linux-toradex.git/arch/s390/include, branch v3.2.46

s390: move dummy io_remap_pfn_range() to asm/pgtable.h

2013-05-13T14:02:33+00:00

commit 4f2e29031e6c67802e7370292dd050fd62f337ee upstream.

Commit b4cbb197c7e7 ("vm: add vm_iomap_memory() helper function") added
a helper function wrapper around io_remap_pfn_range(), and every other
architecture defined it in .

The s390 choice of  may make sense, but is not very convenient
for this case, and gratuitous differences like that cause unexpected errors like this:

   mm/memory.c: In function 'vm_iomap_memory':
   mm/memory.c:2439:2: error: implicit declaration of function 'io_remap_pfn_range' [-Werror=implicit-function-declaration]

Glory be the kbuild test robot who noticed this, bisected it, and
reported it to the guilty parties (ie me).

Cc: Martin Schwidefsky 
Cc: Heiko Carstens 
Signed-off-by: Linus Torvalds 
[bwh: Backported to 3.2: the macro was not defined, so this is an addition
 and not a move]
Signed-off-by: Ben Hutchings

signal: Define __ARCH_HAS_SA_RESTORER so we know whether to clear sa_restorer

2013-03-27T02:41:25+00:00

flush_signal_handlers() needs to know whether sigaction::sa_restorer
is defined, not whether SA_RESTORER is defined.  Define the
__ARCH_HAS_SA_RESTORER macro to indicate this.

Vaguely based on upstream commit 574c4866e33d 'consolidate kernel-side
struct sigaction declarations'.

Signed-off-by: Ben Hutchings 
Cc: Al Viro

s390/mm: fix flush_tlb_kernel_range()

2013-03-27T02:41:00+00:00

commit f6a70a07079518280022286a1dceb797d12e1edf upstream.

Our flush_tlb_kernel_range() implementation calls __tlb_flush_mm() with
&init_mm as argument. __tlb_flush_mm() however will only flush tlbs
for the passed in mm if its mm_cpumask is not empty.

For the init_mm however its mm_cpumask has never any bits set. Which in
turn means that our flush_tlb_kernel_range() implementation doesn't
work at all.

This can be easily verified with a vmalloc/vfree loop which allocates
a page, writes to it and then frees the page again. A crash will follow
almost instantly.

To fix this remove the cpumask_empty() check in __tlb_flush_mm() since
there shouldn't be too many mms with a zero mm_cpumask, besides the
init_mm of course.

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky 
Signed-off-by: Ben Hutchings

s390/time: fix sched_clock() overflow

2013-02-06T04:33:35+00:00

commit ed4f20943cd4c7b55105c04daedf8d63ab6d499c upstream.

Converting a 64 Bit TOD format value to nanoseconds means that the value
must be divided by 4.096. In order to achieve that we multiply with 125
and divide by 512.
When used within sched_clock() this triggers an overflow after appr.
417 days. Resulting in a sched_clock() return value that is much smaller
than previously and therefore may cause all sort of weird things in
subsystems that rely on a monotonic sched_clock() behaviour.

To fix this implement a tod_to_ns() helper function which converts TOD
values without overflow and call this function from both places that
open coded the conversion: sched_clock() and kvm_s390_handle_wait().

Reviewed-by: Martin Schwidefsky 
Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky 
Signed-off-by: Ben Hutchings

s390/signal: set correct address space control

2012-12-06T11:20:04+00:00

commit fa968ee215c0ca91e4a9c3a69ac2405aae6e5d2f upstream.

If user space is running in primary mode it can switch to secondary
or access register mode, this is used e.g. in the clock_gettime code
of the vdso. If a signal is delivered to the user space process while
it has been running in access register mode the signal handler is
executed in access register mode as well which will result in a crash
most of the time.

Set the address space control bits in the PSW to the default for the
execution of the signal handler and make sure that the previous
address space control is restored on signal return. Take care
that user space can not switch to the kernel address space by
modifying the registers in the signal frame.

Signed-off-by: Martin Schwidefsky 
[bwh: Backported to 3.2:
 - Adjust filename
 - The RI bit is not included in PSW_MASK_USER]
Signed-off-by: Ben Hutchings

s390/mm: downgrade page table after fork of a 31 bit process

2012-08-09T23:24:54+00:00

commit 0f6f281b731d20bfe75c13f85d33f3f05b440222 upstream.

The downgrade of the 4 level page table created by init_new_context is
currently done only in start_thread31. If a 31 bit process forks the
new mm uses a 4 level page table, including the task size of 2<<42
that goes along with it. This is incorrect as now a 31 bit process
can map memory beyond 2GB. Define arch_dup_mmap to do the downgrade
after fork.

Signed-off-by: Martin Schwidefsky 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

fix tlb flushing for page table pages

2012-04-22T22:31:10+00:00

commit cd94154cc6a28dd9dc271042c1a59c08d26da886 upstream.

Git commit 36409f6353fc2d7b6516e631415f938eadd92ffa "use generic RCU
page-table freeing code" introduced a tlb flushing bug. Partially revert
the above git commit and go back to s390 specific page table flush code.

For s390 the TLB can contain three types of entries, "normal" TLB
page-table entries, TLB combined region-and-segment-table (CRST) entries
and real-space entries. Linux does not use real-space entries which
leaves normal TLB entries and CRST entries. The CRST entries are
intermediate steps in the page-table translation called translation paths.
For example a 4K page access in a three-level page table setup will
create two CRST TLB entries and one page-table TLB entry. The advantage
of that approach is that a page access next to the previous one can reuse
the CRST entries and needs just a single read from memory to create the
page-table TLB entry. The disadvantage is that the TLB flushing rules are
more complicated, before any page-table may be freed the TLB needs to be
flushed.

In short: the generic RCU page-table freeing code is incorrect for the
CRST entries, in particular the check for mm_users < 2 is troublesome.

This is applicable to 3.0+ kernels.

Signed-off-by: Martin Schwidefsky 
Signed-off-by: Greg Kroah-Hartman

compat: fix compile breakage on s390

2012-03-12T19:31:22+00:00

commit 048cd4e51d24ebf7f3552226d03c769d6ad91658 upstream.

The new is_compat_task() define for the !COMPAT case in
include/linux/compat.h conflicts with a similar define in
arch/s390/include/asm/compat.h.

This is the minimal patch which fixes the build issues.

Signed-off-by: Heiko Carstens 
Signed-off-by: Linus Torvalds 
Cc: Jonathan Nieder 
Signed-off-by: Greg Kroah-Hartman

procfs: do not confuse jiffies with cputime64_t

2011-12-30T00:31:57+00:00

Commit 2a95ea6c0d129b4 ("procfs: do not overflow get_{idle,iowait}_time
for nohz") did not take into account that one some architectures jiffies
and cputime use different units.

This causes get_idle_time() to return numbers in the wrong units, making
the idle time fields in /proc/stat wrong.

Instead of converting the usec value returned by
get_cpu_{idle,iowait}_time_us to units of jiffies, use the new function
usecs_to_cputime64 to convert it to the correct unit of cputime64_t.

Signed-off-by: Andreas Schwab 
Acked-by: Michal Hocko 
Cc: Arnd Bergmann 
Cc: "Artem S. Tashkinov" 
Cc: Dave Jones 
Cc: Alexey Dobriyan 
Cc: Thomas Gleixner 
Cc: "Luck, Tony" 
Cc: Benjamin Herrenschmidt 
Cc: Martin Schwidefsky 
Cc: Heiko Carstens 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[S390] fix page change underindication in pgste_update_all

2011-12-01T12:32:17+00:00

This patch makes sure we don't underindicate _PAGE_CHANGED in case
we have a race between an operation that changes the page and this
code path that hits us between page_get_storage_key and
page_set_storage_key. Note that we still have a potential
underindication on _PAGE_REFERENCED in the unlikely event that
the page was changed but not referenced _and_ someone references
the page in the race window. That's not considered to be a problem.

Signed-off-by: Carsten Otte 
Signed-off-by: Martin Schwidefsky