arch/powerpc/mm/pgtable_64.c
index b8c75e6..216e2bd 100644
--- a/arch/powerpc/mm/pgtable_64.c
+++ b/arch/powerpc/mm/pgtable_64.c
@@ -97,9 +97,20 @@
 EXPORT_SYMBOL(__pud_val_bits);
 unsigned long __pgd_val_bits;
 EXPORT_SYMBOL(__pgd_val_bits);
-
-#endif
+unsigned long __kernel_virt_start;
+EXPORT_SYMBOL(__kernel_virt_start);
+unsigned long __kernel_virt_size;
+EXPORT_SYMBOL(__kernel_virt_size);
+unsigned long __vmalloc_start;
+EXPORT_SYMBOL(__vmalloc_start);
+unsigned long __vmalloc_end;
+EXPORT_SYMBOL(__vmalloc_end);
+struct page *vmemmap;
+EXPORT_SYMBOL(vmemmap);
+unsigned long ioremap_bot;
+#else /* !CONFIG_PPC_BOOK3S_64 */
 unsigned long ioremap_bot = IOREMAP_BASE;
+#endif
 
 /**
  * __ioremap_at - Low level function to establish the page tables