uml: fix page table data sizes

Get the sizes of various pieces of data right when using three-level
page tables.  pgd and pmd entries remain at 32 bits in a 32-bit
compilation because page tables will remain in low memory.  So,
PGDIR_SHIFT, the PTRS_PER_* values, set_pud, set_pmd are conditional
on 64BIT.

More use of phys_t is made when there are physical memory addresses
floating around.

ObCheckpatchViolationJustification - the new typedef is an alternate
definition of pmd_t, which I can't really live without.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/asm-um/page.h b/include/asm-um/page.h
index 4b424c7..fe2374d 100644
--- a/include/asm-um/page.h
+++ b/include/asm-um/page.h
@@ -30,7 +30,7 @@
 #if defined(CONFIG_3_LEVEL_PGTABLES) && !defined(CONFIG_64BIT)
 
 typedef struct { unsigned long pte_low, pte_high; } pte_t;
-typedef struct { unsigned long long pmd; } pmd_t;
+typedef struct { unsigned long pmd; } pmd_t;
 typedef struct { unsigned long pgd; } pgd_t;
 #define pte_val(x) ((x).pte_low | ((unsigned long long) (x).pte_high << 32))
 
@@ -106,8 +106,8 @@
 #define __pa(virt) to_phys((void *) (unsigned long) (virt))
 #define __va(phys) to_virt((unsigned long) (phys))
 
-#define phys_to_pfn(p) ((p) >> PAGE_SHIFT)
-#define pfn_to_phys(pfn) ((pfn) << PAGE_SHIFT)
+#define phys_to_pfn(p) ((pfn_t) ((p) >> PAGE_SHIFT))
+#define pfn_to_phys(pfn) ((phys_t) ((pfn) << PAGE_SHIFT))
 
 #define pfn_valid(pfn) ((pfn) < max_mapnr)
 #define virt_addr_valid(v) pfn_valid(phys_to_pfn(__pa(v)))