Commit Graph

40 Commits

Author SHA1 Message Date
Joe Perches
33def8498f treewide: Convert macro and uses of __section(foo) to __section("foo")
Use a more generic form for __section that requires quotes to avoid
complications with clang and gcc differences.

Remove the quote operator # from compiler_attributes.h __section macro.

Convert all unquoted __section(foo) uses to quoted __section("foo").
Also convert __attribute__((section("foo"))) uses to __section("foo")
even if the __attribute__ has multiple list entry forms.

Conversion done using the script at:

    https://lore.kernel.org/lkml/75393e5ddc272dc7403de74d645e6c6e0f4e70eb.camel@perches.com/2-convert_section.pl

Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@gooogle.com>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-25 14:51:49 -07:00
Erdem Aktas
264b0d2bee percpu: Separate decrypted varaibles anytime encryption can be enabled
CONFIG_VIRTUALIZATION may not be enabled for memory encrypted guests.  If
disabled, decrypted per-CPU variables may end up sharing the same page
with variables that should be left encrypted.

Always separate per-CPU variables that should be decrypted into their own
page anytime memory encryption can be enabled in the guest rather than
rely on any other config option that may not be enabled.

Fixes: ac26963a11 ("percpu: Introduce DEFINE_PER_CPU_DECRYPTED")
Cc: stable@vger.kernel.org # 4.15+
Signed-off-by: Erdem Aktas <erdemaktas@google.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
2020-01-31 11:15:59 -08:00
Thomas Gleixner
457c899653 treewide: Add SPDX license identifier for missed files
Add SPDX license identifiers to all files which:

 - Have no license information of any form

 - Have EXPORT_.*_SYMBOL_GPL inside which was used in the
   initial scan/conversion to ignore the file

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21 10:50:45 +02:00
Alexander Pateenok
69a60bc75f percpu: remove PER_CPU_DEF_ATTRIBUTES macro
The macro is not used:

  $ grep -r PER_CPU_DEF_ATTRIBUTES
  include/linux/percpu-defs.h:	__PCPU_ATTRS(sec) PER_CPU_DEF_ATTRIBUTES __weak		\
  include/linux/percpu-defs.h:	__PCPU_ATTRS(sec) PER_CPU_DEF_ATTRIBUTES		\
  include/asm-generic/percpu.h:#ifndef PER_CPU_DEF_ATTRIBUTES
  include/asm-generic/percpu.h:#define PER_CPU_DEF_ATTRIBUTES

It was added with b01e8dc343 ("alpha: fix percpu build breakage") and
removed in 2009 with b01e8dc34379..6088464cf1ae.

Link: http://lkml.kernel.org/r/20180821164904.qqhcduimjznods66@K55DR.localdomain
Signed-off-by: Alexander Pateenok <pateenoc@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-10-31 08:54:14 -07:00
Brijesh Singh
ac26963a11 percpu: Introduce DEFINE_PER_CPU_DECRYPTED
KVM guest defines three per-CPU variables (steal-time, apf_reason, and
kvm_pic_eoi) which are shared between a guest and a hypervisor.

When SEV is active, memory is encrypted with a guest-specific key, and if
the guest OS wants to share the memory region with the hypervisor then it
must clear the C-bit (i.e set decrypted) before sharing it.

DEFINE_PER_CPU_DECRYPTED can be used to define the per-CPU variables
which will be shared between a guest and a hypervisor.

Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Borislav Petkov <bp@suse.de>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: linux-arch@vger.kernel.org
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: kvm@vger.kernel.org
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christoph Lameter <cl@linux.com>
Link: https://lkml.kernel.org/r/20171020143059.3291-16-brijesh.singh@amd.com
2017-11-07 15:35:59 +01:00
Tejun Heo
83cb8557e8 percpu: update incorrect comment for this_cpu_*() operations
this_cpu_*() ops have been protected against both preemption and
interrupts for quite a while now.  We apparently forgot to update the
comment.  Fix it.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Lameter <cl@linux-foundation.org>
2015-07-14 17:43:56 -04:00
Christoph Lameter
6c51ec4d18 percpu: remove __get_cpu_var and __raw_get_cpu_var macros
No user is left in the kernel source tree.  Therefore we can drop the
definitions.

This is the final merge of the transition away from __get_cpu_var.  After
this patch the kernel will not build if anyone uses __get_cpu_var.

Signed-off-by: Christoph Lameter <cl@linux.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:53 -08:00
Christoph Lameter
47405a253d percpu: Remove __this_cpu_ptr
The __this_cpu_ptr macro is no longer in use so drop it.

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2014-08-26 13:45:56 -04:00
Linus Torvalds
f2a84170ed Merge branch 'for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
Pull percpu updates from Tejun Heo:

 - Major reorganization of percpu header files which I think makes
   things a lot more readable and logical than before.

 - percpu-refcount is updated so that it requires explicit destruction
   and can be reinitialized if necessary.  This was pulled into the
   block tree to replace the custom percpu refcnting implemented in
   blk-mq.

 - In the process, percpu and percpu-refcount got cleaned up a bit

* 'for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (21 commits)
  percpu-refcount: implement percpu_ref_reinit() and percpu_ref_is_zero()
  percpu-refcount: require percpu_ref to be exited explicitly
  percpu-refcount: use unsigned long for pcpu_count pointer
  percpu-refcount: add helpers for ->percpu_count accesses
  percpu-refcount: one bit is enough for REF_STATUS
  percpu-refcount, aio: use percpu_ref_cancel_init() in ioctx_alloc()
  workqueue: stronger test in process_one_work()
  workqueue: clear POOL_DISASSOCIATED in rebind_workers()
  percpu: Use ALIGN macro instead of hand coding alignment calculation
  percpu: invoke __verify_pcpu_ptr() from the generic part of accessors and operations
  percpu: preffity percpu header files
  percpu: use raw_cpu_*() to define __this_cpu_*()
  percpu: reorder macros in percpu header files
  percpu: move {raw|this}_cpu_*() definitions to include/linux/percpu-defs.h
  percpu: move generic {raw|this}_cpu_*_N() definitions to include/asm-generic/percpu.h
  percpu: only allow sized arch overrides for {raw|this}_cpu_*() ops
  percpu: reorganize include/linux/percpu-defs.h
  percpu: move accessors from include/linux/percpu.h to percpu-defs.h
  percpu: include/asm-generic/percpu.h should contain only arch-overridable parts
  percpu: introduce arch_raw_cpu_ptr()
  ...
2014-08-04 10:09:27 -07:00
Zhengyu He
330d282216 core: fix typo in percpu read_mostly section
This fixes a typo that named the read_mostly section of percpu as
readmostly. It works fine with SMP because the linker script specifies
.data..percpu..readmostly. However, UP kernel builds don't have percpu
sections defined and the non-percpu version of the section is called
data..read_mostly, so .data..readmostly will float around and may break
things unexpectedly.

Looking at the original change that introduced data..percpu..readmostly
(commit c957ef2c59), it looks like this
was the original intention.

Tested: Built UP kernel and confirmed the sections got merged.

- Before the patch:
$ objdump -h vmlinux.o  | grep '\.data\.\.read.*mostly'
38 .data..read_mostly 00004418  0000000000000000  0000000000000000  00431ac0  2**6
50 .data..readmostly 00000014  0000000000000000  0000000000000000  00444000  2**3

- After the patch:
$ objdump -h vmlinux.o  | grep '\.data\.\.read.*mostly'
38 .data..read_mostly 00004438  0000000000000000  0000000000000000  00431ac0  2**6

Signed-off-by: Zhengyu He <hzy@google.com>
Signed-off-by: Filipe Brandenburger <filbranden@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2014-07-01 16:45:22 -04:00
Tejun Heo
6fbc07bbe2 percpu: invoke __verify_pcpu_ptr() from the generic part of accessors and operations
__verify_pcpu_ptr() is used to verify that a specified parameter is
actually an percpu pointer by percpu accessor and operation
implementations.  Currently, where it's called isn't clearly defined
and we just ensure that it's invoked at least once for all accessors
and operations.

The lack of clarity on when it should be called isn't nice and given
that this is a completely generic issue, there's no reason to make
archs worry about it.

This patch updates __verify_pcpu_ptr() invocations such that it's
always invoked from the final generic wrapper once per access or
operation.  As this is already the case for {raw|this}_cpu_*()
definitions through __pcpu_size_*(), only the {raw|per|this}_cpu_ptr()
accessors need to be updated.

This change makes it unnecessary for archs to worry about
__verify_pcpu_ptr().  x86's arch_raw_cpu_ptr() is updated accordingly.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
2014-06-17 19:12:40 -04:00
Tejun Heo
eba117889a percpu: preffity percpu header files
percpu macros are difficult to read.  It's partly because they're
fairly complex but also because they simply lack visual and
conventional consistency to an unusual degree.  The preceding patches
tried to organize macro definitions consistently by their roles.  This
patch makes the following cosmetic changes to improve overall
readability.

* Use consistent convention for multi-line macro definitions - "do {"
  or "({" are now put on their own lines and the line continuing '\'
  are all put on the same column.

* Temp variables used inside macro are consistently given "__" prefix.

* When a macro argument is passed to another macro or a function,
  putting extra parenthses around it doesn't help anything.  Don't put
  them.

* _this_cpu_generic_*() are renamed to this_cpu_generic_*() so that
  they're consistent with raw_cpu_generic_*().

* Reorganize raw_cpu_*() and this_cpu_*() definitions so that trivial
  wrappers are collected in one place after actual operation
  definitions.

* Other misc cleanups including reorganizing comments.

All changes in this patch are cosmetic and cause no functional
difference.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Christoph Lameter <cl@linux.com>
2014-06-17 19:12:40 -04:00
Tejun Heo
cadb1c4db2 percpu: use raw_cpu_*() to define __this_cpu_*()
__this_cpu_*() operations are the same as raw_cpu_*() operations
except for the added __this_cpu_preempt_check().  Curiously, these
were defined using __pcu_size_call_*() instead of being layered on top
of raw_cpu_*().

Let's layer them so that __this_cpu_*() are defined in terms of
raw_cpu_*().  It's simpler and less error-prone this way.

This patch doesn't introduce any functional difference.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Christoph Lameter <cl@linux.com>
2014-06-17 19:12:39 -04:00
Tejun Heo
9c28278a24 percpu: reorder macros in percpu header files
* In include/asm-generic/percpu.h, collect {raw|_this}_cpu_generic*()
  macros into one place.  They were dispersed through
  {raw|this}_cpu_*_N() definitions and the visiual inconsistency was
  making following the code unnecessarily difficult.

* In include/linux/percpu-defs.h, move __verify_pcpu_ptr() later in
  the file so that it's right above accessor definitions where it's
  actually used.

This is pure reorganization.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Christoph Lameter <cl@linux.com>
2014-06-17 19:12:39 -04:00
Tejun Heo
a32f8d8eda percpu: move {raw|this}_cpu_*() definitions to include/linux/percpu-defs.h
We're in the process of moving all percpu accessors and operations to
include/linux/percpu-defs.h so that they're available to arch headers
without having to include full include/linux/percpu.h which may cause
cyclic inclusion dependency.

This patch moves {raw|this}_cpu_*() definitions from
include/linux/percpu.h to include/linux/percpu-defs.h.  The code is
moved mostly verbatim; however, raw_cpu_*() are placed above
this_cpu_*() which is more conventional as the raw operations may be
used to defined other variants.

This is pure reorganization.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Christoph Lameter <cl@linux.com>
2014-06-17 19:12:39 -04:00
Tejun Heo
3b8ed91d64 percpu: reorganize include/linux/percpu-defs.h
Reorganize for better readability.

* Accessor definitions are collected into one place and SMP and UP now
  define them in the same order.

* Definitions are layered when possible - e.g. per_cpu() is now
  defined in terms of this_cpu_ptr().

* Rather pointless comment dropped.

* per_cpu(), __raw_get_cpu_var() and __get_cpu_var() are defined in a
  way which can be shared between SMP and UP and moved out of
  CONFIG_SMP blocks.

This patch doesn't introduce any functional difference.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Lameter <cl@linux-foundation.org>
2014-06-17 19:12:37 -04:00
Tejun Heo
9defda18f9 percpu: move accessors from include/linux/percpu.h to percpu-defs.h
include/linux/percpu-defs.h is gonna host all accessors and operations
so that arch headers can make use of them too without worrying about
circular dependency through include/linux/percpu.h.

This patch moves the following accessors from include/linux/percpu.h
to include/linux/percpu-defs.h.

* get/put_cpu_var()
* get/put_cpu_ptr()
* per_cpu_ptr()

This is pure reorgniazation.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Christoph Lameter <cl@linux.com>
2014-06-17 19:12:34 -04:00
Tejun Heo
62fde54123 percpu: include/asm-generic/percpu.h should contain only arch-overridable parts
The roles of the various percpu header files has become unclear.
There are four header files involved.

 include/linux/percpu-defs.h
 include/linux/percpu.h
 include/asm-generic/percpu.h
 arch/*/include/asm/percpu.h

The original intention for include/asm-generic/percpu.h is providing
generic definitions for arch-overridable parts; however, it now hosts
various stuff which can't be overridden by archs.

Also, include/linux/percpu-defs.h was initially added to contain
section and percpu variable definition macros so that arch header
files can make use of them without worrying about introducing cyclic
inclusion dependency by including include/linux/percpu.h; however,
arch headers sometimes need to access percpu variables too and this is
one of the reasons why some accessors were implemented in
include/linux/asm-generic/percpu.h.

Let's clear up the situation by making include/asm-generic/percpu.h
contain only arch-overridable parts and moving accessors and
operations into include/linux/percpu-defs.  Note that this patch only
moves things from include/asm-generic/percpu.h.
include/linux/percpu.h will be taken care of by later patches.

This patch moves the followings.

* SHIFT_PERCPU_PTR() / VERIFY_PERCPU_PTR()
* per_cpu()
* raw_cpu_ptr()
* this_cpu_ptr()
* __get_cpu_var()
* __raw_get_cpu_var()
* __this_cpu_ptr()
* PER_CPU_[SHARED_]ALIGNED_SECTION
* PER_CPU_[SHARED_]ALIGNED_SECTION
* PER_CPU_FIRST_SECTION

This patch is pure reorganization.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Christoph Lameter <cl@linux.com>
2014-06-17 19:12:34 -04:00
Tejun Heo
b1a0fbfdde percpu: fix spurious sparse warnings from DEFINE_PER_CPU()
When CONFIG_DEBUG_FORCE_WEAK_PER_CPU or CONFIG_ARCH_NEEDS_WEAK_PER_CPU
is set, DEFINE_PER_CPU() explodes into cryptic series of definitions
to still allow using "static" for percpu variables while keeping all
per-cpu symbols unique in the kernel image which is required for weak
symbols.  This ultimately converts the actual symbol to global whether
DEFINE_PER_CPU() is prefixed with static or not.

Unfortunately, the macro forgot to add explicit extern declartion of
the actual symbol ending up defining global symbol without preceding
declaration for static definitions which naturally don't have matching
DECLARE_PER_CPU().  The only ill effect is triggering of the following
warnings.

 fs/inode.c:74:8: warning: symbol 'nr_inodes' was not declared. Should it be static?
 fs/inode.c:75:8: warning: symbol 'nr_unused' was not declared. Should it be static?

Fix it by adding extern declaration in the DEFINE_PER_CPU() macro.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Tested-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
2013-12-05 12:59:23 -05:00
Christoph Lameter
abec1a806e percpu: Make __verify_pcu_ptr handle per cpu pointers to arrays
__verify_pcpu_ptr() will cause a compilation failure if the type of the
pointer is a pointer to a fixed array of objects. Adding zero to the
pointer converts the type of pointer to that pointing to a single
object of the array.

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2013-08-23 16:08:27 -04:00
Ingo Molnar
47f19a0814 percpu: Remove the multi-page alignment facility
[DECLARE|DEFINE]_PER_CPU_MULTIPAGE_ALIGNED never really worked because
the head percpu section was only page aligned. Now that the last user
is gone (32-bit IRQ stacks), remove the generic percpu facility.

Cc: Brian Gerst <brgerst@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <1288158182-1753-1-git-send-email-brgerst@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-27 17:53:25 +02:00
Linus Torvalds
91151240ed Merge branch 'x86-irq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-irq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, 32-bit: Align percpu area and irq stacks to THREAD_SIZE
  x86: Move alloc_desk_mask variables inside ifdef
  x86-32: Align IRQ stacks properly
  x86: Remove CONFIG_4KSTACKS
  x86: Always use irq stacks

Fixed up trivial conflicts in include/linux/{irq.h, percpu-defs.h}
2010-10-22 08:54:21 -07:00
Shaohua Li
c957ef2c59 percpu: Introduce a read-mostly percpu API
Add a new readmostly percpu section and API.  This can be used to
avoid dirtying data lines which are generally not written to, which is
especially important for data which may be accessed by processors
other than the one for which the percpu area belongs to.

[ hpa: moved it *after* the page-aligned section, for obvious
  reasons. ]

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
LKML-Reference: <1287544022.4571.7.camel@sli10-conroe.sh.intel.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2010-10-20 14:33:58 -07:00
Alexander van Heukelum
fe8e0c25ca x86, 32-bit: Align percpu area and irq stacks to THREAD_SIZE
The irq stacks, located in the percpu-area, need to be
THREAD_SIZE aligned. Add the infrastucture to align percpu
variables to larger-than-pagesize amounts within the percpu
area, and use it to specify the alignment for the irq stacks.
Also align the percpu area itself to THREAD_SIZE.

This should make irq stacks work with 8K THREAD_SIZE.

Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Cc: Tejun Heo <tj@kernel.org>
Cc: hch@lst.de
LKML-Reference: <1283799222.15941.1393621887@webmail.messagingengine.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-09-07 05:07:00 +02:00
Linus Torvalds
1f73897861 Merge branch 'for-35' of git://repo.or.cz/linux-kbuild
* 'for-35' of git://repo.or.cz/linux-kbuild: (81 commits)
  kbuild: Revert part of e8d400a to resolve a conflict
  kbuild: Fix checking of scm-identifier variable
  gconfig: add support to show hidden options that have prompts
  menuconfig: add support to show hidden options which have prompts
  gconfig: remove show_debug option
  gconfig: remove dbg_print_ptype() and dbg_print_stype()
  kconfig: fix zconfdump()
  kconfig: some small fixes
  add random binaries to .gitignore
  kbuild: Include gen_initramfs_list.sh and the file list in the .d file
  kconfig: recalc symbol value before showing search results
  .gitignore: ignore *.lzo files
  headerdep: perlcritic warning
  scripts/Makefile.lib: Align the output of LZO
  kbuild: Generate modules.builtin in make modules_install
  Revert "kbuild: specify absolute paths for cscope"
  kbuild: Do not unnecessarily regenerate modules.builtin
  headers_install: use local file handles
  headers_check: fix perl warnings
  export_report: fix perl warnings
  ...
2010-06-01 08:55:52 -07:00