For the MIPS remote processor implementation, we need additional IPIs to
talk to the remote processor. Since MIPS GIC reserves exactly the right
number of IPI IRQs required by Linux for the number of VPs in the
system, this is not possible without releasing some recources.
This commit introduces mips_smp_ipi_allocate() which allocates IPIs to a
given cpumask. It is called as normal with the cpu_possible_mask at
bootup to initialise IPIs to all CPUs. mips_smp_ipi_free() may then be
used to free IPIs to a subset of those CPUs so that their hardware
resources can be reused.
Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Ohad Ben-Cohen <ohad@wizery.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Lisa Parratt <Lisa.Parratt@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Qais Yousef <qsyousef@gmail.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-remoteproc@vger.kernel.org
Cc: lisa.parratt@imgtec.com
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14285/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
When performing SMP calls to foreign cores, exclude sibling CPUs from
the provided map, as we already handle the local core on the current
CPU. This prevents an SMP call from for example core 0, VPE 1 to VPE 0
on the same core.
In the process the cpu_foreign_map cpumask is turned into an array of
cpumasks, so that each CPU has its own version of it which excludes
sibling CPUs. r4k_op_needs_ipi() is also updated to reflect that cache
management SMP calls are not needed when all CPUs are siblings (i.e.
there are no foreign CPUs according to the new cpu_foreign_map[]
semantics which exclude siblings).
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com>
Cc: Felix Fietkau <nbd@nbd.name>
Cc: Jayachandran C. <jchandra@broadcom.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13801/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
When a CPU is disabled via CPU hotplug, cpu_foreign_map is not updated.
This could result in cache management SMP calls being sent to offline
CPUs instead of online siblings in the same core.
Add a call to calculate_cpu_foreign_map() in the various MIPS cpu
disable callbacks after set_cpu_online(). All cases are updated for
consistency and to keep cpu_foreign_map strictly up to date, not just
those which may support hardware multithreading.
Fixes: cccf34e941 ("MIPS: c-r4k: Fix cache flushing for MT cores")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: David Daney <david.daney@cavium.com>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: Hongliang Tao <taohl@lemote.com>
Cc: Hua Yan <yanh@lemote.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13799/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The majority of SMP platforms handle their IPIs through do_IRQ()
which calls irq_{enter/exit}(). When a call function IPI is received,
smp_call_function_interrupt() is called which also calls
irq_{enter,exit}(), meaning irq_count is raised twice.
When tick broadcasting is used (which is implemented via a call
function IPI), this incorrectly causes all CPU idle time on the core
receiving broadcast ticks to be accounted as time spent servicing
IRQs, as account_process_tick() will account as such if irq_count is
greater than 1. This results in 100% CPU usage being reported on a
core which receives its ticks via broadcast.
This patch removes the SMP smp_call_function_interrupt() wrapper which
calls irq_{enter,exit}(). Platforms which handle their IPIs through
do_IRQ() now call generic_smp_call_function_interrupt() directly to
avoid incrementing irq_count a second time. Platforms which don't
(loongson, sgi-ip27, sibyte) call generic_smp_call_function_interrupt()
wrapped in irq_{enter,exit}().
Signed-off-by: Alex Smith <alex.smith@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/10770/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
MT_SMP is not the only SMP option for MT cores. The MT_SMP option
allows more than one VPE per core to appear as a secondary CPU in the
system. Because of how CM works, it propagates the address-based
cache ops to the secondary cores but not the index-based ones.
Because of that, the code does not use IPIs to flush the L1 caches on
secondary cores because the CM would have done that already. However,
the CM functionality is independent of the type of SMP kernel so even in
non-MT kernels, IPIs are not necessary. As a result of which, we change
the conditional to depend on the CM presence. Moreover, since VPEs on
the same core share the same L1 caches, there is no need to send an
IPI on all of them so we calculate a suitable cpumask with only one
VPE per core.
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: <stable@vger.kernel.org> # 3.15+
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/10654/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
CC arch/mips/kernel/smp.o
arch/mips/kernel/smp.c: In function ‘start_secondary’:
arch/mips/kernel/smp.c:149:2: error: passing argument 2 of ‘cpumask_set_cpu’ discards ‘volatile’ qualifier from pointer target type [-Werror]
cpumask_set_cpu(cpu, &cpu_callin_map);
^
In file included from ./arch/mips/include/asm/processor.h:14:0,
from ./arch/mips/include/asm/thread_info.h:15,
from include/linux/thread_info.h:54,
from include/asm-generic/preempt.h:4,
from arch/mips/include/generated/asm/preempt.h:1,
from include/linux/preempt.h:18,
from include/linux/interrupt.h:8,
from arch/mips/kernel/smp.c:24:
include/linux/cpumask.h:272:91: note: expected ‘struct cpumask *’ but argument is of type ‘volatile struct cpumask_t *’
static inline void cpumask_set_cpu(unsigned int cpu, struct cpumask *dstp)
^
arch/mips/kernel/smp.c: In function ‘smp_prepare_boot_cpu’:
arch/mips/kernel/smp.c:211:2: error: passing argument 2 of ‘cpumask_set_cpu’ discards ‘volatile’ qualifier from pointer target type [-Werror]
cpumask_set_cpu(0, &cpu_callin_map);
^
In file included from ./arch/mips/include/asm/processor.h:14:0,
from ./arch/mips/include/asm/thread_info.h:15,
from include/linux/thread_info.h:54,
from include/asm-generic/preempt.h:4,
from arch/mips/include/generated/asm/preempt.h:1,
from include/linux/preempt.h:18,
from include/linux/interrupt.h:8,
from arch/mips/kernel/smp.c:24:
include/linux/cpumask.h:272:91: note: expected ‘struct cpumask *’ but argument is of type ‘volatile struct cpumask_t *’
static inline void cpumask_set_cpu(unsigned int cpu, struct cpumask *dstp)
^
arch/mips/kernel/smp.c: In function ‘__cpu_up’:
arch/mips/kernel/smp.c:221:10: error: passing argument 2 of ‘cpumask_test_cpu’ discards ‘volatile’ qualifier from pointer target type [-Werror]
while (!cpumask_test_cpu(cpu, &cpu_callin_map))
^
In file included from ./arch/mips/include/asm/processor.h:14:0,
from ./arch/mips/include/asm/thread_info.h:15,
from include/linux/thread_info.h:54,
from include/asm-generic/preempt.h:4,
from arch/mips/include/generated/asm/preempt.h:1,
from include/linux/preempt.h:18,
from include/linux/interrupt.h:8,
from arch/mips/kernel/smp.c:24:
include/linux/cpumask.h:294:90: note: expected ‘const struct cpumask *’ but argument is of type ‘volatile struct cpumask_t *’
static inline int cpumask_test_cpu(int cpu, const struct cpumask *cpumask)
^
cc1: all warnings being treated as errors
make[2]: *** [arch/mips/kernel/smp.o] Error 1
make[1]: *** [arch/mips/kernel] Error 2
make: *** [arch/mips] Error 2
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The correct position is topology.h, and this fix macros redefinition
problems for Netlogic.
[ralf@linux-mips.org: Fix build - the original patch broke most
configurations.]
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Cc: Jayachandran C. <jchandra@broadcom.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/7575/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This patch is prepared for Loongson's NUMA support, it offer meaningful
sysfs files such as physical_package_id, core_id, core_siblings and
thread_siblings in /sys/devices/system/cpu/cpu?/topology.
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Reviewed-by: Andreas Herrmann <andreas.herrmann@caviumnetworks.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/7184/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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: Paul Burton <paul.burton@imgtec.com>
Tips of Loongson's CPU hotplug:
1, To fully shutdown a core in Loongson 3, the target core should go to
CKSEG1 and flush all L1 cache entries at first. Then, another core
(usually Core 0) can safely disable the clock of the target core. So
play_dead() call loongson3_play_dead() via CKSEG1 (both uncached and
unmmaped).
2, The default clocksource of Loongson is MIPS. Since clock source is a
global device, timekeeping need the CP0' Count registers of each core
be synchronous. Thus, when a core is up, we use a SMP_ASK_C0COUNT IPI
to ask Core-0's Count.
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Signed-off-by: Hongliang Tao <taohl@lemote.com>
Signed-off-by: Hua Yan <yanh@lemote.com>
Tested-by: Alex Smith <alex.smith@imgtec.com>
Reviewed-by: Alex 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/6639
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Having received another series of whitespace patches I decided to do this
once and for all rather than dealing with this kind of patches trickling
in forever.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>
Signed-off-by: Arun Sharma <asharma@fb.com>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We're weaning the core code off handing cpumask's around on-stack.
This introduces arch_send_call_function_ipi_mask(), and by defining
it, the old arch_send_call_function_ipi is defined by the core code.
We also take the chance to wean the implementations off the
obsolescent for_each_cpu_mask(): making send_ipi_mask take the pointer
seemed the most natural way to ensure all implementations used
for_each_cpu.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Each platform has to add support for CPU hotplugging itself by providing
suitable definitions for the cpu_disable and cpu_die of the smp_ops
methods and setting SYS_SUPPORTS_HOTPLUG_CPU. A platform should only set
SYS_SUPPORTS_HOTPLUG_CPU once all it's smp_ops definitions have the
necessary changes. This patch contains the changes to the dummy smp_ops
definition for uni-processor systems.
Parts of the code contributed by Cavium Inc.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Some of the were relying into smp.h being dragged in by another header
which of course is fragile. <asm/cpu-info.h> uses smp_processor_id()
only in macros and including smp.h there leads to an include loop, so
don't change cpu-info.h.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Impact: cleanup
Each SMP arch defines these themselves. Move them to a central
location.
Twists:
1) Some archs (m32, parisc, s390) set possible_map to all 1, so we add a
CONFIG_INIT_ALL_POSSIBLE for this rather than break them.
2) mips and sparc32 '#define cpu_possible_map phys_cpu_present_map'.
Those archs simply have phys_cpu_present_map replaced everywhere.
3) Alpha defined cpu_possible_map to cpu_present_map; this is tricky
so I just manipulate them both in sync.
4) IA64, cris and m32r have gratuitous 'extern cpumask_t cpu_possible_map'
declarations.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Grant Grundler <grundler@parisc-linux.org>
Tested-by: Tony Luck <tony.luck@intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Mike Travis <travis@sgi.com>
Cc: ink@jurassic.park.msu.ru
Cc: rmk@arm.linux.org.uk
Cc: starvik@axis.com
Cc: tony.luck@intel.com
Cc: takata@linux-m32r.org
Cc: ralf@linux-mips.org
Cc: grundler@parisc-linux.org
Cc: paulus@samba.org
Cc: schwidefsky@de.ibm.com
Cc: lethal@linux-sh.org
Cc: wli@holomorphy.com
Cc: davem@davemloft.net
Cc: jdike@addtoit.com
Cc: mingo@redhat.com
