[PATCH 1/8] x86/dump_pagetables: Generalize address normalization

From: Kirill A. Shutemov
Date: Sun Jul 16 2017 - 19:01:24 EST


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>
---
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 0470826d2bdc..a824d575bb84 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;
}

/*
--
2.11.0