diff --git a/arch/sparc/include/asm/pgtable_64.h
b/arch/sparc/include/asm/pgtable_64.h
index bb9ec2c..09615a6 100644
--- a/arch/sparc/include/asm/pgtable_64.h
+++ b/arch/sparc/include/asm/pgtable_64.h
@@ -726,11 +726,17 @@ extern unsigned long pte_file(pte_t);
 extern pte_t pgoff_to_pte(unsigned long);
 #define PTE_FILE_MAX_BITS	(64UL - PAGE_SHIFT - 1UL)

-extern unsigned long *sparc64_valid_addr_bitmap;
+extern unsigned long sparc64_valid_addr_bitmap[];

 /* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
-#define kern_addr_valid(addr)	\
-	(test_bit(__pa((unsigned long)(addr))>>22, sparc64_valid_addr_bitmap))
+static inline bool kern_addr_valid(unsigned long addr)
+{
+       unsigned long paddr = __pa(addr);
+
+       if ((paddr >> 41UL) != 0UL)
+               return false;
+       return test_bit(paddr >> 22, sparc64_valid_addr_bitmap);
+}

 extern int page_in_phys_avail(unsigned long paddr);

diff --git a/arch/sparc64/kernel/ktlb.S b/arch/sparc64/kernel/ktlb.S
index cef8def..a041fd0 100644
--- a/arch/sparc64/kernel/ktlb.S
+++ b/arch/sparc64/kernel/ktlb.S
@@ -151,12 +151,46 @@ kvmap_dtlb_4v:
 	 * Must preserve %g1 and %g6 (TAG).
 	 */
 kvmap_dtlb_tsb4m_miss:
-	sethi		%hi(kpte_linear_bitmap), %g2
-	or		%g2, %lo(kpte_linear_bitmap), %g2
-
-	/* Clear the PAGE_OFFSET top virtual bits, then shift
-	 * down to get a 256MB physical address index.
-	 */
+       /* Clear the PAGE_OFFSET top virtual bits, shift
+        * down to get PFN, and make sure PFN is in range.
+        */
+       sllx            %g4, 21, %g5
+
+        /* Check to see if we know about valid memory at the 4MB
+        * chunk this physical address will reside within.
+        */
+       srlx            %g5, 21 + 41, %g2
+       brnz,pn         %g2, kvmap_dtlb_longpath
+        nop
+
+       /* This unconditional branch and delay-slot nop gets patched
+        * by the sethi sequence once the bitmap is properly setup.
+        */
+       .globl          valid_addr_bitmap_insn
+valid_addr_bitmap_insn:
+       ba,pt           %xcc, 2f
+        nop
+       .subsection     2
+       .globl          valid_addr_bitmap_patch
+valid_addr_bitmap_patch:
+       sethi           %hi(sparc64_valid_addr_bitmap), %g7
+       or              %g7, %lo(sparc64_valid_addr_bitmap), %g7
+       .previous
+
+       srlx            %g5, 21 + 22, %g2
+       srlx            %g2, 6, %g5
+       and             %g2, 63, %g2
+       sllx            %g5, 3, %g5
+       ldx             [%g7 + %g5], %g5
+       mov             1, %g7
+       sllx            %g7, %g2, %g7
+       andcc           %g5, %g7, %g0
+       be,pn           %xcc, kvmap_dtlb_longpath
+
+2:      sethi          %hi(kpte_linear_bitmap), %g2
+       or              %g2, %lo(kpte_linear_bitmap), %g2
+
+       /* Get the 256MB physical address index. */
 	sllx		%g4, 21, %g5
 	mov		1, %g7
 	srlx		%g5, 21 + 28, %g5
diff --git a/arch/sparc64/mm/init.c b/arch/sparc64/mm/init.c
index a41df7b..d2b4f70 100644
--- a/arch/sparc64/mm/init.c
+++ b/arch/sparc64/mm/init.c
@@ -51,11 +51,13 @@
 #include <asm/cpudata.h>
 #include <asm/irq.h>

-#define MAX_PHYS_ADDRESS	(1UL << 42UL)
-#define KPTE_BITMAP_CHUNK_SZ	(256UL * 1024UL * 1024UL)
+#define MAX_PHYS_ADDRESS       (1UL << 41UL)
+#define KPTE_BITMAP_CHUNK_SZ           (256UL * 1024UL * 1024UL)
 #define KPTE_BITMAP_BYTES	\
 	((MAX_PHYS_ADDRESS / KPTE_BITMAP_CHUNK_SZ) / 8)
-
+#define VALID_ADDR_BITMAP_CHUNK_SZ     (4UL * 1024UL * 1024UL)
+#define VALID_ADDR_BITMAP_BYTES        \
+       ((MAX_PHYS_ADDRESS / VALID_ADDR_BITMAP_CHUNK_SZ) / 8)
 unsigned long kern_linear_pte_xor[2] __read_mostly;

 /* A bitmap, one bit for every 256MB of physical memory.  If the bit
@@ -149,7 +151,9 @@ static void __init read_obp_memory(const char *property,
 	     cmp_p64, NULL);
 }

-unsigned long *sparc64_valid_addr_bitmap __read_mostly;
+unsigned long sparc64_valid_addr_bitmap[VALID_ADDR_BITMAP_BYTES /
+                                       sizeof(unsigned long)];
+EXPORT_SYMBOL(sparc64_valid_addr_bitmap);

 /* Kernel physical address base and size in bytes.  */
 unsigned long kern_base __read_mostly;
@@ -1843,7 +1847,7 @@ static int pavail_rescan_ents __initdata;
  * memory list again, and make sure it provides at least as much
  * memory as 'pavail' does.
  */
-static void __init setup_valid_addr_bitmap_from_pavail(void)
+static void __init setup_valid_addr_bitmap_from_pavail(unsigned long *bitmap)
 {
 	int i;

@@ -1866,8 +1870,7 @@ static void __init
setup_valid_addr_bitmap_from_pavail(void)

 				if (new_start <= old_start &&
 				    new_end >= (old_start + PAGE_SIZE)) {
-					set_bit(old_start >> 22,
-						sparc64_valid_addr_bitmap);
+					set_bit(old_start >> 22, bitmap);
 					goto do_next_page;
 				}