xref: /openbmc/linux/arch/sparc/kernel/sun4m_smp.c (revision 643d1f7f)
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/interrupt.h>
13 #include <linux/kernel_stat.h>
14 #include <linux/init.h>
15 #include <linux/spinlock.h>
16 #include <linux/mm.h>
17 #include <linux/swap.h>
18 #include <linux/profile.h>
19 #include <asm/cacheflush.h>
20 #include <asm/tlbflush.h>
21 #include <asm/irq_regs.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 #include "irq.h"
35 
36 #define IRQ_RESCHEDULE		13
37 #define IRQ_STOP_CPU		14
38 #define IRQ_CROSS_CALL		15
39 
40 extern ctxd_t *srmmu_ctx_table_phys;
41 
42 extern void calibrate_delay(void);
43 
44 extern volatile unsigned long cpu_callin_map[NR_CPUS];
45 extern unsigned char boot_cpu_id;
46 
47 extern cpumask_t smp_commenced_mask;
48 
49 extern int __smp4m_processor_id(void);
50 
51 /*#define SMP_DEBUG*/
52 
53 #ifdef SMP_DEBUG
54 #define SMP_PRINTK(x)	printk x
55 #else
56 #define SMP_PRINTK(x)
57 #endif
58 
59 static inline unsigned long swap(volatile unsigned long *ptr, unsigned long val)
60 {
61 	__asm__ __volatile__("swap [%1], %0\n\t" :
62 			     "=&r" (val), "=&r" (ptr) :
63 			     "0" (val), "1" (ptr));
64 	return val;
65 }
66 
67 static void smp_setup_percpu_timer(void);
68 extern void cpu_probe(void);
69 
70 void __cpuinit smp4m_callin(void)
71 {
72 	int cpuid = hard_smp_processor_id();
73 
74 	local_flush_cache_all();
75 	local_flush_tlb_all();
76 
77 	/* Get our local ticker going. */
78 	smp_setup_percpu_timer();
79 
80 	calibrate_delay();
81 	smp_store_cpu_info(cpuid);
82 
83 	local_flush_cache_all();
84 	local_flush_tlb_all();
85 
86 	/*
87 	 * Unblock the master CPU _only_ when the scheduler state
88 	 * of all secondary CPUs will be up-to-date, so after
89 	 * the SMP initialization the master will be just allowed
90 	 * to call the scheduler code.
91 	 */
92 	/* Allow master to continue. */
93 	swap(&cpu_callin_map[cpuid], 1);
94 
95 	/* XXX: What's up with all the flushes? */
96 	local_flush_cache_all();
97 	local_flush_tlb_all();
98 
99 	cpu_probe();
100 
101 	/* Fix idle thread fields. */
102 	__asm__ __volatile__("ld [%0], %%g6\n\t"
103 			     : : "r" (&current_set[cpuid])
104 			     : "memory" /* paranoid */);
105 
106 	/* Attach to the address space of init_task. */
107 	atomic_inc(&init_mm.mm_count);
108 	current->active_mm = &init_mm;
109 
110 	while (!cpu_isset(cpuid, smp_commenced_mask))
111 		mb();
112 
113 	local_irq_enable();
114 
115 	cpu_set(cpuid, cpu_online_map);
116 }
117 
118 /*
119  *	Cycle through the processors asking the PROM to start each one.
120  */
121 
122 extern struct linux_prom_registers smp_penguin_ctable;
123 extern unsigned long trapbase_cpu1[];
124 extern unsigned long trapbase_cpu2[];
125 extern unsigned long trapbase_cpu3[];
126 
127 void __init smp4m_boot_cpus(void)
128 {
129 	smp_setup_percpu_timer();
130 	local_flush_cache_all();
131 }
132 
133 int __cpuinit smp4m_boot_one_cpu(int i)
134 {
135 	extern unsigned long sun4m_cpu_startup;
136 	unsigned long *entry = &sun4m_cpu_startup;
137 	struct task_struct *p;
138 	int timeout;
139 	int cpu_node;
140 
141 	cpu_find_by_mid(i, &cpu_node);
142 
143 	/* Cook up an idler for this guy. */
144 	p = fork_idle(i);
145 	current_set[i] = task_thread_info(p);
146 	/* See trampoline.S for details... */
147 	entry += ((i-1) * 3);
148 
149 	/*
150 	 * Initialize the contexts table
151 	 * Since the call to prom_startcpu() trashes the structure,
152 	 * we need to re-initialize it for each cpu
153 	 */
154 	smp_penguin_ctable.which_io = 0;
155 	smp_penguin_ctable.phys_addr = (unsigned int) srmmu_ctx_table_phys;
156 	smp_penguin_ctable.reg_size = 0;
157 
158 	/* whirrr, whirrr, whirrrrrrrrr... */
159 	printk("Starting CPU %d at %p\n", i, entry);
160 	local_flush_cache_all();
161 	prom_startcpu(cpu_node,
162 		      &smp_penguin_ctable, 0, (char *)entry);
163 
164 	/* wheee... it's going... */
165 	for(timeout = 0; timeout < 10000; timeout++) {
166 		if(cpu_callin_map[i])
167 			break;
168 		udelay(200);
169 	}
170 
171 	if (!(cpu_callin_map[i])) {
172 		printk("Processor %d is stuck.\n", i);
173 		return -ENODEV;
174 	}
175 
176 	local_flush_cache_all();
177 	return 0;
178 }
179 
180 void __init smp4m_smp_done(void)
181 {
182 	int i, first;
183 	int *prev;
184 
185 	/* setup cpu list for irq rotation */
186 	first = 0;
187 	prev = &first;
188 	for (i = 0; i < NR_CPUS; i++) {
189 		if (cpu_online(i)) {
190 			*prev = i;
191 			prev = &cpu_data(i).next;
192 		}
193 	}
194 	*prev = first;
195 	local_flush_cache_all();
196 
197 	/* Free unneeded trap tables */
198 	if (!cpu_isset(1, cpu_present_map)) {
199 		ClearPageReserved(virt_to_page(trapbase_cpu1));
200 		init_page_count(virt_to_page(trapbase_cpu1));
201 		free_page((unsigned long)trapbase_cpu1);
202 		totalram_pages++;
203 		num_physpages++;
204 	}
205 	if (!cpu_isset(2, cpu_present_map)) {
206 		ClearPageReserved(virt_to_page(trapbase_cpu2));
207 		init_page_count(virt_to_page(trapbase_cpu2));
208 		free_page((unsigned long)trapbase_cpu2);
209 		totalram_pages++;
210 		num_physpages++;
211 	}
212 	if (!cpu_isset(3, cpu_present_map)) {
213 		ClearPageReserved(virt_to_page(trapbase_cpu3));
214 		init_page_count(virt_to_page(trapbase_cpu3));
215 		free_page((unsigned long)trapbase_cpu3);
216 		totalram_pages++;
217 		num_physpages++;
218 	}
219 
220 	/* Ok, they are spinning and ready to go. */
221 }
222 
223 /* At each hardware IRQ, we get this called to forward IRQ reception
224  * to the next processor.  The caller must disable the IRQ level being
225  * serviced globally so that there are no double interrupts received.
226  *
227  * XXX See sparc64 irq.c.
228  */
229 void smp4m_irq_rotate(int cpu)
230 {
231 	int next = cpu_data(cpu).next;
232 	if (next != cpu)
233 		set_irq_udt(next);
234 }
235 
236 /* Cross calls, in order to work efficiently and atomically do all
237  * the message passing work themselves, only stopcpu and reschedule
238  * messages come through here.
239  */
240 void smp4m_message_pass(int target, int msg, unsigned long data, int wait)
241 {
242 	static unsigned long smp_cpu_in_msg[NR_CPUS];
243 	cpumask_t mask;
244 	int me = smp_processor_id();
245 	int irq, i;
246 
247 	if(msg == MSG_RESCHEDULE) {
248 		irq = IRQ_RESCHEDULE;
249 
250 		if(smp_cpu_in_msg[me])
251 			return;
252 	} else if(msg == MSG_STOP_CPU) {
253 		irq = IRQ_STOP_CPU;
254 	} else {
255 		goto barf;
256 	}
257 
258 	smp_cpu_in_msg[me]++;
259 	if(target == MSG_ALL_BUT_SELF || target == MSG_ALL) {
260 		mask = cpu_online_map;
261 		if(target == MSG_ALL_BUT_SELF)
262 			cpu_clear(me, mask);
263 		for(i = 0; i < 4; i++) {
264 			if (cpu_isset(i, mask))
265 				set_cpu_int(i, irq);
266 		}
267 	} else {
268 		set_cpu_int(target, irq);
269 	}
270 	smp_cpu_in_msg[me]--;
271 
272 	return;
273 barf:
274 	printk("Yeeee, trying to send SMP msg(%d) on cpu %d\n", msg, me);
275 	panic("Bogon SMP message pass.");
276 }
277 
278 static struct smp_funcall {
279 	smpfunc_t func;
280 	unsigned long arg1;
281 	unsigned long arg2;
282 	unsigned long arg3;
283 	unsigned long arg4;
284 	unsigned long arg5;
285 	unsigned long processors_in[SUN4M_NCPUS];  /* Set when ipi entered. */
286 	unsigned long processors_out[SUN4M_NCPUS]; /* Set when ipi exited. */
287 } ccall_info;
288 
289 static DEFINE_SPINLOCK(cross_call_lock);
290 
291 /* Cross calls must be serialized, at least currently. */
292 void smp4m_cross_call(smpfunc_t func, unsigned long arg1, unsigned long arg2,
293 		    unsigned long arg3, unsigned long arg4, unsigned long arg5)
294 {
295 		register int ncpus = SUN4M_NCPUS;
296 		unsigned long flags;
297 
298 		spin_lock_irqsave(&cross_call_lock, flags);
299 
300 		/* Init function glue. */
301 		ccall_info.func = func;
302 		ccall_info.arg1 = arg1;
303 		ccall_info.arg2 = arg2;
304 		ccall_info.arg3 = arg3;
305 		ccall_info.arg4 = arg4;
306 		ccall_info.arg5 = arg5;
307 
308 		/* Init receive/complete mapping, plus fire the IPI's off. */
309 		{
310 			cpumask_t mask = cpu_online_map;
311 			register int i;
312 
313 			cpu_clear(smp_processor_id(), mask);
314 			for(i = 0; i < ncpus; i++) {
315 				if (cpu_isset(i, mask)) {
316 					ccall_info.processors_in[i] = 0;
317 					ccall_info.processors_out[i] = 0;
318 					set_cpu_int(i, IRQ_CROSS_CALL);
319 				} else {
320 					ccall_info.processors_in[i] = 1;
321 					ccall_info.processors_out[i] = 1;
322 				}
323 			}
324 		}
325 
326 		{
327 			register int i;
328 
329 			i = 0;
330 			do {
331 				while(!ccall_info.processors_in[i])
332 					barrier();
333 			} while(++i < ncpus);
334 
335 			i = 0;
336 			do {
337 				while(!ccall_info.processors_out[i])
338 					barrier();
339 			} while(++i < ncpus);
340 		}
341 
342 		spin_unlock_irqrestore(&cross_call_lock, flags);
343 }
344 
345 /* Running cross calls. */
346 void smp4m_cross_call_irq(void)
347 {
348 	int i = smp_processor_id();
349 
350 	ccall_info.processors_in[i] = 1;
351 	ccall_info.func(ccall_info.arg1, ccall_info.arg2, ccall_info.arg3,
352 			ccall_info.arg4, ccall_info.arg5);
353 	ccall_info.processors_out[i] = 1;
354 }
355 
356 void smp4m_percpu_timer_interrupt(struct pt_regs *regs)
357 {
358 	struct pt_regs *old_regs;
359 	int cpu = smp_processor_id();
360 
361 	old_regs = set_irq_regs(regs);
362 
363 	clear_profile_irq(cpu);
364 
365 	profile_tick(CPU_PROFILING);
366 
367 	if(!--prof_counter(cpu)) {
368 		int user = user_mode(regs);
369 
370 		irq_enter();
371 		update_process_times(user);
372 		irq_exit();
373 
374 		prof_counter(cpu) = prof_multiplier(cpu);
375 	}
376 	set_irq_regs(old_regs);
377 }
378 
379 extern unsigned int lvl14_resolution;
380 
381 static void __init smp_setup_percpu_timer(void)
382 {
383 	int cpu = smp_processor_id();
384 
385 	prof_counter(cpu) = prof_multiplier(cpu) = 1;
386 	load_profile_irq(cpu, lvl14_resolution);
387 
388 	if(cpu == boot_cpu_id)
389 		enable_pil_irq(14);
390 }
391 
392 void __init smp4m_blackbox_id(unsigned *addr)
393 {
394 	int rd = *addr & 0x3e000000;
395 	int rs1 = rd >> 11;
396 
397 	addr[0] = 0x81580000 | rd;		/* rd %tbr, reg */
398 	addr[1] = 0x8130200c | rd | rs1;    	/* srl reg, 0xc, reg */
399 	addr[2] = 0x80082003 | rd | rs1;	/* and reg, 3, reg */
400 }
401 
402 void __init smp4m_blackbox_current(unsigned *addr)
403 {
404 	int rd = *addr & 0x3e000000;
405 	int rs1 = rd >> 11;
406 
407 	addr[0] = 0x81580000 | rd;		/* rd %tbr, reg */
408 	addr[2] = 0x8130200a | rd | rs1;    	/* srl reg, 0xa, reg */
409 	addr[4] = 0x8008200c | rd | rs1;	/* and reg, 0xc, reg */
410 }
411 
412 void __init sun4m_init_smp(void)
413 {
414 	BTFIXUPSET_BLACKBOX(hard_smp_processor_id, smp4m_blackbox_id);
415 	BTFIXUPSET_BLACKBOX(load_current, smp4m_blackbox_current);
416 	BTFIXUPSET_CALL(smp_cross_call, smp4m_cross_call, BTFIXUPCALL_NORM);
417 	BTFIXUPSET_CALL(smp_message_pass, smp4m_message_pass, BTFIXUPCALL_NORM);
418 	BTFIXUPSET_CALL(__hard_smp_processor_id, __smp4m_processor_id, BTFIXUPCALL_NORM);
419 }
420