xref: /openbmc/linux/arch/sparc/kernel/sun4m_smp.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
1 /* sun4m_smp.c: Sparc SUN4M SMP support.
2  *
3  * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
4  */
5 
6 #include <asm/head.h>
7 
8 #include <linux/kernel.h>
9 #include <linux/sched.h>
10 #include <linux/threads.h>
11 #include <linux/smp.h>
12 #include <linux/smp_lock.h>
13 #include <linux/interrupt.h>
14 #include <linux/kernel_stat.h>
15 #include <linux/init.h>
16 #include <linux/spinlock.h>
17 #include <linux/mm.h>
18 #include <linux/swap.h>
19 #include <linux/profile.h>
20 #include <asm/cacheflush.h>
21 #include <asm/tlbflush.h>
22 
23 #include <asm/ptrace.h>
24 #include <asm/atomic.h>
25 
26 #include <asm/delay.h>
27 #include <asm/irq.h>
28 #include <asm/page.h>
29 #include <asm/pgalloc.h>
30 #include <asm/pgtable.h>
31 #include <asm/oplib.h>
32 #include <asm/cpudata.h>
33 
34 #define IRQ_RESCHEDULE		13
35 #define IRQ_STOP_CPU		14
36 #define IRQ_CROSS_CALL		15
37 
38 extern ctxd_t *srmmu_ctx_table_phys;
39 
40 extern void calibrate_delay(void);
41 
42 extern volatile int smp_processors_ready;
43 extern int smp_num_cpus;
44 extern volatile unsigned long cpu_callin_map[NR_CPUS];
45 extern unsigned char boot_cpu_id;
46 extern int smp_activated;
47 extern volatile int __cpu_number_map[NR_CPUS];
48 extern volatile int __cpu_logical_map[NR_CPUS];
49 extern volatile unsigned long ipi_count;
50 extern volatile int smp_process_available;
51 extern volatile int smp_commenced;
52 extern int __smp4m_processor_id(void);
53 
54 /*#define SMP_DEBUG*/
55 
56 #ifdef SMP_DEBUG
57 #define SMP_PRINTK(x)	printk x
58 #else
59 #define SMP_PRINTK(x)
60 #endif
61 
62 static inline unsigned long swap(volatile unsigned long *ptr, unsigned long val)
63 {
64 	__asm__ __volatile__("swap [%1], %0\n\t" :
65 			     "=&r" (val), "=&r" (ptr) :
66 			     "0" (val), "1" (ptr));
67 	return val;
68 }
69 
70 static void smp_setup_percpu_timer(void);
71 extern void cpu_probe(void);
72 
73 void __init smp4m_callin(void)
74 {
75 	int cpuid = hard_smp_processor_id();
76 
77 	local_flush_cache_all();
78 	local_flush_tlb_all();
79 
80 	set_irq_udt(boot_cpu_id);
81 
82 	/* Get our local ticker going. */
83 	smp_setup_percpu_timer();
84 
85 	calibrate_delay();
86 	smp_store_cpu_info(cpuid);
87 
88 	local_flush_cache_all();
89 	local_flush_tlb_all();
90 
91 	/*
92 	 * Unblock the master CPU _only_ when the scheduler state
93 	 * of all secondary CPUs will be up-to-date, so after
94 	 * the SMP initialization the master will be just allowed
95 	 * to call the scheduler code.
96 	 */
97 	/* Allow master to continue. */
98 	swap((unsigned long *)&cpu_callin_map[cpuid], 1);
99 
100 	local_flush_cache_all();
101 	local_flush_tlb_all();
102 
103 	cpu_probe();
104 
105 	/* Fix idle thread fields. */
106 	__asm__ __volatile__("ld [%0], %%g6\n\t"
107 			     : : "r" (&current_set[cpuid])
108 			     : "memory" /* paranoid */);
109 
110 	/* Attach to the address space of init_task. */
111 	atomic_inc(&init_mm.mm_count);
112 	current->active_mm = &init_mm;
113 
114 	while(!smp_commenced)
115 		barrier();
116 
117 	local_flush_cache_all();
118 	local_flush_tlb_all();
119 
120 	local_irq_enable();
121 }
122 
123 extern void init_IRQ(void);
124 extern void cpu_panic(void);
125 
126 /*
127  *	Cycle through the processors asking the PROM to start each one.
128  */
129 
130 extern struct linux_prom_registers smp_penguin_ctable;
131 extern unsigned long trapbase_cpu1[];
132 extern unsigned long trapbase_cpu2[];
133 extern unsigned long trapbase_cpu3[];
134 
135 void __init smp4m_boot_cpus(void)
136 {
137 	int cpucount = 0;
138 	int i, mid;
139 
140 	printk("Entering SMP Mode...\n");
141 
142 	local_irq_enable();
143 	cpus_clear(cpu_present_map);
144 
145 	for (i = 0; !cpu_find_by_instance(i, NULL, &mid); i++)
146 		cpu_set(mid, cpu_present_map);
147 
148 	for(i=0; i < NR_CPUS; i++) {
149 		__cpu_number_map[i] = -1;
150 		__cpu_logical_map[i] = -1;
151 	}
152 
153 	__cpu_number_map[boot_cpu_id] = 0;
154 	__cpu_logical_map[0] = boot_cpu_id;
155 	current_thread_info()->cpu = boot_cpu_id;
156 
157 	smp_store_cpu_info(boot_cpu_id);
158 	set_irq_udt(boot_cpu_id);
159 	smp_setup_percpu_timer();
160 	local_flush_cache_all();
161 	if(cpu_find_by_instance(1, NULL, NULL))
162 		return;  /* Not an MP box. */
163 	for(i = 0; i < NR_CPUS; i++) {
164 		if(i == boot_cpu_id)
165 			continue;
166 
167 		if (cpu_isset(i, cpu_present_map)) {
168 			extern unsigned long sun4m_cpu_startup;
169 			unsigned long *entry = &sun4m_cpu_startup;
170 			struct task_struct *p;
171 			int timeout;
172 
173 			/* Cook up an idler for this guy. */
174 			p = fork_idle(i);
175 			cpucount++;
176 			current_set[i] = p->thread_info;
177 			/* See trampoline.S for details... */
178 			entry += ((i-1) * 3);
179 
180 			/*
181 			 * Initialize the contexts table
182 			 * Since the call to prom_startcpu() trashes the structure,
183 			 * we need to re-initialize it for each cpu
184 			 */
185 			smp_penguin_ctable.which_io = 0;
186 			smp_penguin_ctable.phys_addr = (unsigned int) srmmu_ctx_table_phys;
187 			smp_penguin_ctable.reg_size = 0;
188 
189 			/* whirrr, whirrr, whirrrrrrrrr... */
190 			printk("Starting CPU %d at %p\n", i, entry);
191 			local_flush_cache_all();
192 			prom_startcpu(cpu_data(i).prom_node,
193 				      &smp_penguin_ctable, 0, (char *)entry);
194 
195 			/* wheee... it's going... */
196 			for(timeout = 0; timeout < 10000; timeout++) {
197 				if(cpu_callin_map[i])
198 					break;
199 				udelay(200);
200 			}
201 			if(cpu_callin_map[i]) {
202 				/* Another "Red Snapper". */
203 				__cpu_number_map[i] = i;
204 				__cpu_logical_map[i] = i;
205 			} else {
206 				cpucount--;
207 				printk("Processor %d is stuck.\n", i);
208 			}
209 		}
210 		if(!(cpu_callin_map[i])) {
211 			cpu_clear(i, cpu_present_map);
212 			__cpu_number_map[i] = -1;
213 		}
214 	}
215 	local_flush_cache_all();
216 	if(cpucount == 0) {
217 		printk("Error: only one Processor found.\n");
218 		cpu_present_map = cpumask_of_cpu(smp_processor_id());
219 	} else {
220 		unsigned long bogosum = 0;
221 		for(i = 0; i < NR_CPUS; i++) {
222 			if (cpu_isset(i, cpu_present_map))
223 				bogosum += cpu_data(i).udelay_val;
224 		}
225 		printk("Total of %d Processors activated (%lu.%02lu BogoMIPS).\n",
226 		       cpucount + 1,
227 		       bogosum/(500000/HZ),
228 		       (bogosum/(5000/HZ))%100);
229 		smp_activated = 1;
230 		smp_num_cpus = cpucount + 1;
231 	}
232 
233 	/* Free unneeded trap tables */
234 	if (!cpu_isset(i, cpu_present_map)) {
235 		ClearPageReserved(virt_to_page(trapbase_cpu1));
236 		set_page_count(virt_to_page(trapbase_cpu1), 1);
237 		free_page((unsigned long)trapbase_cpu1);
238 		totalram_pages++;
239 		num_physpages++;
240 	}
241 	if (!cpu_isset(2, cpu_present_map)) {
242 		ClearPageReserved(virt_to_page(trapbase_cpu2));
243 		set_page_count(virt_to_page(trapbase_cpu2), 1);
244 		free_page((unsigned long)trapbase_cpu2);
245 		totalram_pages++;
246 		num_physpages++;
247 	}
248 	if (!cpu_isset(3, cpu_present_map)) {
249 		ClearPageReserved(virt_to_page(trapbase_cpu3));
250 		set_page_count(virt_to_page(trapbase_cpu3), 1);
251 		free_page((unsigned long)trapbase_cpu3);
252 		totalram_pages++;
253 		num_physpages++;
254 	}
255 
256 	/* Ok, they are spinning and ready to go. */
257 	smp_processors_ready = 1;
258 }
259 
260 /* At each hardware IRQ, we get this called to forward IRQ reception
261  * to the next processor.  The caller must disable the IRQ level being
262  * serviced globally so that there are no double interrupts received.
263  *
264  * XXX See sparc64 irq.c.
265  */
266 void smp4m_irq_rotate(int cpu)
267 {
268 }
269 
270 /* Cross calls, in order to work efficiently and atomically do all
271  * the message passing work themselves, only stopcpu and reschedule
272  * messages come through here.
273  */
274 void smp4m_message_pass(int target, int msg, unsigned long data, int wait)
275 {
276 	static unsigned long smp_cpu_in_msg[NR_CPUS];
277 	cpumask_t mask;
278 	int me = smp_processor_id();
279 	int irq, i;
280 
281 	if(msg == MSG_RESCHEDULE) {
282 		irq = IRQ_RESCHEDULE;
283 
284 		if(smp_cpu_in_msg[me])
285 			return;
286 	} else if(msg == MSG_STOP_CPU) {
287 		irq = IRQ_STOP_CPU;
288 	} else {
289 		goto barf;
290 	}
291 
292 	smp_cpu_in_msg[me]++;
293 	if(target == MSG_ALL_BUT_SELF || target == MSG_ALL) {
294 		mask = cpu_present_map;
295 		if(target == MSG_ALL_BUT_SELF)
296 			cpu_clear(me, mask);
297 		for(i = 0; i < 4; i++) {
298 			if (cpu_isset(i, mask))
299 				set_cpu_int(i, irq);
300 		}
301 	} else {
302 		set_cpu_int(target, irq);
303 	}
304 	smp_cpu_in_msg[me]--;
305 
306 	return;
307 barf:
308 	printk("Yeeee, trying to send SMP msg(%d) on cpu %d\n", msg, me);
309 	panic("Bogon SMP message pass.");
310 }
311 
312 static struct smp_funcall {
313 	smpfunc_t func;
314 	unsigned long arg1;
315 	unsigned long arg2;
316 	unsigned long arg3;
317 	unsigned long arg4;
318 	unsigned long arg5;
319 	unsigned long processors_in[NR_CPUS];  /* Set when ipi entered. */
320 	unsigned long processors_out[NR_CPUS]; /* Set when ipi exited. */
321 } ccall_info;
322 
323 static DEFINE_SPINLOCK(cross_call_lock);
324 
325 /* Cross calls must be serialized, at least currently. */
326 void smp4m_cross_call(smpfunc_t func, unsigned long arg1, unsigned long arg2,
327 		    unsigned long arg3, unsigned long arg4, unsigned long arg5)
328 {
329 	if(smp_processors_ready) {
330 		register int ncpus = smp_num_cpus;
331 		unsigned long flags;
332 
333 		spin_lock_irqsave(&cross_call_lock, flags);
334 
335 		/* Init function glue. */
336 		ccall_info.func = func;
337 		ccall_info.arg1 = arg1;
338 		ccall_info.arg2 = arg2;
339 		ccall_info.arg3 = arg3;
340 		ccall_info.arg4 = arg4;
341 		ccall_info.arg5 = arg5;
342 
343 		/* Init receive/complete mapping, plus fire the IPI's off. */
344 		{
345 			cpumask_t mask = cpu_present_map;
346 			register int i;
347 
348 			cpu_clear(smp_processor_id(), mask);
349 			for(i = 0; i < ncpus; i++) {
350 				if (cpu_isset(i, mask)) {
351 					ccall_info.processors_in[i] = 0;
352 					ccall_info.processors_out[i] = 0;
353 					set_cpu_int(i, IRQ_CROSS_CALL);
354 				} else {
355 					ccall_info.processors_in[i] = 1;
356 					ccall_info.processors_out[i] = 1;
357 				}
358 			}
359 		}
360 
361 		{
362 			register int i;
363 
364 			i = 0;
365 			do {
366 				while(!ccall_info.processors_in[i])
367 					barrier();
368 			} while(++i < ncpus);
369 
370 			i = 0;
371 			do {
372 				while(!ccall_info.processors_out[i])
373 					barrier();
374 			} while(++i < ncpus);
375 		}
376 
377 		spin_unlock_irqrestore(&cross_call_lock, flags);
378 	}
379 }
380 
381 /* Running cross calls. */
382 void smp4m_cross_call_irq(void)
383 {
384 	int i = smp_processor_id();
385 
386 	ccall_info.processors_in[i] = 1;
387 	ccall_info.func(ccall_info.arg1, ccall_info.arg2, ccall_info.arg3,
388 			ccall_info.arg4, ccall_info.arg5);
389 	ccall_info.processors_out[i] = 1;
390 }
391 
392 void smp4m_percpu_timer_interrupt(struct pt_regs *regs)
393 {
394 	int cpu = smp_processor_id();
395 
396 	clear_profile_irq(cpu);
397 
398 	profile_tick(CPU_PROFILING, regs);
399 
400 	if(!--prof_counter(cpu)) {
401 		int user = user_mode(regs);
402 
403 		irq_enter();
404 		update_process_times(user);
405 		irq_exit();
406 
407 		prof_counter(cpu) = prof_multiplier(cpu);
408 	}
409 }
410 
411 extern unsigned int lvl14_resolution;
412 
413 static void __init smp_setup_percpu_timer(void)
414 {
415 	int cpu = smp_processor_id();
416 
417 	prof_counter(cpu) = prof_multiplier(cpu) = 1;
418 	load_profile_irq(cpu, lvl14_resolution);
419 
420 	if(cpu == boot_cpu_id)
421 		enable_pil_irq(14);
422 }
423 
424 void __init smp4m_blackbox_id(unsigned *addr)
425 {
426 	int rd = *addr & 0x3e000000;
427 	int rs1 = rd >> 11;
428 
429 	addr[0] = 0x81580000 | rd;		/* rd %tbr, reg */
430 	addr[1] = 0x8130200c | rd | rs1;    	/* srl reg, 0xc, reg */
431 	addr[2] = 0x80082003 | rd | rs1;	/* and reg, 3, reg */
432 }
433 
434 void __init smp4m_blackbox_current(unsigned *addr)
435 {
436 	int rd = *addr & 0x3e000000;
437 	int rs1 = rd >> 11;
438 
439 	addr[0] = 0x81580000 | rd;		/* rd %tbr, reg */
440 	addr[2] = 0x8130200a | rd | rs1;    	/* srl reg, 0xa, reg */
441 	addr[4] = 0x8008200c | rd | rs1;	/* and reg, 3, reg */
442 }
443 
444 void __init sun4m_init_smp(void)
445 {
446 	BTFIXUPSET_BLACKBOX(hard_smp_processor_id, smp4m_blackbox_id);
447 	BTFIXUPSET_BLACKBOX(load_current, smp4m_blackbox_current);
448 	BTFIXUPSET_CALL(smp_cross_call, smp4m_cross_call, BTFIXUPCALL_NORM);
449 	BTFIXUPSET_CALL(smp_message_pass, smp4m_message_pass, BTFIXUPCALL_NORM);
450 	BTFIXUPSET_CALL(__hard_smp_processor_id, __smp4m_processor_id, BTFIXUPCALL_NORM);
451 }
452