In order to achieve more reasonable load balancing behavior, add
SCHED_MC (Multi-core scheduler) support.
The LLC distribution of LoongArch now is consistent with NUMA node,
the balancing domain of SCHED_MC can effectively reduce the situation
where processes are awakened to smt_sibling.
Co-developed-by: Hongliang Wang <wanghongliang@loongson.cn>
Signed-off-by: Hongliang Wang <wanghongliang@loongson.cn>
Signed-off-by: Tianyang Zhang <zhangtianyang@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
When CONFIG_RANDOM_KMALLOC_CACHES or other randomization infrastructrue
enabled, the idle_task's stack may different between the booting kernel
and target kernel. So when resuming from hibernation, an ACTION_BOOT_CPU
IPI wakeup the idle instruction in arch_cpu_idle_dead() and jump to the
interrupt handler. But since the stack pointer is changed, the interrupt
handler cannot restore correct context.
So rename the current arch_cpu_idle_dead() to idle_play_dead(), make it
as the default version of play_dead(), and the new arch_cpu_idle_dead()
call play_dead() directly. For hibernation, implement an arch-specific
hibernate_resume_nonboot_cpu_disable() to use the polling version (idle
instruction is replace by nop, and irq is disabled) of play_dead(), i.e.
poll_play_dead(), to avoid IPI handler corrupting the idle_task's stack
when resuming from hibernation.
This solution is a little similar to commit 406f992e4a ("x86 /
hibernate: Use hlt_play_dead() when resuming from hibernation").
Cc: stable@vger.kernel.org
Tested-by: Erpeng Xu <xuerpeng@uniontech.com>
Tested-by: Yuli Wang <wangyuli@uniontech.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Performance improvement for reading /proc/interrupts on LoongArch.
On a system with n CPUs and m interrupts, there will be n*m decimal
values yielded via seq_printf(.."%10u "..) which is less efficient than
seq_put_decimal_ull_width(), stress reading /proc/interrupts indicates
~30% performance improvement with this patch (and its friends).
Signed-off-by: David Wang <00107082@163.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
early_numa_add_cpu() applies on physical CPU id rather than logical CPU
id, so use cpuid instead of cpu.
Cc: stable@vger.kernel.org
Fixes: 3de9c42d02 ("LoongArch: Add all CPUs enabled by fdt to NUMA node 0")
Reported-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
In order to support ACPI-based physical CPU hotplug, we suppose for all
"possible" CPUs cpu_logical_map() can work. Because some drivers want to
use cpu_logical_map() for all "possible" CPUs, while currently we only
setup logical-physical mapping for "present" CPUs. This lack of mapping
also causes cpu_to_node() cannot work for hot-added CPUs.
All "possible" CPUs are listed in MADT, and the "present" subset is
marked as ACPI_MADT_ENABLED. To setup logical-physical CPU mapping for
all possible CPUs and keep present CPUs continuous in cpu_present_mask,
we parse MADT twice. The first pass handles CPUs with ACPI_MADT_ENABLED
and the second pass handles CPUs without ACPI_MADT_ENABLED.
The global flag (cpu_enumerated) is removed because acpi_map_cpu() calls
cpu_number_map() rather than set_processor_mask() now.
Reported-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
- Core:
- Remove a global lock in the affinity setting code
The lock protects a cpumask for intermediate results and the lock
causes a bottleneck on simultaneous start of multiple virtual
machines. Replace the lock and the static cpumask with a per CPU
cpumask which is nicely serialized by raw spinlock held when
executing this code.
- Provide support for giving a suffix to interrupt domain names.
That's required to support devices with subfunctions so that the
domain names are distinct even if they originate from the same
device node.
- The usual set of cleanups and enhancements all over the place
- Drivers:
- Support for longarch AVEC interrupt chip
- Refurbishment of the Armada driver so it can be extended for new
variants.
- The usual set of cleanups and enhancements all over the place
-----BEGIN PGP SIGNATURE-----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=JlJ2
-----END PGP SIGNATURE-----
Merge tag 'irq-core-2024-09-16' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq updates from Thomas Gleixner:
"Core:
- Remove a global lock in the affinity setting code
The lock protects a cpumask for intermediate results and the lock
causes a bottleneck on simultaneous start of multiple virtual
machines. Replace the lock and the static cpumask with a per CPU
cpumask which is nicely serialized by raw spinlock held when
executing this code.
- Provide support for giving a suffix to interrupt domain names.
That's required to support devices with subfunctions so that the
domain names are distinct even if they originate from the same
device node.
- The usual set of cleanups and enhancements all over the place
Drivers:
- Support for longarch AVEC interrupt chip
- Refurbishment of the Armada driver so it can be extended for new
variants.
- The usual set of cleanups and enhancements all over the place"
* tag 'irq-core-2024-09-16' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (73 commits)
genirq: Use cpumask_intersects()
genirq/cpuhotplug: Use cpumask_intersects()
irqchip/apple-aic: Only access system registers on SoCs which provide them
irqchip/apple-aic: Add a new "Global fast IPIs only" feature level
irqchip/apple-aic: Skip unnecessary enabling of use_fast_ipi
dt-bindings: apple,aic: Document A7-A11 compatibles
irqdomain: Use IS_ERR_OR_NULL() in irq_domain_trim_hierarchy()
genirq/msi: Use kmemdup_array() instead of kmemdup()
genirq/proc: Change the return value for set affinity permission error
genirq/proc: Use irq_move_pending() in show_irq_affinity()
genirq/proc: Correctly set file permissions for affinity control files
genirq: Get rid of global lock in irq_do_set_affinity()
genirq: Fix typo in struct comment
irqchip/loongarch-avec: Add AVEC irqchip support
irqchip/loongson-pch-msi: Prepare get_pch_msi_handle() for AVECINTC
irqchip/loongson-eiointc: Rename CPUHP_AP_IRQ_LOONGARCH_STARTING
LoongArch: Architectural preparation for AVEC irqchip
LoongArch: Move irqchip function prototypes to irq-loongson.h
irqchip/loongson-pch-msi: Switch to MSI parent domains
softirq: Remove unused 'action' parameter from action callback
...
Similar with x86, when VM is detected, revert to a simple test-and-set
lock to avoid the horrors of queue preemption.
Tested on 3C5000 Dual-way machine with 32 cores and 2 numa nodes,
test case is kcbench on kernel mainline 6.10, the detailed command is
"kcbench --src /root/src/linux"
Performance on host machine
kernel compile time performance impact
Original 150.29 seconds
With patch 150.19 seconds almost no impact
Performance on virtual machine:
1. 1 VM with 32 vCPUs and 2 numa node, numa node pinned
kernel compile time performance impact
Original 170.87 seconds
With patch 171.73 seconds almost no impact
2. 2 VMs, each VM with 32 vCPUs and 2 numa node, numa node pinned
kernel compile time performance impact
Original 2362.04 seconds
With patch 354.73 seconds +565%
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Add irq_work support for LoongArch via self IPIs. This make it possible
to run works in hardware interrupt context, which is a prerequisite for
NOHZ_FULL.
Implement:
- arch_irq_work_raise()
- arch_irq_work_has_interrupt()
Reviewed-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Some drivers want to use cpu_logical_map(), early_cpu_to_node() and some
other CPU mapping APIs, even if we use "nr_cpus=1" to hard limit the CPU
number. This is strongly required for the multi-bridges machines.
Currently, we stop parsing the MADT if the nr_cpus limit is reached, but
to achieve the above goal we should always enumerate the MADT table and
setup logical-physical CPU mapping whether there is a nr_cpus limit.
Rework the MADT enumeration:
1. Define a flag "cpu_enumerated" to distinguish the first enumeration
(cpu_enumerated=0) and the physical hotplug case (cpu_enumerated=1)
for set_processor_mask().
2. If cpu_enumerated=0, stop parsing only when NR_CPUS limit is reached,
so we can setup logical-physical CPU mapping; if cpu_enumerated=1,
stop parsing when nr_cpu_ids limit is reached, so we can avoid some
runtime bugs. Once logical-physical CPU mapping is setup, we will let
cpu_enumerated=1.
3. Use find_first_zero_bit() instead of cpumask_next_zero() to find the
next zero bit (free logical CPU id) in the cpu_present_mask, because
cpumask_next_zero() will stop at nr_cpu_ids.
4. Only touch cpu_possible_mask if cpu_enumerated=0, this is in order to
avoid some potential crashes, because cpu_possible_mask is marked as
__ro_after_init.
5. In prefill_possible_map(), clear cpu_present_mask bits greater than
nr_cpu_ids, in order to avoid a CPU be "present" but not "possible".
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
NUMA enabled kernel on FDT based machine fails to boot because CPUs
are all in NUMA_NO_NODE and mm subsystem won't accept that.
Fix by adding them to default NUMA node at FDT parsing phase and move
numa_add_cpu(0) to a later point.
Cc: stable@vger.kernel.org
Fixes: 88d4d957ed ("LoongArch: Add FDT booting support from efi system table")
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
PARAVIRT config option and PV IPI is added for the guest side, function
pv_ipi_init() is used to add IPI sending and IPI receiving hooks. This
function firstly checks whether system runs in VM mode, and if kernel
runs in VM mode, it will call function kvm_para_available() to detect
the current hypervirsor type (now only KVM type detection is supported).
The paravirt functions can work only if current hypervisor type is KVM,
since there is only KVM supported on LoongArch now.
PV IPI uses virtual IPI sender and virtual IPI receiver functions. With
virtual IPI sender, IPI message is stored in memory rather than emulated
HW. IPI multicast is also supported, and 128 vcpus can received IPIs
at the same time like X86 KVM method. Hypercall method is used for IPI
sending.
With virtual IPI receiver, HW SWI0 is used rather than real IPI HW.
Since VCPU has separate HW SWI0 like HW timer, there is no trap in IPI
interrupt acknowledge. Since IPI message is stored in memory, there is
no trap in getting IPI message.
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Refine the ipi handling on LoongArch platform, there are three
modifications:
1. Add generic function get_percpu_irq(), replacing some percpu irq
functions such as get_ipi_irq()/get_pmc_irq()/get_timer_irq() with
get_percpu_irq().
2. Change definition about parameter action called by function
loongson_send_ipi_single() and loongson_send_ipi_mask(), and it is
defined as decimal encoding format at ipi sender side. Normal decimal
encoding is used rather than binary bitmap encoding for ipi action, ipi
hw sender uses decimal encoding code, and ipi receiver will get binary
bitmap encoding, the ipi hw will convert it into bitmap in ipi message
buffer.
3. Add a structure smp_ops on LoongArch platform so that pv ipi can be
used later.
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Machines which have more than 8 nodes fail to boot SMP after commit
a2ccf46333 ("LoongArch/smp: Call rcutree_report_cpu_starting()
earlier"). Because such machines use tlb-based per-cpu base address
rather than dmw-based per-cpu base address, resulting per-cpu variables
can only be accessed after tlb_init(). But rcutree_report_cpu_starting()
is now called before tlb_init() and accesses per-cpu variables indeed.
Since the original patch want to avoid the lockdep warning caused by
page allocation in tlb_init(), we can move rcutree_report_cpu_starting()
to tlb_init() where after tlb exception configuration but before page
allocation.
Fixes: a2ccf46333 ("LoongArch/smp: Call rcutree_report_cpu_starting() earlier")
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Now loongson_system_configuration::cores_io_master only covers 64 cpus,
if NR_CPUS > 64 there will be memory corruption. So let cores_io_master
cover the largest NR_CPUS (256).
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Generally, we can get cpu-related information, such as model name, from
/proc/cpuinfo. For FDT-based systems, we need to parse the relevant
information from DTS.
BTW, set loongson_sysconf.cores_per_package to num_processors if SMBIOS
doesn't provide a valid number (usually FDT-based systems).
Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn>
Signed-off-by: Hongliang Wang <wanghongliang@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
The initial aim is to silence the following objtool warning:
arch/loongarch/kernel/process.o: warning: objtool: arch_cpu_idle_dead() falls through to next function start_thread()
According to tools/objtool/Documentation/objtool.txt, this is because
the last instruction of arch_cpu_idle_dead() is a call to a noreturn
function play_dead(). In order to silence the warning, one simple way
is to add the noreturn function play_dead() to objtool's hard-coded
global_noreturns array, that is to say, just put "NORETURN(play_dead)"
into tools/objtool/noreturns.h, it works well.
But I noticed that play_dead() is only defined once and only called by
arch_cpu_idle_dead(), so put the body of play_dead() into the caller
arch_cpu_idle_dead(), then remove the noreturn function play_dead() is
an alternative way which can reduce the overhead of the function call
at the same time.
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Traditionally, LoongArch uses "dbar 0" (full completion barrier) for
everything. But the full completion barrier is a performance killer, so
Loongson-3A6000 and newer processors have made finer granularity hints
available:
Bit4: ordering or completion (0: completion, 1: ordering)
Bit3: barrier for previous read (0: true, 1: false)
Bit2: barrier for previous write (0: true, 1: false)
Bit1: barrier for succeeding read (0: true, 1: false)
Bit0: barrier for succeeding write (0: true, 1: false)
Hint 0x700: barrier for "read after read" from the same address, which
is needed by LL-SC loops on old models (dbar 0x700 behaves the same as
nop if such reordering is disabled on new models).
This patch makes use of the various new hints for different kinds of
memory barriers. It brings performance improvements on Loongson-3A6000
series, while not affecting the existing models because all variants are
treated as 'dbar 0' there.
Why override queued_spin_unlock()?
After commit 01e3b958ef ("drivers: Remove explicit invocations
of mmiowb()") we need a completion barrier in queued_spin_unlock(), but
the generic implementation use smp_store_release() which only provide an
ordering barrier.
Signed-off-by: Jun Yi <yijun@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Loongson-3A6000 has SMT (Simultaneous Multi-Threading) support, each
physical core has two logical cores (threads). This patch add SMT probe
and scheduler support via ACPI PPTT.
If SCHED_SMT enabled, Loongson-3A6000 is treated as 4 cores, 8 threads;
If SCHED_SMT disabled, Loongson-3A6000 is treated as 8 cores, 8 threads.
Remove smp_num_siblings to support HMP (Heterogeneous Multi-Processing).
Signed-off-by: Liupu Wang <wangliupu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
ACPI systems set io masters by parsing ACPI MADT, FDT systems have no
MADT so we explicitly set CPU#0 as the io master. Otherwise CPU#0 will
be considered as hotpluggable.
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
- Remove diagnostics and adjust config for CSD lock diagnostics
- Add a generic IPI-sending tracepoint, as currently there's no easy
way to instrument IPI origins: it's arch dependent and for some
major architectures it's not even consistently available.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
-----BEGIN PGP SIGNATURE-----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=Wp7f
-----END PGP SIGNATURE-----
Merge tag 'smp-core-2023-04-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull SMP cross-CPU function-call updates from Ingo Molnar:
- Remove diagnostics and adjust config for CSD lock diagnostics
- Add a generic IPI-sending tracepoint, as currently there's no easy
way to instrument IPI origins: it's arch dependent and for some major
architectures it's not even consistently available.
* tag 'smp-core-2023-04-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
trace,smp: Trace all smp_function_call*() invocations
trace: Add trace_ipi_send_cpu()
sched, smp: Trace smp callback causing an IPI
smp: reword smp call IPI comment
treewide: Trace IPIs sent via smp_send_reschedule()
irq_work: Trace self-IPIs sent via arch_irq_work_raise()
smp: Trace IPIs sent via arch_send_call_function_ipi_mask()
sched, smp: Trace IPIs sent via send_call_function_single_ipi()
trace: Add trace_ipi_send_cpumask()
kernel/smp: Make csdlock_debug= resettable
locking/csd_lock: Remove per-CPU data indirection from CSD lock debugging
locking/csd_lock: Remove added data from CSD lock debugging
locking/csd_lock: Add Kconfig option for csd_debug default
To be able to trace invocations of smp_send_reschedule(), rename the
arch-specific definitions of it to arch_smp_send_reschedule() and wrap it
into an smp_send_reschedule() that contains a tracepoint.
Changes to include the declaration of the tracepoint were driven by the
following coccinelle script:
@func_use@
@@
smp_send_reschedule(...);
@include@
@@
#include <trace/events/ipi.h>
@no_include depends on func_use && !include@
@@
#include <...>
+
+ #include <trace/events/ipi.h>
[csky bits]
[riscv bits]
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Guo Ren <guoren@kernel.org>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Link: https://lore.kernel.org/r/20230307143558.294354-6-vschneid@redhat.com
play_dead() doesn't return. Make that more explicit with a BUG().
BUG() is preferable to unreachable() because BUG() is a more explicit
failure mode and avoids undefined behavior like falling off the edge of
the function into whatever code happens to be next.
Link: https://lore.kernel.org/r/21245d687ffeda34dbcf04961a2df3724f04f7c8.1676358308.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Since commit 40cd01a9c324("efi/loongarch: libstub: remove dependency on
flattened DT"), we can parse the FDT from efi system table.
And now, LoongArch is coming to support booting with FDT, so we add the
relevant booting support as well as parameter parsing.
Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Function smp_send_reschedule() is standard kernel API, which is defined
in header file include/linux/smp.h. However, on LoongArch it is defined
as an inline function, this is confusing and kernel modules can not use
this function.
Now we define smp_send_reschedule() as a general function, and add a
EXPORT_SYMBOL_GPL on this function, so that kernel modules can use it.
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
SMP operations can be shared by Loongson-2 series and Loongson-3 series,
so we change the prefix from loongson3 to loongson for all functions and
data structures.
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Now io master CPUs are not hotpluggable on LoongArch, but in the current
code only /sys/devices/system/cpu/cpu0/online is not created. Let us set
the hotpluggable field of all the io master CPUs as 0, then prevent to
create sysfs control file for all the io master CPUs which confuses some
user space tools. This is similar with commit 9cce844abf ("MIPS: CPU#0
is not hotpluggable").
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Parse MADT to get multi-processor information, in order to fix the boot
problem and cpu-hotplug problem for SMP platform.
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
On physical machine we can save power by disabling clock of hot removed
cpu. However as different platforms require different methods to
configure clocks, the code is platform-specific, and probably belongs to
firmware/pmu or cpu regulator, rather than generic arch/loongarch code.
Also, there is no such register on QEMU virt machine since the
clock/frequency regulation is not emulated.
This patch removes the hard-coded clock register accesses in generic
LoongArch cpu hotplug flow.
Reviewed-by: WANG Xuerui <git@xen0n.name>
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
1, We assume arch/loongarch/include/asm/smp.h be included in include/
linux/smp.h is valid and the reverse inclusion isn't. So remove the
<linux/smp.h> in arch/loongarch/include/asm/smp.h.
2, arch/loongarch/include/asm/smp.h is only needed when CONFIG_SMP,
and setup.c include it only because it need plat_smp_setup(). So,
reorganize setup.c & smp.h, and then remove <asm/smp.h> in setup.c.
3, Fix cacheinfo.c and percpu.h build error by adding the missing header
files when !CONFIG_SMP.
4, Fix acpi.c build error by adding CONFIG_SMP guards.
5, Move irq_stat definition from smp.c to irq.c and fix its declaration.
6, Select CONFIG_SMP for CONFIG_NUMA, similar as other architectures do.
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Add Non-Uniform Memory Access (NUMA) support for LoongArch. LoongArch
has 48-bit physical address, but the HyperTransport I/O bus only support
40-bit address, so we need a custom phys_to_dma() and dma_to_phys() to
extract the 4-bit node id (bit 44~47) from Loongson-3's 48-bit physical
address space and embed it into 40-bit. In the 40-bit dma address, node
id offset can be read from the LS7A_DMA_CFG register.
Reviewed-by: WANG Xuerui <git@xen0n.name>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
LoongArch-based procesors have 4, 8 or 16 cores per package. This patch
adds multi-processor (SMP) support for LoongArch.
Reviewed-by: WANG Xuerui <git@xen0n.name>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
