1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
4 *
5 * Derived from MIPS:
6 * Copyright (C) 2000, 2001 Kanoj Sarcar
7 * Copyright (C) 2000, 2001 Ralf Baechle
8 * Copyright (C) 2000, 2001 Silicon Graphics, Inc.
9 * Copyright (C) 2000, 2001, 2003 Broadcom Corporation
10 */
11#include <linux/acpi.h>
12#include <linux/cpu.h>
13#include <linux/cpumask.h>
14#include <linux/init.h>
15#include <linux/interrupt.h>
16#include <linux/profile.h>
17#include <linux/seq_file.h>
18#include <linux/smp.h>
19#include <linux/threads.h>
20#include <linux/export.h>
21#include <linux/syscore_ops.h>
22#include <linux/time.h>
23#include <linux/tracepoint.h>
24#include <linux/sched/hotplug.h>
25#include <linux/sched/task_stack.h>
26
27#include <asm/cpu.h>
28#include <asm/idle.h>
29#include <asm/loongson.h>
30#include <asm/mmu_context.h>
31#include <asm/numa.h>
32#include <asm/processor.h>
33#include <asm/setup.h>
34#include <asm/time.h>
35
36int __cpu_number_map[NR_CPUS]; /* Map physical to logical */
37EXPORT_SYMBOL(__cpu_number_map);
38
39int __cpu_logical_map[NR_CPUS]; /* Map logical to physical */
40EXPORT_SYMBOL(__cpu_logical_map);
41
42/* Representing the threads (siblings) of each logical CPU */
43cpumask_t cpu_sibling_map[NR_CPUS] __read_mostly;
44EXPORT_SYMBOL(cpu_sibling_map);
45
46/* Representing the core map of multi-core chips of each logical CPU */
47cpumask_t cpu_core_map[NR_CPUS] __read_mostly;
48EXPORT_SYMBOL(cpu_core_map);
49
50static DECLARE_COMPLETION(cpu_starting);
51static DECLARE_COMPLETION(cpu_running);
52
53/*
54 * A logcal cpu mask containing only one VPE per core to
55 * reduce the number of IPIs on large MT systems.
56 */
57cpumask_t cpu_foreign_map[NR_CPUS] __read_mostly;
58EXPORT_SYMBOL(cpu_foreign_map);
59
60/* representing cpus for which sibling maps can be computed */
61static cpumask_t cpu_sibling_setup_map;
62
63/* representing cpus for which core maps can be computed */
64static cpumask_t cpu_core_setup_map;
65
66struct secondary_data cpuboot_data;
67static DEFINE_PER_CPU(int, cpu_state);
68
69enum ipi_msg_type {
70 IPI_RESCHEDULE,
71 IPI_CALL_FUNCTION,
72};
73
74static const char *ipi_types[NR_IPI] __tracepoint_string = {
75 [IPI_RESCHEDULE] = "Rescheduling interrupts",
76 [IPI_CALL_FUNCTION] = "Function call interrupts",
77};
78
79void show_ipi_list(struct seq_file *p, int prec)
80{
81 unsigned int cpu, i;
82
83 for (i = 0; i < NR_IPI; i++) {
84 seq_printf(m: p, fmt: "%*s%u:%s", prec - 1, "IPI", i, prec >= 4 ? " " : "");
85 for_each_online_cpu(cpu)
86 seq_printf(m: p, fmt: "%10u ", per_cpu(irq_stat, cpu).ipi_irqs[i]);
87 seq_printf(m: p, fmt: " LoongArch %d %s\n", i + 1, ipi_types[i]);
88 }
89}
90
91static inline void set_cpu_core_map(int cpu)
92{
93 int i;
94
95 cpumask_set_cpu(cpu, dstp: &cpu_core_setup_map);
96
97 for_each_cpu(i, &cpu_core_setup_map) {
98 if (cpu_data[cpu].package == cpu_data[i].package) {
99 cpumask_set_cpu(cpu: i, dstp: &cpu_core_map[cpu]);
100 cpumask_set_cpu(cpu, dstp: &cpu_core_map[i]);
101 }
102 }
103}
104
105static inline void set_cpu_sibling_map(int cpu)
106{
107 int i;
108
109 cpumask_set_cpu(cpu, dstp: &cpu_sibling_setup_map);
110
111 for_each_cpu(i, &cpu_sibling_setup_map) {
112 if (cpus_are_siblings(cpu, i)) {
113 cpumask_set_cpu(cpu: i, dstp: &cpu_sibling_map[cpu]);
114 cpumask_set_cpu(cpu, dstp: &cpu_sibling_map[i]);
115 }
116 }
117}
118
119static inline void clear_cpu_sibling_map(int cpu)
120{
121 int i;
122
123 for_each_cpu(i, &cpu_sibling_setup_map) {
124 if (cpus_are_siblings(cpu, i)) {
125 cpumask_clear_cpu(cpu: i, dstp: &cpu_sibling_map[cpu]);
126 cpumask_clear_cpu(cpu, dstp: &cpu_sibling_map[i]);
127 }
128 }
129
130 cpumask_clear_cpu(cpu, dstp: &cpu_sibling_setup_map);
131}
132
133/*
134 * Calculate a new cpu_foreign_map mask whenever a
135 * new cpu appears or disappears.
136 */
137void calculate_cpu_foreign_map(void)
138{
139 int i, k, core_present;
140 cpumask_t temp_foreign_map;
141
142 /* Re-calculate the mask */
143 cpumask_clear(dstp: &temp_foreign_map);
144 for_each_online_cpu(i) {
145 core_present = 0;
146 for_each_cpu(k, &temp_foreign_map)
147 if (cpus_are_siblings(i, k))
148 core_present = 1;
149 if (!core_present)
150 cpumask_set_cpu(cpu: i, dstp: &temp_foreign_map);
151 }
152
153 for_each_online_cpu(i)
154 cpumask_andnot(dstp: &cpu_foreign_map[i],
155 src1p: &temp_foreign_map, src2p: &cpu_sibling_map[i]);
156}
157
158/* Send mailbox buffer via Mail_Send */
159static void csr_mail_send(uint64_t data, int cpu, int mailbox)
160{
161 uint64_t val;
162
163 /* Send high 32 bits */
164 val = IOCSR_MBUF_SEND_BLOCKING;
165 val |= (IOCSR_MBUF_SEND_BOX_HI(mailbox) << IOCSR_MBUF_SEND_BOX_SHIFT);
166 val |= (cpu << IOCSR_MBUF_SEND_CPU_SHIFT);
167 val |= (data & IOCSR_MBUF_SEND_H32_MASK);
168 iocsr_write64(val, LOONGARCH_IOCSR_MBUF_SEND);
169
170 /* Send low 32 bits */
171 val = IOCSR_MBUF_SEND_BLOCKING;
172 val |= (IOCSR_MBUF_SEND_BOX_LO(mailbox) << IOCSR_MBUF_SEND_BOX_SHIFT);
173 val |= (cpu << IOCSR_MBUF_SEND_CPU_SHIFT);
174 val |= (data << IOCSR_MBUF_SEND_BUF_SHIFT);
175 iocsr_write64(val, LOONGARCH_IOCSR_MBUF_SEND);
176};
177
178static u32 ipi_read_clear(int cpu)
179{
180 u32 action;
181
182 /* Load the ipi register to figure out what we're supposed to do */
183 action = iocsr_read32(LOONGARCH_IOCSR_IPI_STATUS);
184 /* Clear the ipi register to clear the interrupt */
185 iocsr_write32(action, LOONGARCH_IOCSR_IPI_CLEAR);
186 wbflush();
187
188 return action;
189}
190
191static void ipi_write_action(int cpu, u32 action)
192{
193 unsigned int irq = 0;
194
195 while ((irq = ffs(action))) {
196 uint32_t val = IOCSR_IPI_SEND_BLOCKING;
197
198 val |= (irq - 1);
199 val |= (cpu << IOCSR_IPI_SEND_CPU_SHIFT);
200 iocsr_write32(val, LOONGARCH_IOCSR_IPI_SEND);
201 action &= ~BIT(irq - 1);
202 }
203}
204
205void loongson_send_ipi_single(int cpu, unsigned int action)
206{
207 ipi_write_action(cpu: cpu_logical_map(cpu), action: (u32)action);
208}
209
210void loongson_send_ipi_mask(const struct cpumask *mask, unsigned int action)
211{
212 unsigned int i;
213
214 for_each_cpu(i, mask)
215 ipi_write_action(cpu: cpu_logical_map(i), action: (u32)action);
216}
217
218/*
219 * This function sends a 'reschedule' IPI to another CPU.
220 * it goes straight through and wastes no time serializing
221 * anything. Worst case is that we lose a reschedule ...
222 */
223void arch_smp_send_reschedule(int cpu)
224{
225 loongson_send_ipi_single(cpu, action: SMP_RESCHEDULE);
226}
227EXPORT_SYMBOL_GPL(arch_smp_send_reschedule);
228
229irqreturn_t loongson_ipi_interrupt(int irq, void *dev)
230{
231 unsigned int action;
232 unsigned int cpu = smp_processor_id();
233
234 action = ipi_read_clear(cpu: cpu_logical_map(cpu));
235
236 if (action & SMP_RESCHEDULE) {
237 scheduler_ipi();
238 per_cpu(irq_stat, cpu).ipi_irqs[IPI_RESCHEDULE]++;
239 }
240
241 if (action & SMP_CALL_FUNCTION) {
242 generic_smp_call_function_interrupt();
243 per_cpu(irq_stat, cpu).ipi_irqs[IPI_CALL_FUNCTION]++;
244 }
245
246 return IRQ_HANDLED;
247}
248
249static void __init fdt_smp_setup(void)
250{
251#ifdef CONFIG_OF
252 unsigned int cpu, cpuid;
253 struct device_node *node = NULL;
254
255 for_each_of_cpu_node(node) {
256 if (!of_device_is_available(device: node))
257 continue;
258
259 cpuid = of_get_cpu_hwid(cpun: node, thread: 0);
260 if (cpuid >= nr_cpu_ids)
261 continue;
262
263 if (cpuid == loongson_sysconf.boot_cpu_id) {
264 cpu = 0;
265 numa_add_cpu(cpu);
266 } else {
267 cpu = cpumask_next_zero(n: -1, cpu_present_mask);
268 }
269
270 num_processors++;
271 set_cpu_possible(cpu, possible: true);
272 set_cpu_present(cpu, present: true);
273 __cpu_number_map[cpuid] = cpu;
274 __cpu_logical_map[cpu] = cpuid;
275 }
276
277 loongson_sysconf.nr_cpus = num_processors;
278 set_bit(nr: 0, addr: loongson_sysconf.cores_io_master);
279#endif
280}
281
282void __init loongson_smp_setup(void)
283{
284 fdt_smp_setup();
285
286 if (loongson_sysconf.cores_per_package == 0)
287 loongson_sysconf.cores_per_package = num_processors;
288
289 cpu_data[0].core = cpu_logical_map(0) % loongson_sysconf.cores_per_package;
290 cpu_data[0].package = cpu_logical_map(0) / loongson_sysconf.cores_per_package;
291
292 iocsr_write32(0xffffffff, LOONGARCH_IOCSR_IPI_EN);
293 pr_info("Detected %i available CPU(s)\n", loongson_sysconf.nr_cpus);
294}
295
296void __init loongson_prepare_cpus(unsigned int max_cpus)
297{
298 int i = 0;
299
300 parse_acpi_topology();
301
302 for (i = 0; i < loongson_sysconf.nr_cpus; i++) {
303 set_cpu_present(i, true);
304 csr_mail_send(0, __cpu_logical_map[i], 0);
305 cpu_data[i].global_id = __cpu_logical_map[i];
306 }
307
308 per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
309}
310
311/*
312 * Setup the PC, SP, and TP of a secondary processor and start it running!
313 */
314void loongson_boot_secondary(int cpu, struct task_struct *idle)
315{
316 unsigned long entry;
317
318 pr_info("Booting CPU#%d...\n", cpu);
319
320 entry = __pa_symbol((unsigned long)&smpboot_entry);
321 cpuboot_data.stack = (unsigned long)__KSTK_TOS(idle);
322 cpuboot_data.thread_info = (unsigned long)task_thread_info(idle);
323
324 csr_mail_send(data: entry, cpu: cpu_logical_map(cpu), mailbox: 0);
325
326 loongson_send_ipi_single(cpu, SMP_BOOT_CPU);
327}
328
329/*
330 * SMP init and finish on secondary CPUs
331 */
332void loongson_init_secondary(void)
333{
334 unsigned int cpu = smp_processor_id();
335 unsigned int imask = ECFGF_IP0 | ECFGF_IP1 | ECFGF_IP2 |
336 ECFGF_IPI | ECFGF_PMC | ECFGF_TIMER;
337
338 change_csr_ecfg(ECFG0_IM, imask);
339
340 iocsr_write32(0xffffffff, LOONGARCH_IOCSR_IPI_EN);
341
342#ifdef CONFIG_NUMA
343 numa_add_cpu(cpu);
344#endif
345 per_cpu(cpu_state, cpu) = CPU_ONLINE;
346 cpu_data[cpu].package =
347 cpu_logical_map(cpu) / loongson_sysconf.cores_per_package;
348 cpu_data[cpu].core = pptt_enabled ? cpu_data[cpu].core :
349 cpu_logical_map(cpu) % loongson_sysconf.cores_per_package;
350}
351
352void loongson_smp_finish(void)
353{
354 local_irq_enable();
355 iocsr_write64(0, LOONGARCH_IOCSR_MBUF0);
356 pr_info("CPU#%d finished\n", smp_processor_id());
357}
358
359#ifdef CONFIG_HOTPLUG_CPU
360
361int loongson_cpu_disable(void)
362{
363 unsigned long flags;
364 unsigned int cpu = smp_processor_id();
365
366 if (io_master(cpu))
367 return -EBUSY;
368
369#ifdef CONFIG_NUMA
370 numa_remove_cpu(cpu);
371#endif
372 set_cpu_online(cpu, online: false);
373 clear_cpu_sibling_map(cpu);
374 calculate_cpu_foreign_map();
375 local_irq_save(flags);
376 irq_migrate_all_off_this_cpu();
377 clear_csr_ecfg(ECFG0_IM);
378 local_irq_restore(flags);
379 local_flush_tlb_all();
380
381 return 0;
382}
383
384void loongson_cpu_die(unsigned int cpu)
385{
386 while (per_cpu(cpu_state, cpu) != CPU_DEAD)
387 cpu_relax();
388
389 mb();
390}
391
392void __noreturn arch_cpu_idle_dead(void)
393{
394 register uint64_t addr;
395 register void (*init_fn)(void);
396
397 idle_task_exit();
398 local_irq_enable();
399 set_csr_ecfg(ECFGF_IPI);
400 __this_cpu_write(cpu_state, CPU_DEAD);
401
402 __smp_mb();
403 do {
404 __asm__ __volatile__("idle 0\n\t");
405 addr = iocsr_read64(LOONGARCH_IOCSR_MBUF0);
406 } while (addr == 0);
407
408 local_irq_disable();
409 init_fn = (void *)TO_CACHE(addr);
410 iocsr_write32(0xffffffff, LOONGARCH_IOCSR_IPI_CLEAR);
411
412 init_fn();
413 BUG();
414}
415
416#endif
417
418/*
419 * Power management
420 */
421#ifdef CONFIG_PM
422
423static int loongson_ipi_suspend(void)
424{
425 return 0;
426}
427
428static void loongson_ipi_resume(void)
429{
430 iocsr_write32(0xffffffff, LOONGARCH_IOCSR_IPI_EN);
431}
432
433static struct syscore_ops loongson_ipi_syscore_ops = {
434 .resume = loongson_ipi_resume,
435 .suspend = loongson_ipi_suspend,
436};
437
438/*
439 * Enable boot cpu ipi before enabling nonboot cpus
440 * during syscore_resume.
441 */
442static int __init ipi_pm_init(void)
443{
444 register_syscore_ops(ops: &loongson_ipi_syscore_ops);
445 return 0;
446}
447
448core_initcall(ipi_pm_init);
449#endif
450
451/* Preload SMP state for boot cpu */
452void smp_prepare_boot_cpu(void)
453{
454 unsigned int cpu, node, rr_node;
455
456 set_cpu_possible(cpu: 0, possible: true);
457 set_cpu_online(cpu: 0, online: true);
458 set_my_cpu_offset(per_cpu_offset(0));
459
460 rr_node = first_node(node_online_map);
461 for_each_possible_cpu(cpu) {
462 node = early_cpu_to_node(cpu);
463
464 /*
465 * The mapping between present cpus and nodes has been
466 * built during MADT and SRAT parsing.
467 *
468 * If possible cpus = present cpus here, early_cpu_to_node
469 * will return valid node.
470 *
471 * If possible cpus > present cpus here (e.g. some possible
472 * cpus will be added by cpu-hotplug later), for possible but
473 * not present cpus, early_cpu_to_node will return NUMA_NO_NODE,
474 * and we just map them to online nodes in round-robin way.
475 * Once hotplugged, new correct mapping will be built for them.
476 */
477 if (node != NUMA_NO_NODE)
478 set_cpu_numa_node(cpu, node);
479 else {
480 set_cpu_numa_node(cpu, node: rr_node);
481 rr_node = next_node_in(rr_node, node_online_map);
482 }
483 }
484}
485
486/* called from main before smp_init() */
487void __init smp_prepare_cpus(unsigned int max_cpus)
488{
489 init_new_context(current, mm: &init_mm);
490 current_thread_info()->cpu = 0;
491 loongson_prepare_cpus(max_cpus);
492 set_cpu_sibling_map(0);
493 set_cpu_core_map(0);
494 calculate_cpu_foreign_map();
495#ifndef CONFIG_HOTPLUG_CPU
496 init_cpu_present(cpu_possible_mask);
497#endif
498}
499
500int __cpu_up(unsigned int cpu, struct task_struct *tidle)
501{
502 loongson_boot_secondary(cpu, idle: tidle);
503
504 /* Wait for CPU to start and be ready to sync counters */
505 if (!wait_for_completion_timeout(x: &cpu_starting,
506 timeout: msecs_to_jiffies(m: 5000))) {
507 pr_crit("CPU%u: failed to start\n", cpu);
508 return -EIO;
509 }
510
511 /* Wait for CPU to finish startup & mark itself online before return */
512 wait_for_completion(&cpu_running);
513
514 return 0;
515}
516
517/*
518 * First C code run on the secondary CPUs after being started up by
519 * the master.
520 */
521asmlinkage void start_secondary(void)
522{
523 unsigned int cpu;
524
525 sync_counter();
526 cpu = raw_smp_processor_id();
527 set_my_cpu_offset(per_cpu_offset(cpu));
528
529 cpu_probe();
530 constant_clockevent_init();
531 loongson_init_secondary();
532
533 set_cpu_sibling_map(cpu);
534 set_cpu_core_map(cpu);
535
536 notify_cpu_starting(cpu);
537
538 /* Notify boot CPU that we're starting */
539 complete(&cpu_starting);
540
541 /* The CPU is running, now mark it online */
542 set_cpu_online(cpu, online: true);
543
544 calculate_cpu_foreign_map();
545
546 /*
547 * Notify boot CPU that we're up & online and it can safely return
548 * from __cpu_up()
549 */
550 complete(&cpu_running);
551
552 /*
553 * irq will be enabled in loongson_smp_finish(), enabling it too
554 * early is dangerous.
555 */
556 WARN_ON_ONCE(!irqs_disabled());
557 loongson_smp_finish();
558
559 cpu_startup_entry(state: CPUHP_AP_ONLINE_IDLE);
560}
561
562void __init smp_cpus_done(unsigned int max_cpus)
563{
564}
565
566static void stop_this_cpu(void *dummy)
567{
568 set_cpu_online(smp_processor_id(), online: false);
569 calculate_cpu_foreign_map();
570 local_irq_disable();
571 while (true);
572}
573
574void smp_send_stop(void)
575{
576 smp_call_function(func: stop_this_cpu, NULL, wait: 0);
577}
578
579#ifdef CONFIG_PROFILING
580int setup_profiling_timer(unsigned int multiplier)
581{
582 return 0;
583}
584#endif
585
586static void flush_tlb_all_ipi(void *info)
587{
588 local_flush_tlb_all();
589}
590
591void flush_tlb_all(void)
592{
593 on_each_cpu(func: flush_tlb_all_ipi, NULL, wait: 1);
594}
595
596static void flush_tlb_mm_ipi(void *mm)
597{
598 local_flush_tlb_mm((struct mm_struct *)mm);
599}
600
601void flush_tlb_mm(struct mm_struct *mm)
602{
603 if (atomic_read(v: &mm->mm_users) == 0)
604 return; /* happens as a result of exit_mmap() */
605
606 preempt_disable();
607
608 if ((atomic_read(v: &mm->mm_users) != 1) || (current->mm != mm)) {
609 on_each_cpu_mask(mask: mm_cpumask(mm), func: flush_tlb_mm_ipi, info: mm, wait: 1);
610 } else {
611 unsigned int cpu;
612
613 for_each_online_cpu(cpu) {
614 if (cpu != smp_processor_id() && cpu_context(cpu, mm))
615 cpu_context(cpu, mm) = 0;
616 }
617 local_flush_tlb_mm(mm);
618 }
619
620 preempt_enable();
621}
622
623struct flush_tlb_data {
624 struct vm_area_struct *vma;
625 unsigned long addr1;
626 unsigned long addr2;
627};
628
629static void flush_tlb_range_ipi(void *info)
630{
631 struct flush_tlb_data *fd = info;
632
633 local_flush_tlb_range(fd->vma, fd->addr1, fd->addr2);
634}
635
636void flush_tlb_range(struct vm_area_struct *vma, unsigned long start, unsigned long end)
637{
638 struct mm_struct *mm = vma->vm_mm;
639
640 preempt_disable();
641 if ((atomic_read(v: &mm->mm_users) != 1) || (current->mm != mm)) {
642 struct flush_tlb_data fd = {
643 .vma = vma,
644 .addr1 = start,
645 .addr2 = end,
646 };
647
648 on_each_cpu_mask(mask: mm_cpumask(mm), func: flush_tlb_range_ipi, info: &fd, wait: 1);
649 } else {
650 unsigned int cpu;
651
652 for_each_online_cpu(cpu) {
653 if (cpu != smp_processor_id() && cpu_context(cpu, mm))
654 cpu_context(cpu, mm) = 0;
655 }
656 local_flush_tlb_range(vma, start, end);
657 }
658 preempt_enable();
659}
660
661static void flush_tlb_kernel_range_ipi(void *info)
662{
663 struct flush_tlb_data *fd = info;
664
665 local_flush_tlb_kernel_range(fd->addr1, fd->addr2);
666}
667
668void flush_tlb_kernel_range(unsigned long start, unsigned long end)
669{
670 struct flush_tlb_data fd = {
671 .addr1 = start,
672 .addr2 = end,
673 };
674
675 on_each_cpu(func: flush_tlb_kernel_range_ipi, info: &fd, wait: 1);
676}
677
678static void flush_tlb_page_ipi(void *info)
679{
680 struct flush_tlb_data *fd = info;
681
682 local_flush_tlb_page(fd->vma, fd->addr1);
683}
684
685void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
686{
687 preempt_disable();
688 if ((atomic_read(v: &vma->vm_mm->mm_users) != 1) || (current->mm != vma->vm_mm)) {
689 struct flush_tlb_data fd = {
690 .vma = vma,
691 .addr1 = page,
692 };
693
694 on_each_cpu_mask(mask: mm_cpumask(mm: vma->vm_mm), func: flush_tlb_page_ipi, info: &fd, wait: 1);
695 } else {
696 unsigned int cpu;
697
698 for_each_online_cpu(cpu) {
699 if (cpu != smp_processor_id() && cpu_context(cpu, vma->vm_mm))
700 cpu_context(cpu, vma->vm_mm) = 0;
701 }
702 local_flush_tlb_page(vma, page);
703 }
704 preempt_enable();
705}
706EXPORT_SYMBOL(flush_tlb_page);
707
708static void flush_tlb_one_ipi(void *info)
709{
710 unsigned long vaddr = (unsigned long) info;
711
712 local_flush_tlb_one(vaddr);
713}
714
715void flush_tlb_one(unsigned long vaddr)
716{
717 on_each_cpu(func: flush_tlb_one_ipi, info: (void *)vaddr, wait: 1);
718}
719EXPORT_SYMBOL(flush_tlb_one);
720

source code of linux/arch/loongarch/kernel/smp.c