1// SPDX-License-Identifier: GPL-2.0
2/* Sparc SS1000/SC2000 SMP support.
3 *
4 * Copyright (C) 1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
5 *
6 * Based on sun4m's smp.c, which is:
7 * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
8 */
9
10#include <linux/clockchips.h>
11#include <linux/interrupt.h>
12#include <linux/profile.h>
13#include <linux/delay.h>
14#include <linux/sched/mm.h>
15#include <linux/cpu.h>
16
17#include <asm/cacheflush.h>
18#include <asm/switch_to.h>
19#include <asm/tlbflush.h>
20#include <asm/timer.h>
21#include <asm/oplib.h>
22#include <asm/sbi.h>
23#include <asm/mmu.h>
24
25#include "kernel.h"
26#include "irq.h"
27
28#define IRQ_CROSS_CALL 15
29
30static volatile int smp_processors_ready;
31static int smp_highest_cpu;
32
33static inline unsigned long sun4d_swap(volatile unsigned long *ptr, unsigned long val)
34{
35 __asm__ __volatile__("swap [%1], %0\n\t" :
36 "=&r" (val), "=&r" (ptr) :
37 "0" (val), "1" (ptr));
38 return val;
39}
40
41static void smp4d_ipi_init(void);
42
43static unsigned char cpu_leds[32];
44
45static inline void show_leds(int cpuid)
46{
47 cpuid &= 0x1e;
48 __asm__ __volatile__ ("stba %0, [%1] %2" : :
49 "r" ((cpu_leds[cpuid] << 4) | cpu_leds[cpuid+1]),
50 "r" (ECSR_BASE(cpuid) | BB_LEDS),
51 "i" (ASI_M_CTL));
52}
53
54void sun4d_cpu_pre_starting(void *arg)
55{
56 int cpuid = hard_smp_processor_id();
57
58 /* Show we are alive */
59 cpu_leds[cpuid] = 0x6;
60 show_leds(cpuid);
61
62 /* Enable level15 interrupt, disable level14 interrupt for now */
63 cc_set_imsk((cc_get_imsk() & ~0x8000) | 0x4000);
64}
65
66void sun4d_cpu_pre_online(void *arg)
67{
68 unsigned long flags;
69 int cpuid;
70
71 cpuid = hard_smp_processor_id();
72
73 /* Unblock the master CPU _only_ when the scheduler state
74 * of all secondary CPUs will be up-to-date, so after
75 * the SMP initialization the master will be just allowed
76 * to call the scheduler code.
77 */
78 sun4d_swap(ptr: (unsigned long *)&cpu_callin_map[cpuid], val: 1);
79 local_ops->cache_all();
80 local_ops->tlb_all();
81
82 while ((unsigned long)current_set[cpuid] < PAGE_OFFSET)
83 barrier();
84
85 while (current_set[cpuid]->cpu != cpuid)
86 barrier();
87
88 /* Fix idle thread fields. */
89 __asm__ __volatile__("ld [%0], %%g6\n\t"
90 : : "r" (&current_set[cpuid])
91 : "memory" /* paranoid */);
92
93 cpu_leds[cpuid] = 0x9;
94 show_leds(cpuid);
95
96 /* Attach to the address space of init_task. */
97 mmgrab(mm: &init_mm);
98 current->active_mm = &init_mm;
99
100 local_ops->cache_all();
101 local_ops->tlb_all();
102
103 while (!cpumask_test_cpu(cpu: cpuid, cpumask: &smp_commenced_mask))
104 barrier();
105
106 spin_lock_irqsave(&sun4d_imsk_lock, flags);
107 cc_set_imsk(cc_get_imsk() & ~0x4000); /* Allow PIL 14 as well */
108 spin_unlock_irqrestore(lock: &sun4d_imsk_lock, flags);
109}
110
111/*
112 * Cycle through the processors asking the PROM to start each one.
113 */
114void __init smp4d_boot_cpus(void)
115{
116 smp4d_ipi_init();
117 if (boot_cpu_id)
118 current_set[0] = NULL;
119 local_ops->cache_all();
120}
121
122int smp4d_boot_one_cpu(int i, struct task_struct *idle)
123{
124 unsigned long *entry = &sun4d_cpu_startup;
125 int timeout;
126 int cpu_node;
127
128 cpu_find_by_instance(i, &cpu_node, NULL);
129 current_set[i] = task_thread_info(idle);
130 /*
131 * Initialize the contexts table
132 * Since the call to prom_startcpu() trashes the structure,
133 * we need to re-initialize it for each cpu
134 */
135 smp_penguin_ctable.which_io = 0;
136 smp_penguin_ctable.phys_addr = (unsigned int) srmmu_ctx_table_phys;
137 smp_penguin_ctable.reg_size = 0;
138
139 /* whirrr, whirrr, whirrrrrrrrr... */
140 printk(KERN_INFO "Starting CPU %d at %p\n", i, entry);
141 local_ops->cache_all();
142 prom_startcpu(cpu_node,
143 &smp_penguin_ctable, 0, (char *)entry);
144
145 printk(KERN_INFO "prom_startcpu returned :)\n");
146
147 /* wheee... it's going... */
148 for (timeout = 0; timeout < 10000; timeout++) {
149 if (cpu_callin_map[i])
150 break;
151 udelay(200);
152 }
153
154 if (!(cpu_callin_map[i])) {
155 printk(KERN_ERR "Processor %d is stuck.\n", i);
156 return -ENODEV;
157
158 }
159 local_ops->cache_all();
160 return 0;
161}
162
163void __init smp4d_smp_done(void)
164{
165 int i, first;
166 int *prev;
167
168 /* setup cpu list for irq rotation */
169 first = 0;
170 prev = &first;
171 for_each_online_cpu(i) {
172 *prev = i;
173 prev = &cpu_data(i).next;
174 }
175 *prev = first;
176 local_ops->cache_all();
177
178 /* Ok, they are spinning and ready to go. */
179 smp_processors_ready = 1;
180 sun4d_distribute_irqs();
181}
182
183/* Memory structure giving interrupt handler information about IPI generated */
184struct sun4d_ipi_work {
185 int single;
186 int msk;
187 int resched;
188};
189
190static DEFINE_PER_CPU_SHARED_ALIGNED(struct sun4d_ipi_work, sun4d_ipi_work);
191
192/* Initialize IPIs on the SUN4D SMP machine */
193static void __init smp4d_ipi_init(void)
194{
195 int cpu;
196 struct sun4d_ipi_work *work;
197
198 printk(KERN_INFO "smp4d: setup IPI at IRQ %d\n", SUN4D_IPI_IRQ);
199
200 for_each_possible_cpu(cpu) {
201 work = &per_cpu(sun4d_ipi_work, cpu);
202 work->single = work->msk = work->resched = 0;
203 }
204}
205
206void sun4d_ipi_interrupt(void)
207{
208 struct sun4d_ipi_work *work = this_cpu_ptr(&sun4d_ipi_work);
209
210 if (work->single) {
211 work->single = 0;
212 smp_call_function_single_interrupt();
213 }
214 if (work->msk) {
215 work->msk = 0;
216 smp_call_function_interrupt();
217 }
218 if (work->resched) {
219 work->resched = 0;
220 smp_resched_interrupt();
221 }
222}
223
224/* +-------+-------------+-----------+------------------------------------+
225 * | bcast | devid | sid | levels mask |
226 * +-------+-------------+-----------+------------------------------------+
227 * 31 30 23 22 15 14 0
228 */
229#define IGEN_MESSAGE(bcast, devid, sid, levels) \
230 (((bcast) << 31) | ((devid) << 23) | ((sid) << 15) | (levels))
231
232static void sun4d_send_ipi(int cpu, int level)
233{
234 cc_set_igen(IGEN_MESSAGE(0, cpu << 3, 6 + ((level >> 1) & 7), 1 << (level - 1)));
235}
236
237static void sun4d_ipi_single(int cpu)
238{
239 struct sun4d_ipi_work *work = &per_cpu(sun4d_ipi_work, cpu);
240
241 /* Mark work */
242 work->single = 1;
243
244 /* Generate IRQ on the CPU */
245 sun4d_send_ipi(cpu, SUN4D_IPI_IRQ);
246}
247
248static void sun4d_ipi_mask_one(int cpu)
249{
250 struct sun4d_ipi_work *work = &per_cpu(sun4d_ipi_work, cpu);
251
252 /* Mark work */
253 work->msk = 1;
254
255 /* Generate IRQ on the CPU */
256 sun4d_send_ipi(cpu, SUN4D_IPI_IRQ);
257}
258
259static void sun4d_ipi_resched(int cpu)
260{
261 struct sun4d_ipi_work *work = &per_cpu(sun4d_ipi_work, cpu);
262
263 /* Mark work */
264 work->resched = 1;
265
266 /* Generate IRQ on the CPU (any IRQ will cause resched) */
267 sun4d_send_ipi(cpu, SUN4D_IPI_IRQ);
268}
269
270static struct smp_funcall {
271 void *func;
272 unsigned long arg1;
273 unsigned long arg2;
274 unsigned long arg3;
275 unsigned long arg4;
276 unsigned long arg5;
277 unsigned char processors_in[NR_CPUS]; /* Set when ipi entered. */
278 unsigned char processors_out[NR_CPUS]; /* Set when ipi exited. */
279} ccall_info __attribute__((aligned(8)));
280
281static DEFINE_SPINLOCK(cross_call_lock);
282
283/* Cross calls must be serialized, at least currently. */
284static void sun4d_cross_call(void *func, cpumask_t mask, unsigned long arg1,
285 unsigned long arg2, unsigned long arg3,
286 unsigned long arg4)
287{
288 if (smp_processors_ready) {
289 register int high = smp_highest_cpu;
290 unsigned long flags;
291
292 spin_lock_irqsave(&cross_call_lock, flags);
293
294 {
295 /*
296 * If you make changes here, make sure
297 * gcc generates proper code...
298 */
299 register void *f asm("i0") = func;
300 register unsigned long a1 asm("i1") = arg1;
301 register unsigned long a2 asm("i2") = arg2;
302 register unsigned long a3 asm("i3") = arg3;
303 register unsigned long a4 asm("i4") = arg4;
304 register unsigned long a5 asm("i5") = 0;
305
306 __asm__ __volatile__(
307 "std %0, [%6]\n\t"
308 "std %2, [%6 + 8]\n\t"
309 "std %4, [%6 + 16]\n\t" : :
310 "r"(f), "r"(a1), "r"(a2), "r"(a3), "r"(a4), "r"(a5),
311 "r" (&ccall_info.func));
312 }
313
314 /* Init receive/complete mapping, plus fire the IPI's off. */
315 {
316 register int i;
317
318 cpumask_clear_cpu(smp_processor_id(), dstp: &mask);
319 cpumask_and(dstp: &mask, cpu_online_mask, src2p: &mask);
320 for (i = 0; i <= high; i++) {
321 if (cpumask_test_cpu(cpu: i, cpumask: &mask)) {
322 ccall_info.processors_in[i] = 0;
323 ccall_info.processors_out[i] = 0;
324 sun4d_send_ipi(cpu: i, IRQ_CROSS_CALL);
325 }
326 }
327 }
328
329 {
330 register int i;
331
332 i = 0;
333 do {
334 if (!cpumask_test_cpu(cpu: i, cpumask: &mask))
335 continue;
336 while (!ccall_info.processors_in[i])
337 barrier();
338 } while (++i <= high);
339
340 i = 0;
341 do {
342 if (!cpumask_test_cpu(cpu: i, cpumask: &mask))
343 continue;
344 while (!ccall_info.processors_out[i])
345 barrier();
346 } while (++i <= high);
347 }
348
349 spin_unlock_irqrestore(lock: &cross_call_lock, flags);
350 }
351}
352
353/* Running cross calls. */
354void smp4d_cross_call_irq(void)
355{
356 void (*func)(unsigned long, unsigned long, unsigned long, unsigned long,
357 unsigned long) = ccall_info.func;
358 int i = hard_smp_processor_id();
359
360 ccall_info.processors_in[i] = 1;
361 func(ccall_info.arg1, ccall_info.arg2, ccall_info.arg3, ccall_info.arg4,
362 ccall_info.arg5);
363 ccall_info.processors_out[i] = 1;
364}
365
366void smp4d_percpu_timer_interrupt(struct pt_regs *regs)
367{
368 struct pt_regs *old_regs;
369 int cpu = hard_smp_processor_id();
370 struct clock_event_device *ce;
371 static int cpu_tick[NR_CPUS];
372 static char led_mask[] = { 0xe, 0xd, 0xb, 0x7, 0xb, 0xd };
373
374 old_regs = set_irq_regs(regs);
375 bw_get_prof_limit(cpu);
376 bw_clear_intr_mask(0, 1); /* INTR_TABLE[0] & 1 is Profile IRQ */
377
378 cpu_tick[cpu]++;
379 if (!(cpu_tick[cpu] & 15)) {
380 if (cpu_tick[cpu] == 0x60)
381 cpu_tick[cpu] = 0;
382 cpu_leds[cpu] = led_mask[cpu_tick[cpu] >> 4];
383 show_leds(cpuid: cpu);
384 }
385
386 ce = &per_cpu(sparc32_clockevent, cpu);
387
388 irq_enter();
389 ce->event_handler(ce);
390 irq_exit();
391
392 set_irq_regs(old_regs);
393}
394
395static const struct sparc32_ipi_ops sun4d_ipi_ops = {
396 .cross_call = sun4d_cross_call,
397 .resched = sun4d_ipi_resched,
398 .single = sun4d_ipi_single,
399 .mask_one = sun4d_ipi_mask_one,
400};
401
402void __init sun4d_init_smp(void)
403{
404 int i;
405
406 /* Patch ipi15 trap table */
407 t_nmi[1] = t_nmi[1] + (linux_trap_ipi15_sun4d - linux_trap_ipi15_sun4m);
408
409 sparc32_ipi_ops = &sun4d_ipi_ops;
410
411 for (i = 0; i < NR_CPUS; i++) {
412 ccall_info.processors_in[i] = 1;
413 ccall_info.processors_out[i] = 1;
414 }
415}
416

source code of linux/arch/sparc/kernel/sun4d_smp.c