Commit Graph

30 Commits

Author SHA1 Message Date
Paul Burton
6422a91385 MIPS: smp-cps: Add nothreads kernel parameter
When debugging a new system or core it can be useful to disable the use
of multithreading. Introduce a "nothreads" kernel command line parameter
that can be set in order to do so.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Niklas Cassel <niklas.cassel@axis.com>
Cc: Ezequiel Garcia <ezequiel.garcia@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12340/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-13 14:01:50 +02:00
Paul Burton
5a3e7c02d8 MIPS: smp-cps: Support MIPSr6 Virtual Processors
Introduce support for bringing up Virtual Processors in MIPSr6 systems
as CPUs, much like their VPE parallel from the now-deprecated MT ASE.
The existing mips_cps_boot_vpes function fits the MIPSr6 architecture
pretty well - it can now simply write the mask of running VPs to the
VC_RUN register, rather than looping through each & starting or stopping
as appropriate as is done for VPEs from the MT ASE. Thus the VP support
is in general an extension & simplification of the existing MT ASE VPE
(aka SMVP) support.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Niklas Cassel <niklas.cassel@axis.com>
Cc: Ezequiel Garcia <ezequiel.garcia@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12339/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-13 14:01:50 +02:00
Paul Burton
f12401d721 MIPS: smp-cps: Pull boot config retrieval out of mips_cps_boot_vpes
The mips_cps_boot_vpes function previously included code to retrieve
pointers to the core & VPE boot configuration structs. These structures
were used both by mips_cps_boot_vpes and by its mips_cps_core_entry
callsite. In preparation for skipping the call to mips_cps_boot_vpes on
some invocations of mips_cps_core_entry, pull the calculation of those
pointers out into a separate function such that it can continue to be
shared.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Niklas Cassel <niklas.cassel@axis.com>
Cc: Ezequiel Garcia <ezequiel.garcia@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12337/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-13 14:01:50 +02:00
Paul Burton
ba1c0a490a MIPS: smp-cps: Ensure our VP ident calculation is correct
When bringing up a CPU, ensure that its local ID as provided by the GIC
matches up with our calculation of it. This is vital, since if the
condition doesn't hold then we won't have configured interrupts
correctly for the VP.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Niklas Cassel <niklas.cassel@axis.com>
Cc: Ezequiel Garcia <ezequiel.garcia@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12335/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-13 14:01:49 +02:00
Qais Yousef
bb11cff327 MIPS: Make smp CMP, CPS and MT use the new generic IPI functions
This commit does several things to avoid breaking bisectability.

	1- Remove IPI init code from irqchip/mips-gic
	2- Implement the new irqchip->send_ipi() in irqchip/mips-gic
	3- Select GENERIC_IRQ_IPI Kconfig symbol for MIPS_GIC
	4- Change MIPS SMP to use the generic IPI implementation

Only the SMP variants that use GIC were converted as it's the only irqchip that
will have the support for generic IPI for now.

Signed-off-by: Qais Yousef <qais.yousef@imgtec.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Cc: <jason@lakedaemon.net>
Cc: <marc.zyngier@arm.com>
Cc: <jiang.liu@linux.intel.com>
Cc: <linux-mips@linux-mips.org>
Cc: <lisa.parratt@imgtec.com>
Cc: Qais Yousef <qsyousef@gmail.com>
Link: http://lkml.kernel.org/r/1449580830-23652-18-git-send-email-qais.yousef@imgtec.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-02-25 10:56:58 +01:00
Matt Redfearn
497e803ebf MIPS: smp-cps: Ensure secondary cores start with EVA disabled
The kernel currently assumes that a core will start up in legacy mode
using the exception base provided through the CM GCR registers. If a
core has been configured in hardware to start in EVA mode, these
assumptions will fail.

This patch ensures that secondary cores are initialized to meet these
assumptions.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11907/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-01-24 02:09:53 +01:00
Paul Burton
4ede316170 MIPS: CM: make use of mips_cm_{lock,unlock}_other
Document that CPC core-other accesses must take place within the bounds
of the CM lock, and begin using the CM lock functions where we access
the GCRs of other cores. This is required because with CM3 the CPC began
using GCR_CL_OTHER instead of CPC_CL_OTHER.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andrew Bresticker <abrestic@chromium.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-kernel@vger.kernel.org
Cc: Niklas Cassel <niklas.cassel@axis.com>
Cc: Ezequiel Garcia <ezequiel.garcia@imgtec.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/11208/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-11-11 08:35:17 +01:00
Paul Burton
a8c20614b0 MIPS: CPS: Warn if a core doesn't start
When debugging core bringup it is useful to see the state of the CPC
sequencer, so output that value if the core hasn't started within a
reasonable amount of time (1 second). This avoids simply appearing to
the user to hang if a secondary core fails to start.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andrew Bresticker <abrestic@chromium.org>
Cc: linux-kernel@vger.kernel.org
Cc: Niklas Cassel <niklas.cassel@axis.com>
Cc: Ezequiel Garcia <ezequiel.garcia@imgtec.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/11205/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-11-11 08:35:08 +01:00
Paul Burton
946db17349 MIPS: CPS: Read CM GCR base from cop0
Rather than patching the start of mips_cps_core_entry to provide the
base address of the CM GCRs, simply read that base address from the cop0
CMGCRBase register, converting from the physical address to an uncached
virtual address.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andrew Bresticker <abrestic@chromium.org>
Cc: linux-kernel@vger.kernel.org
Cc: Niklas Cassel <niklas.cassel@axis.com>
Cc: Ezequiel Garcia <ezequiel.garcia@imgtec.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/11203/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-11-11 08:35:01 +01:00
Markos Chandras
fd5ed3066b MIPS: kernel: smp-cps: Fix 64-bit compatibility errors due to pointer casting
Commit 1d8f1f5a78 ("MIPS: smp-cps: hotplug support") added hotplug
support in the SMP/CPS implementation but it introduced a few build problems
on 64-bit kernels due to pointer being casted to and from 'int' C types. We
fix this problem by using 'unsigned long' instead which should match the size
of the pointers in 32/64-bit kernels. Finally, we fix the comment since the
CM base address is loaded to v1($3) instead of v0.

Fixes the following build problems:

arch/mips/kernel/smp-cps.c: In function 'wait_for_sibling_halt':
arch/mips/kernel/smp-cps.c:366:17: error: cast from pointer to integer of
different size [-Werror=pointer-to-int-cast]
[...]
arch/mips/kernel/smp-cps.c: In function 'cps_cpu_die':
arch/mips/kernel/smp-cps.c:427:13: error: cast to pointer
from integer of different size [-Werror=int-to-pointer-cast]

cc1: all warnings being treated as errors

Fixes: 1d8f1f5a78 ("MIPS: smp-cps: hotplug support")
Cc: <stable@vger.kernel.org> # 3.16+
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/10586/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-07-09 11:12:57 +02:00
Ezequiel Garcia
7363cb7de3 MIPS: Fix up obsolete cpu_set usage
cpu_set was removed (along with a bunch of cpumask helpers) by
commit 2f0f267ea0 ("cpumask: remove deprecated functions.").

Fix this by replacing cpu_set with cpumask_set_cpu. Without this
fix the following error is triggered when CONFIG_MIPS_MT_FPAFF=y.

  arch/mips/kernel/smp-cps.c: In function 'cps_smp_setup':
  arch/mips/kernel/smp-cps.c:95:3: error: implicit declaration of function 'cpu_set' [-Werror=implicit-function-declaration]

Fixes: 90db024f14 ("MIPS: smp-cps: cpu_set FPU mask if FPU present")
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@imgtec.com>
Acked-by: Niklas Cassel <niklass@axis.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9912/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-05-15 22:02:48 +02:00
Linus Torvalds
6496edfce9 This is the final removal (after several years!) of the obsolete cpus_*
functions, prompted by their mis-use in staging.
 
 With these function removed, all cpu functions should only iterate to
 nr_cpu_ids, so we finally only allocate that many bits when cpumasks
 are allocated offstack.
 
 Thanks,
 Rusty.
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Merge tag 'cpumask-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

Pull final removal of deprecated cpus_* cpumask functions from Rusty Russell:
 "This is the final removal (after several years!) of the obsolete
  cpus_* functions, prompted by their mis-use in staging.

  With these function removed, all cpu functions should only iterate to
  nr_cpu_ids, so we finally only allocate that many bits when cpumasks
  are allocated offstack"

* tag 'cpumask-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (25 commits)
  cpumask: remove __first_cpu / __next_cpu
  cpumask: resurrect CPU_MASK_CPU0
  linux/cpumask.h: add typechecking to cpumask_test_cpu
  cpumask: only allocate nr_cpumask_bits.
  Fix weird uses of num_online_cpus().
  cpumask: remove deprecated functions.
  mips: fix obsolete cpumask_of_cpu usage.
  x86: fix more deprecated cpu function usage.
  ia64: remove deprecated cpus_ usage.
  powerpc: fix deprecated CPU_MASK_CPU0 usage.
  CPU_MASK_ALL/CPU_MASK_NONE: remove from deprecated region.
  staging/lustre/o2iblnd: Don't use cpus_weight
  staging/lustre/libcfs: replace deprecated cpus_ calls with cpumask_
  staging/lustre/ptlrpc: Do not use deprecated cpus_* functions
  blackfin: fix up obsolete cpu function usage.
  parisc: fix up obsolete cpu function usage.
  tile: fix up obsolete cpu function usage.
  arm64: fix up obsolete cpu function usage.
  mips: fix up obsolete cpu function usage.
  x86: fix up obsolete cpu function usage.
  ...
2015-04-20 10:19:03 -07:00
Niklas Cassel
90db024f14 MIPS: smp-cps: cpu_set FPU mask if FPU present
If we have an FPU, enroll ourselves in the FPU-full mask.
Matching the MT_SMP and CMP implementations of smp_setup.

Signed-off-by: Niklas Cassel <niklass@axis.com>
Cc: paul.burton@imgtec.com
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8948/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-04-10 15:41:52 +02:00
Rusty Russell
8dd928915a mips: fix up obsolete cpu function usage.
Thanks to spatch, plus manual removal of "&*".  Then a sweep for
for_each_cpu_mask => for_each_cpu.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: linux-mips@linux-mips.org
2015-03-05 15:25:06 +10:30
Andrew Bresticker
4060bbe993 MIPS: Move gic.h to include/linux/irqchip/mips-gic.h
Now that the MIPS GIC irqchip lives in drivers/irqchip/, move
its header over to include/linux/irqchip/.

Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Qais Yousef <qais.yousef@imgtec.com>
Cc: John Crispin <blogic@openwrt.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/8129/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24 07:44:59 +01:00
Andrew Bresticker
ff1e29ade4 MIPS: smp-cps: Enable all hardware interrupts on secondary CPUs
Currently interrupt vectors 2 and 5 are left disabled on secondary CPUs.
Since systems using CPS must also have a GIC, which is responsible for
routing all external interrupts and can map them to any hardware interrupt
vector, enable the remaining vectors.  The two software interrupt vectors
are left disabled since they are not used with CPS.

Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Reviewed-by: Qais Yousef <qais.yousef@imgtec.com>
Tested-by: Qais Yousef <qais.yousef@imgtec.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Andrew Bresticker <abrestic@chromium.org>
Cc: Jeffrey Deans <jeffrey.deans@imgtec.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Qais Yousef <qais.yousef@imgtec.com>
Cc: Jonas Gorski <jogo@openwrt.org>
Cc: John Crispin <blogic@openwrt.org>
Cc: David Daney <ddaney.cavm@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/7803/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24 07:44:53 +01:00
Paul Burton
0fc0708a8a MIPS: smp-cps: Fix entry code cache flush for systems with coherent I/O
The dma_cache_wback_inv function performs exactly as is required here,
unless the system has coherent I/O in which case it's a no-op. Call the
underlying cache writeback functions directly, which is arguably clearer
anyway given that the code doesn't actually have anything to do with
DMA in a strict sense.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7282/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-07-30 20:49:36 +02:00
Paul Burton
c90e49f264 MIPS: {pm,smp}-cps: use cpu_vpe_id macro
When determining the VPE ID of a CPU, make use of the cpu_vpe_id macro
which will return 0 in a non-MT kernel build. Most code is already doing
so but a couple of places weren't. Fixing this prevents a build failure
for non-MT kernels where struct cpuinfo_mips does not contain the vpe_id
field:

  arch/mips/kernel/pm-cps.c: In function 'cps_pm_enter_state':
  arch/mips/kernel/pm-cps.c:153:51: error: 'struct cpuinfo_mips' has no
      member named 'vpe_id'
    vpe_cfg = &core_cfg->vpe_config[current_cpu_data.vpe_id];

  arch/mips/kernel/smp-cps.c: In function 'wait_for_sibling_halt':
  arch/mips/kernel/smp-cps.c:363:33: error: 'struct cpuinfo_mips' has no
      member named 'vpe_id'
    unsigned vpe_id = cpu_data[cpu].vpe_id;

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reviewed-by: Markos Chandras <markos.chandras@imgtec.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-07-30 20:48:42 +02:00
Paul Burton
e114ba20fe MIPS: smp-cps: Convert smp_mb__after_atomic_dec()
Commit 91bbefe6b0 "arch,mips: Convert smp_mb__*()" replaced the
smp_mb__after_atomic_dec function with smp_mb__after_atomic, whilst
commit 1d8f1f5a78 "MIPS: smp-cps: hotplug support" introduced a new
use of it. Replace that use with smp_mb__after_atomic in order to avoid
a build failure:

  arch/mips/kernel/smp-cps.c: In function 'cps_cpu_disable':
  arch/mips/kernel/smp-cps.c:304:2: error: 'smp_mb__after_atomic_dec' is
    deprecated (declared at include/linux/atomic.h:35)
    [-Werror=deprecated-declarations]

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reviewed-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7085/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-06-16 12:47:47 +01:00
Ralf Baechle
2e2d663d2d Merge branch 'wip-mips-pm' of https://github.com/paulburton/linux into mips-for-linux-next 2014-05-29 15:08:23 +02:00
Paul Burton
0155a06529 MIPS: smp-cps: duplicate core0 CCA on secondary cores
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: Paul Burton <paul.burton@imgtec.com>
2014-05-28 16:20:33 +01:00
Paul Burton
33b6866568 MIPS: smp-cps: set a coherent default CCA
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: Paul Burton <paul.burton@imgtec.com>
2014-05-28 16:20:33 +01:00
Paul Burton
5c399f6eb2 MIPS: smp-cps: prevent multi-core SMP with unsuitable CCA
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: Paul Burton <paul.burton@imgtec.com>
2014-05-28 16:20:32 +01:00
Paul Burton
1d8f1f5a78 MIPS: smp-cps: hotplug support
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: Paul Burton <paul.burton@imgtec.com>
2014-05-28 16:20:31 +01:00
Paul Burton
dd9233d047 MIPS: smp-cps: use CPC core-other locking
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: Paul Burton <paul.burton@imgtec.com>
2014-05-28 16:20:30 +01:00
Paul Burton
0f4d3d1155 MIPS: smp-cps: flush cache after patching mips_cps_core_entry
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: Paul Burton <paul.burton@imgtec.com>
2014-05-28 16:20:29 +01:00
Paul Burton
68c1232f51 MIPS: smp-cps: function to determine whether CPS SMP is in use
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: Paul Burton <paul.burton@imgtec.com>
2014-05-28 16:20:29 +01:00
Paul Burton
245a7868d2 MIPS: smp-cps: rework core/VPE initialisation
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: Paul Burton <paul.burton@imgtec.com>
2014-05-28 16:20:28 +01:00
Ralf Baechle
1461df59f0 MIPS: SMP: Remove plat_smp_ops cpus_done method.
Nothing was using the method and there isn't any need for this hook.  This
leaves smp_cpus_done() empty for the moment.

As suggested by Paul Bolle <pebolle@tiscali.nl>.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-05-27 11:06:42 +02:00
Paul Burton
0ee958e102 MIPS: Coherent Processing System SMP implementation
This patch introduces a new SMP implementation for systems implementing
the MIPS Coherent Processing System architecture. The kernel will make
use of the Coherence Manager, Cluster Power Controller & Global
Interrupt Controller in order to detect, bring up & make use of other
cores in the system. SMTC is not supported, so only a single TC per VPE
in the system is used. That is, this option enables an SMVP style setup
but across multiple cores.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6362/
Patchwork: https://patchwork.linux-mips.org/patch/6611/
Patchwork: https://patchwork.linux-mips.org/patch/6651/
Patchwork: https://patchwork.linux-mips.org/patch/6652/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-03-26 23:00:12 +01:00