linux.git/arch/sh/kernel, branch v4.6-rc2

arch, ftrace: for KASAN put hard/soft IRQ entries into separate sections

2016-03-25T23:37:42+00:00

KASAN needs to know whether the allocation happens in an IRQ handler.
This lets us strip everything below the IRQ entry point to reduce the
number of unique stack traces needed to be stored.

Move the definition of __irq_entry to  so that the
users don't need to pull in .  Also introduce the
__softirq_entry macro which is similar to __irq_entry, but puts the
corresponding functions to the .softirqentry.text section.

Signed-off-by: Alexander Potapenko 
Acked-by: Steven Rostedt 
Cc: Christoph Lameter 
Cc: Pekka Enberg 
Cc: David Rientjes 
Cc: Joonsoo Kim 
Cc: Andrey Konovalov 
Cc: Dmitry Vyukov 
Cc: Andrey Ryabinin 
Cc: Konstantin Serebryany 
Cc: Dmitry Chernenkov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge tag 'tag-sh-for-4.6' of git://git.libc.org/linux-sh

2016-03-19T23:09:43+00:00

Pull arch/sh updates from Rich Felker:
 "This includes minor cleanups, a fix for a crash that likely affects
  all sh models with MMU, and introduction of a framework for boards
  described by device tree, which sets the stage for future J2 support"

* tag 'tag-sh-for-4.6' of git://git.libc.org/linux-sh:
  sched/preempt, sh: kmap_coherent relies on disabled preemption
  sh: add SMP method selection to device tree pseudo-board
  sh: add device tree support and generic board using device tree
  sh: remove arch-specific localtimer and use generic one
  sh: make MMU-specific SMP code conditional on CONFIG_MMU
  sh: provide unified syscall trap compatible with all SH models
  sh: New gcc support
  sh: Disable trace for kernel uncompressing.
  sh: Use generic clkdev.h header

sh: add device tree support and generic board using device tree

2016-03-17T19:46:11+00:00

Add a new pseudo-board, within the existing SH boards/machine-vectors
framework, which does not represent any actual hardware but instead
requires all hardware to be described by the device tree blob provided
by the boot loader. Changes made are thus non-invasive and do not risk
breaking support for legacy boards.

New hardware, including the open-hardware J2 and associated SoC
devices, will use device free from the outset. Legacy SH boards can
transition to device tree once all their hardware has device tree
bindings, driver support for device tree, and a dts file for the
board.

It is intented that, once all boards are supported in the new
framework, the existing machine-vectors framework should be removed
and the new device tree setup code integrated directly.

Signed-off-by: Rich Felker

sh: remove arch-specific localtimer and use generic one

2016-03-17T19:46:09+00:00

The code being removed was copied from arm, where the corresponding
code was removed in 2013. The only functional change should be that
the rating of the dummy local timer changes from 400 to 100.

Signed-off-by: Rich Felker

sh: make MMU-specific SMP code conditional on CONFIG_MMU

2016-03-17T19:46:08+00:00

This is a prerequisite for adding NOMMU SMP support.

Signed-off-by: Rich Felker

sh: provide unified syscall trap compatible with all SH models

2016-03-17T19:46:06+00:00

Historically SH-2 Linux (and originally uClinux) used a syscall
calling convention incompatible with the established SH-3/4 Linux ABI.
This choice was made because the trap range used by the existing ABI,
0x10-0x17, overlaps with the hardware exception/interrupt trap range
reserved by SH-2, and in particular, with the SH-2A divide-by-zero and
division-overflow exceptions.

Despite the documented syscall convention using the low bits of the
trap number to signal the number of arguments the kernel should
expect, no version of the kernel has ever used this information, nor
is it useful; all of the registers need to be saved anyway. Therefore,
it is possible to pick a new trap number, 0x1f, that is both supported
by all existing SH-3/4 kernels and unassigned as a hardware trap in
the SH-2 range. This makes it possible to produce SH-2 application
binaries that are forwards-compatible with running on SH-3/4 kernels
and to treat SH as a unified platform with varying ISA support levels
rather than multiple gratuitously-incompatible platforms.

This patch adjusts the range checking SH-2 and SH-2A kernels make for
the syscall trap to accept the range 0x1f-0x2f rather than just
0x20-0x2f. As a result, trap 0x1f now acts as a syscall for all SH
models.

Signed-off-by: Rich Felker

sh: New gcc support

2016-03-17T19:45:44+00:00

New gcc (4.8 or later) used new shift helper functions.
So we need added new helper to private libgcc.

Signed-off-by: Yoshinori Sato 
Signed-off-by: Rich Felker

Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2016-03-15T20:50:29+00:00

Pull cpu hotplug updates from Thomas Gleixner:
"This is the first part of the ongoing cpu hotplug rework:

- Initial implementation of the state machine

- Runs all online and prepare down callbacks on the plugged cpu and
not on some random processor

- Replaces busy loop waiting with completions

- Adds tracepoints so the states can be followed"

More detailed commentary on this work from an earlier email:
"What's wrong with the current cpu hotplug infrastructure?

- Asymmetry

The hotplug notifier mechanism is asymmetric versus the bringup and
teardown. This is mostly caused by the notifier mechanism.

- Largely undocumented dependencies

While some notifiers use explicitely defined notifier priorities,
we have quite some notifiers which use numerical priorities to
express dependencies without any documentation why.

- Control processor driven

Most of the bringup/teardown of a cpu is driven by a control
processor. While it is understandable, that preperatory steps,
like idle thread creation, memory allocation for and initialization
of essential facilities needs to be done before a cpu can boot,
there is no reason why everything else must run on a control
processor. Before this patch series, bringup looks like this:

Control CPU Booting CPU

do preparatory steps
kick cpu into life

do low level init

sync with booting cpu sync with control cpu

bring the rest up

- All or nothing approach

There is no way to do partial bringups. That's something which is
really desired because we waste e.g. at boot substantial amount of
time just busy waiting that the cpu comes to life. That's stupid
as we could very well do preparatory steps and the initial IPI for
other cpus and then go back and do the necessary low level
synchronization with the freshly booted cpu.

- Minimal debuggability

Due to the notifier based design, it's impossible to switch between
two stages of the bringup/teardown back and forth in order to test
the correctness. So in many hotplug notifiers the cancel
mechanisms are either not existant or completely untested.

- Notifier [un]registering is tedious

To [un]register notifiers we need to protect against hotplug at
every callsite. There is no mechanism that bringup/teardown
callbacks are issued on the online cpus, so every caller needs to
do it itself. That also includes error rollback.

What's the new design?

The base of the new design is a symmetric state machine, where both
the control processor and the booting/dying cpu execute a well
defined set of states. Each state is symmetric in the end, except
for some well defined exceptions, and the bringup/teardown can be
stopped and reversed at almost all states.

So the bringup of a cpu will look like this in the future:

Control CPU Booting CPU

do preparatory steps
kick cpu into life

do low level init

sync with booting cpu sync with control cpu

bring itself up

The synchronization step does not require the control cpu to wait.
That mechanism can be done asynchronously via a worker or some
other mechanism.

The teardown can be made very similar, so that the dying cpu cleans
up and brings itself down. Cleanups which need to be done after
the cpu is gone, can be scheduled asynchronously as well.

There is a long way to this, as we need to refactor the notion when a
cpu is available. Today we set the cpu online right after it comes
out of the low level bringup, which is not really correct.

The proper mechanism is to set it to available, i.e. cpu local
threads, like softirqd, hotplug thread etc. can be scheduled on that
cpu, and once it finished all booting steps, it's set to online, so
general workloads can be scheduled on it. The reverse happens on
teardown. First thing to do is to forbid scheduling of general
workloads, then teardown all the per cpu resources and finally shut it
off completely.

This patch series implements the basic infrastructure for this at the
core level. This includes the following:

- Basic state machine implementation with well defined states, so
ordering and prioritization can be expressed.

- Interfaces to [un]register state callbacks

This invokes the bringup/teardown callback on all online cpus with
the proper protection in place and [un]installs the callbacks in
the state machine array.

For callbacks which have no particular ordering requirement we have
a dynamic state space, so that drivers don't have to register an
explicit hotplug state.

If a callback fails, the code automatically does a rollback to the
previous state.

- Sysfs interface to drive the state machine to a particular step.

This is only partially functional today. Full functionality and
therefor testability will be achieved once we converted all
existing hotplug notifiers over to the new scheme.

- Run all CPU_ONLINE/DOWN_PREPARE notifiers on the booting/dying
processor:

Control CPU Booting CPU

do preparatory steps
kick cpu into life

do low level init

sync with booting cpu sync with control cpu
wait for boot
bring itself up

Signal completion to control cpu

In a previous step of this work we've done a full tree mechanical
conversion of all hotplug notifiers to the new scheme. The balance
is a net removal of about 4000 lines of code.

This is not included in this series, as we decided to take a
different approach. Instead of mechanically converting everything
over, we will do a proper overhaul of the usage sites one by one so
they nicely fit into the symmetric callback scheme.

I decided to do that after I looked at the ugliness of some of the
converted sites and figured out that their hotplug mechanism is
completely buggered anyway. So there is no point to do a
mechanical conversion first as we need to go through the usage
sites one by one again in order to achieve a full symmetric and
testable behaviour"

* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
cpu/hotplug: Document states better
cpu/hotplug: Fix smpboot thread ordering
cpu/hotplug: Remove redundant state check
cpu/hotplug: Plug death reporting race
rcu: Make CPU_DYING_IDLE an explicit call
cpu/hotplug: Make wait for dead cpu completion based
cpu/hotplug: Let upcoming cpu bring itself fully up
arch/hotplug: Call into idle with a proper state
cpu/hotplug: Move online calls to hotplugged cpu
cpu/hotplug: Create hotplug threads
cpu/hotplug: Split out the state walk into functions
cpu/hotplug: Unpark smpboot threads from the state machine
cpu/hotplug: Move scheduler cpu_online notifier to hotplug core
cpu/hotplug: Implement setup/removal interface
cpu/hotplug: Make target state writeable
cpu/hotplug: Add sysfs state interface
cpu/hotplug: Hand in target state to _cpu_up/down
cpu/hotplug: Convert the hotplugged cpu work to a state machine
cpu/hotplug: Convert to a state machine for the control processor
cpu/hotplug: Add tracepoints
...

arch/hotplug: Call into idle with a proper state

2016-03-01T19:36:57+00:00

Let the non boot cpus call into idle with the corresponding hotplug state, so
the hotplug core can handle the further bringup. That's a first step to
convert the boot side of the hotplugged cpus to do all the synchronization
with the other side through the state machine. For now it'll only start the
hotplug thread and kick the full bringup of the cpu.

Signed-off-by: Thomas Gleixner 
Cc: linux-arch@vger.kernel.org
Cc: Rik van Riel 
Cc: Rafael Wysocki 
Cc: "Srivatsa S. Bhat" 
Cc: Peter Zijlstra 
Cc: Arjan van de Ven 
Cc: Sebastian Siewior 
Cc: Rusty Russell 
Cc: Steven Rostedt 
Cc: Oleg Nesterov 
Cc: Tejun Heo 
Cc: Andrew Morton 
Cc: Paul McKenney 
Cc: Linus Torvalds 
Cc: Paul Turner 
Link: http://lkml.kernel.org/r/20160226182341.614102639@linutronix.de
Signed-off-by: Thomas Gleixner

arch: Set IORESOURCE_SYSTEM_RAM flag for System RAM

2016-01-30T08:49:57+00:00

Set IORESOURCE_SYSTEM_RAM in flags of resource ranges with
"System RAM", "Kernel code", "Kernel data", and "Kernel bss".

Note that:

 - IORESOURCE_SYSRAM (i.e. modifier bit) is set in flags when
   IORESOURCE_MEM is already set. IORESOURCE_SYSTEM_RAM is defined
   as (IORESOURCE_MEM|IORESOURCE_SYSRAM).

 - Some archs do not set 'flags' for children nodes, such as
   "Kernel code".  This patch does not change 'flags' in this
   case.

Signed-off-by: Toshi Kani 
Signed-off-by: Borislav Petkov 
Cc: Andrew Morton 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Luis R. Rodriguez 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: Toshi Kani 
Cc: linux-arch@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-mips@linux-mips.org
Cc: linux-mm 
Cc: linux-parisc@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: sparclinux@vger.kernel.org
Link: http://lkml.kernel.org/r/1453841853-11383-7-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar