sparc64: Clean up 64-bit mmap exclusion defines.
Older UltraSPARC chips had an address space hole due to the MMU only
supporting 44-bit virtual addresses.
The top end of this hole also has the same value as the current
definition of PAGE_OFFSET, so this can be confusing.
Consolidate the defines for the userspace mmap exclusion range into
page_64.h and use them in sys_sparc_64.c and hugetlbpage.c
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Bob Picco <bob.picco@oracle.com>
diff --git a/arch/sparc/include/asm/page_64.h b/arch/sparc/include/asm/page_64.h
index e155388..d959312 100644
--- a/arch/sparc/include/asm/page_64.h
+++ b/arch/sparc/include/asm/page_64.h
@@ -93,9 +93,22 @@
typedef pte_t *pgtable_t;
+/* These two values define the virtual address space range in which we
+ * must forbid 64-bit user processes from making mappings. It
+ * represents the virtual address space hole present in most early
+ * sparc64 chips including UltraSPARC-I. The next two defines specify
+ * the actual exclusion region we enforce, wherein we use a 4GB red
+ * zone on each side of the VA hole.
+ */
+#define SPARC64_VA_HOLE_TOP _AC(0xfffff80000000000,UL)
+#define SPARC64_VA_HOLE_BOTTOM _AC(0x0000080000000000,UL)
+
+#define VA_EXCLUDE_START (SPARC64_VA_HOLE_BOTTOM - (1UL << 32UL))
+#define VA_EXCLUDE_END (SPARC64_VA_HOLE_TOP + (1UL << 32UL))
+
#define TASK_UNMAPPED_BASE (test_thread_flag(TIF_32BIT) ? \
- (_AC(0x0000000070000000,UL)) : \
- (_AC(0xfffff80000000000,UL) + (1UL << 32UL)))
+ _AC(0x0000000070000000,UL) : \
+ VA_EXCLUDE_END)
#include <asm-generic/memory_model.h>