When a 64-bit x86 processor runs in 32-bit PAE mode, a pte can
potentially have the same number of physical address bits as the
64-bit host ("Enhanced Legacy PAE Paging"). This means, in theory,
we could have up to 52 bits of physical address in a pte.
The 32-bit kernel uses a 32-bit unsigned long to represent a pfn.
This means that it can only represent physical addresses up to 32+12=44
bits wide. Rather than widening pfns everywhere, just set 2^44 as the
Linux x86_32-PAE architectural limit for physical address size.
This is a bugfix for two cases:
1. running a 32-bit PAE kernel on a machine with
more than 64GB RAM.
2. running a 32-bit PAE Xen guest on a host machine with
more than 64GB RAM
In both cases, a pte could need to have more than 36 bits of physical,
and masking it to 36-bits will cause fairly severe havoc.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Jan Beulich <jbeulich@novell.com>
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Make them similar so that both use THREAD_ORDER and THREAD_FLAGS and have a
THREAD_SIZE definition that is setup in asm/page_xx.h
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Specifically the boot time page tables in a CONFIG_X86_PAE=y enabled
kernel are in PAE format.
early_ioremap is updated to use the standard page table accessors.
Clear any mappings beyond max_low_pfn from the boot page tables in
native_pagetable_setup_start because the initial mappings can extend
beyond the range of physical memory and into the vmalloc area.
Derived from patches by Eric Biederman and H. Peter Anvin.
[ jeremy@goop.org: PAE swapper_pg_dir needs to be page-sized fix ]
Signed-off-by: Ian Campbell <ijc@hellion.org.uk>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Mika Penttilä <mika.penttila@kolumbus.fi>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Commit 2f569afd9c ("CONFIG_HIGHPTE vs.
sub-page page tables") caused some build breakage due to pgtable_t only
getting declared in the CONFIG_X86_PAE case.
Move the declaration outside the PAE section.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Background: I've implemented 1K/2K page tables for s390. These sub-page
page tables are required to properly support the s390 virtualization
instruction with KVM. The SIE instruction requires that the page tables
have 256 page table entries (pte) followed by 256 page status table entries
(pgste). The pgstes are only required if the process is using the SIE
instruction. The pgstes are updated by the hardware and by the hypervisor
for a number of reasons, one of them is dirty and reference bit tracking.
To avoid wasting memory the standard pte table allocation should return
1K/2K (31/64 bit) and 2K/4K if the process is using SIE.
Problem: Page size on s390 is 4K, page table size is 1K or 2K. That means
the s390 version for pte_alloc_one cannot return a pointer to a struct
page. Trouble is that with the CONFIG_HIGHPTE feature on x86 pte_alloc_one
cannot return a pointer to a pte either, since that would require more than
32 bit for the return value of pte_alloc_one (and the pte * would not be
accessible since its not kmapped).
Solution: The only solution I found to this dilemma is a new typedef: a
pgtable_t. For s390 pgtable_t will be a (pte *) - to be introduced with a
later patch. For everybody else it will be a (struct page *). The
additional problem with the initialization of the ptl lock and the
NR_PAGETABLE accounting is solved with a constructor pgtable_page_ctor and
a destructor pgtable_page_dtor. The page table allocation and free
functions need to call these two whenever a page table page is allocated or
freed. pmd_populate will get a pgtable_t instead of a struct page pointer.
To get the pgtable_t back from a pmd entry that has been installed with
pmd_populate a new function pmd_pgtable is added. It replaces the pmd_page
call in free_pte_range and apply_to_pte_range.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make sure pte_t, whatever its definition, has a pte element with type
pteval_t. This allows common code to access it without needing to be
specifically parameterised on what pagetable mode we're compiling for.
For 32-bit, this means that pte_t becomes a union with "pte" and "{
pte_low, pte_high }" (PAE) or just "pte_low" (non-PAE).
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
# HG changeset patch
# User Jeremy Fitzhardinge <jeremy@xensource.com>
# Date 1199321648 28800
# Node ID 22f6a5902285b58bfc1fbbd9e183498c9017bd78
# Parent bba9287641ff90e836d090d80b5c0a846aab7162
x86: page.h: move things back to their own files
Oops, asm/page.h has turned into an #ifdef hellhole. Move
32/64-specific things back to their own headers to make it somewhat
comprehensible...
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
# HG changeset patch
# User Jeremy Fitzhardinge <jeremy@xensource.com>
# Date 1199319657 28800
# Node ID bba9287641ff90e836d090d80b5c0a846aab7162
# Parent d617b72a0cc9d14bde2087d065c36d4ed3265761
x86: page.h: move remaining bits and pieces
Move the remaining odds and ends into page.h.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
# HG changeset patch
# User Jeremy Fitzhardinge <jeremy@xensource.com>
# Date 1199319656 28800
# Node ID d617b72a0cc9d14bde2087d065c36d4ed3265761
# Parent 3bd7db6e85e66e7f3362874802df26a82fcb2d92
x86: page.h: move pa and va related things
Move and unify the virtual<->physical address space conversion
functions.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
# HG changeset patch
# User Jeremy Fitzhardinge <jeremy@xensource.com>
# Date 1199319654 28800
# Node ID 3bd7db6e85e66e7f3362874802df26a82fcb2d92
# Parent f7e7db3facd9406545103164f9be8f9ba1a2b549
x86: page.h: move and unify types for pagetable entry definitions
This patch:
1. Defines arch-specific types for the contents of a pagetable entry.
That is, 32-bit entries for 32-bit non-PAE, and 64-bit entries for
32-bit PAE and 64-bit. However, even though the latter two are the
same size, they're defined with different types in order to retain
compatibility with printk format strings, etc.
2. Defines arch-specific pte_t. This is different because 32-bit PAE
defines it in two halves, whereas 32-bit PAE and 64-bit define it as a
single entry. All the other pagetable levels can be defined in a
common way. This also defines arch-specific pte_val/make_pte functions.
3. Define PAGETABLE_LEVELS for each architecture variation, for later use.
4. Define common pagetable entry accessors in a paravirt-compatible
way. (64-bit does not yet use paravirt-ops in any way).
5. Convert a few instances of using a *_val() as an lvalue where it is
no longer a macro. There are still places in the 64-bit code which
use pte_val() as an lvalue.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
# HG changeset patch
# User Jeremy Fitzhardinge <jeremy@xensource.com>
# Date 1199317362 28800
# Node ID 4d9a413a0f4c1d98dbea704f0366457b5117045d
# Parent ba0ec40a50a7aef1a3153cea124c35e261f5a2df
x86: page.h: unify page copying and clearing
Move, and to some extent unify, the various page copying and clearing
functions. The only unification here is that both architectures use
the same function for copying/clearing user and kernel pages.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
# HG changeset patch
# User Jeremy Fitzhardinge <jeremy@xensource.com>
# Date 1199317360 28800
# Node ID ba0ec40a50a7aef1a3153cea124c35e261f5a2df
# Parent c45c263179cb78284b6b869c574457df088027d1
x86: page.h: unify constants
There are many constants which are shared by 32 and 64-bit.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Convert clear_page/copy_page macros to inline functions for type-checking.
Andrew wants to extirpate these ugly macros. (Ingo too. Thomas as well.
Please send us more "kill ugly macros" patches! :-)
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Move the headers to include/asm-x86 and fixup the
header install make rules
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
