[tip:x86/mm] x86/mm/dump_pagetables: Generalize address normalization

[tip-bot for Kirill A. Shutemov]

Commit-ID:  3a366f791d83c690f3042e37f410f38de04fb4c7
Gitweb:     http://git.kernel.org/tip/3a366f791d83c690f3042e37f410f38de04fb4c7
Author:     Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
AuthorDate: Mon, 17 Jul 2017 01:59:47 +0300
Committer:  Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Fri, 21 Jul 2017 10:05:17 +0200

x86/mm/dump_pagetables: Generalize address normalization

Modify normalize_addr to handle different sizes of virtual address
space.

It's preparation for enabling 5-level paging.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: linux-arch@xxxxxxxxxxxxxxx
Cc: linux-mm@xxxxxxxxx
Link: http://lkml.kernel.org/r/20170716225954.74185-2-kirill.shutemov@xxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 arch/x86/mm/dump_pagetables.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c
index 0470826..a824d57 100644
--- a/arch/x86/mm/dump_pagetables.c
+++ b/arch/x86/mm/dump_pagetables.c
@@ -188,11 +188,12 @@ static void printk_prot(struct seq_file *m, pgprot_t prot, int level, bool dmsg)
  */
 static unsigned long normalize_addr(unsigned long u)
 {
-#ifdef CONFIG_X86_64
-	return (signed long)(u << 16) >> 16;
-#else
-	return u;
-#endif
+	int shift;
+	if (!IS_ENABLED(CONFIG_X86_64))
+		return u;
+
+	shift = 64 - (__VIRTUAL_MASK_SHIFT + 1);
+	return (signed long)(u << shift) >> shift;
 }
 
 /*