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((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" (&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(&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 */
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(), &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. */
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(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