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2025-03-08LoongArch: Use polling play_dead() when resuming from hibernationHuacai Chen
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 406f992e4a372dafbe3c ("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>
2024-12-02LoongArch/irq: Use seq_put_decimal_ull_width() for decimal valuesDavid Wang
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>
2024-11-12LoongArch: Fix early_numa_add_cpu() usage for FDT systemsHuacai Chen
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: 3de9c42d02a79a5 ("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>
2024-11-12LoongArch: For all possible CPUs setup logical-physical CPU mappingHuacai Chen
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>
2024-09-17Merge tag 'irq-core-2024-09-16' of ↵Linus Torvalds
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 ...
2024-09-11LoongArch: Revert qspinlock to test-and-set simple lock on VMBibo Mao
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>
2024-08-23irqchip/loongarch-avec: Add AVEC irqchip supportTianyang Zhang
Introduce the advanced extended interrupt controllers (AVECINTC). This feature will allow each core to have 256 independent interrupt vectors and MSI interrupts can be independently routed to any vector on any CPU. The whole topology of irqchips in LoongArch machines looks like this if AVECINTC is supported: +-----+ +-----------------------+ +-------+ | IPI | --> | CPUINTC | <-- | Timer | +-----+ +-----------------------+ +-------+ ^ ^ ^ | | | +---------+ +----------+ +---------+ +-------+ | EIOINTC | | AVECINTC | | LIOINTC | <-- | UARTs | +---------+ +----------+ +---------+ +-------+ ^ ^ | | +---------+ +---------+ | PCH-PIC | | PCH-MSI | +---------+ +---------+ ^ ^ ^ | | | +---------+ +---------+ +---------+ | Devices | | PCH-LPC | | Devices | +---------+ +---------+ +---------+ ^ | +---------+ | Devices | +---------+ Co-developed-by: Jianmin Lv <lvjianmin@loongson.cn> Signed-off-by: Jianmin Lv <lvjianmin@loongson.cn> Co-developed-by: Liupu Wang <wangliupu@loongson.cn> Signed-off-by: Liupu Wang <wangliupu@loongson.cn> Co-developed-by: Huacai Chen <chenhuacai@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> Signed-off-by: Tianyang Zhang <zhangtianyang@loongson.cn> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20240823104337.25577-2-zhangtianyang@loongson.cn
2024-07-20LoongArch: Add irq_work support via self IPIsHuacai Chen
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>
2024-07-20LoongArch: Always enumerate MADT and setup logical-physical CPU mappingHuacai Chen
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>
2024-06-03LoongArch: Add all CPUs enabled by fdt to NUMA node 0Jiaxun Yang
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: 88d4d957edc7 ("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>
2024-05-06LoongArch: KVM: Add PV IPI support on guest sideBibo Mao
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>
2024-05-06LoongArch/smp: Refine some ipi functions on LoongArch platformBibo Mao
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>
2024-02-23LoongArch: Update cpu_sibling_map when disabling nonboot CPUsHuacai Chen
Update cpu_sibling_map when disabling nonboot CPUs by defining & calling clear_cpu_sibling_map(), otherwise we get such errors on SMT systems: jump label: negative count! WARNING: CPU: 6 PID: 45 at kernel/jump_label.c:263 __static_key_slow_dec_cpuslocked+0xec/0x100 CPU: 6 PID: 45 Comm: cpuhp/6 Not tainted 6.8.0-rc5+ #1340 pc 90000000004c302c ra 90000000004c302c tp 90000001005bc000 sp 90000001005bfd20 a0 000000000000001b a1 900000000224c278 a2 90000001005bfb58 a3 900000000224c280 a4 900000000224c278 a5 90000001005bfb50 a6 0000000000000001 a7 0000000000000001 t0 ce87a4763eb5234a t1 ce87a4763eb5234a t2 0000000000000000 t3 0000000000000000 t4 0000000000000006 t5 0000000000000000 t6 0000000000000064 t7 0000000000001964 t8 000000000009ebf6 u0 9000000001f2a068 s9 0000000000000000 s0 900000000246a2d8 s1 ffffffffffffffff s2 ffffffffffffffff s3 90000000021518c0 s4 0000000000000040 s5 9000000002151058 s6 9000000009828e40 s7 00000000000000b4 s8 0000000000000006 ra: 90000000004c302c __static_key_slow_dec_cpuslocked+0xec/0x100 ERA: 90000000004c302c __static_key_slow_dec_cpuslocked+0xec/0x100 CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE) PRMD: 00000004 (PPLV0 +PIE -PWE) EUEN: 00000000 (-FPE -SXE -ASXE -BTE) ECFG: 00071c1c (LIE=2-4,10-12 VS=7) ESTAT: 000c0000 [BRK] (IS= ECode=12 EsubCode=0) PRID: 0014d000 (Loongson-64bit, Loongson-3A6000-HV) CPU: 6 PID: 45 Comm: cpuhp/6 Not tainted 6.8.0-rc5+ #1340 Stack : 0000000000000000 900000000203f258 900000000179afc8 90000001005bc000 90000001005bf980 0000000000000000 90000001005bf988 9000000001fe0be0 900000000224c280 900000000224c278 90000001005bf8c0 0000000000000001 0000000000000001 ce87a4763eb5234a 0000000007f38000 90000001003f8cc0 0000000000000000 0000000000000006 0000000000000000 4c206e6f73676e6f 6f4c203a656d616e 000000000009ec99 0000000007f38000 0000000000000000 900000000214b000 9000000001fe0be0 0000000000000004 0000000000000000 0000000000000107 0000000000000009 ffffffffffafdabe 00000000000000b4 0000000000000006 90000000004c302c 9000000000224528 00005555939a0c7c 00000000000000b0 0000000000000004 0000000000000000 0000000000071c1c ... Call Trace: [<9000000000224528>] show_stack+0x48/0x1a0 [<900000000179afc8>] dump_stack_lvl+0x78/0xa0 [<9000000000263ed0>] __warn+0x90/0x1a0 [<90000000017419b8>] report_bug+0x1b8/0x280 [<900000000179c564>] do_bp+0x264/0x420 [<90000000004c302c>] __static_key_slow_dec_cpuslocked+0xec/0x100 [<90000000002b4d7c>] sched_cpu_deactivate+0x2fc/0x300 [<9000000000266498>] cpuhp_invoke_callback+0x178/0x8a0 [<9000000000267f70>] cpuhp_thread_fun+0xf0/0x240 [<90000000002a117c>] smpboot_thread_fn+0x1dc/0x2e0 [<900000000029a720>] kthread+0x140/0x160 [<9000000000222288>] ret_from_kernel_thread+0xc/0xa4 Cc: stable@vger.kernel.org Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-02-23LoongArch: Disable IRQ before init_fn() for nonboot CPUsHuacai Chen
Disable IRQ before init_fn() for nonboot CPUs when hotplug, in order to silence such warnings (and also avoid potential errors due to unexpected interrupts): WARNING: CPU: 1 PID: 0 at kernel/rcu/tree.c:4503 rcu_cpu_starting+0x214/0x280 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.6.17+ #1198 pc 90000000048e3334 ra 90000000047bd56c tp 900000010039c000 sp 900000010039fdd0 a0 0000000000000001 a1 0000000000000006 a2 900000000802c040 a3 0000000000000000 a4 0000000000000001 a5 0000000000000004 a6 0000000000000000 a7 90000000048e3f4c t0 0000000000000001 t1 9000000005c70968 t2 0000000004000000 t3 000000000005e56e t4 00000000000002e4 t5 0000000000001000 t6 ffffffff80000000 t7 0000000000040000 t8 9000000007931638 u0 0000000000000006 s9 0000000000000004 s0 0000000000000001 s1 9000000006356ac0 s2 9000000007244000 s3 0000000000000001 s4 0000000000000001 s5 900000000636f000 s6 7fffffffffffffff s7 9000000002123940 s8 9000000001ca55f8 ra: 90000000047bd56c tlb_init+0x24c/0x528 ERA: 90000000048e3334 rcu_cpu_starting+0x214/0x280 CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE) PRMD: 00000000 (PPLV0 -PIE -PWE) EUEN: 00000000 (-FPE -SXE -ASXE -BTE) ECFG: 00071000 (LIE=12 VS=7) ESTAT: 000c0000 [BRK] (IS= ECode=12 EsubCode=0) PRID: 0014c010 (Loongson-64bit, Loongson-3A5000) CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.6.17+ #1198 Stack : 0000000000000000 9000000006375000 9000000005b61878 900000010039c000 900000010039fa30 0000000000000000 900000010039fa38 900000000619a140 9000000006456888 9000000006456880 900000010039f950 0000000000000001 0000000000000001 cb0cb028ec7e52e1 0000000002b90000 9000000100348700 0000000000000000 0000000000000001 ffffffff916d12f1 0000000000000003 0000000000040000 9000000007930370 0000000002b90000 0000000000000004 9000000006366000 900000000619a140 0000000000000000 0000000000000004 0000000000000000 0000000000000009 ffffffffffc681f2 9000000002123940 9000000001ca55f8 9000000006366000 90000000047a4828 00007ffff057ded8 00000000000000b0 0000000000000000 0000000000000000 0000000000071000 ... Call Trace: [<90000000047a4828>] show_stack+0x48/0x1a0 [<9000000005b61874>] dump_stack_lvl+0x84/0xcc [<90000000047f60ac>] __warn+0x8c/0x1e0 [<9000000005b0ab34>] report_bug+0x1b4/0x280 [<9000000005b63110>] do_bp+0x2d0/0x480 [<90000000047a2e20>] handle_bp+0x120/0x1c0 [<90000000048e3334>] rcu_cpu_starting+0x214/0x280 [<90000000047bd568>] tlb_init+0x248/0x528 [<90000000047a4c44>] per_cpu_trap_init+0x124/0x160 [<90000000047a19f4>] cpu_probe+0x494/0xa00 [<90000000047b551c>] start_secondary+0x3c/0xc0 [<9000000005b66134>] smpboot_entry+0x50/0x58 Cc: stable@vger.kernel.org Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-01-26LoongArch/smp: Call rcutree_report_cpu_starting() at tlb_init()Huacai Chen
Machines which have more than 8 nodes fail to boot SMP after commit a2ccf46333d7b2cf96 ("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: a2ccf46333d7b2cf96 ("LoongArch/smp: Call rcutree_report_cpu_starting() earlier") Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-01-17LoongArch: Let cores_io_master cover the largest NR_CPUSHuacai Chen
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>
2024-01-17LoongArch: Parsing CPU-related information from DTSBinbin Zhou
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>
2023-11-08LoongArch/smp: Call rcutree_report_cpu_starting() earlierHuacai Chen
rcutree_report_cpu_starting() must be called before cpu_probe() to avoid the following lockdep splat that triggered by calling __alloc_pages() when CONFIG_PROVE_RCU_LIST=y: ============================= WARNING: suspicious RCU usage 6.6.0+ #980 Not tainted ----------------------------- kernel/locking/lockdep.c:3761 RCU-list traversed in non-reader section!! other info that might help us debug this: RCU used illegally from offline CPU! rcu_scheduler_active = 1, debug_locks = 1 1 lock held by swapper/1/0: #0: 900000000c82ef98 (&pcp->lock){+.+.}-{2:2}, at: get_page_from_freelist+0x894/0x1790 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.6.0+ #980 Stack : 0000000000000001 9000000004f79508 9000000004893670 9000000100310000 90000001003137d0 0000000000000000 90000001003137d8 9000000004f79508 0000000000000000 0000000000000001 0000000000000000 90000000048a3384 203a656d616e2065 ca43677b3687e616 90000001002c3480 0000000000000008 000000000000009d 0000000000000000 0000000000000001 80000000ffffe0b8 000000000000000d 0000000000000033 0000000007ec0000 13bbf50562dad831 9000000005140748 0000000000000000 9000000004f79508 0000000000000004 0000000000000000 9000000005140748 90000001002bad40 0000000000000000 90000001002ba400 0000000000000000 9000000003573ec8 0000000000000000 00000000000000b0 0000000000000004 0000000000000000 0000000000070000 ... Call Trace: [<9000000003573ec8>] show_stack+0x38/0x150 [<9000000004893670>] dump_stack_lvl+0x74/0xa8 [<900000000360d2bc>] lockdep_rcu_suspicious+0x14c/0x190 [<900000000361235c>] __lock_acquire+0xd0c/0x2740 [<90000000036146f4>] lock_acquire+0x104/0x2c0 [<90000000048a955c>] _raw_spin_lock_irqsave+0x5c/0x90 [<900000000381cd5c>] rmqueue_bulk+0x6c/0x950 [<900000000381fc0c>] get_page_from_freelist+0xd4c/0x1790 [<9000000003821c6c>] __alloc_pages+0x1bc/0x3e0 [<9000000003583b40>] tlb_init+0x150/0x2a0 [<90000000035742a0>] per_cpu_trap_init+0xf0/0x110 [<90000000035712fc>] cpu_probe+0x3dc/0x7a0 [<900000000357ed20>] start_secondary+0x40/0xb0 [<9000000004897138>] smpboot_entry+0x54/0x58 raw_smp_processor_id() is required in order to avoid calling into lockdep before RCU has declared the CPU to be watched for readers. See also commit 29368e093921 ("x86/smpboot: Move rcu_cpu_starting() earlier"), commit de5d9dae150c ("s390/smp: move rcu_cpu_starting() earlier") and commit 99f070b62322 ("powerpc/smp: Call rcu_cpu_starting() earlier"). Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-09-20LoongArch: Fix some build warnings with W=1Bibo Mao
There are some building warnings when building LoongArch kernel with W=1 as following, this patch fixes them. arch/loongarch/kernel/acpi.c:284:13: warning: no previous prototype for ‘acpi_numa_arch_fixup’ [-Wmissing-prototypes] 284 | void __init acpi_numa_arch_fixup(void) {} | ^~~~~~~~~~~~~~~~~~~~ arch/loongarch/kernel/time.c:32:13: warning: no previous prototype for ‘constant_timer_interrupt’ [-Wmissing-prototypes] 32 | irqreturn_t constant_timer_interrupt(int irq, void *data) | ^~~~~~~~~~~~~~~~~~~~~~~~ arch/loongarch/kernel/traps.c:496:25: warning: no previous prototype for 'do_fpe' [-Wmissing-prototypes] 496 | asmlinkage void noinstr do_fpe(struct pt_regs *regs | ^~~~~~ arch/loongarch/kernel/traps.c:813:22: warning: variable ‘opcode’ set but not used [-Wunused-but-set-variable] 813 | unsigned int opcode; | ^~~~~~ arch/loongarch/kernel/signal.c:895:14: warning: no previous prototype for ‘get_sigframe’ [-Wmissing-prototypes] 895 | void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, | ^~~~~~~~~~~~ arch/loongarch/kernel/syscall.c:21:40: warning: initialized field overwritten [-Woverride-init] 21 | #define __SYSCALL(nr, call) [nr] = (call), | ^ arch/loongarch/kernel/syscall.c:40:14: warning: no previous prototype for ‘do_syscall’ [-Wmissing-prototypes] 40 | void noinstr do_syscall(struct pt_regs *regs) | ^~~~~~~~~~ arch/loongarch/kernel/smp.c:502:17: warning: no previous prototype for ‘start_secondary’ [-Wmissing-prototypes] 502 | asmlinkage void start_secondary(void) | ^~~~~~~~~~~~~~~ arch/loongarch/kernel/process.c:309:15: warning: no previous prototype for ‘arch_align_stack’ [-Wmissing-prototypes] 309 | unsigned long arch_align_stack(unsigned long sp) | ^~~~~~~~~~~~~~~~ arch/loongarch/kernel/topology.c:13:5: warning: no previous prototype for ‘arch_register_cpu’ [-Wmissing-prototypes] 13 | int arch_register_cpu(int cpu) | ^~~~~~~~~~~~~~~~~ arch/loongarch/kernel/topology.c:27:6: warning: no previous prototype for ‘arch_unregister_cpu’ [-Wmissing-prototypes] 27 | void arch_unregister_cpu(int cpu) | ^~~~~~~~~~~~~~~~~~~ arch/loongarch/kernel/module-sections.c:103:5: warning: no previous prototype for ‘module_frob_arch_sections’ [-Wmissing-prototypes] 103 | int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, | ^~~~~~~~~~~~~~~~~~~~~~~~~ arch/loongarch/mm/hugetlbpage.c:56:5: warning: no previous prototype for ‘is_aligned_hugepage_range’ [-Wmissing-prototypes] 56 | int is_aligned_hugepage_range(unsigned long addr, unsigned long len) | ^~~~~~~~~~~~~~~~~~~~~~~~~ Signed-off-by: Bibo Mao <maobibo@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-08-25LoongArch: Put the body of play_dead() into arch_cpu_idle_dead()Tiezhu Yang
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>
2023-06-29LoongArch: Support dbar with different hintsHuacai Chen
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 01e3b958efe85a26d9b ("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>
2023-06-29LoongArch: Add SMT (Simultaneous Multi-Threading) supportHuacai Chen
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>
2023-06-29LoongArch: Set CPU#0 as the io master for FDTHuacai Chen
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>
2023-04-28Merge tag 'smp-core-2023-04-27' of ↵Linus Torvalds
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
2023-03-24treewide: Trace IPIs sent via smp_send_reschedule()Valentin Schneider
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
2023-03-06loongarch/cpu: Make sure play_dead() doesn't returnJosh Poimboeuf
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>
2022-12-14LoongArch: Add suspend (ACPI S3) supportHuacai Chen
Add suspend (Suspend To RAM, aka ACPI S3) support for LoongArch. Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-12-14LoongArch: Add FDT booting support from efi system tableBinbin Zhou
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>
2022-12-08LoongArch: Export symbol for function smp_send_reschedule()Bibo Mao
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>
2022-11-21LoongArch: SMP: Change prefix from loongson3 to loongsonHuacai Chen
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>
2022-10-12LoongArch: Do not create sysfs control file for io master CPUsTiezhu Yang
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 9cce844abf07 ("MIPS: CPU#0 is not hotpluggable"). Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-08-12LoongArch: Parse MADT to get multi-processor informationHuacai Chen
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>
2022-07-29LoongArch: Remove clock setting during cpu hotplug stageBibo Mao
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>
2022-06-08LoongArch: Fix the !CONFIG_SMP buildHuacai Chen
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>
2022-06-03LoongArch: Add Non-Uniform Memory Access (NUMA) supportHuacai Chen
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>
2022-06-03LoongArch: Add multi-processor (SMP) supportHuacai Chen
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>