xref: /openbmc/linux/arch/sparc/kernel/leon_kernel.c (revision 39b6f3aa)
1 /*
2  * Copyright (C) 2009 Daniel Hellstrom (daniel@gaisler.com) Aeroflex Gaisler AB
3  * Copyright (C) 2009 Konrad Eisele (konrad@gaisler.com) Aeroflex Gaisler AB
4  */
5 
6 #include <linux/kernel.h>
7 #include <linux/errno.h>
8 #include <linux/mutex.h>
9 #include <linux/of.h>
10 #include <linux/of_platform.h>
11 #include <linux/interrupt.h>
12 #include <linux/of_device.h>
13 #include <linux/clocksource.h>
14 #include <linux/clockchips.h>
15 
16 #include <asm/oplib.h>
17 #include <asm/timer.h>
18 #include <asm/prom.h>
19 #include <asm/leon.h>
20 #include <asm/leon_amba.h>
21 #include <asm/traps.h>
22 #include <asm/cacheflush.h>
23 #include <asm/smp.h>
24 #include <asm/setup.h>
25 
26 #include "kernel.h"
27 #include "prom.h"
28 #include "irq.h"
29 
30 struct leon3_irqctrl_regs_map *leon3_irqctrl_regs; /* interrupt controller base address */
31 struct leon3_gptimer_regs_map *leon3_gptimer_regs; /* timer controller base address */
32 
33 int leondebug_irq_disable;
34 int leon_debug_irqout;
35 static int dummy_master_l10_counter;
36 unsigned long amba_system_id;
37 static DEFINE_SPINLOCK(leon_irq_lock);
38 
39 unsigned long leon3_gptimer_irq; /* interrupt controller irq number */
40 unsigned long leon3_gptimer_idx; /* Timer Index (0..6) within Timer Core */
41 int leon3_ticker_irq; /* Timer ticker IRQ */
42 unsigned int sparc_leon_eirq;
43 #define LEON_IMASK(cpu) (&leon3_irqctrl_regs->mask[cpu])
44 #define LEON_IACK (&leon3_irqctrl_regs->iclear)
45 #define LEON_DO_ACK_HW 1
46 
47 /* Return the last ACKed IRQ by the Extended IRQ controller. It has already
48  * been (automatically) ACKed when the CPU takes the trap.
49  */
50 static inline unsigned int leon_eirq_get(int cpu)
51 {
52 	return LEON3_BYPASS_LOAD_PA(&leon3_irqctrl_regs->intid[cpu]) & 0x1f;
53 }
54 
55 /* Handle one or multiple IRQs from the extended interrupt controller */
56 static void leon_handle_ext_irq(unsigned int irq, struct irq_desc *desc)
57 {
58 	unsigned int eirq;
59 	struct irq_bucket *p;
60 	int cpu = sparc_leon3_cpuid();
61 
62 	eirq = leon_eirq_get(cpu);
63 	p = irq_map[eirq];
64 	if ((eirq & 0x10) && p && p->irq) /* bit4 tells if IRQ happened */
65 		generic_handle_irq(p->irq);
66 }
67 
68 /* The extended IRQ controller has been found, this function registers it */
69 void leon_eirq_setup(unsigned int eirq)
70 {
71 	unsigned long mask, oldmask;
72 	unsigned int veirq;
73 
74 	if (eirq < 1 || eirq > 0xf) {
75 		printk(KERN_ERR "LEON EXT IRQ NUMBER BAD: %d\n", eirq);
76 		return;
77 	}
78 
79 	veirq = leon_build_device_irq(eirq, leon_handle_ext_irq, "extirq", 0);
80 
81 	/*
82 	 * Unmask the Extended IRQ, the IRQs routed through the Ext-IRQ
83 	 * controller have a mask-bit of their own, so this is safe.
84 	 */
85 	irq_link(veirq);
86 	mask = 1 << eirq;
87 	oldmask = LEON3_BYPASS_LOAD_PA(LEON_IMASK(boot_cpu_id));
88 	LEON3_BYPASS_STORE_PA(LEON_IMASK(boot_cpu_id), (oldmask | mask));
89 	sparc_leon_eirq = eirq;
90 }
91 
92 unsigned long leon_get_irqmask(unsigned int irq)
93 {
94 	unsigned long mask;
95 
96 	if (!irq || ((irq > 0xf) && !sparc_leon_eirq)
97 	    || ((irq > 0x1f) && sparc_leon_eirq)) {
98 		printk(KERN_ERR
99 		       "leon_get_irqmask: false irq number: %d\n", irq);
100 		mask = 0;
101 	} else {
102 		mask = LEON_HARD_INT(irq);
103 	}
104 	return mask;
105 }
106 
107 #ifdef CONFIG_SMP
108 static int irq_choose_cpu(const struct cpumask *affinity)
109 {
110 	cpumask_t mask;
111 
112 	cpumask_and(&mask, cpu_online_mask, affinity);
113 	if (cpumask_equal(&mask, cpu_online_mask) || cpumask_empty(&mask))
114 		return boot_cpu_id;
115 	else
116 		return cpumask_first(&mask);
117 }
118 #else
119 #define irq_choose_cpu(affinity) boot_cpu_id
120 #endif
121 
122 static int leon_set_affinity(struct irq_data *data, const struct cpumask *dest,
123 			     bool force)
124 {
125 	unsigned long mask, oldmask, flags;
126 	int oldcpu, newcpu;
127 
128 	mask = (unsigned long)data->chip_data;
129 	oldcpu = irq_choose_cpu(data->affinity);
130 	newcpu = irq_choose_cpu(dest);
131 
132 	if (oldcpu == newcpu)
133 		goto out;
134 
135 	/* unmask on old CPU first before enabling on the selected CPU */
136 	spin_lock_irqsave(&leon_irq_lock, flags);
137 	oldmask = LEON3_BYPASS_LOAD_PA(LEON_IMASK(oldcpu));
138 	LEON3_BYPASS_STORE_PA(LEON_IMASK(oldcpu), (oldmask & ~mask));
139 	oldmask = LEON3_BYPASS_LOAD_PA(LEON_IMASK(newcpu));
140 	LEON3_BYPASS_STORE_PA(LEON_IMASK(newcpu), (oldmask | mask));
141 	spin_unlock_irqrestore(&leon_irq_lock, flags);
142 out:
143 	return IRQ_SET_MASK_OK;
144 }
145 
146 static void leon_unmask_irq(struct irq_data *data)
147 {
148 	unsigned long mask, oldmask, flags;
149 	int cpu;
150 
151 	mask = (unsigned long)data->chip_data;
152 	cpu = irq_choose_cpu(data->affinity);
153 	spin_lock_irqsave(&leon_irq_lock, flags);
154 	oldmask = LEON3_BYPASS_LOAD_PA(LEON_IMASK(cpu));
155 	LEON3_BYPASS_STORE_PA(LEON_IMASK(cpu), (oldmask | mask));
156 	spin_unlock_irqrestore(&leon_irq_lock, flags);
157 }
158 
159 static void leon_mask_irq(struct irq_data *data)
160 {
161 	unsigned long mask, oldmask, flags;
162 	int cpu;
163 
164 	mask = (unsigned long)data->chip_data;
165 	cpu = irq_choose_cpu(data->affinity);
166 	spin_lock_irqsave(&leon_irq_lock, flags);
167 	oldmask = LEON3_BYPASS_LOAD_PA(LEON_IMASK(cpu));
168 	LEON3_BYPASS_STORE_PA(LEON_IMASK(cpu), (oldmask & ~mask));
169 	spin_unlock_irqrestore(&leon_irq_lock, flags);
170 }
171 
172 static unsigned int leon_startup_irq(struct irq_data *data)
173 {
174 	irq_link(data->irq);
175 	leon_unmask_irq(data);
176 	return 0;
177 }
178 
179 static void leon_shutdown_irq(struct irq_data *data)
180 {
181 	leon_mask_irq(data);
182 	irq_unlink(data->irq);
183 }
184 
185 /* Used by external level sensitive IRQ handlers on the LEON: ACK IRQ ctrl */
186 static void leon_eoi_irq(struct irq_data *data)
187 {
188 	unsigned long mask = (unsigned long)data->chip_data;
189 
190 	if (mask & LEON_DO_ACK_HW)
191 		LEON3_BYPASS_STORE_PA(LEON_IACK, mask & ~LEON_DO_ACK_HW);
192 }
193 
194 static struct irq_chip leon_irq = {
195 	.name			= "leon",
196 	.irq_startup		= leon_startup_irq,
197 	.irq_shutdown		= leon_shutdown_irq,
198 	.irq_mask		= leon_mask_irq,
199 	.irq_unmask		= leon_unmask_irq,
200 	.irq_eoi		= leon_eoi_irq,
201 	.irq_set_affinity	= leon_set_affinity,
202 };
203 
204 /*
205  * Build a LEON IRQ for the edge triggered LEON IRQ controller:
206  *  Edge (normal) IRQ           - handle_simple_irq, ack=DONT-CARE, never ack
207  *  Level IRQ (PCI|Level-GPIO)  - handle_fasteoi_irq, ack=1, ack after ISR
208  *  Per-CPU Edge                - handle_percpu_irq, ack=0
209  */
210 unsigned int leon_build_device_irq(unsigned int real_irq,
211 				    irq_flow_handler_t flow_handler,
212 				    const char *name, int do_ack)
213 {
214 	unsigned int irq;
215 	unsigned long mask;
216 	struct irq_desc *desc;
217 
218 	irq = 0;
219 	mask = leon_get_irqmask(real_irq);
220 	if (mask == 0)
221 		goto out;
222 
223 	irq = irq_alloc(real_irq, real_irq);
224 	if (irq == 0)
225 		goto out;
226 
227 	if (do_ack)
228 		mask |= LEON_DO_ACK_HW;
229 
230 	desc = irq_to_desc(irq);
231 	if (!desc || !desc->handle_irq || desc->handle_irq == handle_bad_irq) {
232 		irq_set_chip_and_handler_name(irq, &leon_irq,
233 					      flow_handler, name);
234 		irq_set_chip_data(irq, (void *)mask);
235 	}
236 
237 out:
238 	return irq;
239 }
240 
241 static unsigned int _leon_build_device_irq(struct platform_device *op,
242 					   unsigned int real_irq)
243 {
244 	return leon_build_device_irq(real_irq, handle_simple_irq, "edge", 0);
245 }
246 
247 void leon_update_virq_handling(unsigned int virq,
248 			      irq_flow_handler_t flow_handler,
249 			      const char *name, int do_ack)
250 {
251 	unsigned long mask = (unsigned long)irq_get_chip_data(virq);
252 
253 	mask &= ~LEON_DO_ACK_HW;
254 	if (do_ack)
255 		mask |= LEON_DO_ACK_HW;
256 
257 	irq_set_chip_and_handler_name(virq, &leon_irq,
258 				      flow_handler, name);
259 	irq_set_chip_data(virq, (void *)mask);
260 }
261 
262 static u32 leon_cycles_offset(void)
263 {
264 	u32 rld, val, off;
265 	rld = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].rld);
266 	val = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].val);
267 	off = rld - val;
268 	return rld - val;
269 }
270 
271 #ifdef CONFIG_SMP
272 
273 /* smp clockevent irq */
274 irqreturn_t leon_percpu_timer_ce_interrupt(int irq, void *unused)
275 {
276 	struct clock_event_device *ce;
277 	int cpu = smp_processor_id();
278 
279 	leon_clear_profile_irq(cpu);
280 
281 	ce = &per_cpu(sparc32_clockevent, cpu);
282 
283 	irq_enter();
284 	if (ce->event_handler)
285 		ce->event_handler(ce);
286 	irq_exit();
287 
288 	return IRQ_HANDLED;
289 }
290 
291 #endif /* CONFIG_SMP */
292 
293 void __init leon_init_timers(void)
294 {
295 	int irq, eirq;
296 	struct device_node *rootnp, *np, *nnp;
297 	struct property *pp;
298 	int len;
299 	int icsel;
300 	int ampopts;
301 	int err;
302 
303 	sparc_config.get_cycles_offset = leon_cycles_offset;
304 	sparc_config.cs_period = 1000000 / HZ;
305 	sparc_config.features |= FEAT_L10_CLOCKSOURCE;
306 
307 #ifndef CONFIG_SMP
308 	sparc_config.features |= FEAT_L10_CLOCKEVENT;
309 #endif
310 
311 	leondebug_irq_disable = 0;
312 	leon_debug_irqout = 0;
313 	master_l10_counter = (unsigned int *)&dummy_master_l10_counter;
314 	dummy_master_l10_counter = 0;
315 
316 	rootnp = of_find_node_by_path("/ambapp0");
317 	if (!rootnp)
318 		goto bad;
319 
320 	/* Find System ID: GRLIB build ID and optional CHIP ID */
321 	pp = of_find_property(rootnp, "systemid", &len);
322 	if (pp)
323 		amba_system_id = *(unsigned long *)pp->value;
324 
325 	/* Find IRQMP IRQ Controller Registers base adr otherwise bail out */
326 	np = of_find_node_by_name(rootnp, "GAISLER_IRQMP");
327 	if (!np) {
328 		np = of_find_node_by_name(rootnp, "01_00d");
329 		if (!np)
330 			goto bad;
331 	}
332 	pp = of_find_property(np, "reg", &len);
333 	if (!pp)
334 		goto bad;
335 	leon3_irqctrl_regs = *(struct leon3_irqctrl_regs_map **)pp->value;
336 
337 	/* Find GPTIMER Timer Registers base address otherwise bail out. */
338 	nnp = rootnp;
339 	do {
340 		np = of_find_node_by_name(nnp, "GAISLER_GPTIMER");
341 		if (!np) {
342 			np = of_find_node_by_name(nnp, "01_011");
343 			if (!np)
344 				goto bad;
345 		}
346 
347 		ampopts = 0;
348 		pp = of_find_property(np, "ampopts", &len);
349 		if (pp) {
350 			ampopts = *(int *)pp->value;
351 			if (ampopts == 0) {
352 				/* Skip this instance, resource already
353 				 * allocated by other OS */
354 				nnp = np;
355 				continue;
356 			}
357 		}
358 
359 		/* Select Timer-Instance on Timer Core. Default is zero */
360 		leon3_gptimer_idx = ampopts & 0x7;
361 
362 		pp = of_find_property(np, "reg", &len);
363 		if (pp)
364 			leon3_gptimer_regs = *(struct leon3_gptimer_regs_map **)
365 						pp->value;
366 		pp = of_find_property(np, "interrupts", &len);
367 		if (pp)
368 			leon3_gptimer_irq = *(unsigned int *)pp->value;
369 	} while (0);
370 
371 	if (!(leon3_gptimer_regs && leon3_irqctrl_regs && leon3_gptimer_irq))
372 		goto bad;
373 
374 	LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].val, 0);
375 	LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].rld,
376 				(((1000000 / HZ) - 1)));
377 	LEON3_BYPASS_STORE_PA(
378 			&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl, 0);
379 
380 #ifdef CONFIG_SMP
381 	leon3_ticker_irq = leon3_gptimer_irq + 1 + leon3_gptimer_idx;
382 
383 	if (!(LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->config) &
384 	      (1<<LEON3_GPTIMER_SEPIRQ))) {
385 		printk(KERN_ERR "timer not configured with separate irqs\n");
386 		BUG();
387 	}
388 
389 	LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx+1].val,
390 				0);
391 	LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx+1].rld,
392 				(((1000000/HZ) - 1)));
393 	LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx+1].ctrl,
394 				0);
395 #endif
396 
397 	/*
398 	 * The IRQ controller may (if implemented) consist of multiple
399 	 * IRQ controllers, each mapped on a 4Kb boundary.
400 	 * Each CPU may be routed to different IRQCTRLs, however
401 	 * we assume that all CPUs (in SMP system) is routed to the
402 	 * same IRQ Controller, and for non-SMP only one IRQCTRL is
403 	 * accessed anyway.
404 	 * In AMP systems, Linux must run on CPU0 for the time being.
405 	 */
406 	icsel = LEON3_BYPASS_LOAD_PA(&leon3_irqctrl_regs->icsel[boot_cpu_id/8]);
407 	icsel = (icsel >> ((7 - (boot_cpu_id&0x7)) * 4)) & 0xf;
408 	leon3_irqctrl_regs += icsel;
409 
410 	/* Mask all IRQs on boot-cpu IRQ controller */
411 	LEON3_BYPASS_STORE_PA(&leon3_irqctrl_regs->mask[boot_cpu_id], 0);
412 
413 	/* Probe extended IRQ controller */
414 	eirq = (LEON3_BYPASS_LOAD_PA(&leon3_irqctrl_regs->mpstatus)
415 		>> 16) & 0xf;
416 	if (eirq != 0)
417 		leon_eirq_setup(eirq);
418 
419 	irq = _leon_build_device_irq(NULL, leon3_gptimer_irq+leon3_gptimer_idx);
420 	err = request_irq(irq, timer_interrupt, IRQF_TIMER, "timer", NULL);
421 	if (err) {
422 		printk(KERN_ERR "unable to attach timer IRQ%d\n", irq);
423 		prom_halt();
424 	}
425 
426 #ifdef CONFIG_SMP
427 	{
428 		unsigned long flags;
429 
430 		/*
431 		 * In SMP, sun4m adds a IPI handler to IRQ trap handler that
432 		 * LEON never must take, sun4d and LEON overwrites the branch
433 		 * with a NOP.
434 		 */
435 		local_irq_save(flags);
436 		patchme_maybe_smp_msg[0] = 0x01000000; /* NOP out the branch */
437 		local_ops->cache_all();
438 		local_irq_restore(flags);
439 	}
440 #endif
441 
442 	LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl,
443 			      LEON3_GPTIMER_EN |
444 			      LEON3_GPTIMER_RL |
445 			      LEON3_GPTIMER_LD |
446 			      LEON3_GPTIMER_IRQEN);
447 
448 #ifdef CONFIG_SMP
449 	/* Install per-cpu IRQ handler for broadcasted ticker */
450 	irq = leon_build_device_irq(leon3_ticker_irq, handle_percpu_irq,
451 				    "per-cpu", 0);
452 	err = request_irq(irq, leon_percpu_timer_ce_interrupt,
453 			  IRQF_PERCPU | IRQF_TIMER, "ticker",
454 			  NULL);
455 	if (err) {
456 		printk(KERN_ERR "unable to attach ticker IRQ%d\n", irq);
457 		prom_halt();
458 	}
459 
460 	LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx+1].ctrl,
461 			      LEON3_GPTIMER_EN |
462 			      LEON3_GPTIMER_RL |
463 			      LEON3_GPTIMER_LD |
464 			      LEON3_GPTIMER_IRQEN);
465 #endif
466 	return;
467 bad:
468 	printk(KERN_ERR "No Timer/irqctrl found\n");
469 	BUG();
470 	return;
471 }
472 
473 static void leon_clear_clock_irq(void)
474 {
475 }
476 
477 static void leon_load_profile_irq(int cpu, unsigned int limit)
478 {
479 }
480 
481 void __init leon_trans_init(struct device_node *dp)
482 {
483 	if (strcmp(dp->type, "cpu") == 0 && strcmp(dp->name, "<NULL>") == 0) {
484 		struct property *p;
485 		p = of_find_property(dp, "mid", (void *)0);
486 		if (p) {
487 			int mid;
488 			dp->name = prom_early_alloc(5 + 1);
489 			memcpy(&mid, p->value, p->length);
490 			sprintf((char *)dp->name, "cpu%.2d", mid);
491 		}
492 	}
493 }
494 
495 #ifdef CONFIG_SMP
496 void leon_clear_profile_irq(int cpu)
497 {
498 }
499 
500 void leon_enable_irq_cpu(unsigned int irq_nr, unsigned int cpu)
501 {
502 	unsigned long mask, flags, *addr;
503 	mask = leon_get_irqmask(irq_nr);
504 	spin_lock_irqsave(&leon_irq_lock, flags);
505 	addr = (unsigned long *)LEON_IMASK(cpu);
506 	LEON3_BYPASS_STORE_PA(addr, (LEON3_BYPASS_LOAD_PA(addr) | mask));
507 	spin_unlock_irqrestore(&leon_irq_lock, flags);
508 }
509 
510 #endif
511 
512 void __init leon_init_IRQ(void)
513 {
514 	sparc_config.init_timers      = leon_init_timers;
515 	sparc_config.build_device_irq = _leon_build_device_irq;
516 	sparc_config.clock_rate       = 1000000;
517 	sparc_config.clear_clock_irq  = leon_clear_clock_irq;
518 	sparc_config.load_profile_irq = leon_load_profile_irq;
519 }
520