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: NNoam Camus <noamc@ezchip.com>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

This patch adds implementation of GET_THREAD_AREA ptrace request type. This
is required by GDB to debug NPTL applications.
Signed-off-by: NAnton Kolesov <Anton.Kolesov@synopsys.com>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

using ARC ZOL which reduces tot num of instructions by half
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

Fixes: ec7ac6af (ARC: switch to generic ENTRY/END assembler annotations)
Reported-by: NAnton Kolesov <akolesov@synopsys.com>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

Performing vma lookups without taking the mm->mmap_sem is asking for
trouble.  While doing the search, the vma in question can be modified or
even removed before returning to the caller.  Take the lock (shared) in
order to avoid races while iterating through the vmacache and/or rbtree.

[akpm@linux-foundation.org: CSE current->active_mm, per Vineet]
Signed-off-by: NDavidlohr Bueso <davidlohr@hp.com>
Acked-by: NVineet Gupta <vgupta@synopsys.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Requested-by: NNoam Camus <noamc@ezchip.com>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

[vgupta: fixed changelong + added Randy's suggestion]
Signed-off-by: NTerence Eden <github.com@shkspr.mobi>
Acked-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

Helps move out ISA specific bits from a arch exported header
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

* Move extension specific code out of common SMP code
* Don't enable it by default for SMP
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

There was a very small race window where resume to kernel mode from a
Exception Path (or pure kernel mode which is true for most of ARC
exceptions anyways), was not disabling interrupts in restore_regs,
clobbering the exception regs

Anton found the culprit call flow (after many sleepless nights)

| 1. we got a Trap from user land
| 2. started to service it.
| 3. While doing some stuff on user-land memory (I think it is padzero()),
|     we got a DataTlbMiss
| 4. On return from it we are taking "resume_kernel_mode" path
| 5. NEED_RESHED is not set, so we go to "return from exception" path in
|     restore regs.
| 6. there seems to be IRQ happening
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
Cc: <stable@vger.kernel.org>   #3.10, 3.12, 3.13, 3.14
Cc: Anton Kolesov <Anton.Kolesov@synopsys.com>
Cc: Francois Bedard <Francois.Bedard@synopsys.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Make of_get_flat_dt_prop arguments compatible with libfdt fdt_getprop
call in preparation to convert FDT code to use libfdt. Make the return
value const and the property length ptr type an int.
Signed-off-by: NRob Herring <robh@kernel.org>
Tested-by: NMichal Simek <michal.simek@xilinx.com>
Tested-by: NGrant Likely <grant.likely@linaro.org>
Tested-by: NStephen Chivers <schivers@csc.com>

-Pass the expected arg to non-boot park'ing routine
 (It worked so far because existing SMP backends don't use the arg)

-CONFIG_DEBUG_PREEMPT warning

* Remove one liner IRQ ACK accessor, it was coming in the way of readability.
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

So no point keeping it weak
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

With commit 9df62f05 "arch: use ASM_NL instead of ';'" the generic
macros can handle the arch specific newline quirk. Hence we can get rid
of ARC asm macros and use the "C" style macros.
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

* Moved cmdline copy from asm to "C" - allows for more robust checking
  of pointer validity etc.

* Remove the Kconfig option to do so, base it on a runtime value passed
  by u-boot
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

* 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/2013/11/25/232Suggested-by: NPeter Zijlstra <peterz@infradead.org>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

* 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

Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

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: NVineet Gupta <vgupta@synopsys.com>

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: NVineet Gupta <vgupta@synopsys.com>

Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

The ARC 700 does not have an interrupt associated with it, and as
such it cannot trigger when a counter overflows. As the counters are
48 bit, it will usually take at least 100 days before a counter
overflows, so for mere counting of events, there is no problem.
Sampling is not supported though.
Signed-off-by: NMischa Jonker <mjonker@synopsys.com>
Acked-by: NPeter Zijlstra <peterz@infradead.org>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

This adds basic perf support for ARC700 cores. Most PERF_COUNT_HW* events
are supported now.
Signed-off-by: NMischa Jonker <mjonker@synopsys.com>
Acked-by: NPeter Zijlstra <peterz@infradead.org>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

Commit 9a46ad6d "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: NJiang Liu <jiang.liu@huawei.com>
Cc: Jiang Liu <liuj97@gmail.com>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

RTSC is strictly incore and must not be allowed in SMP configs
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

ST.as only takes S9 (255) for offset. This was going out of range when
accessing a task_struct field with 4k NR_CPUS (due to 128b of coumaks
itself in there).

Workaround by using an intermediate register to do the address scaling.

There is some duplication of fix for ctx_sw.c and ctx_sw_asm.S however
given that C version will go away soon I'm not bothering to factor out
the common code.
Reported-by: NNoam Camus <noamc@ezchip.com>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

- 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: NNoam Camus <noamc@ezchip.com>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

Need export symbol for it, or can not pass compiling, the related error
with allmodconfig:

    MODPOST 2994 modules
  ERROR: "pm_power_off" [drivers/mfd/retu-mfd.ko] undefined!
  ERROR: "pm_power_off" [drivers/char/ipmi/ipmi_poweroff.ko] undefined!
Signed-off-by: NChen Gang <gang.chen@asianux.com>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

Need export its symbol just like other architectures done, or can not
pass compiling with allmodconfig, the related error:

    MODPOST 2994 modules
  ERROR: "save_stack_trace" [kernel/backtracetest.ko] undefined!
  ERROR: "save_stack_trace" [drivers/md/persistent-data/dm-persistent-data.ko] undefined!
Signed-off-by: NChen Gang <gang.chen@asianux.com>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

get_hw_config_num_irq() may be called by normal iss_model_init_smp()
which is a function pointer for 'init_smp' which may be called by
first_lines_of_secondary() which also need be normal too.

The related warning (with allmodconfig):

    MODPOST vmlinux.o
  WARNING: vmlinux.o(.text+0x5814): Section mismatch in reference from the function iss_model_init_smp() to the function .init.text:get_hw_config_num_irq()
  The function iss_model_init_smp() references
  the function __init get_hw_config_num_irq().
  This is often because iss_model_init_smp lacks a __init
  annotation or the annotation of get_hw_config_num_irq is wrong.
Signed-off-by: NChen Gang <gang.chen@asianux.com>

first_lines_of_secondary() is a '__init' function, but it may be called
by __cpu_up() by _cpu_up() by cpu_up() which is a normal export symbol
function. So recommend to remove '__init'.

The related warning (with allmodconfig):

    MODPOST vmlinux.o
  WARNING: vmlinux.o(.text+0x315c): Section mismatch in reference from the function __cpu_up() to the function .init.text:first_lines_of_secondary()
  The function __cpu_up() references
  the function __init first_lines_of_secondary().
  This is often because __cpu_up lacks a __init
  annotation or the annotation of first_lines_of_secondary is wrong.
Signed-off-by: NChen Gang <gang.chen@asianux.com>

arc supports kgdb, but need update -- add function kgdb_roundup_cpus(),
or can not pass compiling. At present, add the simple generic one just
like other architectures(e.g. tile, mips ...).

The related error (with allmodconfig):

  kernel/built-in.o: In function `kgdb_cpu_enter':
  kernel/debug/debug_core.c:580: undefined reference to `kgdb_roundup_cpus'
Signed-off-by: NChen Gang <gang.chen@asianux.com>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

Lockdep required a small fix to stacktrace API which was incorrectly
unwindign out of __switch_to for the current call frame.
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

In case bootloader has changed the priority of one/more IRQ lines
Reported-by: NNoam Camus <noamc@ezchip.com>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

Emulation not enabled is treated as if the fixup failed, so no need for
special #ifdef checks.
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

switch the args (address, pt_regs) to match with all the other "C"
exception handlers.

This removes the awkwardness in EV_ProtV for page fault vs. unaligned
access.
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>