1 /*
2 * Copyright (C) 2014 Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
3 * Copyright (C) 2017 Stafford Horne <shorne@gmail.com>
4 *
5 * Based on arm64 and arc implementations
6 * Copyright (C) 2013 ARM Ltd.
7 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
8 *
9 * This file is licensed under the terms of the GNU General Public License
10 * version 2. This program is licensed "as is" without any warranty of any
11 * kind, whether express or implied.
12 */
13
14 #include <linux/smp.h>
15 #include <linux/cpu.h>
16 #include <linux/sched.h>
17 #include <linux/sched/mm.h>
18 #include <linux/irq.h>
19 #include <linux/of.h>
20 #include <asm/cpuinfo.h>
21 #include <asm/mmu_context.h>
22 #include <asm/tlbflush.h>
23 #include <asm/cacheflush.h>
24 #include <asm/time.h>
25
26 asmlinkage __init void secondary_start_kernel(void);
27
28 static void (*smp_cross_call)(const struct cpumask *, unsigned int);
29
30 unsigned long secondary_release = -1;
31 struct thread_info *secondary_thread_info;
32
33 enum ipi_msg_type {
34 IPI_WAKEUP,
35 IPI_RESCHEDULE,
36 IPI_CALL_FUNC,
37 IPI_CALL_FUNC_SINGLE,
38 };
39
40 static DEFINE_SPINLOCK(boot_lock);
41
42 static void boot_secondary(unsigned int cpu, struct task_struct *idle)
43 {
44 /*
45 * set synchronisation state between this boot processor
46 * and the secondary one
47 */
48 spin_lock(&boot_lock);
49
50 secondary_release = cpu;
51 smp_cross_call(cpumask_of(cpu), IPI_WAKEUP);
52
53 /*
54 * now the secondary core is starting up let it run its
55 * calibrations, then wait for it to finish
56 */
57 spin_unlock(&boot_lock);
58 }
59
60 void __init smp_init_cpus(void)
61 {
62 struct device_node *cpu;
63 u32 cpu_id;
64
65 for_each_of_cpu_node(cpu) {
66 cpu_id = of_get_cpu_hwid(cpu, 0);
67 if (cpu_id < NR_CPUS)
68 set_cpu_possible(cpu_id, true);
69 }
70 }
71
72 void __init smp_prepare_cpus(unsigned int max_cpus)
73 {
74 unsigned int cpu;
75
76 /*
77 * Initialise the present map, which describes the set of CPUs
78 * actually populated at the present time.
79 */
80 for_each_possible_cpu(cpu) {
81 if (cpu < max_cpus)
82 set_cpu_present(cpu, true);
83 }
84 }
85
86 void __init smp_cpus_done(unsigned int max_cpus)
87 {
88 }
89
90 static DECLARE_COMPLETION(cpu_running);
91
92 int __cpu_up(unsigned int cpu, struct task_struct *idle)
93 {
94 if (smp_cross_call == NULL) {
95 pr_warn("CPU%u: failed to start, IPI controller missing",
96 cpu);
97 return -EIO;
98 }
99
100 secondary_thread_info = task_thread_info(idle);
101 current_pgd[cpu] = init_mm.pgd;
102
103 boot_secondary(cpu, idle);
104 if (!wait_for_completion_timeout(&cpu_running,
105 msecs_to_jiffies(1000))) {
106 pr_crit("CPU%u: failed to start\n", cpu);
107 return -EIO;
108 }
109 synchronise_count_master(cpu);
110
111 return 0;
112 }
113
114 asmlinkage __init void secondary_start_kernel(void)
115 {
116 struct mm_struct *mm = &init_mm;
117 unsigned int cpu = smp_processor_id();
118 /*
119 * All kernel threads share the same mm context; grab a
120 * reference and switch to it.
121 */
122 mmgrab(mm);
123 current->active_mm = mm;
124 cpumask_set_cpu(cpu, mm_cpumask(mm));
125
126 pr_info("CPU%u: Booted secondary processor\n", cpu);
127
128 setup_cpuinfo();
129 openrisc_clockevent_init();
130
131 notify_cpu_starting(cpu);
132
133 /*
134 * OK, now it's safe to let the boot CPU continue
135 */
136 complete(&cpu_running);
137
138 synchronise_count_slave(cpu);
139 set_cpu_online(cpu, true);
140
141 local_irq_enable();
142 /*
143 * OK, it's off to the idle thread for us
144 */
145 cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
146 }
147
148 void handle_IPI(unsigned int ipi_msg)
149 {
150 unsigned int cpu = smp_processor_id();
151
152 switch (ipi_msg) {
153 case IPI_WAKEUP:
154 break;
155
156 case IPI_RESCHEDULE:
157 scheduler_ipi();
158 break;
159
160 case IPI_CALL_FUNC:
161 generic_smp_call_function_interrupt();
162 break;
163
164 case IPI_CALL_FUNC_SINGLE:
165 generic_smp_call_function_single_interrupt();
166 break;
167
168 default:
169 WARN(1, "CPU%u: Unknown IPI message 0x%x\n", cpu, ipi_msg);
170 break;
171 }
172 }
173
174 void arch_smp_send_reschedule(int cpu)
175 {
176 smp_cross_call(cpumask_of(cpu), IPI_RESCHEDULE);
177 }
178
179 static void stop_this_cpu(void *dummy)
180 {
181 /* Remove this CPU */
182 set_cpu_online(smp_processor_id(), false);
183
184 local_irq_disable();
185 /* CPU Doze */
186 if (mfspr(SPR_UPR) & SPR_UPR_PMP)
187 mtspr(SPR_PMR, mfspr(SPR_PMR) | SPR_PMR_DME);
188 /* If that didn't work, infinite loop */
189 while (1)
190 ;
191 }
192
193 void smp_send_stop(void)
194 {
195 smp_call_function(stop_this_cpu, NULL, 0);
196 }
197
198 void __init set_smp_cross_call(void (*fn)(const struct cpumask *, unsigned int))
199 {
200 smp_cross_call = fn;
201 }
202
203 void arch_send_call_function_single_ipi(int cpu)
204 {
205 smp_cross_call(cpumask_of(cpu), IPI_CALL_FUNC_SINGLE);
206 }
207
208 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
209 {
210 smp_cross_call(mask, IPI_CALL_FUNC);
211 }
212
213 /* TLB flush operations - Performed on each CPU*/
214 static inline void ipi_flush_tlb_all(void *ignored)
215 {
216 local_flush_tlb_all();
217 }
218
219 static inline void ipi_flush_tlb_mm(void *info)
220 {
221 struct mm_struct *mm = (struct mm_struct *)info;
222
223 local_flush_tlb_mm(mm);
224 }
225
226 static void smp_flush_tlb_mm(struct cpumask *cmask, struct mm_struct *mm)
227 {
228 unsigned int cpuid;
229
230 if (cpumask_empty(cmask))
231 return;
232
233 cpuid = get_cpu();
234
235 if (cpumask_any_but(cmask, cpuid) >= nr_cpu_ids) {
236 /* local cpu is the only cpu present in cpumask */
237 local_flush_tlb_mm(mm);
238 } else {
239 on_each_cpu_mask(cmask, ipi_flush_tlb_mm, mm, 1);
240 }
241 put_cpu();
242 }
243
244 struct flush_tlb_data {
245 unsigned long addr1;
246 unsigned long addr2;
247 };
248
249 static inline void ipi_flush_tlb_page(void *info)
250 {
251 struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
252
253 local_flush_tlb_page(NULL, fd->addr1);
254 }
255
256 static inline void ipi_flush_tlb_range(void *info)
257 {
258 struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
259
260 local_flush_tlb_range(NULL, fd->addr1, fd->addr2);
261 }
262
263 static void smp_flush_tlb_range(const struct cpumask *cmask, unsigned long start,
264 unsigned long end)
265 {
266 unsigned int cpuid;
267
268 if (cpumask_empty(cmask))
269 return;
270
271 cpuid = get_cpu();
272
273 if (cpumask_any_but(cmask, cpuid) >= nr_cpu_ids) {
274 /* local cpu is the only cpu present in cpumask */
275 if ((end - start) <= PAGE_SIZE)
276 local_flush_tlb_page(NULL, start);
277 else
278 local_flush_tlb_range(NULL, start, end);
279 } else {
280 struct flush_tlb_data fd;
281
282 fd.addr1 = start;
283 fd.addr2 = end;
284
285 if ((end - start) <= PAGE_SIZE)
286 on_each_cpu_mask(cmask, ipi_flush_tlb_page, &fd, 1);
287 else
288 on_each_cpu_mask(cmask, ipi_flush_tlb_range, &fd, 1);
289 }
290 put_cpu();
291 }
292
293 void flush_tlb_all(void)
294 {
295 on_each_cpu(ipi_flush_tlb_all, NULL, 1);
296 }
297
298 void flush_tlb_mm(struct mm_struct *mm)
299 {
300 smp_flush_tlb_mm(mm_cpumask(mm), mm);
301 }
302
303 void flush_tlb_page(struct vm_area_struct *vma, unsigned long uaddr)
304 {
305 smp_flush_tlb_range(mm_cpumask(vma->vm_mm), uaddr, uaddr + PAGE_SIZE);
306 }
307
308 void flush_tlb_range(struct vm_area_struct *vma,
309 unsigned long start, unsigned long end)
310 {
311 const struct cpumask *cmask = vma ? mm_cpumask(vma->vm_mm)
312 : cpu_online_mask;
313 smp_flush_tlb_range(cmask, start, end);
314 }
315
316 /* Instruction cache invalidate - performed on each cpu */
317 static void ipi_icache_page_inv(void *arg)
318 {
319 struct page *page = arg;
320
321 local_icache_page_inv(page);
322 }
323
324 void smp_icache_page_inv(struct page *page)
325 {
326 on_each_cpu(ipi_icache_page_inv, page, 1);
327 }
328 EXPORT_SYMBOL(smp_icache_page_inv);
329
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