xref: /openbmc/linux/arch/sparc/kernel/leon_smp.c (revision 75f25bd3)
1 /* leon_smp.c: Sparc-Leon SMP support.
2  *
3  * based on sun4m_smp.c
4  * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
5  * Copyright (C) 2009 Daniel Hellstrom (daniel@gaisler.com) Aeroflex Gaisler AB
6  * Copyright (C) 2009 Konrad Eisele (konrad@gaisler.com) Aeroflex Gaisler AB
7  */
8 
9 #include <asm/head.h>
10 
11 #include <linux/kernel.h>
12 #include <linux/sched.h>
13 #include <linux/threads.h>
14 #include <linux/smp.h>
15 #include <linux/interrupt.h>
16 #include <linux/kernel_stat.h>
17 #include <linux/of.h>
18 #include <linux/init.h>
19 #include <linux/spinlock.h>
20 #include <linux/mm.h>
21 #include <linux/swap.h>
22 #include <linux/profile.h>
23 #include <linux/pm.h>
24 #include <linux/delay.h>
25 #include <linux/gfp.h>
26 
27 #include <asm/cacheflush.h>
28 #include <asm/tlbflush.h>
29 
30 #include <asm/ptrace.h>
31 #include <linux/atomic.h>
32 #include <asm/irq_regs.h>
33 #include <asm/traps.h>
34 
35 #include <asm/delay.h>
36 #include <asm/irq.h>
37 #include <asm/page.h>
38 #include <asm/pgalloc.h>
39 #include <asm/pgtable.h>
40 #include <asm/oplib.h>
41 #include <asm/cpudata.h>
42 #include <asm/asi.h>
43 #include <asm/leon.h>
44 #include <asm/leon_amba.h>
45 
46 #include "kernel.h"
47 
48 #ifdef CONFIG_SPARC_LEON
49 
50 #include "irq.h"
51 
52 extern ctxd_t *srmmu_ctx_table_phys;
53 static int smp_processors_ready;
54 extern volatile unsigned long cpu_callin_map[NR_CPUS];
55 extern cpumask_t smp_commenced_mask;
56 void __init leon_configure_cache_smp(void);
57 static void leon_ipi_init(void);
58 
59 /* IRQ number of LEON IPIs */
60 int leon_ipi_irq = LEON3_IRQ_IPI_DEFAULT;
61 
62 static inline unsigned long do_swap(volatile unsigned long *ptr,
63 				    unsigned long val)
64 {
65 	__asm__ __volatile__("swapa [%2] %3, %0\n\t" : "=&r"(val)
66 			     : "0"(val), "r"(ptr), "i"(ASI_LEON_DCACHE_MISS)
67 			     : "memory");
68 	return val;
69 }
70 
71 static void smp_setup_percpu_timer(void);
72 
73 void __cpuinit leon_callin(void)
74 {
75 	int cpuid = hard_smpleon_processor_id();
76 
77 	local_flush_cache_all();
78 	local_flush_tlb_all();
79 	leon_configure_cache_smp();
80 
81 	/* Get our local ticker going. */
82 	smp_setup_percpu_timer();
83 
84 	calibrate_delay();
85 	smp_store_cpu_info(cpuid);
86 
87 	local_flush_cache_all();
88 	local_flush_tlb_all();
89 
90 	/*
91 	 * Unblock the master CPU _only_ when the scheduler state
92 	 * of all secondary CPUs will be up-to-date, so after
93 	 * the SMP initialization the master will be just allowed
94 	 * to call the scheduler code.
95 	 * Allow master to continue.
96 	 */
97 	do_swap(&cpu_callin_map[cpuid], 1);
98 
99 	local_flush_cache_all();
100 	local_flush_tlb_all();
101 
102 	/* Fix idle thread fields. */
103 	__asm__ __volatile__("ld [%0], %%g6\n\t" : : "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 (!cpumask_test_cpu(cpuid, &smp_commenced_mask))
111 		mb();
112 
113 	local_irq_enable();
114 	set_cpu_online(cpuid, true);
115 }
116 
117 /*
118  *	Cycle through the processors asking the PROM to start each one.
119  */
120 
121 extern struct linux_prom_registers smp_penguin_ctable;
122 
123 void __init leon_configure_cache_smp(void)
124 {
125 	unsigned long cfg = sparc_leon3_get_dcachecfg();
126 	int me = smp_processor_id();
127 
128 	if (ASI_LEON3_SYSCTRL_CFG_SSIZE(cfg) > 4) {
129 		printk(KERN_INFO "Note: SMP with snooping only works on 4k cache, found %dk(0x%x) on cpu %d, disabling caches\n",
130 		     (unsigned int)ASI_LEON3_SYSCTRL_CFG_SSIZE(cfg),
131 		     (unsigned int)cfg, (unsigned int)me);
132 		sparc_leon3_disable_cache();
133 	} else {
134 		if (cfg & ASI_LEON3_SYSCTRL_CFG_SNOOPING) {
135 			sparc_leon3_enable_snooping();
136 		} else {
137 			printk(KERN_INFO "Note: You have to enable snooping in the vhdl model cpu %d, disabling caches\n",
138 			     me);
139 			sparc_leon3_disable_cache();
140 		}
141 	}
142 
143 	local_flush_cache_all();
144 	local_flush_tlb_all();
145 }
146 
147 void leon_smp_setbroadcast(unsigned int mask)
148 {
149 	int broadcast =
150 	    ((LEON3_BYPASS_LOAD_PA(&(leon3_irqctrl_regs->mpstatus)) >>
151 	      LEON3_IRQMPSTATUS_BROADCAST) & 1);
152 	if (!broadcast) {
153 		prom_printf("######## !!!! The irqmp-ctrl must have broadcast enabled, smp wont work !!!!! ####### nr cpus: %d\n",
154 		     leon_smp_nrcpus());
155 		if (leon_smp_nrcpus() > 1) {
156 			BUG();
157 		} else {
158 			prom_printf("continue anyway\n");
159 			return;
160 		}
161 	}
162 	LEON_BYPASS_STORE_PA(&(leon3_irqctrl_regs->mpbroadcast), mask);
163 }
164 
165 unsigned int leon_smp_getbroadcast(void)
166 {
167 	unsigned int mask;
168 	mask = LEON_BYPASS_LOAD_PA(&(leon3_irqctrl_regs->mpbroadcast));
169 	return mask;
170 }
171 
172 int leon_smp_nrcpus(void)
173 {
174 	int nrcpu =
175 	    ((LEON3_BYPASS_LOAD_PA(&(leon3_irqctrl_regs->mpstatus)) >>
176 	      LEON3_IRQMPSTATUS_CPUNR) & 0xf) + 1;
177 	return nrcpu;
178 }
179 
180 void __init leon_boot_cpus(void)
181 {
182 	int nrcpu = leon_smp_nrcpus();
183 	int me = smp_processor_id();
184 
185 	/* Setup IPI */
186 	leon_ipi_init();
187 
188 	printk(KERN_INFO "%d:(%d:%d) cpus mpirq at 0x%x\n", (unsigned int)me,
189 	       (unsigned int)nrcpu, (unsigned int)NR_CPUS,
190 	       (unsigned int)&(leon3_irqctrl_regs->mpstatus));
191 
192 	leon_enable_irq_cpu(LEON3_IRQ_CROSS_CALL, me);
193 	leon_enable_irq_cpu(LEON3_IRQ_TICKER, me);
194 	leon_enable_irq_cpu(leon_ipi_irq, me);
195 
196 	leon_smp_setbroadcast(1 << LEON3_IRQ_TICKER);
197 
198 	leon_configure_cache_smp();
199 	smp_setup_percpu_timer();
200 	local_flush_cache_all();
201 
202 }
203 
204 int __cpuinit leon_boot_one_cpu(int i)
205 {
206 
207 	struct task_struct *p;
208 	int timeout;
209 
210 	/* Cook up an idler for this guy. */
211 	p = fork_idle(i);
212 
213 	current_set[i] = task_thread_info(p);
214 
215 	/* See trampoline.S:leon_smp_cpu_startup for details...
216 	 * Initialize the contexts table
217 	 * Since the call to prom_startcpu() trashes the structure,
218 	 * we need to re-initialize it for each cpu
219 	 */
220 	smp_penguin_ctable.which_io = 0;
221 	smp_penguin_ctable.phys_addr = (unsigned int)srmmu_ctx_table_phys;
222 	smp_penguin_ctable.reg_size = 0;
223 
224 	/* whirrr, whirrr, whirrrrrrrrr... */
225 	printk(KERN_INFO "Starting CPU %d : (irqmp: 0x%x)\n", (unsigned int)i,
226 	       (unsigned int)&leon3_irqctrl_regs->mpstatus);
227 	local_flush_cache_all();
228 
229 	/* Make sure all IRQs are of from the start for this new CPU */
230 	LEON_BYPASS_STORE_PA(&leon3_irqctrl_regs->mask[i], 0);
231 
232 	/* Wake one CPU */
233 	LEON_BYPASS_STORE_PA(&(leon3_irqctrl_regs->mpstatus), 1 << i);
234 
235 	/* wheee... it's going... */
236 	for (timeout = 0; timeout < 10000; timeout++) {
237 		if (cpu_callin_map[i])
238 			break;
239 		udelay(200);
240 	}
241 	printk(KERN_INFO "Started CPU %d\n", (unsigned int)i);
242 
243 	if (!(cpu_callin_map[i])) {
244 		printk(KERN_ERR "Processor %d is stuck.\n", i);
245 		return -ENODEV;
246 	} else {
247 		leon_enable_irq_cpu(LEON3_IRQ_CROSS_CALL, i);
248 		leon_enable_irq_cpu(LEON3_IRQ_TICKER, i);
249 		leon_enable_irq_cpu(leon_ipi_irq, i);
250 	}
251 
252 	local_flush_cache_all();
253 	return 0;
254 }
255 
256 void __init leon_smp_done(void)
257 {
258 
259 	int i, first;
260 	int *prev;
261 
262 	/* setup cpu list for irq rotation */
263 	first = 0;
264 	prev = &first;
265 	for (i = 0; i < NR_CPUS; i++) {
266 		if (cpu_online(i)) {
267 			*prev = i;
268 			prev = &cpu_data(i).next;
269 		}
270 	}
271 	*prev = first;
272 	local_flush_cache_all();
273 
274 	/* Free unneeded trap tables */
275 	if (!cpu_present(1)) {
276 		ClearPageReserved(virt_to_page(&trapbase_cpu1));
277 		init_page_count(virt_to_page(&trapbase_cpu1));
278 		free_page((unsigned long)&trapbase_cpu1);
279 		totalram_pages++;
280 		num_physpages++;
281 	}
282 	if (!cpu_present(2)) {
283 		ClearPageReserved(virt_to_page(&trapbase_cpu2));
284 		init_page_count(virt_to_page(&trapbase_cpu2));
285 		free_page((unsigned long)&trapbase_cpu2);
286 		totalram_pages++;
287 		num_physpages++;
288 	}
289 	if (!cpu_present(3)) {
290 		ClearPageReserved(virt_to_page(&trapbase_cpu3));
291 		init_page_count(virt_to_page(&trapbase_cpu3));
292 		free_page((unsigned long)&trapbase_cpu3);
293 		totalram_pages++;
294 		num_physpages++;
295 	}
296 	/* Ok, they are spinning and ready to go. */
297 	smp_processors_ready = 1;
298 
299 }
300 
301 void leon_irq_rotate(int cpu)
302 {
303 }
304 
305 struct leon_ipi_work {
306 	int single;
307 	int msk;
308 	int resched;
309 };
310 
311 static DEFINE_PER_CPU_SHARED_ALIGNED(struct leon_ipi_work, leon_ipi_work);
312 
313 /* Initialize IPIs on the LEON, in order to save IRQ resources only one IRQ
314  * is used for all three types of IPIs.
315  */
316 static void __init leon_ipi_init(void)
317 {
318 	int cpu, len;
319 	struct leon_ipi_work *work;
320 	struct property *pp;
321 	struct device_node *rootnp;
322 	struct tt_entry *trap_table;
323 	unsigned long flags;
324 
325 	/* Find IPI IRQ or stick with default value */
326 	rootnp = of_find_node_by_path("/ambapp0");
327 	if (rootnp) {
328 		pp = of_find_property(rootnp, "ipi_num", &len);
329 		if (pp && (*(int *)pp->value))
330 			leon_ipi_irq = *(int *)pp->value;
331 	}
332 	printk(KERN_INFO "leon: SMP IPIs at IRQ %d\n", leon_ipi_irq);
333 
334 	/* Adjust so that we jump directly to smpleon_ipi */
335 	local_irq_save(flags);
336 	trap_table = &sparc_ttable[SP_TRAP_IRQ1 + (leon_ipi_irq - 1)];
337 	trap_table->inst_three += smpleon_ipi - real_irq_entry;
338 	local_flush_cache_all();
339 	local_irq_restore(flags);
340 
341 	for_each_possible_cpu(cpu) {
342 		work = &per_cpu(leon_ipi_work, cpu);
343 		work->single = work->msk = work->resched = 0;
344 	}
345 }
346 
347 static void leon_ipi_single(int cpu)
348 {
349 	struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
350 
351 	/* Mark work */
352 	work->single = 1;
353 
354 	/* Generate IRQ on the CPU */
355 	set_cpu_int(cpu, leon_ipi_irq);
356 }
357 
358 static void leon_ipi_mask_one(int cpu)
359 {
360 	struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
361 
362 	/* Mark work */
363 	work->msk = 1;
364 
365 	/* Generate IRQ on the CPU */
366 	set_cpu_int(cpu, leon_ipi_irq);
367 }
368 
369 static void leon_ipi_resched(int cpu)
370 {
371 	struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
372 
373 	/* Mark work */
374 	work->resched = 1;
375 
376 	/* Generate IRQ on the CPU (any IRQ will cause resched) */
377 	set_cpu_int(cpu, leon_ipi_irq);
378 }
379 
380 void leonsmp_ipi_interrupt(void)
381 {
382 	struct leon_ipi_work *work = &__get_cpu_var(leon_ipi_work);
383 
384 	if (work->single) {
385 		work->single = 0;
386 		smp_call_function_single_interrupt();
387 	}
388 	if (work->msk) {
389 		work->msk = 0;
390 		smp_call_function_interrupt();
391 	}
392 	if (work->resched) {
393 		work->resched = 0;
394 		smp_resched_interrupt();
395 	}
396 }
397 
398 static struct smp_funcall {
399 	smpfunc_t func;
400 	unsigned long arg1;
401 	unsigned long arg2;
402 	unsigned long arg3;
403 	unsigned long arg4;
404 	unsigned long arg5;
405 	unsigned long processors_in[NR_CPUS];	/* Set when ipi entered. */
406 	unsigned long processors_out[NR_CPUS];	/* Set when ipi exited. */
407 } ccall_info;
408 
409 static DEFINE_SPINLOCK(cross_call_lock);
410 
411 /* Cross calls must be serialized, at least currently. */
412 static void leon_cross_call(smpfunc_t func, cpumask_t mask, unsigned long arg1,
413 			    unsigned long arg2, unsigned long arg3,
414 			    unsigned long arg4)
415 {
416 	if (smp_processors_ready) {
417 		register int high = NR_CPUS - 1;
418 		unsigned long flags;
419 
420 		spin_lock_irqsave(&cross_call_lock, flags);
421 
422 		{
423 			/* If you make changes here, make sure gcc generates proper code... */
424 			register smpfunc_t f asm("i0") = func;
425 			register unsigned long a1 asm("i1") = arg1;
426 			register unsigned long a2 asm("i2") = arg2;
427 			register unsigned long a3 asm("i3") = arg3;
428 			register unsigned long a4 asm("i4") = arg4;
429 			register unsigned long a5 asm("i5") = 0;
430 
431 			__asm__ __volatile__("std %0, [%6]\n\t"
432 					     "std %2, [%6 + 8]\n\t"
433 					     "std %4, [%6 + 16]\n\t" : :
434 					     "r"(f), "r"(a1), "r"(a2), "r"(a3),
435 					     "r"(a4), "r"(a5),
436 					     "r"(&ccall_info.func));
437 		}
438 
439 		/* Init receive/complete mapping, plus fire the IPI's off. */
440 		{
441 			register int i;
442 
443 			cpumask_clear_cpu(smp_processor_id(), &mask);
444 			cpumask_and(&mask, cpu_online_mask, &mask);
445 			for (i = 0; i <= high; i++) {
446 				if (cpumask_test_cpu(i, &mask)) {
447 					ccall_info.processors_in[i] = 0;
448 					ccall_info.processors_out[i] = 0;
449 					set_cpu_int(i, LEON3_IRQ_CROSS_CALL);
450 
451 				}
452 			}
453 		}
454 
455 		{
456 			register int i;
457 
458 			i = 0;
459 			do {
460 				if (!cpumask_test_cpu(i, &mask))
461 					continue;
462 
463 				while (!ccall_info.processors_in[i])
464 					barrier();
465 			} while (++i <= high);
466 
467 			i = 0;
468 			do {
469 				if (!cpumask_test_cpu(i, &mask))
470 					continue;
471 
472 				while (!ccall_info.processors_out[i])
473 					barrier();
474 			} while (++i <= high);
475 		}
476 
477 		spin_unlock_irqrestore(&cross_call_lock, flags);
478 	}
479 }
480 
481 /* Running cross calls. */
482 void leon_cross_call_irq(void)
483 {
484 	int i = smp_processor_id();
485 
486 	ccall_info.processors_in[i] = 1;
487 	ccall_info.func(ccall_info.arg1, ccall_info.arg2, ccall_info.arg3,
488 			ccall_info.arg4, ccall_info.arg5);
489 	ccall_info.processors_out[i] = 1;
490 }
491 
492 irqreturn_t leon_percpu_timer_interrupt(int irq, void *unused)
493 {
494 	int cpu = smp_processor_id();
495 
496 	leon_clear_profile_irq(cpu);
497 
498 	profile_tick(CPU_PROFILING);
499 
500 	if (!--prof_counter(cpu)) {
501 		int user = user_mode(get_irq_regs());
502 
503 		update_process_times(user);
504 
505 		prof_counter(cpu) = prof_multiplier(cpu);
506 	}
507 
508 	return IRQ_HANDLED;
509 }
510 
511 static void __init smp_setup_percpu_timer(void)
512 {
513 	int cpu = smp_processor_id();
514 
515 	prof_counter(cpu) = prof_multiplier(cpu) = 1;
516 }
517 
518 void __init leon_blackbox_id(unsigned *addr)
519 {
520 	int rd = *addr & 0x3e000000;
521 	int rs1 = rd >> 11;
522 
523 	/* patch places where ___b_hard_smp_processor_id appears */
524 	addr[0] = 0x81444000 | rd;	/* rd %asr17, reg */
525 	addr[1] = 0x8130201c | rd | rs1;	/* srl reg, 0x1c, reg */
526 	addr[2] = 0x01000000;	/* nop */
527 }
528 
529 void __init leon_blackbox_current(unsigned *addr)
530 {
531 	int rd = *addr & 0x3e000000;
532 	int rs1 = rd >> 11;
533 
534 	/* patch LOAD_CURRENT macro where ___b_load_current appears */
535 	addr[0] = 0x81444000 | rd;	/* rd %asr17, reg */
536 	addr[2] = 0x8130201c | rd | rs1;	/* srl reg, 0x1c, reg */
537 	addr[4] = 0x81282002 | rd | rs1;	/* sll reg, 0x2, reg */
538 
539 }
540 
541 void __init leon_init_smp(void)
542 {
543 	/* Patch ipi15 trap table */
544 	t_nmi[1] = t_nmi[1] + (linux_trap_ipi15_leon - linux_trap_ipi15_sun4m);
545 
546 	BTFIXUPSET_BLACKBOX(hard_smp_processor_id, leon_blackbox_id);
547 	BTFIXUPSET_BLACKBOX(load_current, leon_blackbox_current);
548 	BTFIXUPSET_CALL(smp_cross_call, leon_cross_call, BTFIXUPCALL_NORM);
549 	BTFIXUPSET_CALL(__hard_smp_processor_id, __leon_processor_id,
550 			BTFIXUPCALL_NORM);
551 	BTFIXUPSET_CALL(smp_ipi_resched, leon_ipi_resched, BTFIXUPCALL_NORM);
552 	BTFIXUPSET_CALL(smp_ipi_single, leon_ipi_single, BTFIXUPCALL_NORM);
553 	BTFIXUPSET_CALL(smp_ipi_mask_one, leon_ipi_mask_one, BTFIXUPCALL_NORM);
554 }
555 
556 #endif /* CONFIG_SPARC_LEON */
557