xref: /openbmc/linux/arch/sparc/kernel/sun4d_smp.c (revision 95e9fd10)
1 /* Sparc SS1000/SC2000 SMP support.
2  *
3  * Copyright (C) 1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
4  *
5  * Based on sun4m's smp.c, which is:
6  * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
7  */
8 
9 #include <linux/clockchips.h>
10 #include <linux/interrupt.h>
11 #include <linux/profile.h>
12 #include <linux/delay.h>
13 #include <linux/sched.h>
14 #include <linux/cpu.h>
15 
16 #include <asm/cacheflush.h>
17 #include <asm/switch_to.h>
18 #include <asm/tlbflush.h>
19 #include <asm/timer.h>
20 #include <asm/oplib.h>
21 #include <asm/sbi.h>
22 #include <asm/mmu.h>
23 
24 #include "kernel.h"
25 #include "irq.h"
26 
27 #define IRQ_CROSS_CALL		15
28 
29 static volatile int smp_processors_ready;
30 static int smp_highest_cpu;
31 
32 static inline unsigned long sun4d_swap(volatile unsigned long *ptr, unsigned long val)
33 {
34 	__asm__ __volatile__("swap [%1], %0\n\t" :
35 			     "=&r" (val), "=&r" (ptr) :
36 			     "0" (val), "1" (ptr));
37 	return val;
38 }
39 
40 static void smp4d_ipi_init(void);
41 
42 static unsigned char cpu_leds[32];
43 
44 static inline void show_leds(int cpuid)
45 {
46 	cpuid &= 0x1e;
47 	__asm__ __volatile__ ("stba %0, [%1] %2" : :
48 			      "r" ((cpu_leds[cpuid] << 4) | cpu_leds[cpuid+1]),
49 			      "r" (ECSR_BASE(cpuid) | BB_LEDS),
50 			      "i" (ASI_M_CTL));
51 }
52 
53 void __cpuinit smp4d_callin(void)
54 {
55 	int cpuid = hard_smp_processor_id();
56 	unsigned long flags;
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 	local_ops->cache_all();
66 	local_ops->tlb_all();
67 
68 	notify_cpu_starting(cpuid);
69 	/*
70 	 * Unblock the master CPU _only_ when the scheduler state
71 	 * of all secondary CPUs will be up-to-date, so after
72 	 * the SMP initialization the master will be just allowed
73 	 * to call the scheduler code.
74 	 */
75 	/* Get our local ticker going. */
76 	register_percpu_ce(cpuid);
77 
78 	calibrate_delay();
79 	smp_store_cpu_info(cpuid);
80 	local_ops->cache_all();
81 	local_ops->tlb_all();
82 
83 	/* Allow master to continue. */
84 	sun4d_swap((unsigned long *)&cpu_callin_map[cpuid], 1);
85 	local_ops->cache_all();
86 	local_ops->tlb_all();
87 
88 	while ((unsigned long)current_set[cpuid] < PAGE_OFFSET)
89 		barrier();
90 
91 	while (current_set[cpuid]->cpu != cpuid)
92 		barrier();
93 
94 	/* Fix idle thread fields. */
95 	__asm__ __volatile__("ld [%0], %%g6\n\t"
96 			     : : "r" (&current_set[cpuid])
97 			     : "memory" /* paranoid */);
98 
99 	cpu_leds[cpuid] = 0x9;
100 	show_leds(cpuid);
101 
102 	/* Attach to the address space of init_task. */
103 	atomic_inc(&init_mm.mm_count);
104 	current->active_mm = &init_mm;
105 
106 	local_ops->cache_all();
107 	local_ops->tlb_all();
108 
109 	local_irq_enable();	/* We don't allow PIL 14 yet */
110 
111 	while (!cpumask_test_cpu(cpuid, &smp_commenced_mask))
112 		barrier();
113 
114 	spin_lock_irqsave(&sun4d_imsk_lock, flags);
115 	cc_set_imsk(cc_get_imsk() & ~0x4000); /* Allow PIL 14 as well */
116 	spin_unlock_irqrestore(&sun4d_imsk_lock, flags);
117 	set_cpu_online(cpuid, true);
118 
119 }
120 
121 /*
122  *	Cycle through the processors asking the PROM to start each one.
123  */
124 void __init smp4d_boot_cpus(void)
125 {
126 	smp4d_ipi_init();
127 	if (boot_cpu_id)
128 		current_set[0] = NULL;
129 	local_ops->cache_all();
130 }
131 
132 int __cpuinit smp4d_boot_one_cpu(int i, struct task_struct *idle)
133 {
134 	unsigned long *entry = &sun4d_cpu_startup;
135 	int timeout;
136 	int cpu_node;
137 
138 	cpu_find_by_instance(i, &cpu_node, NULL);
139 	current_set[i] = task_thread_info(idle);
140 	/*
141 	 * Initialize the contexts table
142 	 * Since the call to prom_startcpu() trashes the structure,
143 	 * we need to re-initialize it for each cpu
144 	 */
145 	smp_penguin_ctable.which_io = 0;
146 	smp_penguin_ctable.phys_addr = (unsigned int) srmmu_ctx_table_phys;
147 	smp_penguin_ctable.reg_size = 0;
148 
149 	/* whirrr, whirrr, whirrrrrrrrr... */
150 	printk(KERN_INFO "Starting CPU %d at %p\n", i, entry);
151 	local_ops->cache_all();
152 	prom_startcpu(cpu_node,
153 		      &smp_penguin_ctable, 0, (char *)entry);
154 
155 	printk(KERN_INFO "prom_startcpu returned :)\n");
156 
157 	/* wheee... it's going... */
158 	for (timeout = 0; timeout < 10000; timeout++) {
159 		if (cpu_callin_map[i])
160 			break;
161 		udelay(200);
162 	}
163 
164 	if (!(cpu_callin_map[i])) {
165 		printk(KERN_ERR "Processor %d is stuck.\n", i);
166 		return -ENODEV;
167 
168 	}
169 	local_ops->cache_all();
170 	return 0;
171 }
172 
173 void __init smp4d_smp_done(void)
174 {
175 	int i, first;
176 	int *prev;
177 
178 	/* setup cpu list for irq rotation */
179 	first = 0;
180 	prev = &first;
181 	for_each_online_cpu(i) {
182 		*prev = i;
183 		prev = &cpu_data(i).next;
184 	}
185 	*prev = first;
186 	local_ops->cache_all();
187 
188 	/* Ok, they are spinning and ready to go. */
189 	smp_processors_ready = 1;
190 	sun4d_distribute_irqs();
191 }
192 
193 /* Memory structure giving interrupt handler information about IPI generated */
194 struct sun4d_ipi_work {
195 	int single;
196 	int msk;
197 	int resched;
198 };
199 
200 static DEFINE_PER_CPU_SHARED_ALIGNED(struct sun4d_ipi_work, sun4d_ipi_work);
201 
202 /* Initialize IPIs on the SUN4D SMP machine */
203 static void __init smp4d_ipi_init(void)
204 {
205 	int cpu;
206 	struct sun4d_ipi_work *work;
207 
208 	printk(KERN_INFO "smp4d: setup IPI at IRQ %d\n", SUN4D_IPI_IRQ);
209 
210 	for_each_possible_cpu(cpu) {
211 		work = &per_cpu(sun4d_ipi_work, cpu);
212 		work->single = work->msk = work->resched = 0;
213 	}
214 }
215 
216 void sun4d_ipi_interrupt(void)
217 {
218 	struct sun4d_ipi_work *work = &__get_cpu_var(sun4d_ipi_work);
219 
220 	if (work->single) {
221 		work->single = 0;
222 		smp_call_function_single_interrupt();
223 	}
224 	if (work->msk) {
225 		work->msk = 0;
226 		smp_call_function_interrupt();
227 	}
228 	if (work->resched) {
229 		work->resched = 0;
230 		smp_resched_interrupt();
231 	}
232 }
233 
234 /* +-------+-------------+-----------+------------------------------------+
235  * | bcast |  devid      |   sid     |              levels mask           |
236  * +-------+-------------+-----------+------------------------------------+
237  *  31      30         23 22       15 14                                 0
238  */
239 #define IGEN_MESSAGE(bcast, devid, sid, levels) \
240 	(((bcast) << 31) | ((devid) << 23) | ((sid) << 15) | (levels))
241 
242 static void sun4d_send_ipi(int cpu, int level)
243 {
244 	cc_set_igen(IGEN_MESSAGE(0, cpu << 3, 6 + ((level >> 1) & 7), 1 << (level - 1)));
245 }
246 
247 static void sun4d_ipi_single(int cpu)
248 {
249 	struct sun4d_ipi_work *work = &per_cpu(sun4d_ipi_work, cpu);
250 
251 	/* Mark work */
252 	work->single = 1;
253 
254 	/* Generate IRQ on the CPU */
255 	sun4d_send_ipi(cpu, SUN4D_IPI_IRQ);
256 }
257 
258 static void sun4d_ipi_mask_one(int cpu)
259 {
260 	struct sun4d_ipi_work *work = &per_cpu(sun4d_ipi_work, cpu);
261 
262 	/* Mark work */
263 	work->msk = 1;
264 
265 	/* Generate IRQ on the CPU */
266 	sun4d_send_ipi(cpu, SUN4D_IPI_IRQ);
267 }
268 
269 static void sun4d_ipi_resched(int cpu)
270 {
271 	struct sun4d_ipi_work *work = &per_cpu(sun4d_ipi_work, cpu);
272 
273 	/* Mark work */
274 	work->resched = 1;
275 
276 	/* Generate IRQ on the CPU (any IRQ will cause resched) */
277 	sun4d_send_ipi(cpu, SUN4D_IPI_IRQ);
278 }
279 
280 static struct smp_funcall {
281 	smpfunc_t func;
282 	unsigned long arg1;
283 	unsigned long arg2;
284 	unsigned long arg3;
285 	unsigned long arg4;
286 	unsigned long arg5;
287 	unsigned char processors_in[NR_CPUS];  /* Set when ipi entered. */
288 	unsigned char processors_out[NR_CPUS]; /* Set when ipi exited. */
289 } ccall_info __attribute__((aligned(8)));
290 
291 static DEFINE_SPINLOCK(cross_call_lock);
292 
293 /* Cross calls must be serialized, at least currently. */
294 static void sun4d_cross_call(smpfunc_t func, cpumask_t mask, unsigned long arg1,
295 			     unsigned long arg2, unsigned long arg3,
296 			     unsigned long arg4)
297 {
298 	if (smp_processors_ready) {
299 		register int high = smp_highest_cpu;
300 		unsigned long flags;
301 
302 		spin_lock_irqsave(&cross_call_lock, flags);
303 
304 		{
305 			/*
306 			 * If you make changes here, make sure
307 			 * gcc generates proper code...
308 			 */
309 			register smpfunc_t f asm("i0") = func;
310 			register unsigned long a1 asm("i1") = arg1;
311 			register unsigned long a2 asm("i2") = arg2;
312 			register unsigned long a3 asm("i3") = arg3;
313 			register unsigned long a4 asm("i4") = arg4;
314 			register unsigned long a5 asm("i5") = 0;
315 
316 			__asm__ __volatile__(
317 				"std %0, [%6]\n\t"
318 				"std %2, [%6 + 8]\n\t"
319 				"std %4, [%6 + 16]\n\t" : :
320 				"r"(f), "r"(a1), "r"(a2), "r"(a3), "r"(a4), "r"(a5),
321 				"r" (&ccall_info.func));
322 		}
323 
324 		/* Init receive/complete mapping, plus fire the IPI's off. */
325 		{
326 			register int i;
327 
328 			cpumask_clear_cpu(smp_processor_id(), &mask);
329 			cpumask_and(&mask, cpu_online_mask, &mask);
330 			for (i = 0; i <= high; i++) {
331 				if (cpumask_test_cpu(i, &mask)) {
332 					ccall_info.processors_in[i] = 0;
333 					ccall_info.processors_out[i] = 0;
334 					sun4d_send_ipi(i, IRQ_CROSS_CALL);
335 				}
336 			}
337 		}
338 
339 		{
340 			register int i;
341 
342 			i = 0;
343 			do {
344 				if (!cpumask_test_cpu(i, &mask))
345 					continue;
346 				while (!ccall_info.processors_in[i])
347 					barrier();
348 			} while (++i <= high);
349 
350 			i = 0;
351 			do {
352 				if (!cpumask_test_cpu(i, &mask))
353 					continue;
354 				while (!ccall_info.processors_out[i])
355 					barrier();
356 			} while (++i <= high);
357 		}
358 
359 		spin_unlock_irqrestore(&cross_call_lock, flags);
360 	}
361 }
362 
363 /* Running cross calls. */
364 void smp4d_cross_call_irq(void)
365 {
366 	int i = hard_smp_processor_id();
367 
368 	ccall_info.processors_in[i] = 1;
369 	ccall_info.func(ccall_info.arg1, ccall_info.arg2, ccall_info.arg3,
370 			ccall_info.arg4, ccall_info.arg5);
371 	ccall_info.processors_out[i] = 1;
372 }
373 
374 void smp4d_percpu_timer_interrupt(struct pt_regs *regs)
375 {
376 	struct pt_regs *old_regs;
377 	int cpu = hard_smp_processor_id();
378 	struct clock_event_device *ce;
379 	static int cpu_tick[NR_CPUS];
380 	static char led_mask[] = { 0xe, 0xd, 0xb, 0x7, 0xb, 0xd };
381 
382 	old_regs = set_irq_regs(regs);
383 	bw_get_prof_limit(cpu);
384 	bw_clear_intr_mask(0, 1);	/* INTR_TABLE[0] & 1 is Profile IRQ */
385 
386 	cpu_tick[cpu]++;
387 	if (!(cpu_tick[cpu] & 15)) {
388 		if (cpu_tick[cpu] == 0x60)
389 			cpu_tick[cpu] = 0;
390 		cpu_leds[cpu] = led_mask[cpu_tick[cpu] >> 4];
391 		show_leds(cpu);
392 	}
393 
394 	ce = &per_cpu(sparc32_clockevent, cpu);
395 
396 	irq_enter();
397 	ce->event_handler(ce);
398 	irq_exit();
399 
400 	set_irq_regs(old_regs);
401 }
402 
403 static const struct sparc32_ipi_ops sun4d_ipi_ops = {
404 	.cross_call = sun4d_cross_call,
405 	.resched    = sun4d_ipi_resched,
406 	.single     = sun4d_ipi_single,
407 	.mask_one   = sun4d_ipi_mask_one,
408 };
409 
410 void __init sun4d_init_smp(void)
411 {
412 	int i;
413 
414 	/* Patch ipi15 trap table */
415 	t_nmi[1] = t_nmi[1] + (linux_trap_ipi15_sun4d - linux_trap_ipi15_sun4m);
416 
417 	sparc32_ipi_ops = &sun4d_ipi_ops;
418 
419 	for (i = 0; i < NR_CPUS; i++) {
420 		ccall_info.processors_in[i] = 1;
421 		ccall_info.processors_out[i] = 1;
422 	}
423 }
424