1 // SPDX-License-Identifier: GPL-2.0
2 /* smp.c: Sparc SMP support.
3  *
4  * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
5  * Copyright (C) 1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
6  * Copyright (C) 2004 Keith M Wesolowski (wesolows@foobazco.org)
7  */
8 
9 #include <asm/head.h>
10 
11 #include <linux/kernel.h>
12 #include <linux/sched.h>
13 #include <linux/threads.h>
14 #include <linux/smp.h>
15 #include <linux/interrupt.h>
16 #include <linux/kernel_stat.h>
17 #include <linux/init.h>
18 #include <linux/spinlock.h>
19 #include <linux/mm.h>
20 #include <linux/fs.h>
21 #include <linux/seq_file.h>
22 #include <linux/cache.h>
23 #include <linux/delay.h>
24 #include <linux/profile.h>
25 #include <linux/cpu.h>
26 
27 #include <asm/ptrace.h>
28 #include <linux/atomic.h>
29 
30 #include <asm/irq.h>
31 #include <asm/page.h>
32 #include <asm/oplib.h>
33 #include <asm/cacheflush.h>
34 #include <asm/tlbflush.h>
35 #include <asm/cpudata.h>
36 #include <asm/timer.h>
37 #include <asm/leon.h>
38 
39 #include "kernel.h"
40 #include "irq.h"
41 
42 volatile unsigned long cpu_callin_map[NR_CPUS] = {0,};
43 
44 cpumask_t smp_commenced_mask = CPU_MASK_NONE;
45 
46 const struct sparc32_ipi_ops *sparc32_ipi_ops;
47 
48 /* The only guaranteed locking primitive available on all Sparc
49  * processors is 'ldstub [%reg + immediate], %dest_reg' which atomically
50  * places the current byte at the effective address into dest_reg and
51  * places 0xff there afterwards.  Pretty lame locking primitive
52  * compared to the Alpha and the Intel no?  Most Sparcs have 'swap'
53  * instruction which is much better...
54  */
55 
smp_store_cpu_info(int id)56 void smp_store_cpu_info(int id)
57 {
58 	int cpu_node;
59 	int mid;
60 
61 	cpu_data(id).udelay_val = loops_per_jiffy;
62 
63 	cpu_find_by_mid(id, &cpu_node);
64 	cpu_data(id).clock_tick = prom_getintdefault(cpu_node,
65 						     "clock-frequency", 0);
66 	cpu_data(id).prom_node = cpu_node;
67 	mid = cpu_get_hwmid(cpu_node);
68 
69 	if (mid < 0) {
70 		printk(KERN_NOTICE "No MID found for CPU%d at node 0x%08x", id, cpu_node);
71 		mid = 0;
72 	}
73 	cpu_data(id).mid = mid;
74 }
75 
smp_cpus_done(unsigned int max_cpus)76 void __init smp_cpus_done(unsigned int max_cpus)
77 {
78 	unsigned long bogosum = 0;
79 	int cpu, num = 0;
80 
81 	for_each_online_cpu(cpu) {
82 		num++;
83 		bogosum += cpu_data(cpu).udelay_val;
84 	}
85 
86 	printk("Total of %d processors activated (%lu.%02lu BogoMIPS).\n",
87 		num, bogosum/(500000/HZ),
88 		(bogosum/(5000/HZ))%100);
89 
90 	switch(sparc_cpu_model) {
91 	case sun4m:
92 		smp4m_smp_done();
93 		break;
94 	case sun4d:
95 		smp4d_smp_done();
96 		break;
97 	case sparc_leon:
98 		leon_smp_done();
99 		break;
100 	case sun4e:
101 		printk("SUN4E\n");
102 		BUG();
103 		break;
104 	case sun4u:
105 		printk("SUN4U\n");
106 		BUG();
107 		break;
108 	default:
109 		printk("UNKNOWN!\n");
110 		BUG();
111 		break;
112 	}
113 }
114 
cpu_panic(void)115 void cpu_panic(void)
116 {
117 	printk("CPU[%d]: Returns from cpu_idle!\n", smp_processor_id());
118 	panic("SMP bolixed\n");
119 }
120 
121 struct linux_prom_registers smp_penguin_ctable = { 0 };
122 
arch_smp_send_reschedule(int cpu)123 void arch_smp_send_reschedule(int cpu)
124 {
125 	/*
126 	 * CPU model dependent way of implementing IPI generation targeting
127 	 * a single CPU. The trap handler needs only to do trap entry/return
128 	 * to call schedule.
129 	 */
130 	sparc32_ipi_ops->resched(cpu);
131 }
132 
smp_send_stop(void)133 void smp_send_stop(void)
134 {
135 }
136 
arch_send_call_function_single_ipi(int cpu)137 void arch_send_call_function_single_ipi(int cpu)
138 {
139 	/* trigger one IPI single call on one CPU */
140 	sparc32_ipi_ops->single(cpu);
141 }
142 
arch_send_call_function_ipi_mask(const struct cpumask * mask)143 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
144 {
145 	int cpu;
146 
147 	/* trigger IPI mask call on each CPU */
148 	for_each_cpu(cpu, mask)
149 		sparc32_ipi_ops->mask_one(cpu);
150 }
151 
smp_resched_interrupt(void)152 void smp_resched_interrupt(void)
153 {
154 	irq_enter();
155 	scheduler_ipi();
156 	local_cpu_data().irq_resched_count++;
157 	irq_exit();
158 	/* re-schedule routine called by interrupt return code. */
159 }
160 
smp_call_function_single_interrupt(void)161 void smp_call_function_single_interrupt(void)
162 {
163 	irq_enter();
164 	generic_smp_call_function_single_interrupt();
165 	local_cpu_data().irq_call_count++;
166 	irq_exit();
167 }
168 
smp_call_function_interrupt(void)169 void smp_call_function_interrupt(void)
170 {
171 	irq_enter();
172 	generic_smp_call_function_interrupt();
173 	local_cpu_data().irq_call_count++;
174 	irq_exit();
175 }
176 
smp_prepare_cpus(unsigned int max_cpus)177 void __init smp_prepare_cpus(unsigned int max_cpus)
178 {
179 	int i, cpuid, extra;
180 
181 	printk("Entering SMP Mode...\n");
182 
183 	extra = 0;
184 	for (i = 0; !cpu_find_by_instance(i, NULL, &cpuid); i++) {
185 		if (cpuid >= NR_CPUS)
186 			extra++;
187 	}
188 	/* i = number of cpus */
189 	if (extra && max_cpus > i - extra)
190 		printk("Warning: NR_CPUS is too low to start all cpus\n");
191 
192 	smp_store_cpu_info(boot_cpu_id);
193 
194 	switch(sparc_cpu_model) {
195 	case sun4m:
196 		smp4m_boot_cpus();
197 		break;
198 	case sun4d:
199 		smp4d_boot_cpus();
200 		break;
201 	case sparc_leon:
202 		leon_boot_cpus();
203 		break;
204 	case sun4e:
205 		printk("SUN4E\n");
206 		BUG();
207 		break;
208 	case sun4u:
209 		printk("SUN4U\n");
210 		BUG();
211 		break;
212 	default:
213 		printk("UNKNOWN!\n");
214 		BUG();
215 		break;
216 	}
217 }
218 
219 /* Set this up early so that things like the scheduler can init
220  * properly.  We use the same cpu mask for both the present and
221  * possible cpu map.
222  */
smp_setup_cpu_possible_map(void)223 void __init smp_setup_cpu_possible_map(void)
224 {
225 	int instance, mid;
226 
227 	instance = 0;
228 	while (!cpu_find_by_instance(instance, NULL, &mid)) {
229 		if (mid < NR_CPUS) {
230 			set_cpu_possible(mid, true);
231 			set_cpu_present(mid, true);
232 		}
233 		instance++;
234 	}
235 }
236 
smp_prepare_boot_cpu(void)237 void __init smp_prepare_boot_cpu(void)
238 {
239 	int cpuid = hard_smp_processor_id();
240 
241 	if (cpuid >= NR_CPUS) {
242 		prom_printf("Serious problem, boot cpu id >= NR_CPUS\n");
243 		prom_halt();
244 	}
245 	if (cpuid != 0)
246 		printk("boot cpu id != 0, this could work but is untested\n");
247 
248 	current_thread_info()->cpu = cpuid;
249 	set_cpu_online(cpuid, true);
250 	set_cpu_possible(cpuid, true);
251 }
252 
__cpu_up(unsigned int cpu,struct task_struct * tidle)253 int __cpu_up(unsigned int cpu, struct task_struct *tidle)
254 {
255 	int ret=0;
256 
257 	switch(sparc_cpu_model) {
258 	case sun4m:
259 		ret = smp4m_boot_one_cpu(cpu, tidle);
260 		break;
261 	case sun4d:
262 		ret = smp4d_boot_one_cpu(cpu, tidle);
263 		break;
264 	case sparc_leon:
265 		ret = leon_boot_one_cpu(cpu, tidle);
266 		break;
267 	case sun4e:
268 		printk("SUN4E\n");
269 		BUG();
270 		break;
271 	case sun4u:
272 		printk("SUN4U\n");
273 		BUG();
274 		break;
275 	default:
276 		printk("UNKNOWN!\n");
277 		BUG();
278 		break;
279 	}
280 
281 	if (!ret) {
282 		cpumask_set_cpu(cpu, &smp_commenced_mask);
283 		while (!cpu_online(cpu))
284 			mb();
285 	}
286 	return ret;
287 }
288 
arch_cpu_pre_starting(void * arg)289 static void arch_cpu_pre_starting(void *arg)
290 {
291 	local_ops->cache_all();
292 	local_ops->tlb_all();
293 
294 	switch(sparc_cpu_model) {
295 	case sun4m:
296 		sun4m_cpu_pre_starting(arg);
297 		break;
298 	case sun4d:
299 		sun4d_cpu_pre_starting(arg);
300 		break;
301 	case sparc_leon:
302 		leon_cpu_pre_starting(arg);
303 		break;
304 	default:
305 		BUG();
306 	}
307 }
308 
arch_cpu_pre_online(void * arg)309 static void arch_cpu_pre_online(void *arg)
310 {
311 	unsigned int cpuid = hard_smp_processor_id();
312 
313 	register_percpu_ce(cpuid);
314 
315 	calibrate_delay();
316 	smp_store_cpu_info(cpuid);
317 
318 	local_ops->cache_all();
319 	local_ops->tlb_all();
320 
321 	switch(sparc_cpu_model) {
322 	case sun4m:
323 		sun4m_cpu_pre_online(arg);
324 		break;
325 	case sun4d:
326 		sun4d_cpu_pre_online(arg);
327 		break;
328 	case sparc_leon:
329 		leon_cpu_pre_online(arg);
330 		break;
331 	default:
332 		BUG();
333 	}
334 }
335 
sparc_start_secondary(void * arg)336 static void sparc_start_secondary(void *arg)
337 {
338 	unsigned int cpu;
339 
340 	/*
341 	 * SMP booting is extremely fragile in some architectures. So run
342 	 * the cpu initialization code first before anything else.
343 	 */
344 	arch_cpu_pre_starting(arg);
345 
346 	cpu = smp_processor_id();
347 
348 	notify_cpu_starting(cpu);
349 	arch_cpu_pre_online(arg);
350 
351 	/* Set the CPU in the cpu_online_mask */
352 	set_cpu_online(cpu, true);
353 
354 	/* Enable local interrupts now */
355 	local_irq_enable();
356 
357 	wmb();
358 	cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
359 
360 	/* We should never reach here! */
361 	BUG();
362 }
363 
smp_callin(void)364 void smp_callin(void)
365 {
366 	sparc_start_secondary(NULL);
367 }
368 
smp_bogo(struct seq_file * m)369 void smp_bogo(struct seq_file *m)
370 {
371 	int i;
372 
373 	for_each_online_cpu(i) {
374 		seq_printf(m,
375 			   "Cpu%dBogo\t: %lu.%02lu\n",
376 			   i,
377 			   cpu_data(i).udelay_val/(500000/HZ),
378 			   (cpu_data(i).udelay_val/(5000/HZ))%100);
379 	}
380 }
381 
smp_info(struct seq_file * m)382 void smp_info(struct seq_file *m)
383 {
384 	int i;
385 
386 	seq_printf(m, "State:\n");
387 	for_each_online_cpu(i)
388 		seq_printf(m, "CPU%d\t\t: online\n", i);
389 }
390