Rather than hardcoding CCA=0x5 for secondary cores, re-use the CCA from
the boot CPU. This allows overrides of the CCA using the cca= kernel
parameter to take effect on all CPUs for consistency.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>

This patch sets a default CCA suited for use with multi-core SMP on all
current MIPS CPS based systems. It may still be overriden by the cca=
argument on the kernel command line.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>

If the user or bootloader sets the CCA to a value which is not suited
for multi-core SMP (ie. anything non-coherent) then limit the system to
using only a single core and warn the user.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>

This patch adds support for offlining CPUs via hotplug when using the
CONFIG_MIPS_CPS SMP implementation. When a CPU is offlined one of 2
things will happen:

  - If the CPU is part of a core which implements the MT ASE and there
    is at least one other VPE online within that core then the VPE will
    be halted by settings its TCHalt bit.

  - Otherwise if supported the core will be powered down via the CPC.

  - Otherwise the CPU will hang by executing an infinite loop.

Bringing CPUs back online is then a process of either clearing the
appropriate VPEs TCHalt bit or powering up the appropriate core via the
CPC. Throughout the process the struct core_boot_config vpe_mask field
must be maintained such that mips_cps_boot_vpes will start & stop the
correct VPEs.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>

This patch adds code to generate entry & exit code for various low power
states available on systems based around the MIPS Coherent Processing
System architecture (ie. those with a Coherence Manager, Global
Interrupt Controller & for >=CM2 a Cluster Power Controller). States
supported are:

  - Non-coherent wait. This state first leaves the coherent domain and
    then executes a regular MIPS wait instruction. Power savings are
    found from the elimination of coherency interventions between the
    core and any other coherent requestors in the system.

  - Clock gated. This state leaves the coherent domain and then gates
    the clock input to the core. This removes all dynamic power from the
    core but leaves the core at the mercy of another to restart its
    clock. Register state is preserved, but the core can not service
    interrupts whilst its clock is gated.

  - Power gated. This deepest state removes all power input to the core.
    All register state is lost and the core will restart execution from
    its BEV when another core powers it back up. Because register state
    is lost this state requires cooperation with the CONFIG_MIPS_CPS SMP
    implementation in order for the core to exit the state successfully.

The code will detect which states are available on the current system
during boot & generate the entry/exit code for those states. This will
be used by cpuidle & hotplug implementations.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>

The core which the CPC core-other region relates to is based upon the
core-local core-other addressing register. As its name suggests this
register is shared between all VPEs within a core, and if there is a
possibility that multiple VPEs within a core will attempt to access
another core simultaneously then locking is required. This wasn't
previously a problem with the only user being cpu0 during boot, but will
be an issue once hotplug is implemented & may race with other users such
as cpuidle.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>

The start of mips_cps_core_entry is patched in order to provide the code
with the address of the CM register region at a point where it will be
running non-coherent with the rest of the system. However the cache
wasn't being flushed after that patching which could in principle lead
to secondary cores using an invalid CM base address.

The patching is moved to cps_prepare_cpus since local_flush_icache_range
has not been initialised at the point cps_smp_setup is called.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>

The core power down state for cpuidle will require that the CPS SMP
implementation is in use. This patch provides a mips_cps_smp_in_use
function which determines whether or not the CPS SMP implementation is
currently in use.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>

When hotplug and/or a powered down idle state are supported cases will
arise where a non-zero VPE must be brought online without VPE 0, and it
where multiple VPEs must be onlined simultaneously. This patch prepares
for that by:

  - Splitting struct boot_config into core & VPE boot config structures,
    allocated one per core or VPE respectively. This allows for multiple
    VPEs to be onlined simultaneously without clobbering each others
    configuration.

  - Indicating which VPEs should be online within a core at any given
    time using a bitmap. This allows multiple VPEs to be brought online
    simultaneously and also indicates to VPE 0 whether it should halt
    after starting any non-zero VPEs that should be online within the
    core. For example if all VPEs within a core are offlined via hotplug
    and the user onlines the second VPE within that core:

      1) The core will be powered up.

      2) VPE 0 will run from the BEV (ie. mips_cps_core_entry) to
         initialise the core.

      3) VPE 0 will start VPE 1 because its bit is set in the cores
         bitmap.

      4) VPE 0 will halt itself because its bit is clear in the cores
         bitmap.

  - Moving the core & VPE initialisation to assembly code which does not
    make any use of the stack. This is because if a non-zero VPE is to
    be brought online in a powered down core then when VPE 0 of that
    core runs it may not have a valid stack, and even if it did then
    it's messy to run through parts of generic kernel code on VPE 0
    before starting the correct VPE.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>

This patch allows use of the MT ASE yield instruction from uasm. It will
be used by a subsequent patch.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>

This patch allows use of the wait instruction from uasm. It will be used
by a subsequent patch.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>

This patch allows use of the sync instruction from uasm. It will be used
by a subsequent patch.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>

This patch allows use of the jalr instruction from uasm. It will be used
by a subsequent patch.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>

This patch allows for use of the beq instruction with labels from uasm,
much as bne & others already do. It will be used by a subsequent patch.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>

The opcode for the wait instruction within POOL32AXf was missing. This
patch adds it for use by a subsequent patch.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>

The opcode for the sync instruction within POOL32AXf was missing. This
patch adds it for use by a subsequent patch.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>

The opcode for the MT ASE yield instruction within the spec3 group was
missing. This patch adds it for use by a subsequent patch.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>

The func field for the wait instruction was missing from inst.h - this
patch adds it.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>

Define a macro to write to the current TCs TCHalt register. This will be
used by a subsequent patch.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>

This is identical to kmap_coherent apart from the cache coherency
attribute used for the TLB entry, so kmap_coherent is abstracted to
kmap_prot which is then called for both kmap_coherent &
kmap_noncoherent. This will be used by a subsequent patch.
Suggested-by: NLeonid Yegoshin <leonid.yegoshin@imgtec.com>
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>

This patch provides functions to lock & unlock access to the
"core-other" register region of the CPC. Without performing appropriate
locking it is possible for code using this region to be preempted or to
race with code on another VPE within the same core, with one changing
the core which the "core-other" region is acting upon at an inopportune
time for the other.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>

This patch introduces addr_ functions in addition to the existing read_
& write_ functions. The new functions simply return the address of the
appropriate CPC register rather than performing a memory access. This
will be used in a subsequent patch.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>

Add a mask of CPUs which are currently known to be operating coherently.
This is setup initially to be all present CPUs, but in a subsequent
patch CPUs in a MIPS Coherent Processing System will be cleared in this
mask as they enter non-coherent idle states. This will be used in order
to determine when a CPU within a CPS system may need to be powered back
up, but may also be used in future to optimise away wakeups for cache
operations or TLB invalidations.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>

This patch adds support for generic clockevents broadcast using the a
dummy clockevent device and the tick_broadcast function introduced by
commit 12ad1000 "clockevents: Add generic timer broadcast function".
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>

Having the GIC clockevent driver compiled should not prevent the R4K
timer clockevent driver from functioning. One will be selected as the
CPU local timer based upon their priorities and the other may simply be
unused or in the case of the GIC timer may be used as the tick broadcast
device.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>

The CLOCK_EVT_FEAT_PERCPU flag indicates that a clockevent device is
only configurable by the CPU for which it is registered, and thus cannot
be used as the tick broadcast device. That property is true of the R4K
timer, which is inaccessible from other cores.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>

When a core enters a clock off or power down state its CP0 counter will
be stopped along with it.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>

This patch allows the GIC clockevent device for a CPU to be configured
by another CPU. This makes GIC clockevent devices suitable for use as
the tick broadcast device, where formerly the GIC timer local to the
configuring CPU would have been configured incorrectly.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>

Although the GIC counter will continue when a core is in a low power
state and it will still trigger interrupts, the core will be incapable
of servicing those interrupts rendering them useless.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>

Implement assembler helper macros in asm/pm.h for platform code to use
for saving context across low power states - for example suspend to RAM
or powered down cpuidle states. Macros are provided for saving and
restoring the main CPU context used by C code and doing important
configuration which must be done very early during resume. Notably EVA
needs segmentation control registers to be restored before the stack or
dynamically allocated memory is accessed, so that state is saved in
global data.
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>

Add a CPU power management callback for the r4k TLB which reconfigures
it after the CPU leaves a powered down state.
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>

Implement a CPU power management callback for the r4k cache, to set up
coherency again after leaving a powered down state.
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>

Implement a CPU power management callback for restoring trap related CPU
configuration after CPU power up from a low power state. The following
state is restored:

- Status register
- HWREna register
- Exception vector configuration registers
- Context/XContext register
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>

Add a CPU power management notifier callback for preserving general CPU
context. The CPU PM callbacks will be triggered by the powering down of
CPU cores, for example by cpuidle drivers & in the future by suspend to
RAM implementations.

The current state preserved is mostly related to the process context:
- FPU
- DSP
- ASID
- UserLocal
- Watch registers
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>

The lkdtm module performs tests against executable memory ranges, so it
needs to flush the icache for proper behaviors.  Other architectures
already export this, so do the same for MIPS.

[akpm@linux-foundation.org: relocate export sites]
Signed-off-by: NKees Cook <keescook@chromium.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Sanjay Lal <sanjayl@kymasys.com>
Cc: John Crispin <blogic@openwrt.org>
Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

shiraz.hashim@st.com email-id doesn't exist anymore as he has left the
company.  Replace ST's id with shiraz.linux.kernel@gmail.com.

It also updates .mailmap file to fix address for 'git shortlog'.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Cc: Shiraz Hashim <shiraz.linux.kernel@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

  CHK     include/config/kernel.release
  CHK     include/generated/uapi/linux/version.h
  CHK     include/generated/utsrelease.h
  ...
  Building modules, stage 2.
WARNING: 1 bad relocations
c0000000013d6a30 R_PPC64_ADDR64    uprobes_fetch_type_table
  WRAP    arch/powerpc/boot/zImage.pseries
  WRAP    arch/powerpc/boot/zImage.epapr
  MODPOST 1849 modules
ERROR: ".__node_distance" [drivers/block/nvme.ko] undefined!
make[1]: *** [__modpost] Error 1
make: *** [modules] Error 2
make: *** Waiting for unfinished jobs....

The reason is symbol "__node_distance" not been exported in powerpc.
Signed-off-by: NMike Qiu <qiudayu@linux.vnet.ibm.com>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Jesse Larrew <jlarrew@linux.vnet.ibm.com>
Cc: Robert Jennings <rcj@linux.vnet.ibm.com>
Cc: Alistair Popple <alistair@popple.id.au>
Cc: Mike Qiu <qiudayu@linux.vnet.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 93ea02bb ("arch: Clean up asm/barrier.h implementations")
wired generic barrier.h for ARC, but failed to delete the existing file.

In 3.15, due to rcupdate.h updates, this causes a build breakage on ARC:

      CC      arch/arc/kernel/asm-offsets.s
    In file included from include/linux/sched.h:45:0,
                     from arch/arc/kernel/asm-offsets.c:9:
    include/linux/rculist.h: In function __list_add_rcu:
    include/linux/rculist.h:54:2: error: implicit declaration of function smp_store_release [-Werror=implicit-function-declaration]
      rcu_assign_pointer(list_next_rcu(prev), new);
      ^

Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

CPUs which should support the RAPL counters according to
Family/Model/Stepping may still issue #GP when attempting to access
the RAPL MSRs. This may happen when Linux is running under KVM and
we are passing-through host F/M/S data, for example. Use rdmsrl_safe
to first access the RAPL_POWER_UNIT MSR; if this fails, do not
attempt to use this PMU.
Signed-off-by: NVenkatesh Srinivas <venkateshs@google.com>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1394739386-22260-1-git-send-email-venkateshs@google.com
Cc: zheng.z.yan@intel.com
Cc: eranian@google.com
Cc: ak@linux.intel.com
Cc: linux-kernel@vger.kernel.org
[ The patch also silently fixes another bug: rapl_pmu_init() didn't handle the memory alloc failure case previously. ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Current kprobes in-kernel page fault handler doesn't
expect that its single-stepping can be interrupted by
an NMI handler which may cause a page fault(e.g. perf
with callback tracing).

In that case, the page-fault handled by kprobes and it
misunderstands the page-fault has been caused by the
single-stepping code and tries to recover IP address
to probed address.

But the truth is the page-fault has been caused by the
NMI handler, and do_page_fault failes to handle real
page fault because the IP address is modified and
causes Kernel BUGs like below.

 ----
 [ 2264.726905] BUG: unable to handle kernel NULL pointer dereference at 0000000000000020
 [ 2264.727190] IP: [<ffffffff813c46e0>] copy_user_generic_string+0x0/0x40

To handle this correctly, I fixed the kprobes fault
handler to ensure the faulted ip address is its own
single-step buffer instead of checking current kprobe
state.
Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Sandeepa Prabhu <sandeepa.prabhu@linaro.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: fche@redhat.com
Cc: systemtap@sourceware.org
Link: http://lkml.kernel.org/r/20140417081644.26341.52351.stgit@ltc230.yrl.intra.hitachi.co.jpSigned-off-by: NIngo Molnar <mingo@kernel.org>