Loading...
1// SPDX-License-Identifier: GPL-2.0
2
3#include <linux/module.h>
4#include <linux/init.h>
5#include <linux/kernel.h>
6#include <linux/mm.h>
7#include <linux/sched.h>
8#include <linux/kernel_stat.h>
9#include <linux/notifier.h>
10#include <linux/cpu.h>
11#include <linux/percpu.h>
12#include <linux/delay.h>
13#include <linux/err.h>
14#include <linux/irq.h>
15#include <linux/irq_work.h>
16#include <linux/irqdomain.h>
17#include <linux/of.h>
18#include <linux/seq_file.h>
19#include <linux/sched/task_stack.h>
20#include <linux/sched/mm.h>
21#include <linux/sched/hotplug.h>
22#include <asm/irq.h>
23#include <asm/traps.h>
24#include <asm/sections.h>
25#include <asm/mmu_context.h>
26#ifdef CONFIG_CPU_HAS_FPU
27#include <abi/fpu.h>
28#endif
29
30enum ipi_message_type {
31 IPI_EMPTY,
32 IPI_RESCHEDULE,
33 IPI_CALL_FUNC,
34 IPI_IRQ_WORK,
35 IPI_MAX
36};
37
38struct ipi_data_struct {
39 unsigned long bits ____cacheline_aligned;
40 unsigned long stats[IPI_MAX] ____cacheline_aligned;
41};
42static DEFINE_PER_CPU(struct ipi_data_struct, ipi_data);
43
44static irqreturn_t handle_ipi(int irq, void *dev)
45{
46 unsigned long *stats = this_cpu_ptr(&ipi_data)->stats;
47
48 while (true) {
49 unsigned long ops;
50
51 ops = xchg(&this_cpu_ptr(&ipi_data)->bits, 0);
52 if (ops == 0)
53 return IRQ_HANDLED;
54
55 if (ops & (1 << IPI_RESCHEDULE)) {
56 stats[IPI_RESCHEDULE]++;
57 scheduler_ipi();
58 }
59
60 if (ops & (1 << IPI_CALL_FUNC)) {
61 stats[IPI_CALL_FUNC]++;
62 generic_smp_call_function_interrupt();
63 }
64
65 if (ops & (1 << IPI_IRQ_WORK)) {
66 stats[IPI_IRQ_WORK]++;
67 irq_work_run();
68 }
69
70 BUG_ON((ops >> IPI_MAX) != 0);
71 }
72
73 return IRQ_HANDLED;
74}
75
76static void (*send_arch_ipi)(const struct cpumask *mask);
77
78static int ipi_irq;
79void __init set_send_ipi(void (*func)(const struct cpumask *mask), int irq)
80{
81 if (send_arch_ipi)
82 return;
83
84 send_arch_ipi = func;
85 ipi_irq = irq;
86}
87
88static void
89send_ipi_message(const struct cpumask *to_whom, enum ipi_message_type operation)
90{
91 int i;
92
93 for_each_cpu(i, to_whom)
94 set_bit(operation, &per_cpu_ptr(&ipi_data, i)->bits);
95
96 smp_mb();
97 send_arch_ipi(to_whom);
98}
99
100static const char * const ipi_names[] = {
101 [IPI_EMPTY] = "Empty interrupts",
102 [IPI_RESCHEDULE] = "Rescheduling interrupts",
103 [IPI_CALL_FUNC] = "Function call interrupts",
104 [IPI_IRQ_WORK] = "Irq work interrupts",
105};
106
107int arch_show_interrupts(struct seq_file *p, int prec)
108{
109 unsigned int cpu, i;
110
111 for (i = 0; i < IPI_MAX; i++) {
112 seq_printf(p, "%*s%u:%s", prec - 1, "IPI", i,
113 prec >= 4 ? " " : "");
114 for_each_online_cpu(cpu)
115 seq_printf(p, "%10lu ",
116 per_cpu_ptr(&ipi_data, cpu)->stats[i]);
117 seq_printf(p, " %s\n", ipi_names[i]);
118 }
119
120 return 0;
121}
122
123void arch_send_call_function_ipi_mask(struct cpumask *mask)
124{
125 send_ipi_message(mask, IPI_CALL_FUNC);
126}
127
128void arch_send_call_function_single_ipi(int cpu)
129{
130 send_ipi_message(cpumask_of(cpu), IPI_CALL_FUNC);
131}
132
133static void ipi_stop(void *unused)
134{
135 while (1);
136}
137
138void smp_send_stop(void)
139{
140 on_each_cpu(ipi_stop, NULL, 1);
141}
142
143void arch_smp_send_reschedule(int cpu)
144{
145 send_ipi_message(cpumask_of(cpu), IPI_RESCHEDULE);
146}
147
148#ifdef CONFIG_IRQ_WORK
149void arch_irq_work_raise(void)
150{
151 send_ipi_message(cpumask_of(smp_processor_id()), IPI_IRQ_WORK);
152}
153#endif
154
155void __init smp_prepare_boot_cpu(void)
156{
157}
158
159void __init smp_prepare_cpus(unsigned int max_cpus)
160{
161}
162
163static int ipi_dummy_dev;
164
165void __init setup_smp_ipi(void)
166{
167 int rc;
168
169 if (ipi_irq == 0)
170 return;
171
172 rc = request_percpu_irq(ipi_irq, handle_ipi, "IPI Interrupt",
173 &ipi_dummy_dev);
174 if (rc)
175 panic("%s IRQ request failed\n", __func__);
176
177 enable_percpu_irq(ipi_irq, 0);
178}
179
180void __init setup_smp(void)
181{
182 struct device_node *node = NULL;
183 unsigned int cpu;
184
185 for_each_of_cpu_node(node) {
186 if (!of_device_is_available(node))
187 continue;
188
189 cpu = of_get_cpu_hwid(node, 0);
190 if (cpu >= NR_CPUS)
191 continue;
192
193 set_cpu_possible(cpu, true);
194 set_cpu_present(cpu, true);
195 }
196}
197
198extern void _start_smp_secondary(void);
199
200volatile unsigned int secondary_hint;
201volatile unsigned int secondary_hint2;
202volatile unsigned int secondary_ccr;
203volatile unsigned int secondary_stack;
204volatile unsigned int secondary_msa1;
205volatile unsigned int secondary_pgd;
206
207int __cpu_up(unsigned int cpu, struct task_struct *tidle)
208{
209 unsigned long mask = 1 << cpu;
210
211 secondary_stack =
212 (unsigned int) task_stack_page(tidle) + THREAD_SIZE - 8;
213 secondary_hint = mfcr("cr31");
214 secondary_hint2 = mfcr("cr<21, 1>");
215 secondary_ccr = mfcr("cr18");
216 secondary_msa1 = read_mmu_msa1();
217 secondary_pgd = mfcr("cr<29, 15>");
218
219 /*
220 * Because other CPUs are in reset status, we must flush data
221 * from cache to out and secondary CPUs use them in
222 * csky_start_secondary(void)
223 */
224 mtcr("cr17", 0x22);
225
226 if (mask & mfcr("cr<29, 0>")) {
227 send_arch_ipi(cpumask_of(cpu));
228 } else {
229 /* Enable cpu in SMP reset ctrl reg */
230 mask |= mfcr("cr<29, 0>");
231 mtcr("cr<29, 0>", mask);
232 }
233
234 /* Wait for the cpu online */
235 while (!cpu_online(cpu));
236
237 secondary_stack = 0;
238
239 return 0;
240}
241
242void __init smp_cpus_done(unsigned int max_cpus)
243{
244}
245
246void csky_start_secondary(void)
247{
248 struct mm_struct *mm = &init_mm;
249 unsigned int cpu = smp_processor_id();
250
251 mtcr("cr31", secondary_hint);
252 mtcr("cr<21, 1>", secondary_hint2);
253 mtcr("cr18", secondary_ccr);
254
255 mtcr("vbr", vec_base);
256
257 flush_tlb_all();
258 write_mmu_pagemask(0);
259
260#ifdef CONFIG_CPU_HAS_FPU
261 init_fpu();
262#endif
263
264 enable_percpu_irq(ipi_irq, 0);
265
266 mmget(mm);
267 mmgrab(mm);
268 current->active_mm = mm;
269 cpumask_set_cpu(cpu, mm_cpumask(mm));
270
271 notify_cpu_starting(cpu);
272 set_cpu_online(cpu, true);
273
274 pr_info("CPU%u Online: %s...\n", cpu, __func__);
275
276 local_irq_enable();
277 cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
278}
279
280#ifdef CONFIG_HOTPLUG_CPU
281int __cpu_disable(void)
282{
283 unsigned int cpu = smp_processor_id();
284
285 set_cpu_online(cpu, false);
286
287 irq_migrate_all_off_this_cpu();
288
289 clear_tasks_mm_cpumask(cpu);
290
291 return 0;
292}
293
294void arch_cpuhp_cleanup_dead_cpu(unsigned int cpu)
295{
296 pr_notice("CPU%u: shutdown\n", cpu);
297}
298
299void __noreturn arch_cpu_idle_dead(void)
300{
301 idle_task_exit();
302
303 cpuhp_ap_report_dead();
304
305 while (!secondary_stack)
306 arch_cpu_idle();
307
308 raw_local_irq_disable();
309
310 asm volatile(
311 "mov sp, %0\n"
312 "mov r8, %0\n"
313 "jmpi csky_start_secondary"
314 :
315 : "r" (secondary_stack));
316
317 BUG();
318}
319#endif
1// SPDX-License-Identifier: GPL-2.0
2
3#include <linux/module.h>
4#include <linux/init.h>
5#include <linux/kernel.h>
6#include <linux/mm.h>
7#include <linux/sched.h>
8#include <linux/kernel_stat.h>
9#include <linux/notifier.h>
10#include <linux/cpu.h>
11#include <linux/percpu.h>
12#include <linux/delay.h>
13#include <linux/err.h>
14#include <linux/irq.h>
15#include <linux/irqdomain.h>
16#include <linux/of.h>
17#include <linux/sched/task_stack.h>
18#include <linux/sched/mm.h>
19#include <linux/sched/hotplug.h>
20#include <asm/irq.h>
21#include <asm/traps.h>
22#include <asm/sections.h>
23#include <asm/mmu_context.h>
24#include <asm/pgalloc.h>
25
26struct ipi_data_struct {
27 unsigned long bits ____cacheline_aligned;
28};
29static DEFINE_PER_CPU(struct ipi_data_struct, ipi_data);
30
31enum ipi_message_type {
32 IPI_EMPTY,
33 IPI_RESCHEDULE,
34 IPI_CALL_FUNC,
35 IPI_MAX
36};
37
38static irqreturn_t handle_ipi(int irq, void *dev)
39{
40 while (true) {
41 unsigned long ops;
42
43 ops = xchg(&this_cpu_ptr(&ipi_data)->bits, 0);
44 if (ops == 0)
45 return IRQ_HANDLED;
46
47 if (ops & (1 << IPI_RESCHEDULE))
48 scheduler_ipi();
49
50 if (ops & (1 << IPI_CALL_FUNC))
51 generic_smp_call_function_interrupt();
52
53 BUG_ON((ops >> IPI_MAX) != 0);
54 }
55
56 return IRQ_HANDLED;
57}
58
59static void (*send_arch_ipi)(const struct cpumask *mask);
60
61static int ipi_irq;
62void __init set_send_ipi(void (*func)(const struct cpumask *mask), int irq)
63{
64 if (send_arch_ipi)
65 return;
66
67 send_arch_ipi = func;
68 ipi_irq = irq;
69}
70
71static void
72send_ipi_message(const struct cpumask *to_whom, enum ipi_message_type operation)
73{
74 int i;
75
76 for_each_cpu(i, to_whom)
77 set_bit(operation, &per_cpu_ptr(&ipi_data, i)->bits);
78
79 smp_mb();
80 send_arch_ipi(to_whom);
81}
82
83void arch_send_call_function_ipi_mask(struct cpumask *mask)
84{
85 send_ipi_message(mask, IPI_CALL_FUNC);
86}
87
88void arch_send_call_function_single_ipi(int cpu)
89{
90 send_ipi_message(cpumask_of(cpu), IPI_CALL_FUNC);
91}
92
93static void ipi_stop(void *unused)
94{
95 while (1);
96}
97
98void smp_send_stop(void)
99{
100 on_each_cpu(ipi_stop, NULL, 1);
101}
102
103void smp_send_reschedule(int cpu)
104{
105 send_ipi_message(cpumask_of(cpu), IPI_RESCHEDULE);
106}
107
108void __init smp_prepare_boot_cpu(void)
109{
110}
111
112void __init smp_prepare_cpus(unsigned int max_cpus)
113{
114}
115
116static int ipi_dummy_dev;
117
118void __init setup_smp_ipi(void)
119{
120 int rc;
121
122 if (ipi_irq == 0)
123 panic("%s IRQ mapping failed\n", __func__);
124
125 rc = request_percpu_irq(ipi_irq, handle_ipi, "IPI Interrupt",
126 &ipi_dummy_dev);
127 if (rc)
128 panic("%s IRQ request failed\n", __func__);
129
130 enable_percpu_irq(ipi_irq, 0);
131}
132
133void __init setup_smp(void)
134{
135 struct device_node *node = NULL;
136 int cpu;
137
138 for_each_of_cpu_node(node) {
139 if (!of_device_is_available(node))
140 continue;
141
142 if (of_property_read_u32(node, "reg", &cpu))
143 continue;
144
145 if (cpu >= NR_CPUS)
146 continue;
147
148 set_cpu_possible(cpu, true);
149 set_cpu_present(cpu, true);
150 }
151}
152
153extern void _start_smp_secondary(void);
154
155volatile unsigned int secondary_hint;
156volatile unsigned int secondary_ccr;
157volatile unsigned int secondary_stack;
158
159int __cpu_up(unsigned int cpu, struct task_struct *tidle)
160{
161 unsigned long mask = 1 << cpu;
162
163 secondary_stack =
164 (unsigned int) task_stack_page(tidle) + THREAD_SIZE - 8;
165 secondary_hint = mfcr("cr31");
166 secondary_ccr = mfcr("cr18");
167
168 /*
169 * Because other CPUs are in reset status, we must flush data
170 * from cache to out and secondary CPUs use them in
171 * csky_start_secondary(void)
172 */
173 mtcr("cr17", 0x22);
174
175 if (mask & mfcr("cr<29, 0>")) {
176 send_arch_ipi(cpumask_of(cpu));
177 } else {
178 /* Enable cpu in SMP reset ctrl reg */
179 mask |= mfcr("cr<29, 0>");
180 mtcr("cr<29, 0>", mask);
181 }
182
183 /* Wait for the cpu online */
184 while (!cpu_online(cpu));
185
186 secondary_stack = 0;
187
188 return 0;
189}
190
191void __init smp_cpus_done(unsigned int max_cpus)
192{
193}
194
195int setup_profiling_timer(unsigned int multiplier)
196{
197 return -EINVAL;
198}
199
200void csky_start_secondary(void)
201{
202 struct mm_struct *mm = &init_mm;
203 unsigned int cpu = smp_processor_id();
204
205 mtcr("cr31", secondary_hint);
206 mtcr("cr18", secondary_ccr);
207
208 mtcr("vbr", vec_base);
209
210 flush_tlb_all();
211 write_mmu_pagemask(0);
212 TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir);
213 TLBMISS_HANDLER_SETUP_PGD_KERNEL(swapper_pg_dir);
214
215#ifdef CONFIG_CPU_HAS_FPU
216 init_fpu();
217#endif
218
219 enable_percpu_irq(ipi_irq, 0);
220
221 mmget(mm);
222 mmgrab(mm);
223 current->active_mm = mm;
224 cpumask_set_cpu(cpu, mm_cpumask(mm));
225
226 notify_cpu_starting(cpu);
227 set_cpu_online(cpu, true);
228
229 pr_info("CPU%u Online: %s...\n", cpu, __func__);
230
231 local_irq_enable();
232 preempt_disable();
233 cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
234}
235
236#ifdef CONFIG_HOTPLUG_CPU
237int __cpu_disable(void)
238{
239 unsigned int cpu = smp_processor_id();
240
241 set_cpu_online(cpu, false);
242
243 irq_migrate_all_off_this_cpu();
244
245 clear_tasks_mm_cpumask(cpu);
246
247 return 0;
248}
249
250void __cpu_die(unsigned int cpu)
251{
252 if (!cpu_wait_death(cpu, 5)) {
253 pr_crit("CPU%u: shutdown failed\n", cpu);
254 return;
255 }
256 pr_notice("CPU%u: shutdown\n", cpu);
257}
258
259void arch_cpu_idle_dead(void)
260{
261 idle_task_exit();
262
263 cpu_report_death();
264
265 while (!secondary_stack)
266 arch_cpu_idle();
267
268 local_irq_disable();
269
270 asm volatile(
271 "mov sp, %0\n"
272 "mov r8, %0\n"
273 "jmpi csky_start_secondary"
274 :
275 : "r" (secondary_stack));
276}
277#endif