linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
To: Ingo Molnar <mingo@redhat.com>,
	x86@kernel.org, Thomas Gleixner <tglx@linutronix.de>,
	"H. Peter Anvin" <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	Andy Lutomirski <luto@amacapital.net>,
	Borislav Petkov <bp@suse.de>, Andi Kleen <ak@linux.intel.com>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Subject: [PATCH 1/9] x86/mm/64: Make __PHYSICAL_MASK_SHIFT always 52
Date: Wed, 14 Feb 2018 14:16:48 +0300	[thread overview]
Message-ID: <20180214111656.88514-2-kirill.shutemov@linux.intel.com> (raw)
In-Reply-To: <20180214111656.88514-1-kirill.shutemov@linux.intel.com>

__PHYSICAL_MASK_SHIFT is used to define the mask that helps to extract
physical address from a page table entry.

Although, real physical address space available may differ between
machines, it's safe to use 52 as __PHYSICAL_MASK_SHIFT. Unused bits
above log2(MAXPHYADDR) up to bit 51 are reserved and must be 0.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
 arch/x86/include/asm/page_64_types.h | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/page_64_types.h b/arch/x86/include/asm/page_64_types.h
index e1407312c412..f68e6526891d 100644
--- a/arch/x86/include/asm/page_64_types.h
+++ b/arch/x86/include/asm/page_64_types.h
@@ -52,11 +52,12 @@
 #define __START_KERNEL_map	_AC(0xffffffff80000000, UL)
 
 /* See Documentation/x86/x86_64/mm.txt for a description of the memory map. */
-#ifdef CONFIG_X86_5LEVEL
+
 #define __PHYSICAL_MASK_SHIFT	52
+
+#ifdef CONFIG_X86_5LEVEL
 #define __VIRTUAL_MASK_SHIFT	56
 #else
-#define __PHYSICAL_MASK_SHIFT	46
 #define __VIRTUAL_MASK_SHIFT	47
 #endif
 
-- 
2.15.1

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

  reply	other threads:[~2018-02-14 11:17 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-02-14 11:16 [PATCH 0/9] x86/mm: Dynamic memory layout Kirill A. Shutemov
2018-02-14 11:16 ` Kirill A. Shutemov [this message]
2018-02-14 11:16 ` [PATCH 2/9] mm/zsmalloc: Prepare to variable MAX_PHYSMEM_BITS Kirill A. Shutemov
2018-02-14 11:16 ` [PATCH 3/9] x86/mm: Make virtual memory layout movable for CONFIG_X86_5LEVEL Kirill A. Shutemov
2018-02-14 11:16 ` [PATCH 4/9] x86: Introduce pgtable_l5_enabled Kirill A. Shutemov
2018-02-14 11:16 ` [PATCH 5/9] x86/mm: Make LDT_BASE_ADDR dynamic Kirill A. Shutemov
2018-02-14 13:32   ` Kirill A. Shutemov
2018-02-14 11:16 ` [PATCH 6/9] x86/mm: Make PGDIR_SHIFT and PTRS_PER_P4D variable Kirill A. Shutemov
2018-02-14 11:16 ` [PATCH 7/9] x86/mm: Make MAX_PHYSADDR_BITS and MAX_PHYSMEM_BITS dynamic Kirill A. Shutemov
2018-02-14 11:16 ` [PATCH 8/9] x86/mm: Make __VIRTUAL_MASK_SHIFT dynamic Kirill A. Shutemov
2018-02-14 17:22   ` Andy Lutomirski
2018-02-14 17:55     ` Kirill A. Shutemov
2018-02-14 18:02       ` Andy Lutomirski
2018-02-14 11:16 ` [PATCH 9/9] x86/mm: Adjust virtual address space layout in early boot Kirill A. Shutemov
2018-02-14 12:10   ` Ingo Molnar
2018-02-14 12:19     ` Kirill A. Shutemov
2018-02-14 12:26       ` Ingo Molnar

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20180214111656.88514-2-kirill.shutemov@linux.intel.com \
    --to=kirill.shutemov@linux.intel.com \
    --cc=ak@linux.intel.com \
    --cc=bp@suse.de \
    --cc=hpa@zytor.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=luto@amacapital.net \
    --cc=mingo@redhat.com \
    --cc=tglx@linutronix.de \
    --cc=torvalds@linux-foundation.org \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).