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
42volatile unsigned long cpu_callin_map[NR_CPUS] = {0,};
43
44cpumask_t smp_commenced_mask = CPU_MASK_NONE;
45
46const 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
56void 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
76void __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
115void cpu_panic(void)
116{
117	printk("CPU[%d]: Returns from cpu_idle!\n", smp_processor_id());
118	panic("SMP bolixed\n");
119}
120
121struct linux_prom_registers smp_penguin_ctable = { 0 };
122
123void 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
133void smp_send_stop(void)
134{
135}
136
137void 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
143void 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
152void 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
161void 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
169void 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
177void __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 */
223void __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
237void __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
253int __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
289static 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
309static 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
336static 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
364void smp_callin(void)
365{
366	sparc_start_secondary(NULL);
367}
368
369void 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
382void 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