Re: recent fix for pgd_addr_end

["Luck, Tony" <tony.luck@intel.com>]

Peter, Dave, and anyone else following along:

How does this look (ignoring for the moment the usage of pgd_addr_end()
in the vmalloc() code path for region 5 ... I'll deal with that next, but
for the moment it is only a theoretical problem as we don't map anywhere
close to enough things in region 5 to trigger the IA64_PGD_OVERFLOW path
in this code).

-Tony

=== include/asm-ia64/pgtable.h 1.55 vs edited ==--- 1.55/include/asm-ia64/pgtable.h	2005-03-16 09:33:36 -08:00
+++ edited/include/asm-ia64/pgtable.h	2005-03-17 16:15:14 -08:00
@@ -557,13 +557,21 @@
  *      +--------+------+--------+-----+-----+--------+
  *      | pgdhi3 | rsvd | pgdlow | pmd | pte | offset |
  *      +--------+------+--------+-----+-----+--------+
- *  The high bit of 'pgdlow' must be sign extended across the 'rsvd' bits.
+ *  'pgdlow' overflows to pgdhi3 (a.k.a. region bits) leaving rsvd=0
  */
-#define IA64_PGD_SIGNEXTEND (PGDIR_SIZE << (PAGE_SHIFT-7))
+#define IA64_PGD_OVERFLOW (PGDIR_SIZE << (PAGE_SHIFT-6))
+
 #define pgd_addr_end(addr, end)						\
 ({	unsigned long __boundary = ((addr) + PGDIR_SIZE) & PGDIR_MASK;	\
-	if (__boundary & IA64_PGD_SIGNEXTEND)				\
-		__boundary |= (RGN_SIZE - 1) & ~(IA64_PGD_SIGNEXTEND-1);\
+	if (__boundary & IA64_PGD_OVERFLOW)				\
+		__boundary += (RGN_SIZE - 1) & ~(IA64_PGD_OVERFLOW - 1);\
+	(__boundary - 1 < (end) - 1)? __boundary: (end);		\
+})
+
+#define pmd_addr_end(addr, end)						\
+({	unsigned long __boundary = ((addr) + PMD_SIZE) & PMD_MASK;	\
+	if (__boundary & IA64_PGD_OVERFLOW)				\
+		__boundary += (RGN_SIZE - 1) & ~(IA64_PGD_OVERFLOW - 1);\
 	(__boundary - 1 < (end) - 1)? __boundary: (end);		\
 })