linux.git/arch/powerpc/kernel/rtas.c, branch v4.19

powerpc: Remove -Wattribute-alias pragmas

2018-06-25T14:21:13+00:00

With SYSCALL_DEFINEx() disabling -Wattribute-alias generically, there's
no need to duplicate that for PowerPC syscalls.

This reverts commit 415520373975 ("powerpc: fix build failure by
disabling attribute-alias warning in pci_32") and commit 2479bfc9bc60
("powerpc: Fix build by disabling attribute-alias warning for
SYSCALL_DEFINEx").

Signed-off-by: Paul Burton 
Acked-by: Christophe Leroy 
Acked-by: Michael Ellerman 
Signed-off-by: Masahiro Yamada

powerpc: Fix build by disabling attribute-alias warning for SYSCALL_DEFINEx

2018-06-03T10:40:24+00:00

GCC 8.1 emits warnings such as the following. As arch/powerpc code is
built with -Werror, this breaks the build with GCC 8.1.

  In file included from arch/powerpc/kernel/pci_64.c:23:
  ./include/linux/syscalls.h:233:18: error: 'sys_pciconfig_iobase' alias
  between functions of incompatible types 'long int(long int, long
  unsigned int, long unsigned int)' and 'long int(long int, long int,
  long int)' [-Werror=attribute-alias]
    asmlinkage long sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) \
                    ^~~
  ./include/linux/syscalls.h:222:2: note: in expansion of macro '__SYSCALL_DEFINEx'
    __SYSCALL_DEFINEx(x, sname, __VA_ARGS__)

This patch inhibits those warnings.

Signed-off-by: Christophe Leroy 
[mpe: Trim change log]
Signed-off-by: Michael Ellerman

powerpc/syscalls: switch rtas(2) to SYSCALL_DEFINE

2018-05-10T13:25:14+00:00

Signed-off-by: Al Viro 
[mpe: Update sys_ni.c for s/ppc_rtas/sys_rtas/]
Signed-off-by: Michael Ellerman

locking/arch, powerpc/rtas: Use arch_spin_lock() instead of arch_spin_lock_flags()

2017-10-18T13:15:07+00:00

arch_spin_lock_flags() is an internal part of the spinlock implementation
and is no longer available when SMP=n and DEBUG_SPINLOCK=y, so the PPC
RTAS code fails to compile in this configuration:

   arch/powerpc/kernel/rtas.c: In function 'lock_rtas':
>> arch/powerpc/kernel/rtas.c:81:2: error: implicit declaration of function 'arch_spin_lock_flags' [-Werror=implicit-function-declaration]
     arch_spin_lock_flags(&rtas.lock, flags);
     ^~~~~~~~~~~~~~~~~~~~

Since there's no good reason to use arch_spin_lock_flags() here (the code
in question already calls local_irq_save(flags)), switch it over to
arch_spin_lock and get things building again.

Reported-by: kbuild test robot 
Signed-off-by: Will Deacon 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/1508327469-20231-1-git-send-email-will.deacon@arm.com
Signed-off-by: Ingo Molnar

mm: treewide: remove GFP_TEMPORARY allocation flag

2017-09-14T01:53:16+00:00

GFP_TEMPORARY was introduced by commit e12ba74d8ff3 ("Group short-lived
and reclaimable kernel allocations") along with __GFP_RECLAIMABLE.  It's
primary motivation was to allow users to tell that an allocation is
short lived and so the allocator can try to place such allocations close
together and prevent long term fragmentation.  As much as this sounds
like a reasonable semantic it becomes much less clear when to use the
highlevel GFP_TEMPORARY allocation flag.  How long is temporary? Can the
context holding that memory sleep? Can it take locks? It seems there is
no good answer for those questions.

The current implementation of GFP_TEMPORARY is basically GFP_KERNEL |
__GFP_RECLAIMABLE which in itself is tricky because basically none of
the existing caller provide a way to reclaim the allocated memory.  So
this is rather misleading and hard to evaluate for any benefits.

I have checked some random users and none of them has added the flag
with a specific justification.  I suspect most of them just copied from
other existing users and others just thought it might be a good idea to
use without any measuring.  This suggests that GFP_TEMPORARY just
motivates for cargo cult usage without any reasoning.

I believe that our gfp flags are quite complex already and especially
those with highlevel semantic should be clearly defined to prevent from
confusion and abuse.  Therefore I propose dropping GFP_TEMPORARY and
replace all existing users to simply use GFP_KERNEL.  Please note that
SLAB users with shrinkers will still get __GFP_RECLAIMABLE heuristic and
so they will be placed properly for memory fragmentation prevention.

I can see reasons we might want some gfp flag to reflect shorterm
allocations but I propose starting from a clear semantic definition and
only then add users with proper justification.

This was been brought up before LSF this year by Matthew [1] and it
turned out that GFP_TEMPORARY really doesn't have a clear semantic.  It
seems to be a heuristic without any measured advantage for most (if not
all) its current users.  The follow up discussion has revealed that
opinions on what might be temporary allocation differ a lot between
developers.  So rather than trying to tweak existing users into a
semantic which they haven't expected I propose to simply remove the flag
and start from scratch if we really need a semantic for short term
allocations.

[1] http://lkml.kernel.org/r/20170118054945.GD18349@bombadil.infradead.org

[akpm@linux-foundation.org: fix typo]
[akpm@linux-foundation.org: coding-style fixes]
[sfr@canb.auug.org.au: drm/i915: fix up]
  Link: http://lkml.kernel.org/r/20170816144703.378d4f4d@canb.auug.org.au
Link: http://lkml.kernel.org/r/20170728091904.14627-1-mhocko@kernel.org
Signed-off-by: Michal Hocko 
Signed-off-by: Stephen Rothwell 
Acked-by: Mel Gorman 
Acked-by: Vlastimil Babka 
Cc: Matthew Wilcox 
Cc: Neil Brown 
Cc: "Theodore Ts'o" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

powerpc/kernel: Fix unbalanced refcount on RTAS device node

2017-01-25T02:34:21+00:00

The RTAS device-tree node's refcount has been increased by one in
the function call of_find_node_by_name(), but it's missed to be
decreased by one in the error path. It leads to unbalanced refcount
on RTAS device-tree node.

This fixes above issue by decreasing RTAS device-tree node's refcount
in error path.

Signed-off-by: Gavin Shan 
Signed-off-by: Michael Ellerman

powerpc/kernel: Use of_property_read_u32() in rtas_initialize()

2017-01-25T02:34:20+00:00

This uses of_property_read_u32() in rtas_initialize() so that we
needn't explicitly care the CPU's endian.

Signed-off-by: Gavin Shan 
Signed-off-by: Michael Ellerman

powerpc/kernel: Remove nested if statements in rtas_initialize()

2017-01-25T02:34:20+00:00

This removes the unnecessary nested if statements in function
rtas_initialize(), to simplify the code. No functional changes
introduced.

Signed-off-by: Gavin Shan 
Signed-off-by: Michael Ellerman

Replace with globally

2016-12-24T19:46:01+00:00

This was entirely automated, using the script by Al:

  PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*'
  sed -i -e "s!$PATT!#include !" \
        $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)

to do the replacement at the end of the merge window.

Requested-by: Al Viro 
Signed-off-by: Linus Torvalds

powerpc: Make ppc_md.{halt, restart} __noreturn

2016-07-14T11:12:06+00:00

powernv marks it's halt and restart calls as __noreturn. However,
ppc_md does not have this annotation. Add the annotation to ppc_md,
and then to every halt/restart function that is missing it.

Additionally, I have verified that all of these functions do not
return. Occasionally I have added a spin loop to be sure.

Signed-off-by: Daniel Axtens 
Signed-off-by: Michael Ellerman