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/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index 64165a7..68aee43 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -889,6 +889,14 @@
 	__pmd_val_bits = 0;
 	__pud_val_bits = 0;
 	__pgd_val_bits = 0;
+
+	__kernel_virt_start = H_KERN_VIRT_START;
+	__kernel_virt_size = H_KERN_VIRT_SIZE;
+	__vmalloc_start = H_VMALLOC_START;
+	__vmalloc_end = H_VMALLOC_END;
+	vmemmap = (struct page *)H_VMEMMAP_BASE;
+	ioremap_bot = IOREMAP_BASE;
+
 	/* Initialize the MMU Hash table and create the linear mapping
 	 * of memory. Has to be done before SLB initialization as this is
 	 * currently where the page size encoding is obtained.