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 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>

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>

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>

Rather than duplicating the GIC IPI send function, share the one already
used by CONFIG_MIPS_CPS & CONFIG_MIPS_CMP.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Paul Burton <paul.burton@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/6653/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This probing is already done by decode_configs as part of cpu_probe, and
furthermore the implementation here was incorrect for any MT core with
a number of VPEs other than 2.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6650/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

With binutils 2.24 the attempt to switch with microMIPS mode to MIPS III
mode through .set mips3 results in *lots* of warnings like

{standard input}: Assembler messages:
{standard input}:397: Warning: the 64-bit MIPS architecture does not support the `smartmips' extension

during a kernel build.  Fixed by using .set arch=r4000 instead.

This breaks support for building the kernel with binutils 2.13 which
was supported for 32 bit kernels only anyway and 2.14 which was a bad
vintage for MIPS anyway.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

In cores which implement the MT ASE, the CPUNum in the EBase register is
a concatenation of the core number & the VPE ID within that core. In
order to retrieve the correct core number CPUNum must be shifted
appropriately to remove the VPE ID bits.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6666/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Basic Loongson-3 CPU support include CPU probing and TLB/cache
initializing.
Signed-off-by: NHuacai Chen <chenhc@lemote.com>
Signed-off-by: NHongliang Tao <taohl@lemote.com>
Signed-off-by: NHua Yan <yanh@lemote.com>
Tested-by: NAlex Smith <alex.smith@imgtec.com>
Reviewed-by: NAlex Smith <alex.smith@imgtec.com>
Cc: John Crispin <john@phrozen.org>
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: linux-mips@linux-mips.org
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/6630Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

And there are more CPUs or configurations that want to provide special
per-CPU information in /proc/cpuinfo.  So I think there needs to be a
hook mechanism, such as a notifier.

This is a first cut only; I need to think about what sort of looking
the notifier needs to have.  But I'd appreciate testing on MT hardware!
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6066/

All architecturally defined bits in the FPU implementation register
are read only & unchanging. It contains some implementation-defined
bits but the architecture manual states "This bits are explicitly not
intended to be used for mode control functions" which seems to provide
justification for viewing the register as a whole as unchanging. This
being the case we can simply re-use the value we read at boot rather
than having to re-read it later, and avoid the complexity which that
read entails.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6147/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

All architecturally defined bits in the FPU implementation register
are read only & unchanging. It contains some implementation-defined
bits but the architecture manual states "This bits are explicitly not
intended to be used for mode control functions" which seems to provide
justification for viewing the register as a whole as unchanging. This
being the case we can simply re-use the value we read at boot rather
than having to re-read it later, and avoid the complexity which that
read entails.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Reviewed-by: NQais Yousef <qais.yousef@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6144/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

If current_cpu_type() is pre-defined in cpu-feature-overrides.h, This
may save about 10k for the compressed kernel image(vmlinuz).
Signed-off-by: NWu Zhangjin <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1901/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Loongson-1 is a 32-bit MIPS CPU and Loongson-2/3 are 64-bit MIPS CPUs,
and both Loongson-2/3 has the same PRID IMP filed (0x6300). As a
result, renaming PRID_IMP_LOONGSON1 and PRID_IMP_LOONGSON2 to
PRID_IMP_LOONGSON_32 and PRID_IMP_LOONGSON_64 will make more sense.
Signed-off-by: NHuacai Chen <chenhc@lemote.com>
Tested-by: NAlex Smith <alex.smith@imgtec.com>
Reviewed-by: NAlex Smith <alex.smith@imgtec.com>
Cc: John Crispin <john@phrozen.org>
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: linux-mips@linux-mips.org
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/6552/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Choose event/cache maps and handle raw event mapping for interAptiv. Update
code comments.
Signed-off-by: NDeng-Cheng Zhu <dengcheng.zhu@imgtec.com>
Reviewed-by: NMarkos Chandras <Markos.Chandras@imgtec.com>
Reviewed-by: NJames Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Steven.Hill@imgtec.com
Patchwork: https://patchwork.linux-mips.org/patch/6528/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Choose event/cache maps and handle raw event mapping for proAptiv. Update
code comments.
Signed-off-by: NDeng-Cheng Zhu <dengcheng.zhu@imgtec.com>
Reviewed-by: NMarkos Chandras <Markos.Chandras@imgtec.com>
Reviewed-by: NJames Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Steven.Hill@imgtec.com
Patchwork: https://patchwork.linux-mips.org/patch/6527/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

74K/proAptiv share the same event/cache maps. So it's better to change the
names of the existing mipsxx74Kcore_[event|cache]_map.
Signed-off-by: NDeng-Cheng Zhu <dengcheng.zhu@imgtec.com>
Reviewed-by: NMarkos Chandras <Markos.Chandras@imgtec.com>
Reviewed-by: NJames Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Steven.Hill@imgtec.com
Patchwork: https://patchwork.linux-mips.org/patch/6526/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NLeonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6597/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The M5150 core is a 32-bit MIPS RISC which implements the
MIPS Architecture Release-5  in a 5-stage pipeline.
In addition, it includes the MIPS Architecture Virtualization Module
that enables virtualization of operating systems,
which provides a scalable, trusted, and secure execution environment.
Signed-off-by: NLeonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6596/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Allow secondary cores to program their segment control registers
during smp bootstrap code. This enables EVA on Malta SMP
configurations
Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>

Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>

Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>

When flushing the icache, make sure the address limit is correct
so the appropriate 'cache' instruction will be used. This has no
impact on cores operating in non-eva mode. However, when EVA is
enabled, we ensure that 'cache' will be used instead of 'cachee'.
Signed-off-by: NLeonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>

EVA does not have FPU specific instructions for reading or writing
FPU registers from userspace memory.
Signed-off-by: NLeonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>

The 'copy_user' symbol can be used to copy from or to
userland so we will use two different symbols for these
operations. This makes no difference in the existing code,
but when the core is operating in EVA mode, different instructions
need to be used to read and write to userland address space.
The old function has also been renamed to 'copy_kernel' to denote
that it is suitable for copy data to and from kernel space.
Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>

Handle unaligned accesses when we access userspace memory
EVA mode.
Signed-off-by: NLeonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>

Use the load/store instruction wrappers from asm/asm.h to
perform such operations when operating in EVA mode.
Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>

Add copy_{to,from,in}_user when the CPU operates in EVA mode.
This is necessary so the EVA specific instructions can be used
to perform the virtual to physical translation for user space
addresses. We will use the non-EVA functions to read from kernel
if needed.
Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>

In non-EVA mode, strncpy_from_user* aliases are used for the
strncpy_from_kernel* symbols since the code is identical. In EVA
mode, new strcpy_from_user* symbols are used which use the EVA
specific instructions to load values from userspace.
Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>

In non-EVA mode, strlen_user* aliases are used for the
strlen_kernel* symbols since the code is identical. In EVA
mode, new strlen_user* symbols are used which use the EVA
specific instructions to load values from userspace.
Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>

In non-EVA mode, a strlen_user* alias is used for the
strlen_kernel* symbols since the code is identical. In EVA
mode, a new strlen_user* symbol is used which uses the EVA
specific instructions to load values from userspace.
Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>

When a breakpoint or trap happens when operating in kernel mode but
on users behalf (eg syscall) it is necessary to change the address
limit to KERNEL_DS so any address checking can be bypassed and print
the correct stack trace.
Signed-off-by: NLeonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>