linux-toradex.git/arch/arc/kernel, branch v3.14.19

ARC: Implement ptrace(PTRACE_GET_THREAD_AREA)

2014-07-28T15:06:04+00:00

commit a4b6cb735b25aa84a462a1985e3e43bebaf5beb4 upstream.

This patch adds implementation of GET_THREAD_AREA ptrace request type. This
is required by GDB to debug NPTL applications.

Signed-off-by: Anton Kolesov 
Signed-off-by: Vineet Gupta 
Signed-off-by: Greg Kroah-Hartman

ARC: !PREEMPT: Ensure Return to kernel mode is IRQ safe

2014-05-13T11:32:50+00:00

commit 8aa9e85adac609588eeec356e5a85059b3b819ba upstream.

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: Vineet Gupta 
Cc: Anton Kolesov 
Cc: Francois Bedard 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

ARC: [cmdline] support External Device Trees from u-boot

2014-01-16T13:23:16+00:00

Signed-off-by: Vineet Gupta

ARC: [cmdline] uboot cmdline handling rework

2014-01-16T13:19:38+00:00

* 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: Vineet Gupta

ARC: [SMP] optimize IPI send and receive

2013-12-23T06:35:04+00:00

* 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 
Signed-off-by: Vineet Gupta

ARC: [SMP] simplify IPI code

2013-12-23T06:35:04+00:00

* 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

ARC: [SMP] cpu halt interface doesn't need "self" cpu-id

2013-12-23T06:35:04+00:00

Signed-off-by: Vineet Gupta

ARC: [SMP] IPI ACK interface doesn't need "self" cpu-id

2013-12-23T06:35:04+00:00

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

ARC: [SMP] cpumask not needed in IPI send path

2013-12-23T06:35:04+00:00

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

ARC: [perf] Fix a few thinkos

2013-11-28T10:19:59+00:00

Signed-off-by: Vineet Gupta