xref: /openbmc/linux/arch/sparc/kernel/leon_smp.c (revision 2223cbec)
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 #include "irq.h"
52 
53 extern ctxd_t *srmmu_ctx_table_phys;
54 static int smp_processors_ready;
55 extern volatile unsigned long cpu_callin_map[NR_CPUS];
56 extern cpumask_t smp_commenced_mask;
57 void __cpuinit leon_configure_cache_smp(void);
58 static void leon_ipi_init(void);
59 
60 /* IRQ number of LEON IPIs */
61 int leon_ipi_irq = LEON3_IRQ_IPI_DEFAULT;
62 
63 static inline unsigned long do_swap(volatile unsigned long *ptr,
64 				    unsigned long val)
65 {
66 	__asm__ __volatile__("swapa [%2] %3, %0\n\t" : "=&r"(val)
67 			     : "0"(val), "r"(ptr), "i"(ASI_LEON_DCACHE_MISS)
68 			     : "memory");
69 	return val;
70 }
71 
72 void __cpuinit leon_callin(void)
73 {
74 	int cpuid = hard_smp_processor_id();
75 
76 	local_ops->cache_all();
77 	local_ops->tlb_all();
78 	leon_configure_cache_smp();
79 
80 	notify_cpu_starting(cpuid);
81 
82 	/* Get our local ticker going. */
83 	register_percpu_ce(cpuid);
84 
85 	calibrate_delay();
86 	smp_store_cpu_info(cpuid);
87 
88 	local_ops->cache_all();
89 	local_ops->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 	 * Allow master to continue.
97 	 */
98 	do_swap(&cpu_callin_map[cpuid], 1);
99 
100 	local_ops->cache_all();
101 	local_ops->tlb_all();
102 
103 	/* Fix idle thread fields. */
104 	__asm__ __volatile__("ld [%0], %%g6\n\t" : : "r"(&current_set[cpuid])
105 			     : "memory" /* paranoid */);
106 
107 	/* Attach to the address space of init_task. */
108 	atomic_inc(&init_mm.mm_count);
109 	current->active_mm = &init_mm;
110 
111 	while (!cpumask_test_cpu(cpuid, &smp_commenced_mask))
112 		mb();
113 
114 	local_irq_enable();
115 	set_cpu_online(cpuid, true);
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 
124 void __cpuinit leon_configure_cache_smp(void)
125 {
126 	unsigned long cfg = sparc_leon3_get_dcachecfg();
127 	int me = smp_processor_id();
128 
129 	if (ASI_LEON3_SYSCTRL_CFG_SSIZE(cfg) > 4) {
130 		printk(KERN_INFO "Note: SMP with snooping only works on 4k cache, found %dk(0x%x) on cpu %d, disabling caches\n",
131 		     (unsigned int)ASI_LEON3_SYSCTRL_CFG_SSIZE(cfg),
132 		     (unsigned int)cfg, (unsigned int)me);
133 		sparc_leon3_disable_cache();
134 	} else {
135 		if (cfg & ASI_LEON3_SYSCTRL_CFG_SNOOPING) {
136 			sparc_leon3_enable_snooping();
137 		} else {
138 			printk(KERN_INFO "Note: You have to enable snooping in the vhdl model cpu %d, disabling caches\n",
139 			     me);
140 			sparc_leon3_disable_cache();
141 		}
142 	}
143 
144 	local_ops->cache_all();
145 	local_ops->tlb_all();
146 }
147 
148 void leon_smp_setbroadcast(unsigned int mask)
149 {
150 	int broadcast =
151 	    ((LEON3_BYPASS_LOAD_PA(&(leon3_irqctrl_regs->mpstatus)) >>
152 	      LEON3_IRQMPSTATUS_BROADCAST) & 1);
153 	if (!broadcast) {
154 		prom_printf("######## !!!! The irqmp-ctrl must have broadcast enabled, smp wont work !!!!! ####### nr cpus: %d\n",
155 		     leon_smp_nrcpus());
156 		if (leon_smp_nrcpus() > 1) {
157 			BUG();
158 		} else {
159 			prom_printf("continue anyway\n");
160 			return;
161 		}
162 	}
163 	LEON_BYPASS_STORE_PA(&(leon3_irqctrl_regs->mpbroadcast), mask);
164 }
165 
166 unsigned int leon_smp_getbroadcast(void)
167 {
168 	unsigned int mask;
169 	mask = LEON_BYPASS_LOAD_PA(&(leon3_irqctrl_regs->mpbroadcast));
170 	return mask;
171 }
172 
173 int leon_smp_nrcpus(void)
174 {
175 	int nrcpu =
176 	    ((LEON3_BYPASS_LOAD_PA(&(leon3_irqctrl_regs->mpstatus)) >>
177 	      LEON3_IRQMPSTATUS_CPUNR) & 0xf) + 1;
178 	return nrcpu;
179 }
180 
181 void __init leon_boot_cpus(void)
182 {
183 	int nrcpu = leon_smp_nrcpus();
184 	int me = smp_processor_id();
185 
186 	/* Setup IPI */
187 	leon_ipi_init();
188 
189 	printk(KERN_INFO "%d:(%d:%d) cpus mpirq at 0x%x\n", (unsigned int)me,
190 	       (unsigned int)nrcpu, (unsigned int)NR_CPUS,
191 	       (unsigned int)&(leon3_irqctrl_regs->mpstatus));
192 
193 	leon_enable_irq_cpu(LEON3_IRQ_CROSS_CALL, me);
194 	leon_enable_irq_cpu(LEON3_IRQ_TICKER, me);
195 	leon_enable_irq_cpu(leon_ipi_irq, me);
196 
197 	leon_smp_setbroadcast(1 << LEON3_IRQ_TICKER);
198 
199 	leon_configure_cache_smp();
200 	local_ops->cache_all();
201 
202 }
203 
204 int __cpuinit leon_boot_one_cpu(int i, struct task_struct *idle)
205 {
206 	int timeout;
207 
208 	current_set[i] = task_thread_info(idle);
209 
210 	/* See trampoline.S:leon_smp_cpu_startup for details...
211 	 * Initialize the contexts table
212 	 * Since the call to prom_startcpu() trashes the structure,
213 	 * we need to re-initialize it for each cpu
214 	 */
215 	smp_penguin_ctable.which_io = 0;
216 	smp_penguin_ctable.phys_addr = (unsigned int)srmmu_ctx_table_phys;
217 	smp_penguin_ctable.reg_size = 0;
218 
219 	/* whirrr, whirrr, whirrrrrrrrr... */
220 	printk(KERN_INFO "Starting CPU %d : (irqmp: 0x%x)\n", (unsigned int)i,
221 	       (unsigned int)&leon3_irqctrl_regs->mpstatus);
222 	local_ops->cache_all();
223 
224 	/* Make sure all IRQs are of from the start for this new CPU */
225 	LEON_BYPASS_STORE_PA(&leon3_irqctrl_regs->mask[i], 0);
226 
227 	/* Wake one CPU */
228 	LEON_BYPASS_STORE_PA(&(leon3_irqctrl_regs->mpstatus), 1 << i);
229 
230 	/* wheee... it's going... */
231 	for (timeout = 0; timeout < 10000; timeout++) {
232 		if (cpu_callin_map[i])
233 			break;
234 		udelay(200);
235 	}
236 	printk(KERN_INFO "Started CPU %d\n", (unsigned int)i);
237 
238 	if (!(cpu_callin_map[i])) {
239 		printk(KERN_ERR "Processor %d is stuck.\n", i);
240 		return -ENODEV;
241 	} else {
242 		leon_enable_irq_cpu(LEON3_IRQ_CROSS_CALL, i);
243 		leon_enable_irq_cpu(LEON3_IRQ_TICKER, i);
244 		leon_enable_irq_cpu(leon_ipi_irq, i);
245 	}
246 
247 	local_ops->cache_all();
248 	return 0;
249 }
250 
251 void __init leon_smp_done(void)
252 {
253 
254 	int i, first;
255 	int *prev;
256 
257 	/* setup cpu list for irq rotation */
258 	first = 0;
259 	prev = &first;
260 	for (i = 0; i < NR_CPUS; i++) {
261 		if (cpu_online(i)) {
262 			*prev = i;
263 			prev = &cpu_data(i).next;
264 		}
265 	}
266 	*prev = first;
267 	local_ops->cache_all();
268 
269 	/* Free unneeded trap tables */
270 	if (!cpu_present(1)) {
271 		ClearPageReserved(virt_to_page(&trapbase_cpu1));
272 		init_page_count(virt_to_page(&trapbase_cpu1));
273 		free_page((unsigned long)&trapbase_cpu1);
274 		totalram_pages++;
275 		num_physpages++;
276 	}
277 	if (!cpu_present(2)) {
278 		ClearPageReserved(virt_to_page(&trapbase_cpu2));
279 		init_page_count(virt_to_page(&trapbase_cpu2));
280 		free_page((unsigned long)&trapbase_cpu2);
281 		totalram_pages++;
282 		num_physpages++;
283 	}
284 	if (!cpu_present(3)) {
285 		ClearPageReserved(virt_to_page(&trapbase_cpu3));
286 		init_page_count(virt_to_page(&trapbase_cpu3));
287 		free_page((unsigned long)&trapbase_cpu3);
288 		totalram_pages++;
289 		num_physpages++;
290 	}
291 	/* Ok, they are spinning and ready to go. */
292 	smp_processors_ready = 1;
293 
294 }
295 
296 void leon_irq_rotate(int cpu)
297 {
298 }
299 
300 struct leon_ipi_work {
301 	int single;
302 	int msk;
303 	int resched;
304 };
305 
306 static DEFINE_PER_CPU_SHARED_ALIGNED(struct leon_ipi_work, leon_ipi_work);
307 
308 /* Initialize IPIs on the LEON, in order to save IRQ resources only one IRQ
309  * is used for all three types of IPIs.
310  */
311 static void __init leon_ipi_init(void)
312 {
313 	int cpu, len;
314 	struct leon_ipi_work *work;
315 	struct property *pp;
316 	struct device_node *rootnp;
317 	struct tt_entry *trap_table;
318 	unsigned long flags;
319 
320 	/* Find IPI IRQ or stick with default value */
321 	rootnp = of_find_node_by_path("/ambapp0");
322 	if (rootnp) {
323 		pp = of_find_property(rootnp, "ipi_num", &len);
324 		if (pp && (*(int *)pp->value))
325 			leon_ipi_irq = *(int *)pp->value;
326 	}
327 	printk(KERN_INFO "leon: SMP IPIs at IRQ %d\n", leon_ipi_irq);
328 
329 	/* Adjust so that we jump directly to smpleon_ipi */
330 	local_irq_save(flags);
331 	trap_table = &sparc_ttable[SP_TRAP_IRQ1 + (leon_ipi_irq - 1)];
332 	trap_table->inst_three += smpleon_ipi - real_irq_entry;
333 	local_ops->cache_all();
334 	local_irq_restore(flags);
335 
336 	for_each_possible_cpu(cpu) {
337 		work = &per_cpu(leon_ipi_work, cpu);
338 		work->single = work->msk = work->resched = 0;
339 	}
340 }
341 
342 static void leon_send_ipi(int cpu, int level)
343 {
344 	unsigned long mask;
345 	mask = leon_get_irqmask(level);
346 	LEON3_BYPASS_STORE_PA(&leon3_irqctrl_regs->force[cpu], mask);
347 }
348 
349 static void leon_ipi_single(int cpu)
350 {
351 	struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
352 
353 	/* Mark work */
354 	work->single = 1;
355 
356 	/* Generate IRQ on the CPU */
357 	leon_send_ipi(cpu, leon_ipi_irq);
358 }
359 
360 static void leon_ipi_mask_one(int cpu)
361 {
362 	struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
363 
364 	/* Mark work */
365 	work->msk = 1;
366 
367 	/* Generate IRQ on the CPU */
368 	leon_send_ipi(cpu, leon_ipi_irq);
369 }
370 
371 static void leon_ipi_resched(int cpu)
372 {
373 	struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
374 
375 	/* Mark work */
376 	work->resched = 1;
377 
378 	/* Generate IRQ on the CPU (any IRQ will cause resched) */
379 	leon_send_ipi(cpu, leon_ipi_irq);
380 }
381 
382 void leonsmp_ipi_interrupt(void)
383 {
384 	struct leon_ipi_work *work = &__get_cpu_var(leon_ipi_work);
385 
386 	if (work->single) {
387 		work->single = 0;
388 		smp_call_function_single_interrupt();
389 	}
390 	if (work->msk) {
391 		work->msk = 0;
392 		smp_call_function_interrupt();
393 	}
394 	if (work->resched) {
395 		work->resched = 0;
396 		smp_resched_interrupt();
397 	}
398 }
399 
400 static struct smp_funcall {
401 	smpfunc_t func;
402 	unsigned long arg1;
403 	unsigned long arg2;
404 	unsigned long arg3;
405 	unsigned long arg4;
406 	unsigned long arg5;
407 	unsigned long processors_in[NR_CPUS];	/* Set when ipi entered. */
408 	unsigned long processors_out[NR_CPUS];	/* Set when ipi exited. */
409 } ccall_info;
410 
411 static DEFINE_SPINLOCK(cross_call_lock);
412 
413 /* Cross calls must be serialized, at least currently. */
414 static void leon_cross_call(smpfunc_t func, cpumask_t mask, unsigned long arg1,
415 			    unsigned long arg2, unsigned long arg3,
416 			    unsigned long arg4)
417 {
418 	if (smp_processors_ready) {
419 		register int high = NR_CPUS - 1;
420 		unsigned long flags;
421 
422 		spin_lock_irqsave(&cross_call_lock, flags);
423 
424 		{
425 			/* If you make changes here, make sure gcc generates proper code... */
426 			register smpfunc_t f asm("i0") = func;
427 			register unsigned long a1 asm("i1") = arg1;
428 			register unsigned long a2 asm("i2") = arg2;
429 			register unsigned long a3 asm("i3") = arg3;
430 			register unsigned long a4 asm("i4") = arg4;
431 			register unsigned long a5 asm("i5") = 0;
432 
433 			__asm__ __volatile__("std %0, [%6]\n\t"
434 					     "std %2, [%6 + 8]\n\t"
435 					     "std %4, [%6 + 16]\n\t" : :
436 					     "r"(f), "r"(a1), "r"(a2), "r"(a3),
437 					     "r"(a4), "r"(a5),
438 					     "r"(&ccall_info.func));
439 		}
440 
441 		/* Init receive/complete mapping, plus fire the IPI's off. */
442 		{
443 			register int i;
444 
445 			cpumask_clear_cpu(smp_processor_id(), &mask);
446 			cpumask_and(&mask, cpu_online_mask, &mask);
447 			for (i = 0; i <= high; i++) {
448 				if (cpumask_test_cpu(i, &mask)) {
449 					ccall_info.processors_in[i] = 0;
450 					ccall_info.processors_out[i] = 0;
451 					leon_send_ipi(i, LEON3_IRQ_CROSS_CALL);
452 
453 				}
454 			}
455 		}
456 
457 		{
458 			register int i;
459 
460 			i = 0;
461 			do {
462 				if (!cpumask_test_cpu(i, &mask))
463 					continue;
464 
465 				while (!ccall_info.processors_in[i])
466 					barrier();
467 			} while (++i <= high);
468 
469 			i = 0;
470 			do {
471 				if (!cpumask_test_cpu(i, &mask))
472 					continue;
473 
474 				while (!ccall_info.processors_out[i])
475 					barrier();
476 			} while (++i <= high);
477 		}
478 
479 		spin_unlock_irqrestore(&cross_call_lock, flags);
480 	}
481 }
482 
483 /* Running cross calls. */
484 void leon_cross_call_irq(void)
485 {
486 	int i = smp_processor_id();
487 
488 	ccall_info.processors_in[i] = 1;
489 	ccall_info.func(ccall_info.arg1, ccall_info.arg2, ccall_info.arg3,
490 			ccall_info.arg4, ccall_info.arg5);
491 	ccall_info.processors_out[i] = 1;
492 }
493 
494 static const struct sparc32_ipi_ops leon_ipi_ops = {
495 	.cross_call = leon_cross_call,
496 	.resched    = leon_ipi_resched,
497 	.single     = leon_ipi_single,
498 	.mask_one   = leon_ipi_mask_one,
499 };
500 
501 void __init leon_init_smp(void)
502 {
503 	/* Patch ipi15 trap table */
504 	t_nmi[1] = t_nmi[1] + (linux_trap_ipi15_leon - linux_trap_ipi15_sun4m);
505 
506 	sparc32_ipi_ops = &leon_ipi_ops;
507 }
508