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
30 static volatile int smp_processors_ready;
31 static int smp_highest_cpu;
32
33 static 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 "" (val), "1" (ptr));
38 return val;
39 }
40
41 static void smp4d_ipi_init(void);
42
43 static unsigned char cpu_leds[32];
44
45 static 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
54 void 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
66 void 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((unsigned long *)&cpu_callin_map[cpuid], 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" (¤t_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(&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(cpuid, &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(&sun4d_imsk_lock, flags);
109 }
110
111 /*
112 * Cycle through the processors asking the PROM to start each one.
113 */
114 void __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
122 int 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
163 void __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 */
184 struct sun4d_ipi_work {
185 int single;
186 int msk;
187 int resched;
188 };
189
190 static DEFINE_PER_CPU_SHARED_ALIGNED(struct sun4d_ipi_work, sun4d_ipi_work);
191
192 /* Initialize IPIs on the SUN4D SMP machine */
193 static 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
206 void 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
232 static 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
237 static 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
248 static 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
259 static 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
270 static 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
281 static DEFINE_SPINLOCK(cross_call_lock);
282
283 /* Cross calls must be serialized, at least currently. */
284 static 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(), &mask);
319 cpumask_and(&mask, cpu_online_mask, &mask);
320 for (i = 0; i <= high; i++) {
321 if (cpumask_test_cpu(i, &mask)) {
322 ccall_info.processors_in[i] = 0;
323 ccall_info.processors_out[i] = 0;
324 sun4d_send_ipi(i, IRQ_CROSS_CALL);
325 }
326 }
327 }
328
329 {
330 register int i;
331
332 i = 0;
333 do {
334 if (!cpumask_test_cpu(i, &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(i, &mask))
343 continue;
344 while (!ccall_info.processors_out[i])
345 barrier();
346 } while (++i <= high);
347 }
348
349 spin_unlock_irqrestore(&cross_call_lock, flags);
350 }
351 }
352
353 /* Running cross calls. */
354 void 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
366 void 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(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
395 static 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
402 void __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
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