| a6c19dfe39941a5d3f4d072121c0a4841e7e26fd |
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08-Aug-2014 |
Andy Lutomirski <luto@amacapital.net> |
arm64,ia64,ppc,s390,sh,tile,um,x86,mm: remove default gate area
The core mm code will provide a default gate area based on
FIXADDR_USER_START and FIXADDR_USER_END if
!defined(__HAVE_ARCH_GATE_AREA) && defined(AT_SYSINFO_EHDR).
This default is only useful for ia64. arm64, ppc, s390, sh, tile, 64-bit
UML, and x86_32 have their own code just to disable it. arm, 32-bit UML,
and x86_64 have gate areas, but they have their own implementations.
This gets rid of the default and moves the code into ia64.
This should save some code on architectures without a gate area: it's now
possible to inline the gate_area functions in the default case.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Acked-by: Nathan Lynch <nathan_lynch@mentor.com>
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [in principle]
Acked-by: Richard Weinberger <richard@nod.at> [for um]
Acked-by: Will Deacon <will.deacon@arm.com> [for arm64]
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Nathan Lynch <Nathan_Lynch@mentor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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| dba6bb60043ed73abca8990f237db63a8cea6c50 |
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19-Nov-2013 |
Heiko Carstens <heiko.carstens@de.ibm.com> |
s390/mm: optimize copy_page
Always use the mvcl instruction to copy a page instead of mvpg or a
couple of mvc instructions.
Copying a huge page is 25% faster this way. Also bypass caches when
copying pages since only parts of a page will be used afterwards.
Especially when copying a huge page this would kick everything out
of the L1 and L2 data caches on a zEC12 machine.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
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| 127c1feffff8078400f01372712c600d0f9eef51 |
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07-Oct-2013 |
Martin Schwidefsky <schwidefsky@de.ibm.com> |
s390/mm: do not initialize storage keys
With dirty and referenced bits implemented in software it is unnecessary
to initialize the storage key for every page. With this patch not a single
storage key operation is done for a system that does not use KVM.
For KVM set_pte_at/pgste_set_key will do the initialization for the guest
view of the storage key when the mapping for the page is established in
the host.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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| 0944fe3f4a323f436180d39402cae7f9c46ead17 |
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23-Jul-2013 |
Martin Schwidefsky <schwidefsky@de.ibm.com> |
s390/mm: implement software referenced bits
The last remaining use for the storage key of the s390 architecture
is reference counting. The alternative is to make page table entries
invalid while they are old. On access the fault handler marks the
pte/pmd as young which makes the pte/pmd valid if the access rights
allow read access. The pte/pmd invalidations required for software
managed reference bits cost a bit of performance, on the other hand
the RRBE/RRBM instructions to read and reset the referenced bits are
quite expensive as well.
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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| 416fd0ffb14afead5b1feea14bbf33c2277942ef |
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25-Jul-2013 |
Heiko Carstens <heiko.carstens@de.ibm.com> |
s390/mm: remove dead pfmf inline assembly
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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| 617e164c35c94c936e3632b387d6dbb3d80c2c02 |
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06-May-2013 |
Christian Borntraeger <borntraeger@de.ibm.com> |
s390: disable pfmf for clear page instruction
Wit the introduction of large pages Linux also used pfmf for page
clearing. The current implementation is not ideal, though:
- currently we set usage intent=0, but cleared pages are often used
directly after the clearing
- z/VM does not yet provide EDAT
- KVM does have to intercept PFMF even for resident pages
Lets just the mvcl loop in all cases until we have a well defined
pattern were pfmf is besser.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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| abf09bed3cceadd809f0356065c2ada6cee90d4a |
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07-Nov-2012 |
Martin Schwidefsky <schwidefsky@de.ibm.com> |
s390/mm: implement software dirty bits
The s390 architecture is unique in respect to dirty page detection,
it uses the change bit in the per-page storage key to track page
modifications. All other architectures track dirty bits by means
of page table entries. This property of s390 has caused numerous
problems in the past, e.g. see git commit ef5d437f71afdf4a
"mm: fix XFS oops due to dirty pages without buffers on s390".
To avoid future issues in regard to per-page dirty bits convert
s390 to a fault based software dirty bit detection mechanism. All
user page table entries which are marked as clean will be hardware
read-only, even if the pte is supposed to be writable. A write by
the user process will trigger a protection fault which will cause
the user pte to be marked as dirty and the hardware read-only bit
is removed.
With this change the dirty bit in the storage key is irrelevant
for Linux as a host, but the storage key is still required for
KVM guests. The effect is that page_test_and_clear_dirty and the
related code can be removed. The referenced bit in the storage
key is still used by the page_test_and_clear_young primitive to
provide page age information.
For page cache pages of mappings with mapping_cap_account_dirty
there will not be any change in behavior as the dirty bit tracking
already uses read-only ptes to control the amount of dirty pages.
Only for swap cache pages and pages of mappings without
mapping_cap_account_dirty there can be additional protection faults.
To avoid an excessive number of additional faults the mk_pte
primitive checks for PageDirty if the pgprot value allows for writes
and pre-dirties the pte. That avoids all additional faults for
tmpfs and shmem pages until these pages are added to the swap cache.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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| e749eb95531ac8349df47f8d46ce2641dcb16589 |
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12-Dec-2012 |
Jan Kara <jack@suse.cz> |
mm: add comment on storage key dirty bit semantics
Add comments that dirty bit in storage key gets set whenever page content
is changed. Hopefully if someone will use this function, he'll have a
look at one of the two places where we comment on this.
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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| 6b70a92080be508e16b2f53efba39e5155eff809 |
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02-Nov-2012 |
Heiko Carstens <heiko.carstens@de.ibm.com> |
s390/memory hotplug: use pfmf instruction to initialize storage keys
Move and rename init_storage_keys() to pageattr.c, so it can also be
used from the sclp memory hotplug code in order to initialize
storage keys.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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| 85e9d0e5ffabfede5facbac5b0d9b90768bc6e90 |
|
27-Sep-2012 |
Heiko Carstens <heiko.carstens@de.ibm.com> |
s390/mm: use pfmf instruction to initialize storage keys
Make use of the pfmf instruction, if available, to initialize storage keys
of whole 1MB or 2GB frames instead of initializing every single page with
the sske instruction.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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| a53c8fab3f87c995c30ac226a03af95361243144 |
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20-Jul-2012 |
Heiko Carstens <heiko.carstens@de.ibm.com> |
s390/comments: unify copyright messages and remove file names
Remove the file name from the comment at top of many files. In most
cases the file name was wrong anyway, so it's rather pointless.
Also unify the IBM copyright statement. We did have a lot of sightly
different statements and wanted to change them one after another
whenever a file gets touched. However that never happened. Instead
people start to take the old/"wrong" statements to use as a template
for new files.
So unify all of them in one go.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
|
| 638ad34a8811119b32247b7722288ef8b90907d1 |
|
30-Oct-2011 |
Martin Schwidefsky <schwidefsky@de.ibm.com> |
[S390] sparse: fix sparse warnings about missing prototypes
Add prototypes and includes for functions used in different modules.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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| b2fa47e6bf5148aa6dbf22ec79f18141b421eeba |
|
23-May-2011 |
Martin Schwidefsky <schwidefsky@de.ibm.com> |
[S390] refactor page table functions for better pgste support
Rework the architecture page table functions to access the bits in the
page table extension array (pgste). There are a number of changes:
1) Fix missing pgste update if the attach_count for the mm is <= 1.
2) For every operation that affects the invalid bit in the pte or the
rcp byte in the pgste the pcl lock needs to be acquired. The function
pgste_get_lock gets the pcl lock and returns the current pgste value
for a pte pointer. The function pgste_set_unlock stores the pgste
and releases the lock. Between these two calls the bits in the pgste
can be shuffled.
3) Define two software bits in the pte _PAGE_SWR and _PAGE_SWC to avoid
calling SetPageDirty and SetPageReferenced from pgtable.h. If the
host reference backup bit or the host change backup bit has been
set the dirty/referenced state is transfered to the pte. The common
code will pick up the state from the pte.
4) Add ptep_modify_prot_start and ptep_modify_prot_commit for mprotect.
5) Remove pgd_populate_kernel, pud_populate_kernel, pmd_populate_kernel
pgd_clear_kernel, pud_clear_kernel, pmd_clear_kernel and ptep_invalidate.
6) Rename kvm_s390_test_and_clear_page_dirty to
ptep_test_and_clear_user_dirty and add ptep_test_and_clear_user_young.
7) Define mm_exclusive() and mm_has_pgste() helper to improve readability.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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| 2d42552d1c1659b014851cf449ad2fe458509128 |
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23-May-2011 |
Martin Schwidefsky <schwidefsky@de.ibm.com> |
[S390] merge page_test_dirty and page_clear_dirty
The page_clear_dirty primitive always sets the default storage key
which resets the access control bits and the fetch protection bit.
That will surprise a KVM guest that sets non-zero access control
bits or the fetch protection bit. Merge page_test_dirty and
page_clear_dirty back to a single function and only clear the
dirty bit from the storage key.
In addition move the function page_test_and_clear_dirty and
page_test_and_clear_young to page.h where they belong. This
requires to change the parameter from a struct page * to a page
frame number.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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| ec6743bb06510c7b629603ce35713d6ae9273579 |
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10-Nov-2010 |
Hendrik Brueckner <brueckner@linux.vnet.ibm.com> |
[S390] mm: add devmem_is_allowed() for STRICT_DEVMEM checking
Provide the devmem_is_allowed() routine to restrict access to
kernel memory from userspace.
Set the CONFIG_STRICT_DEVMEM config option to switch on checking.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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| e2b8d7af0e3a9234de06606f9151f28cf847a8d6 |
|
25-Oct-2010 |
Martin Schwidefsky <schwidefsky@de.ibm.com> |
[S390] add support for nonquiescing sske
Improve performance of the sske operation by using the nonquiescing
variant if the affected page has no mappings established. On machines
with no support for the new sske variant the mask bit will be ignored.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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| d1bf85902c28dd990c08f1703ea94109223549a7 |
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26-Feb-2010 |
Heiko Carstens <heiko.carstens@de.ibm.com> |
[S390] cio: fix storage key handling
Some parts of cio do not shift PAGE_DEFAULT_KEY correctly and end up
with an incorrect key in their data structures.
Since the default key is zero this doesn't really matter. However if
somebody would use key-controlled protection for debugging purposes
it would be quite helpful if all of this would work as expected.
Also remove a stale declaration.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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| 2ddddf3e0a55a7fcd6f240a7416cfcb12dd38b7e |
|
11-Sep-2009 |
Heiko Carstens <heiko.carstens@de.ibm.com> |
[S390] Enable guest page hinting by default.
Get rid of the PAGE_STATES config option and enable guest page hinting
by default.
It can be disabled by specifying "cmma=off" at the command line.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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| 5b17e1cd8928ae65932758ce6478ac6d3e9a86b2 |
|
14-May-2009 |
Arnd Bergmann <arnd@arndb.de> |
asm-generic: rename page.h and uaccess.h
The current asm-generic/page.h only contains the get_order
function, and asm-generic/uaccess.h only implements
unaligned accesses. This renames the file to getorder.h
and uaccess-unaligned.h to make room for new page.h
and uaccess.h file that will be usable by all simple
(e.g. nommu) architectures.
Signed-off-by: Remis Lima Baima <remis.developer@googlemail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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| b020632e40c3ed5e8c0c066d022672907e8401cf |
|
25-Dec-2008 |
Martin Schwidefsky <schwidefsky@de.ibm.com> |
[S390] introduce vdso on s390
Add a vdso to speed up gettimeofday and clock_getres/clock_gettime for
CLOCK_REALTIME/CLOCK_MONOTONIC.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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| c6557e7f2b6ae76a44653d38f835174074c42e05 |
|
01-Aug-2008 |
Martin Schwidefsky <schwidefsky@de.ibm.com> |
[S390] move include/asm-s390 to arch/s390/include/asm
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
|