xref: /linux/arch/sparc/kernel/leon_smp.c (revision 71ca97da9d027009d318d319cbacf54a72f666c1)
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 #include <linux/cpu.h>
27 #include <linux/clockchips.h>
28 
29 #include <asm/cacheflush.h>
30 #include <asm/tlbflush.h>
31 
32 #include <asm/ptrace.h>
33 #include <linux/atomic.h>
34 #include <asm/irq_regs.h>
35 #include <asm/traps.h>
36 
37 #include <asm/delay.h>
38 #include <asm/irq.h>
39 #include <asm/page.h>
40 #include <asm/pgalloc.h>
41 #include <asm/pgtable.h>
42 #include <asm/oplib.h>
43 #include <asm/cpudata.h>
44 #include <asm/asi.h>
45 #include <asm/leon.h>
46 #include <asm/leon_amba.h>
47 #include <asm/timer.h>
48 
49 #include "kernel.h"
50 
51 #ifdef CONFIG_SPARC_LEON
52 
53 #include "irq.h"
54 
55 extern ctxd_t *srmmu_ctx_table_phys;
56 static int smp_processors_ready;
57 extern volatile unsigned long cpu_callin_map[NR_CPUS];
58 extern cpumask_t smp_commenced_mask;
59 void __init leon_configure_cache_smp(void);
60 static void leon_ipi_init(void);
61 
62 /* IRQ number of LEON IPIs */
63 int leon_ipi_irq = LEON3_IRQ_IPI_DEFAULT;
64 
65 static inline unsigned long do_swap(volatile unsigned long *ptr,
66 				    unsigned long val)
67 {
68 	__asm__ __volatile__("swapa [%2] %3, %0\n\t" : "=&r"(val)
69 			     : "0"(val), "r"(ptr), "i"(ASI_LEON_DCACHE_MISS)
70 			     : "memory");
71 	return val;
72 }
73 
74 void __cpuinit leon_callin(void)
75 {
76 	int cpuid = hard_smp_processor_id();
77 
78 	local_ops->cache_all();
79 	local_ops->tlb_all();
80 	leon_configure_cache_smp();
81 
82 	notify_cpu_starting(cpuid);
83 
84 	/* Get our local ticker going. */
85 	register_percpu_ce(cpuid);
86 
87 	calibrate_delay();
88 	smp_store_cpu_info(cpuid);
89 
90 	local_ops->cache_all();
91 	local_ops->tlb_all();
92 
93 	/*
94 	 * Unblock the master CPU _only_ when the scheduler state
95 	 * of all secondary CPUs will be up-to-date, so after
96 	 * the SMP initialization the master will be just allowed
97 	 * to call the scheduler code.
98 	 * Allow master to continue.
99 	 */
100 	do_swap(&cpu_callin_map[cpuid], 1);
101 
102 	local_ops->cache_all();
103 	local_ops->tlb_all();
104 
105 	/* Fix idle thread fields. */
106 	__asm__ __volatile__("ld [%0], %%g6\n\t" : : "r"(&current_set[cpuid])
107 			     : "memory" /* paranoid */);
108 
109 	/* Attach to the address space of init_task. */
110 	atomic_inc(&init_mm.mm_count);
111 	current->active_mm = &init_mm;
112 
113 	while (!cpumask_test_cpu(cpuid, &smp_commenced_mask))
114 		mb();
115 
116 	local_irq_enable();
117 	set_cpu_online(cpuid, true);
118 }
119 
120 /*
121  *	Cycle through the processors asking the PROM to start each one.
122  */
123 
124 extern struct linux_prom_registers smp_penguin_ctable;
125 
126 void __init leon_configure_cache_smp(void)
127 {
128 	unsigned long cfg = sparc_leon3_get_dcachecfg();
129 	int me = smp_processor_id();
130 
131 	if (ASI_LEON3_SYSCTRL_CFG_SSIZE(cfg) > 4) {
132 		printk(KERN_INFO "Note: SMP with snooping only works on 4k cache, found %dk(0x%x) on cpu %d, disabling caches\n",
133 		     (unsigned int)ASI_LEON3_SYSCTRL_CFG_SSIZE(cfg),
134 		     (unsigned int)cfg, (unsigned int)me);
135 		sparc_leon3_disable_cache();
136 	} else {
137 		if (cfg & ASI_LEON3_SYSCTRL_CFG_SNOOPING) {
138 			sparc_leon3_enable_snooping();
139 		} else {
140 			printk(KERN_INFO "Note: You have to enable snooping in the vhdl model cpu %d, disabling caches\n",
141 			     me);
142 			sparc_leon3_disable_cache();
143 		}
144 	}
145 
146 	local_ops->cache_all();
147 	local_ops->tlb_all();
148 }
149 
150 void leon_smp_setbroadcast(unsigned int mask)
151 {
152 	int broadcast =
153 	    ((LEON3_BYPASS_LOAD_PA(&(leon3_irqctrl_regs->mpstatus)) >>
154 	      LEON3_IRQMPSTATUS_BROADCAST) & 1);
155 	if (!broadcast) {
156 		prom_printf("######## !!!! The irqmp-ctrl must have broadcast enabled, smp wont work !!!!! ####### nr cpus: %d\n",
157 		     leon_smp_nrcpus());
158 		if (leon_smp_nrcpus() > 1) {
159 			BUG();
160 		} else {
161 			prom_printf("continue anyway\n");
162 			return;
163 		}
164 	}
165 	LEON_BYPASS_STORE_PA(&(leon3_irqctrl_regs->mpbroadcast), mask);
166 }
167 
168 unsigned int leon_smp_getbroadcast(void)
169 {
170 	unsigned int mask;
171 	mask = LEON_BYPASS_LOAD_PA(&(leon3_irqctrl_regs->mpbroadcast));
172 	return mask;
173 }
174 
175 int leon_smp_nrcpus(void)
176 {
177 	int nrcpu =
178 	    ((LEON3_BYPASS_LOAD_PA(&(leon3_irqctrl_regs->mpstatus)) >>
179 	      LEON3_IRQMPSTATUS_CPUNR) & 0xf) + 1;
180 	return nrcpu;
181 }
182 
183 void __init leon_boot_cpus(void)
184 {
185 	int nrcpu = leon_smp_nrcpus();
186 	int me = smp_processor_id();
187 
188 	/* Setup IPI */
189 	leon_ipi_init();
190 
191 	printk(KERN_INFO "%d:(%d:%d) cpus mpirq at 0x%x\n", (unsigned int)me,
192 	       (unsigned int)nrcpu, (unsigned int)NR_CPUS,
193 	       (unsigned int)&(leon3_irqctrl_regs->mpstatus));
194 
195 	leon_enable_irq_cpu(LEON3_IRQ_CROSS_CALL, me);
196 	leon_enable_irq_cpu(LEON3_IRQ_TICKER, me);
197 	leon_enable_irq_cpu(leon_ipi_irq, me);
198 
199 	leon_smp_setbroadcast(1 << LEON3_IRQ_TICKER);
200 
201 	leon_configure_cache_smp();
202 	local_ops->cache_all();
203 
204 }
205 
206 int __cpuinit leon_boot_one_cpu(int i, struct task_struct *idle)
207 {
208 	int timeout;
209 
210 	current_set[i] = task_thread_info(idle);
211 
212 	/* See trampoline.S:leon_smp_cpu_startup for details...
213 	 * Initialize the contexts table
214 	 * Since the call to prom_startcpu() trashes the structure,
215 	 * we need to re-initialize it for each cpu
216 	 */
217 	smp_penguin_ctable.which_io = 0;
218 	smp_penguin_ctable.phys_addr = (unsigned int)srmmu_ctx_table_phys;
219 	smp_penguin_ctable.reg_size = 0;
220 
221 	/* whirrr, whirrr, whirrrrrrrrr... */
222 	printk(KERN_INFO "Starting CPU %d : (irqmp: 0x%x)\n", (unsigned int)i,
223 	       (unsigned int)&leon3_irqctrl_regs->mpstatus);
224 	local_ops->cache_all();
225 
226 	/* Make sure all IRQs are of from the start for this new CPU */
227 	LEON_BYPASS_STORE_PA(&leon3_irqctrl_regs->mask[i], 0);
228 
229 	/* Wake one CPU */
230 	LEON_BYPASS_STORE_PA(&(leon3_irqctrl_regs->mpstatus), 1 << i);
231 
232 	/* wheee... it's going... */
233 	for (timeout = 0; timeout < 10000; timeout++) {
234 		if (cpu_callin_map[i])
235 			break;
236 		udelay(200);
237 	}
238 	printk(KERN_INFO "Started CPU %d\n", (unsigned int)i);
239 
240 	if (!(cpu_callin_map[i])) {
241 		printk(KERN_ERR "Processor %d is stuck.\n", i);
242 		return -ENODEV;
243 	} else {
244 		leon_enable_irq_cpu(LEON3_IRQ_CROSS_CALL, i);
245 		leon_enable_irq_cpu(LEON3_IRQ_TICKER, i);
246 		leon_enable_irq_cpu(leon_ipi_irq, i);
247 	}
248 
249 	local_ops->cache_all();
250 	return 0;
251 }
252 
253 void __init leon_smp_done(void)
254 {
255 
256 	int i, first;
257 	int *prev;
258 
259 	/* setup cpu list for irq rotation */
260 	first = 0;
261 	prev = &first;
262 	for (i = 0; i < NR_CPUS; i++) {
263 		if (cpu_online(i)) {
264 			*prev = i;
265 			prev = &cpu_data(i).next;
266 		}
267 	}
268 	*prev = first;
269 	local_ops->cache_all();
270 
271 	/* Free unneeded trap tables */
272 	if (!cpu_present(1)) {
273 		ClearPageReserved(virt_to_page(&trapbase_cpu1));
274 		init_page_count(virt_to_page(&trapbase_cpu1));
275 		free_page((unsigned long)&trapbase_cpu1);
276 		totalram_pages++;
277 		num_physpages++;
278 	}
279 	if (!cpu_present(2)) {
280 		ClearPageReserved(virt_to_page(&trapbase_cpu2));
281 		init_page_count(virt_to_page(&trapbase_cpu2));
282 		free_page((unsigned long)&trapbase_cpu2);
283 		totalram_pages++;
284 		num_physpages++;
285 	}
286 	if (!cpu_present(3)) {
287 		ClearPageReserved(virt_to_page(&trapbase_cpu3));
288 		init_page_count(virt_to_page(&trapbase_cpu3));
289 		free_page((unsigned long)&trapbase_cpu3);
290 		totalram_pages++;
291 		num_physpages++;
292 	}
293 	/* Ok, they are spinning and ready to go. */
294 	smp_processors_ready = 1;
295 
296 }
297 
298 void leon_irq_rotate(int cpu)
299 {
300 }
301 
302 struct leon_ipi_work {
303 	int single;
304 	int msk;
305 	int resched;
306 };
307 
308 static DEFINE_PER_CPU_SHARED_ALIGNED(struct leon_ipi_work, leon_ipi_work);
309 
310 /* Initialize IPIs on the LEON, in order to save IRQ resources only one IRQ
311  * is used for all three types of IPIs.
312  */
313 static void __init leon_ipi_init(void)
314 {
315 	int cpu, len;
316 	struct leon_ipi_work *work;
317 	struct property *pp;
318 	struct device_node *rootnp;
319 	struct tt_entry *trap_table;
320 	unsigned long flags;
321 
322 	/* Find IPI IRQ or stick with default value */
323 	rootnp = of_find_node_by_path("/ambapp0");
324 	if (rootnp) {
325 		pp = of_find_property(rootnp, "ipi_num", &len);
326 		if (pp && (*(int *)pp->value))
327 			leon_ipi_irq = *(int *)pp->value;
328 	}
329 	printk(KERN_INFO "leon: SMP IPIs at IRQ %d\n", leon_ipi_irq);
330 
331 	/* Adjust so that we jump directly to smpleon_ipi */
332 	local_irq_save(flags);
333 	trap_table = &sparc_ttable[SP_TRAP_IRQ1 + (leon_ipi_irq - 1)];
334 	trap_table->inst_three += smpleon_ipi - real_irq_entry;
335 	local_ops->cache_all();
336 	local_irq_restore(flags);
337 
338 	for_each_possible_cpu(cpu) {
339 		work = &per_cpu(leon_ipi_work, cpu);
340 		work->single = work->msk = work->resched = 0;
341 	}
342 }
343 
344 static void leon_send_ipi(int cpu, int level)
345 {
346 	unsigned long mask;
347 	mask = leon_get_irqmask(level);
348 	LEON3_BYPASS_STORE_PA(&leon3_irqctrl_regs->force[cpu], mask);
349 }
350 
351 static void leon_ipi_single(int cpu)
352 {
353 	struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
354 
355 	/* Mark work */
356 	work->single = 1;
357 
358 	/* Generate IRQ on the CPU */
359 	leon_send_ipi(cpu, leon_ipi_irq);
360 }
361 
362 static void leon_ipi_mask_one(int cpu)
363 {
364 	struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
365 
366 	/* Mark work */
367 	work->msk = 1;
368 
369 	/* Generate IRQ on the CPU */
370 	leon_send_ipi(cpu, leon_ipi_irq);
371 }
372 
373 static void leon_ipi_resched(int cpu)
374 {
375 	struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
376 
377 	/* Mark work */
378 	work->resched = 1;
379 
380 	/* Generate IRQ on the CPU (any IRQ will cause resched) */
381 	leon_send_ipi(cpu, leon_ipi_irq);
382 }
383 
384 void leonsmp_ipi_interrupt(void)
385 {
386 	struct leon_ipi_work *work = &__get_cpu_var(leon_ipi_work);
387 
388 	if (work->single) {
389 		work->single = 0;
390 		smp_call_function_single_interrupt();
391 	}
392 	if (work->msk) {
393 		work->msk = 0;
394 		smp_call_function_interrupt();
395 	}
396 	if (work->resched) {
397 		work->resched = 0;
398 		smp_resched_interrupt();
399 	}
400 }
401 
402 static struct smp_funcall {
403 	smpfunc_t func;
404 	unsigned long arg1;
405 	unsigned long arg2;
406 	unsigned long arg3;
407 	unsigned long arg4;
408 	unsigned long arg5;
409 	unsigned long processors_in[NR_CPUS];	/* Set when ipi entered. */
410 	unsigned long processors_out[NR_CPUS];	/* Set when ipi exited. */
411 } ccall_info;
412 
413 static DEFINE_SPINLOCK(cross_call_lock);
414 
415 /* Cross calls must be serialized, at least currently. */
416 static void leon_cross_call(smpfunc_t func, cpumask_t mask, unsigned long arg1,
417 			    unsigned long arg2, unsigned long arg3,
418 			    unsigned long arg4)
419 {
420 	if (smp_processors_ready) {
421 		register int high = NR_CPUS - 1;
422 		unsigned long flags;
423 
424 		spin_lock_irqsave(&cross_call_lock, flags);
425 
426 		{
427 			/* If you make changes here, make sure gcc generates proper code... */
428 			register smpfunc_t f asm("i0") = func;
429 			register unsigned long a1 asm("i1") = arg1;
430 			register unsigned long a2 asm("i2") = arg2;
431 			register unsigned long a3 asm("i3") = arg3;
432 			register unsigned long a4 asm("i4") = arg4;
433 			register unsigned long a5 asm("i5") = 0;
434 
435 			__asm__ __volatile__("std %0, [%6]\n\t"
436 					     "std %2, [%6 + 8]\n\t"
437 					     "std %4, [%6 + 16]\n\t" : :
438 					     "r"(f), "r"(a1), "r"(a2), "r"(a3),
439 					     "r"(a4), "r"(a5),
440 					     "r"(&ccall_info.func));
441 		}
442 
443 		/* Init receive/complete mapping, plus fire the IPI's off. */
444 		{
445 			register int i;
446 
447 			cpumask_clear_cpu(smp_processor_id(), &mask);
448 			cpumask_and(&mask, cpu_online_mask, &mask);
449 			for (i = 0; i <= high; i++) {
450 				if (cpumask_test_cpu(i, &mask)) {
451 					ccall_info.processors_in[i] = 0;
452 					ccall_info.processors_out[i] = 0;
453 					leon_send_ipi(i, LEON3_IRQ_CROSS_CALL);
454 
455 				}
456 			}
457 		}
458 
459 		{
460 			register int i;
461 
462 			i = 0;
463 			do {
464 				if (!cpumask_test_cpu(i, &mask))
465 					continue;
466 
467 				while (!ccall_info.processors_in[i])
468 					barrier();
469 			} while (++i <= high);
470 
471 			i = 0;
472 			do {
473 				if (!cpumask_test_cpu(i, &mask))
474 					continue;
475 
476 				while (!ccall_info.processors_out[i])
477 					barrier();
478 			} while (++i <= high);
479 		}
480 
481 		spin_unlock_irqrestore(&cross_call_lock, flags);
482 	}
483 }
484 
485 /* Running cross calls. */
486 void leon_cross_call_irq(void)
487 {
488 	int i = smp_processor_id();
489 
490 	ccall_info.processors_in[i] = 1;
491 	ccall_info.func(ccall_info.arg1, ccall_info.arg2, ccall_info.arg3,
492 			ccall_info.arg4, ccall_info.arg5);
493 	ccall_info.processors_out[i] = 1;
494 }
495 
496 static const struct sparc32_ipi_ops leon_ipi_ops = {
497 	.cross_call = leon_cross_call,
498 	.resched    = leon_ipi_resched,
499 	.single     = leon_ipi_single,
500 	.mask_one   = leon_ipi_mask_one,
501 };
502 
503 void __init leon_init_smp(void)
504 {
505 	/* Patch ipi15 trap table */
506 	t_nmi[1] = t_nmi[1] + (linux_trap_ipi15_leon - linux_trap_ipi15_sun4m);
507 
508 	sparc32_ipi_ops = &leon_ipi_ops;
509 }
510 
511 #endif /* CONFIG_SPARC_LEON */
512