linux-toradex.git/arch/tile, branch v3.12.51

arch: Clean up asm/barrier.h implementations using asm-generic/barrier.h

2015-10-28T15:37:39+00:00

commit 93ea02bb84354370e51de803a9405f171f3edf88 upstream.

We're going to be adding a few new barrier primitives, and in order to
avoid endless duplication make more agressive use of
asm-generic/barrier.h.

Change the asm-generic/barrier.h such that it allows partial barrier
definitions and fills out the rest with defaults.

There are a few architectures (m32r, m68k) that could probably
do away with their barrier.h file entirely but are kept for now due to
their unconventional nop() implementation.

Suggested-by: Geert Uytterhoeven 
Reviewed-by: "Paul E. McKenney" 
Reviewed-by: Mathieu Desnoyers 
Signed-off-by: Peter Zijlstra 
Cc: Michael Ellerman 
Cc: Michael Neuling 
Cc: Russell King 
Cc: Heiko Carstens 
Cc: Linus Torvalds 
Cc: Martin Schwidefsky 
Cc: Victor Kaplansky 
Cc: Tony Luck 
Cc: Oleg Nesterov 
Cc: Benjamin Herrenschmidt 
Cc: Frederic Weisbecker 
Link: http://lkml.kernel.org/r/20131213150640.846368594@infradead.org
Signed-off-by: Ingo Molnar 
Signed-off-by: Jiri Slaby

tile: use free_bootmem_late() for initrd

2015-08-19T06:36:38+00:00

commit 3f81d2447b37ac697b3c600039f2c6b628c06e21 upstream.

We were previously using free_bootmem() and just getting lucky
that nothing too bad happened.

Signed-off-by: Chris Metcalf 
Signed-off-by: Jiri Slaby

mm/hugetlb: reduce arch dependent code around follow_huge_*

2015-03-16T10:09:27+00:00

commit 61f77eda9bbf0d2e922197ed2dcf88638a639ce5 upstream.

Currently we have many duplicates in definitions around
follow_huge_addr(), follow_huge_pmd(), and follow_huge_pud(), so this
patch tries to remove the m.  The basic idea is to put the default
implementation for these functions in mm/hugetlb.c as weak symbols
(regardless of CONFIG_ARCH_WANT_GENERAL_HUGETL B), and to implement
arch-specific code only when the arch needs it.

For follow_huge_addr(), only powerpc and ia64 have their own
implementation, and in all other architectures this function just returns
ERR_PTR(-EINVAL).  So this patch sets returning ERR_PTR(-EINVAL) as
default.

As for follow_huge_(pmd|pud)(), if (pmd|pud)_huge() is implemented to
always return 0 in your architecture (like in ia64 or sparc,) it's never
called (the callsite is optimized away) no matter how implemented it is.
So in such architectures, we don't need arch-specific implementation.

In some architecture (like mips, s390 and tile,) their current
arch-specific follow_huge_(pmd|pud)() are effectively identical with the
common code, so this patch lets these architecture use the common code.

One exception is metag, where pmd_huge() could return non-zero but it
expects follow_huge_pmd() to always return NULL.  This means that we need
arch-specific implementation which returns NULL.  This behavior looks
strange to me (because non-zero pmd_huge() implies that the architecture
supports PMD-based hugepage, so follow_huge_pmd() can/should return some
relevant value,) but that's beyond this cleanup patch, so let's keep it.

Justification of non-trivial changes:
- in s390, follow_huge_pmd() checks !MACHINE_HAS_HPAGE at first, and this
  patch removes the check. This is OK because we can assume MACHINE_HAS_HPAGE
  is true when follow_huge_pmd() can be called (note that pmd_huge() has
  the same check and always returns 0 for !MACHINE_HAS_HPAGE.)
- in s390 and mips, we use HPAGE_MASK instead of PMD_MASK as done in common
  code. This patch forces these archs use PMD_MASK, but it's OK because
  they are identical in both archs.
  In s390, both of HPAGE_SHIFT and PMD_SHIFT are 20.
  In mips, HPAGE_SHIFT is defined as (PAGE_SHIFT + PAGE_SHIFT - 3) and
  PMD_SHIFT is define as (PAGE_SHIFT + PAGE_SHIFT + PTE_ORDER - 3), but
  PTE_ORDER is always 0, so these are identical.

Signed-off-by: Naoya Horiguchi 
Acked-by: Hugh Dickins 
Cc: James Hogan 
Cc: David Rientjes 
Cc: Mel Gorman 
Cc: Johannes Weiner 
Cc: Michal Hocko 
Cc: Rik van Riel 
Cc: Andrea Arcangeli 
Cc: Luiz Capitulino 
Cc: Nishanth Aravamudan 
Cc: Lee Schermerhorn 
Cc: Steve Capper 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Jiri Slaby

vm: add VM_FAULT_SIGSEGV handling support

2015-03-12T16:31:25+00:00

commit 33692f27597fcab536d7cbbcc8f52905133e4aa7 upstream.

The core VM already knows about VM_FAULT_SIGBUS, but cannot return a
"you should SIGSEGV" error, because the SIGSEGV case was generally
handled by the caller - usually the architecture fault handler.

That results in lots of duplication - all the architecture fault
handlers end up doing very similar "look up vma, check permissions, do
retries etc" - but it generally works.  However, there are cases where
the VM actually wants to SIGSEGV, and applications _expect_ SIGSEGV.

In particular, when accessing the stack guard page, libsigsegv expects a
SIGSEGV.  And it usually got one, because the stack growth is handled by
that duplicated architecture fault handler.

However, when the generic VM layer started propagating the error return
from the stack expansion in commit fee7e49d4514 ("mm: propagate error
from stack expansion even for guard page"), that now exposed the
existing VM_FAULT_SIGBUS result to user space.  And user space really
expected SIGSEGV, not SIGBUS.

To fix that case, we need to add a VM_FAULT_SIGSEGV, and teach all those
duplicate architecture fault handlers about it.  They all already have
the code to handle SIGSEGV, so it's about just tying that new return
value to the existing code, but it's all a bit annoying.

This is the mindless minimal patch to do this.  A more extensive patch
would be to try to gather up the mostly shared fault handling logic into
one generic helper routine, and long-term we really should do that
cleanup.

Just from this patch, you can generally see that most architectures just
copied (directly or indirectly) the old x86 way of doing things, but in
the meantime that original x86 model has been improved to hold the VM
semaphore for shorter times etc and to handle VM_FAULT_RETRY and other
"newer" things, so it would be a good idea to bring all those
improvements to the generic case and teach other architectures about
them too.

Reported-and-tested-by: Takashi Iwai 
Tested-by: Jan Engelhardt 
Acked-by: Heiko Carstens  # "s390 still compiles and boots"
Cc: linux-arch@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds 
Signed-off-by: Jiri Slaby

mm: page_alloc: convert hot/cold parameter and immediate callers to bool

2014-09-26T09:52:03+00:00

commit b745bc85f21ea707e4ea1a91948055fa3e72c77b upstream.

cold is a bool, make it one.  Make the likely case the "if" part of the
block instead of the else as according to the optimisation manual this is
preferred.

Signed-off-by: Mel Gorman 
Acked-by: Rik van Riel 
Cc: Johannes Weiner 
Cc: Vlastimil Babka 
Cc: Jan Kara 
Cc: Michal Hocko 
Cc: Hugh Dickins 
Cc: Dave Hansen 
Cc: Theodore Ts'o 
Cc: "Paul E. McKenney" 
Cc: Oleg Nesterov 
Cc: Peter Zijlstra 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Mel Gorman 
Signed-off-by: Jiri Slaby

hugetlb: restrict hugepage_migration_support() to x86_64

2014-07-02T10:06:08+00:00

commit c177c81e09e517bbf75b67762cdab1b83aba6976 upstream.

Currently hugepage migration is available for all archs which support
pmd-level hugepage, but testing is done only for x86_64 and there're
bugs for other archs.  So to avoid breaking such archs, this patch
limits the availability strictly to x86_64 until developers of other
archs get interested in enabling this feature.

Simply disabling hugepage migration on non-x86_64 archs is not enough to
fix the reported problem where sys_move_pages() hits the BUG_ON() in
follow_page(FOLL_GET), so let's fix this by checking if hugepage
migration is supported in vma_migratable().

Signed-off-by: Naoya Horiguchi 
Reported-by: Michael Ellerman 
Tested-by: Michael Ellerman 
Acked-by: Hugh Dickins 
Cc: Benjamin Herrenschmidt 
Cc: Tony Luck 
Cc: Russell King 
Cc: Martin Schwidefsky 
Cc: James Hogan 
Cc: Ralf Baechle 
Cc: David Miller 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Jiri Slaby

tile: remove compat_sys_lookup_dcookie declaration to fix compile error

2014-02-13T21:50:14+00:00

commit 5a5e75f4714a592f31e57f248b8f5c866f278b8d upstream.

With commit d8d14bd09cdd ("fs/compat: fix lookup_dcookie() parameter
handling") I changed the type of the len parameter of the
lookup_dcookie() syscall.

However I missed that there was still a stale declaration in
arch/tile/..  which now causes a compile error on tile:

  In file included from fs/dcookies.c:28:0:
  include/linux/compat.h:425:17: error: conflicting types for 'compat_sys_lookup_dcookie'
  fs/dcookies.c:207:1: error: conflicting types for 'compat_sys_lookup_dcookie'

Simply remove the declaration in the tile architecture, which is only a
leftover from before the different compat lookup_dcookie() versions have
been merged.  The correct declaration is now in include/linux/compat.h

The build error was reported by Fenguang's build bot.

Signed-off-by: Heiko Carstens 
Acked-by: Chris Metcalf 
Signed-off-by: Linus Torvalds 
Cc: Guenter Roeck 
Signed-off-by: Greg Kroah-Hartman

arch: tile: re-use kbasename() helper

2013-09-30T14:34:46+00:00

kbasename() returns the filename part of a pathname.

Signed-off-by: Andy Shevchenko

tile: use a more conservative __my_cpu_offset in CONFIG_PREEMPT

2013-09-30T14:34:41+00:00

It turns out the kernel relies on barrier() to force a reload of the
percpu offset value.  Since we can't easily modify the definition of
barrier() to include "tp" as an output register, we instead provide a
definition of __my_cpu_offset as extended assembly that includes a fake
stack read to hazard against barrier(), forcing gcc to know that it
must reread "tp" and recompute anything based on "tp" after a barrier.

This fixes observed hangs in the slub allocator when we are looping
on a percpu cmpxchg_double.

A similar fix for ARMv7 was made in June in change 509eb76ebf97.

Cc: stable@vger.kernel.org
Signed-off-by: Chris Metcalf

tile: ensure interrupts disabled for preempt_schedule_irq()

2013-09-27T20:09:43+00:00

When coming from a page fault (for example), interrupts might
be enabled as we enter the code to return from interrupt.

Cc: stable@vger.kernel.org
Signed-off-by: Chris Metcalf