Commit Graph

35 Commits

Author SHA1 Message Date
Noam Camus 71f9cf8fdd ARC: Mark secondary cpu online only after all HW setup is done
In SMP setup, master loops for each_present_cpu calling cpu_up().
For ARC it returns as soon as new cpu's status becomes online,
However secondary may still do HW initializing,
machine or platform hook level.

So turn secondary online only after all HW setup is done.
Signed-off-by: Noam Camus <noamc@ezchip.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
2016-05-09 09:32:32 +05:30
Noam Camus eec3c58efa ARC: clockevent: switch to cpu notifier for clockevent setup
ARC Timers so far have been handled as "legacy" w/o explicit description
in DT. This poses challenge for newer platforms wanting to use them.
This series will eventually help move timers over to DT.

This patch does a small change of using a CPU notifier to set clockevent
on non-boot CPUs. So explicit setup is done only on boot CPU (which will
later be done by DT)

Signed-off-by: Noam Camus <noamc@ezchip.com>
[vgupta: broken off from a bigger patch]
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-05-09 09:32:28 +05:30
Vineet Gupta 569579401a ARC: opencode arc_request_percpu_irq
- The idea is to remove the API usage since it has a subltle
  design flaw - relies on being called on cpu0 first. This is true for
  some early per cpu irqs such as TIMER/IPI, but not for late probed
  per cpu peripherals such a perf. And it's usage in perf has already
  bitten us once: see c6317bc7c5
  ("ARCv2: perf: Ensure perf intr gets enabled on all cores") where we
  ended up open coding it anyways

- The seeming duplication will go away once we start using cpu notifier
  for timer setup

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-05-09 09:32:28 +05:30
Thomas Gleixner fc6d73d674 arch/hotplug: Call into idle with a proper state
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 <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: Rik van Riel <riel@redhat.com>
Cc: Rafael Wysocki <rafael.j.wysocki@intel.com>
Cc: "Srivatsa S. Bhat" <srivatsa@mit.edu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Turner <pjt@google.com>
Link: http://lkml.kernel.org/r/20160226182341.614102639@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-03-01 20:36:57 +01:00
Vineet Gupta d73b73f562 ARC: SMP: No need for CONFIG_ARC_IPI_DBG
This was more relevant during SMP bringup.

The warning for bogus msg better be visible always.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-02-24 11:07:32 +05:30
Vineet Gupta 575a9d4e2c ARC: smp: Rename platform hook @init_cpu_smp -> @init_per_cpu
Makes it similar to smp_ops which also has callback with same name

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-12-17 12:56:56 +05:30
Noam Camus b474a02382 ARC: rename smp operation init_irq_cpu() to init_per_cpu()
This will better reflect its description i.e. "any needed setup..."
and not just do an "IPI request".

Signed-off-by: Noam Camus <noamc@ezchip.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-12-17 12:56:43 +05:30
Vineet Gupta 286130ebf1 ARC: smp: Introduce smp hook @init_irq_cpu called for all cores
Note this is not part of platform owned static machine_desc,
but more of device owned plat_smp_ops (rather misnamed) which a IPI
provider or some such typically defines.

This will help us seperate out the IPI registration from platform
specific init_cpu_smp() into device specific init_irq_cpu()

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-28 16:13:41 +05:30
Vineet Gupta 8721a7f5a6 ARC: smp: Rename platform hook @init_smp -> @init_cpu_smp
This conveys better that it is called for each cpu

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-28 16:13:40 +05:30
Vineet Gupta e55af4da02 ARC: smp: Introduce smp hook @init_early_smp for Master core
This adds a platform agnostic early SMP init hook which is called on
Master core before calling setup_processor()

  setup_arch()
     smp_init_cpus()
         smp_ops.init_early_smp()
     ...
     setup_processor()

How this helps:
 - Used for one time init of certain SMP centric IP blocks, before
   calling setup_processor() which probes various bits of core,
   possibly including this block

 - Currently platforms need to call this IP block init from their
   init routines, which doesn't make sense as this is specific to ARC
   core and not platform and otherwise requires copy/paste in all
   (and hence a possible point of failure)

e.g. MCIP init is called from 2 platforms currently (axs10x and sim)
which will go away once we have this.

This change only adds the hooks but they are empty for now. Next commit
will populate them and remove the explicit init calls from platforms.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-28 16:13:40 +05:30
Vineet Gupta f33e9c434b ARC: smp: Move default boot kick/wait code out of MCIP into common code
For non halt-on-reset case, all cores start of simultaneously in @stext.
Master core0 proceeds with kernel boot, while other spin-wait on
@wake_flag being set by master once it is ready. So NO hardware assist
is needed for master to "kick" the others.

This patch moves this soft implementation out of mcip.c (as there is no
hardware assist) into common smp.c

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-17 17:48:27 +05:30
Vineet Gupta aa6083ed50 ARCv2: SMP: ARConnect debug/robustness
- Handle possible interrupt coalescing from MCIP
- chk if prev IPI ack before sending new

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-22 14:06:57 +05:30
Vineet Gupta 173eaafaed ARC: make plat_smp_ops weak to allow over-rides
This allows platforms to provide their own cpu wakeup routines
as well as IPI send / clear backends, while allowing a SMP kernel w/o
any such backend to build/boot

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-22 14:06:56 +05:30
Vineet Gupta b27f739171 ARC: fix section mismatch with allyesconfig
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:27 +05:30
Vineet Gupta 7082a29c22 ARC: use ACCESS_ONCE in cmpxchg loop
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-02-02 17:08:37 +05:30
Vineet Gupta 9fb92eb116 ARC: R-M-W assist locks only needed for !LLSC
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2014-12-12 16:02:34 +05:30
Vineet Gupta 619f30188f ARC: Allow SMP kernel to build/boot on UP-only infrastructure
In light of recent SNAFU with SMP build, allow simple platform to build
as SMP but run UP.

* Remove the dependence on simulation SMP extension to enable quick
  build/test iterations of SMP kernel.

* In absence of platform SMP registration, prevent the NULL smp feature
  name from borkign the system

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2014-09-27 14:49:01 +05:30
Vineet Gupta c16e3e2283 ARC: prune extra header includes from smp.c
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2014-07-23 11:17:51 +05:30
Vineet Gupta 2b75c0f93e ARC: [SMP] unify cpu private IRQ requests (TIMER/IPI)
The current cpu-private IRQ registration is ugly as it requires need to
expose arch_unmask_irq() outside of intc code.
So switch to percpu IRQ APIs:
  -request_percpu_irq [boot core]
  -enable_percpu_irq  [all cores]

Encapsulated in helper arc_request_percpu_irq()

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2014-07-23 11:16:45 +05:30
Noam Camus 7e5122190b ARC: [SMP] Fix IPI IRQ registration
Handle it just like timer. Current request_percpu_irq() would fail on
non-boot cpus and thus IRQ will remian unmasked on those cpus.

[vgupta: fix changelong]
Signed-off-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2014-06-26 11:58:25 +05:30
Vineet Gupta 2d4899f6bd ARC: arc_local_timer_setup() need not pass own cpu id
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2014-06-03 13:26:52 +05:30
Vineet Gupta d8e8c7dda1 ARC: [SMP] optimize IPI send and receive
* Don't send an IPI if receiver already has a pending IPI.
  Atomically piggyback the new msg with pending msg.

* IPI receiver looping on xchg() not required

References: https://lkml.org/lkml/2013/11/25/232
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-12-23 12:05:04 +05:30
Vineet Gupta f2a4aa5646 ARC: [SMP] simplify IPI code
* ipi_data is just a word, no need to keep it as struct

* find_next_bit() not needed to loop thru a 32bit word, ffs suffices
2013-12-23 12:05:04 +05:30
Vineet Gupta 53dc110c97 ARC: [SMP] cpu halt interface doesn't need "self" cpu-id
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-12-23 12:05:04 +05:30
Vineet Gupta ccdaa6e0c8 ARC: [SMP] IPI ACK interface doesn't need "self" cpu-id
The interface is confusing, it feels like we are getting "sender" info,
whereas it is the "receiver", which can very well be retrived by
smp_processor_id(), if need be.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-12-23 12:05:04 +05:30
Vineet Gupta ddf84433f4 ARC: [SMP] cpumask not needed in IPI send path
The current IPI sending callstack needlessly involves cpumask.

   arch_send_call_function_single_ipi(cpu) / smp_send_reschedule(cpu)
      ipi_send_msg(cpumask_of(cpu))	--> [cpu to cpumask]
         plat_smp_ops.ipi_send(callmap)
            for_each_cpu(callmap)	--> [cpuask to cpu]
               do_plat_specific_ipi_PER_CPU

Given that current backends are not capable of 1:N IPIs, lets simplify
the interface for now, by keeping "a" cpu all along.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-12-23 12:05:04 +05:30
Jiang Liu 06b93c347c smp, ARC: kill SMP single function call interrupt
Commit 9a46ad6d6d "smp: make smp_call_function_many() use logic
similar to smp_call_function_single()" has unified the way to handle
single and multiple cross-CPU function calls. Now only one interrupt
is needed for architecture specific code to support generic SMP function
call interfaces, so kill the redundant single function call interrupt.

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Cc: Jiang Liu <liuj97@gmail.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-07 14:34:31 +05:30
Vineet Gupta 5ea72a9026 ARC: [SMP] TLB flush
- Add mm_cpumask setting (aggregating only, unlike some other arches)
  used to restrict the TLB flush cross-calling

- cross-calling versions of TLB flush routines (thanks to Noam)

Signed-off-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-06 10:41:45 +05:30
Vineet Gupta 064a626924 ARC: use __weak instead of __attribute__((weak))
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-06 10:40:37 +05:30
Paul Gortmaker ce7599567e arc: delete __cpuinit usage from all arc files
The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications.  For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.

After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out.  Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.

Note that some harmless section mismatch warnings may result, since
notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c)
are flagged as __cpuinit  -- so if we remove the __cpuinit from
arch specific callers, we will also get section mismatch warnings.
As an intermediate step, we intend to turn the linux/init.h cpuinit
content into no-ops as early as possible, since that will get rid
of these warnings.  In any case, they are temporary and harmless.

This removes all the arch/arc uses of the __cpuinit macros from
all C files.  Currently arc does not have any __CPUINIT used in
assembly files.

[1] https://lkml.org/lkml/2013/5/20/589

Cc: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-27 14:37:58 +05:30
Thomas Gleixner fa35e42a00 arc: Use generic idle loop
The generic idle loop implements all functionality. Aside of that it
allows arc to implement the tsk_is_polling() functionality correctly,
despite the patently (now gone) comment in the original arc cpu_idle()
function:
/* Since we SLEEP in idle loop, TIF_POLLING_NRFLAG can't be set */
See kernel/cpu/idle.c

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Magnus Damm <magnus.damm@gmail.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Tested-by: Vineet Gupta <vgupta@synopsys.com>
Link: http://lkml.kernel.org/r/20130321215233.711253792@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-04-08 17:39:23 +02:00
Vineet Gupta 10b1271875 ARC: [Review] Multi-platform image #7: SMP common code to use callbacks
This again is for switch from singleton platform SMP API to
multi-platform paradigm

Platform code is not yet setup to populate the callbacks, that happens
in next commit

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
2013-02-15 23:16:16 +05:30
Vineet Gupta 877768c84d ARC: [Review] Multi-platform image #3: switch to board callback
-platform API is retired and instead callbacks are used

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
2013-02-15 23:16:14 +05:30
Vineet Gupta 03a6d28cdd ARC: [Review] Multi-platform image #2: Board callback Infrastructure
The orig platform code orgnaization was singleton design pattern - only
one platform (and board thereof) would build at a time.

Thus any platform/board specific code (e.g. irq init, early init ...)
expected by ARC common code was exported as well defined set of APIs,
with only ONE instance building ever.

Now with multiple-platform build requirement, that design of code no
longer holds - multiple board specific calls need to build at the same
time - so ARC common code can't use the API approach, it needs a
callback based design where each board registers it's specific set of
functions, and at runtime, depending on board detection, the callbacks
are used from the registry.

This commit adds all the infrastructure, where board specific callbacks
are specified as a "maThine description".

All the hooks are placed in right spots, no board callbacks registered
yet (with MACHINE_STARt/END constructs) so the hooks will not run.

Next commit will actually convert the platform to this infrastructure.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
2013-02-15 23:16:13 +05:30
Vineet Gupta 41195d236e ARC: SMP support
ARC common code to enable a SMP system + ISS provided SMP extensions.

ARC700 natively lacks SMP support, hence some of the core features are
are only enabled if SoCs have the necessary h/w pixie-dust. This
includes:
-Inter Processor Interrupts (IPI)
-Cache coherency
-load-locked/store-conditional
...

The low level exception handling would be completely broken in SMP
because we don't have hardware assisted stack switching. Thus a fair bit
of this code is repurposing the MMU_SCRATCH reg for event handler
prologues to keep them re-entrant.

Many thanks to Rajeshwar Ranga for his initial "major" contributions to
SMP Port (back in 2008), and to Noam Camus and Gilad Ben-Yossef for help
with resurrecting that in 3.2 kernel (2012).

Note that this platform code is again singleton design pattern - so
multiple SMP platforms won't build at the moment - this deficiency is
addressed in subsequent patches within this series.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Rajeshwar Ranga <rajeshwar.ranga@gmail.com>
Cc: Noam Camus <noamc@ezchip.com>
Cc: Gilad Ben-Yossef <gilad@benyossef.com>
2013-02-15 23:16:02 +05:30