xref: /openbmc/linux/arch/sparc/kernel/sun4d_smp.c (revision a06c488d)
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 sun4d_cpu_pre_starting(void *arg)
54 {
55 	int cpuid = hard_smp_processor_id();
56 
57 	/* Show we are alive */
58 	cpu_leds[cpuid] = 0x6;
59 	show_leds(cpuid);
60 
61 	/* Enable level15 interrupt, disable level14 interrupt for now */
62 	cc_set_imsk((cc_get_imsk() & ~0x8000) | 0x4000);
63 }
64 
65 void sun4d_cpu_pre_online(void *arg)
66 {
67 	unsigned long flags;
68 	int cpuid;
69 
70 	cpuid = hard_smp_processor_id();
71 
72 	/* Unblock the master CPU _only_ when the scheduler state
73 	 * of all secondary CPUs will be up-to-date, so after
74 	 * the SMP initialization the master will be just allowed
75 	 * to call the scheduler code.
76 	 */
77 	sun4d_swap((unsigned long *)&cpu_callin_map[cpuid], 1);
78 	local_ops->cache_all();
79 	local_ops->tlb_all();
80 
81 	while ((unsigned long)current_set[cpuid] < PAGE_OFFSET)
82 		barrier();
83 
84 	while (current_set[cpuid]->cpu != cpuid)
85 		barrier();
86 
87 	/* Fix idle thread fields. */
88 	__asm__ __volatile__("ld [%0], %%g6\n\t"
89 			     : : "r" (&current_set[cpuid])
90 			     : "memory" /* paranoid */);
91 
92 	cpu_leds[cpuid] = 0x9;
93 	show_leds(cpuid);
94 
95 	/* Attach to the address space of init_task. */
96 	atomic_inc(&init_mm.mm_count);
97 	current->active_mm = &init_mm;
98 
99 	local_ops->cache_all();
100 	local_ops->tlb_all();
101 
102 	while (!cpumask_test_cpu(cpuid, &smp_commenced_mask))
103 		barrier();
104 
105 	spin_lock_irqsave(&sun4d_imsk_lock, flags);
106 	cc_set_imsk(cc_get_imsk() & ~0x4000); /* Allow PIL 14 as well */
107 	spin_unlock_irqrestore(&sun4d_imsk_lock, flags);
108 }
109 
110 /*
111  *	Cycle through the processors asking the PROM to start each one.
112  */
113 void __init smp4d_boot_cpus(void)
114 {
115 	smp4d_ipi_init();
116 	if (boot_cpu_id)
117 		current_set[0] = NULL;
118 	local_ops->cache_all();
119 }
120 
121 int smp4d_boot_one_cpu(int i, struct task_struct *idle)
122 {
123 	unsigned long *entry = &sun4d_cpu_startup;
124 	int timeout;
125 	int cpu_node;
126 
127 	cpu_find_by_instance(i, &cpu_node, NULL);
128 	current_set[i] = task_thread_info(idle);
129 	/*
130 	 * Initialize the contexts table
131 	 * Since the call to prom_startcpu() trashes the structure,
132 	 * we need to re-initialize it for each cpu
133 	 */
134 	smp_penguin_ctable.which_io = 0;
135 	smp_penguin_ctable.phys_addr = (unsigned int) srmmu_ctx_table_phys;
136 	smp_penguin_ctable.reg_size = 0;
137 
138 	/* whirrr, whirrr, whirrrrrrrrr... */
139 	printk(KERN_INFO "Starting CPU %d at %p\n", i, entry);
140 	local_ops->cache_all();
141 	prom_startcpu(cpu_node,
142 		      &smp_penguin_ctable, 0, (char *)entry);
143 
144 	printk(KERN_INFO "prom_startcpu returned :)\n");
145 
146 	/* wheee... it's going... */
147 	for (timeout = 0; timeout < 10000; timeout++) {
148 		if (cpu_callin_map[i])
149 			break;
150 		udelay(200);
151 	}
152 
153 	if (!(cpu_callin_map[i])) {
154 		printk(KERN_ERR "Processor %d is stuck.\n", i);
155 		return -ENODEV;
156 
157 	}
158 	local_ops->cache_all();
159 	return 0;
160 }
161 
162 void __init smp4d_smp_done(void)
163 {
164 	int i, first;
165 	int *prev;
166 
167 	/* setup cpu list for irq rotation */
168 	first = 0;
169 	prev = &first;
170 	for_each_online_cpu(i) {
171 		*prev = i;
172 		prev = &cpu_data(i).next;
173 	}
174 	*prev = first;
175 	local_ops->cache_all();
176 
177 	/* Ok, they are spinning and ready to go. */
178 	smp_processors_ready = 1;
179 	sun4d_distribute_irqs();
180 }
181 
182 /* Memory structure giving interrupt handler information about IPI generated */
183 struct sun4d_ipi_work {
184 	int single;
185 	int msk;
186 	int resched;
187 };
188 
189 static DEFINE_PER_CPU_SHARED_ALIGNED(struct sun4d_ipi_work, sun4d_ipi_work);
190 
191 /* Initialize IPIs on the SUN4D SMP machine */
192 static void __init smp4d_ipi_init(void)
193 {
194 	int cpu;
195 	struct sun4d_ipi_work *work;
196 
197 	printk(KERN_INFO "smp4d: setup IPI at IRQ %d\n", SUN4D_IPI_IRQ);
198 
199 	for_each_possible_cpu(cpu) {
200 		work = &per_cpu(sun4d_ipi_work, cpu);
201 		work->single = work->msk = work->resched = 0;
202 	}
203 }
204 
205 void sun4d_ipi_interrupt(void)
206 {
207 	struct sun4d_ipi_work *work = this_cpu_ptr(&sun4d_ipi_work);
208 
209 	if (work->single) {
210 		work->single = 0;
211 		smp_call_function_single_interrupt();
212 	}
213 	if (work->msk) {
214 		work->msk = 0;
215 		smp_call_function_interrupt();
216 	}
217 	if (work->resched) {
218 		work->resched = 0;
219 		smp_resched_interrupt();
220 	}
221 }
222 
223 /* +-------+-------------+-----------+------------------------------------+
224  * | bcast |  devid      |   sid     |              levels mask           |
225  * +-------+-------------+-----------+------------------------------------+
226  *  31      30         23 22       15 14                                 0
227  */
228 #define IGEN_MESSAGE(bcast, devid, sid, levels) \
229 	(((bcast) << 31) | ((devid) << 23) | ((sid) << 15) | (levels))
230 
231 static void sun4d_send_ipi(int cpu, int level)
232 {
233 	cc_set_igen(IGEN_MESSAGE(0, cpu << 3, 6 + ((level >> 1) & 7), 1 << (level - 1)));
234 }
235 
236 static void sun4d_ipi_single(int cpu)
237 {
238 	struct sun4d_ipi_work *work = &per_cpu(sun4d_ipi_work, cpu);
239 
240 	/* Mark work */
241 	work->single = 1;
242 
243 	/* Generate IRQ on the CPU */
244 	sun4d_send_ipi(cpu, SUN4D_IPI_IRQ);
245 }
246 
247 static void sun4d_ipi_mask_one(int cpu)
248 {
249 	struct sun4d_ipi_work *work = &per_cpu(sun4d_ipi_work, cpu);
250 
251 	/* Mark work */
252 	work->msk = 1;
253 
254 	/* Generate IRQ on the CPU */
255 	sun4d_send_ipi(cpu, SUN4D_IPI_IRQ);
256 }
257 
258 static void sun4d_ipi_resched(int cpu)
259 {
260 	struct sun4d_ipi_work *work = &per_cpu(sun4d_ipi_work, cpu);
261 
262 	/* Mark work */
263 	work->resched = 1;
264 
265 	/* Generate IRQ on the CPU (any IRQ will cause resched) */
266 	sun4d_send_ipi(cpu, SUN4D_IPI_IRQ);
267 }
268 
269 static struct smp_funcall {
270 	smpfunc_t func;
271 	unsigned long arg1;
272 	unsigned long arg2;
273 	unsigned long arg3;
274 	unsigned long arg4;
275 	unsigned long arg5;
276 	unsigned char processors_in[NR_CPUS];  /* Set when ipi entered. */
277 	unsigned char processors_out[NR_CPUS]; /* Set when ipi exited. */
278 } ccall_info __attribute__((aligned(8)));
279 
280 static DEFINE_SPINLOCK(cross_call_lock);
281 
282 /* Cross calls must be serialized, at least currently. */
283 static void sun4d_cross_call(smpfunc_t func, cpumask_t mask, unsigned long arg1,
284 			     unsigned long arg2, unsigned long arg3,
285 			     unsigned long arg4)
286 {
287 	if (smp_processors_ready) {
288 		register int high = smp_highest_cpu;
289 		unsigned long flags;
290 
291 		spin_lock_irqsave(&cross_call_lock, flags);
292 
293 		{
294 			/*
295 			 * If you make changes here, make sure
296 			 * gcc generates proper code...
297 			 */
298 			register smpfunc_t f asm("i0") = func;
299 			register unsigned long a1 asm("i1") = arg1;
300 			register unsigned long a2 asm("i2") = arg2;
301 			register unsigned long a3 asm("i3") = arg3;
302 			register unsigned long a4 asm("i4") = arg4;
303 			register unsigned long a5 asm("i5") = 0;
304 
305 			__asm__ __volatile__(
306 				"std %0, [%6]\n\t"
307 				"std %2, [%6 + 8]\n\t"
308 				"std %4, [%6 + 16]\n\t" : :
309 				"r"(f), "r"(a1), "r"(a2), "r"(a3), "r"(a4), "r"(a5),
310 				"r" (&ccall_info.func));
311 		}
312 
313 		/* Init receive/complete mapping, plus fire the IPI's off. */
314 		{
315 			register int i;
316 
317 			cpumask_clear_cpu(smp_processor_id(), &mask);
318 			cpumask_and(&mask, cpu_online_mask, &mask);
319 			for (i = 0; i <= high; i++) {
320 				if (cpumask_test_cpu(i, &mask)) {
321 					ccall_info.processors_in[i] = 0;
322 					ccall_info.processors_out[i] = 0;
323 					sun4d_send_ipi(i, IRQ_CROSS_CALL);
324 				}
325 			}
326 		}
327 
328 		{
329 			register int i;
330 
331 			i = 0;
332 			do {
333 				if (!cpumask_test_cpu(i, &mask))
334 					continue;
335 				while (!ccall_info.processors_in[i])
336 					barrier();
337 			} while (++i <= high);
338 
339 			i = 0;
340 			do {
341 				if (!cpumask_test_cpu(i, &mask))
342 					continue;
343 				while (!ccall_info.processors_out[i])
344 					barrier();
345 			} while (++i <= high);
346 		}
347 
348 		spin_unlock_irqrestore(&cross_call_lock, flags);
349 	}
350 }
351 
352 /* Running cross calls. */
353 void smp4d_cross_call_irq(void)
354 {
355 	int i = hard_smp_processor_id();
356 
357 	ccall_info.processors_in[i] = 1;
358 	ccall_info.func(ccall_info.arg1, ccall_info.arg2, ccall_info.arg3,
359 			ccall_info.arg4, ccall_info.arg5);
360 	ccall_info.processors_out[i] = 1;
361 }
362 
363 void smp4d_percpu_timer_interrupt(struct pt_regs *regs)
364 {
365 	struct pt_regs *old_regs;
366 	int cpu = hard_smp_processor_id();
367 	struct clock_event_device *ce;
368 	static int cpu_tick[NR_CPUS];
369 	static char led_mask[] = { 0xe, 0xd, 0xb, 0x7, 0xb, 0xd };
370 
371 	old_regs = set_irq_regs(regs);
372 	bw_get_prof_limit(cpu);
373 	bw_clear_intr_mask(0, 1);	/* INTR_TABLE[0] & 1 is Profile IRQ */
374 
375 	cpu_tick[cpu]++;
376 	if (!(cpu_tick[cpu] & 15)) {
377 		if (cpu_tick[cpu] == 0x60)
378 			cpu_tick[cpu] = 0;
379 		cpu_leds[cpu] = led_mask[cpu_tick[cpu] >> 4];
380 		show_leds(cpu);
381 	}
382 
383 	ce = &per_cpu(sparc32_clockevent, cpu);
384 
385 	irq_enter();
386 	ce->event_handler(ce);
387 	irq_exit();
388 
389 	set_irq_regs(old_regs);
390 }
391 
392 static const struct sparc32_ipi_ops sun4d_ipi_ops = {
393 	.cross_call = sun4d_cross_call,
394 	.resched    = sun4d_ipi_resched,
395 	.single     = sun4d_ipi_single,
396 	.mask_one   = sun4d_ipi_mask_one,
397 };
398 
399 void __init sun4d_init_smp(void)
400 {
401 	int i;
402 
403 	/* Patch ipi15 trap table */
404 	t_nmi[1] = t_nmi[1] + (linux_trap_ipi15_sun4d - linux_trap_ipi15_sun4m);
405 
406 	sparc32_ipi_ops = &sun4d_ipi_ops;
407 
408 	for (i = 0; i < NR_CPUS; i++) {
409 		ccall_info.processors_in[i] = 1;
410 		ccall_info.processors_out[i] = 1;
411 	}
412 }
413