xref: /openbmc/linux/arch/sparc/kernel/leon_kernel.c (revision 95e9fd10)
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 	int cpu = sparc_leon3_cpuid();
60 
61 	eirq = leon_eirq_get(cpu);
62 	if ((eirq & 0x10) && irq_map[eirq]->irq) /* bit4 tells if IRQ happened */
63 		generic_handle_irq(irq_map[eirq]->irq);
64 }
65 
66 /* The extended IRQ controller has been found, this function registers it */
67 void leon_eirq_setup(unsigned int eirq)
68 {
69 	unsigned long mask, oldmask;
70 	unsigned int veirq;
71 
72 	if (eirq < 1 || eirq > 0xf) {
73 		printk(KERN_ERR "LEON EXT IRQ NUMBER BAD: %d\n", eirq);
74 		return;
75 	}
76 
77 	veirq = leon_build_device_irq(eirq, leon_handle_ext_irq, "extirq", 0);
78 
79 	/*
80 	 * Unmask the Extended IRQ, the IRQs routed through the Ext-IRQ
81 	 * controller have a mask-bit of their own, so this is safe.
82 	 */
83 	irq_link(veirq);
84 	mask = 1 << eirq;
85 	oldmask = LEON3_BYPASS_LOAD_PA(LEON_IMASK(boot_cpu_id));
86 	LEON3_BYPASS_STORE_PA(LEON_IMASK(boot_cpu_id), (oldmask | mask));
87 	sparc_leon_eirq = eirq;
88 }
89 
90 unsigned long leon_get_irqmask(unsigned int irq)
91 {
92 	unsigned long mask;
93 
94 	if (!irq || ((irq > 0xf) && !sparc_leon_eirq)
95 	    || ((irq > 0x1f) && sparc_leon_eirq)) {
96 		printk(KERN_ERR
97 		       "leon_get_irqmask: false irq number: %d\n", irq);
98 		mask = 0;
99 	} else {
100 		mask = LEON_HARD_INT(irq);
101 	}
102 	return mask;
103 }
104 
105 #ifdef CONFIG_SMP
106 static int irq_choose_cpu(const struct cpumask *affinity)
107 {
108 	cpumask_t mask;
109 
110 	cpumask_and(&mask, cpu_online_mask, affinity);
111 	if (cpumask_equal(&mask, cpu_online_mask) || cpumask_empty(&mask))
112 		return boot_cpu_id;
113 	else
114 		return cpumask_first(&mask);
115 }
116 #else
117 #define irq_choose_cpu(affinity) boot_cpu_id
118 #endif
119 
120 static int leon_set_affinity(struct irq_data *data, const struct cpumask *dest,
121 			     bool force)
122 {
123 	unsigned long mask, oldmask, flags;
124 	int oldcpu, newcpu;
125 
126 	mask = (unsigned long)data->chip_data;
127 	oldcpu = irq_choose_cpu(data->affinity);
128 	newcpu = irq_choose_cpu(dest);
129 
130 	if (oldcpu == newcpu)
131 		goto out;
132 
133 	/* unmask on old CPU first before enabling on the selected CPU */
134 	spin_lock_irqsave(&leon_irq_lock, flags);
135 	oldmask = LEON3_BYPASS_LOAD_PA(LEON_IMASK(oldcpu));
136 	LEON3_BYPASS_STORE_PA(LEON_IMASK(oldcpu), (oldmask & ~mask));
137 	oldmask = LEON3_BYPASS_LOAD_PA(LEON_IMASK(newcpu));
138 	LEON3_BYPASS_STORE_PA(LEON_IMASK(newcpu), (oldmask | mask));
139 	spin_unlock_irqrestore(&leon_irq_lock, flags);
140 out:
141 	return IRQ_SET_MASK_OK;
142 }
143 
144 static void leon_unmask_irq(struct irq_data *data)
145 {
146 	unsigned long mask, oldmask, flags;
147 	int cpu;
148 
149 	mask = (unsigned long)data->chip_data;
150 	cpu = irq_choose_cpu(data->affinity);
151 	spin_lock_irqsave(&leon_irq_lock, flags);
152 	oldmask = LEON3_BYPASS_LOAD_PA(LEON_IMASK(cpu));
153 	LEON3_BYPASS_STORE_PA(LEON_IMASK(cpu), (oldmask | mask));
154 	spin_unlock_irqrestore(&leon_irq_lock, flags);
155 }
156 
157 static void leon_mask_irq(struct irq_data *data)
158 {
159 	unsigned long mask, oldmask, flags;
160 	int cpu;
161 
162 	mask = (unsigned long)data->chip_data;
163 	cpu = irq_choose_cpu(data->affinity);
164 	spin_lock_irqsave(&leon_irq_lock, flags);
165 	oldmask = LEON3_BYPASS_LOAD_PA(LEON_IMASK(cpu));
166 	LEON3_BYPASS_STORE_PA(LEON_IMASK(cpu), (oldmask & ~mask));
167 	spin_unlock_irqrestore(&leon_irq_lock, flags);
168 }
169 
170 static unsigned int leon_startup_irq(struct irq_data *data)
171 {
172 	irq_link(data->irq);
173 	leon_unmask_irq(data);
174 	return 0;
175 }
176 
177 static void leon_shutdown_irq(struct irq_data *data)
178 {
179 	leon_mask_irq(data);
180 	irq_unlink(data->irq);
181 }
182 
183 /* Used by external level sensitive IRQ handlers on the LEON: ACK IRQ ctrl */
184 static void leon_eoi_irq(struct irq_data *data)
185 {
186 	unsigned long mask = (unsigned long)data->chip_data;
187 
188 	if (mask & LEON_DO_ACK_HW)
189 		LEON3_BYPASS_STORE_PA(LEON_IACK, mask & ~LEON_DO_ACK_HW);
190 }
191 
192 static struct irq_chip leon_irq = {
193 	.name			= "leon",
194 	.irq_startup		= leon_startup_irq,
195 	.irq_shutdown		= leon_shutdown_irq,
196 	.irq_mask		= leon_mask_irq,
197 	.irq_unmask		= leon_unmask_irq,
198 	.irq_eoi		= leon_eoi_irq,
199 	.irq_set_affinity	= leon_set_affinity,
200 };
201 
202 /*
203  * Build a LEON IRQ for the edge triggered LEON IRQ controller:
204  *  Edge (normal) IRQ           - handle_simple_irq, ack=DONT-CARE, never ack
205  *  Level IRQ (PCI|Level-GPIO)  - handle_fasteoi_irq, ack=1, ack after ISR
206  *  Per-CPU Edge                - handle_percpu_irq, ack=0
207  */
208 unsigned int leon_build_device_irq(unsigned int real_irq,
209 				    irq_flow_handler_t flow_handler,
210 				    const char *name, int do_ack)
211 {
212 	unsigned int irq;
213 	unsigned long mask;
214 
215 	irq = 0;
216 	mask = leon_get_irqmask(real_irq);
217 	if (mask == 0)
218 		goto out;
219 
220 	irq = irq_alloc(real_irq, real_irq);
221 	if (irq == 0)
222 		goto out;
223 
224 	if (do_ack)
225 		mask |= LEON_DO_ACK_HW;
226 
227 	irq_set_chip_and_handler_name(irq, &leon_irq,
228 				      flow_handler, name);
229 	irq_set_chip_data(irq, (void *)mask);
230 
231 out:
232 	return irq;
233 }
234 
235 static unsigned int _leon_build_device_irq(struct platform_device *op,
236 					   unsigned int real_irq)
237 {
238 	return leon_build_device_irq(real_irq, handle_simple_irq, "edge", 0);
239 }
240 
241 void leon_update_virq_handling(unsigned int virq,
242 			      irq_flow_handler_t flow_handler,
243 			      const char *name, int do_ack)
244 {
245 	unsigned long mask = (unsigned long)irq_get_chip_data(virq);
246 
247 	mask &= ~LEON_DO_ACK_HW;
248 	if (do_ack)
249 		mask |= LEON_DO_ACK_HW;
250 
251 	irq_set_chip_and_handler_name(virq, &leon_irq,
252 				      flow_handler, name);
253 	irq_set_chip_data(virq, (void *)mask);
254 }
255 
256 static u32 leon_cycles_offset(void)
257 {
258 	u32 rld, val, off;
259 	rld = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].rld);
260 	val = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].val);
261 	off = rld - val;
262 	return rld - val;
263 }
264 
265 #ifdef CONFIG_SMP
266 
267 /* smp clockevent irq */
268 irqreturn_t leon_percpu_timer_ce_interrupt(int irq, void *unused)
269 {
270 	struct clock_event_device *ce;
271 	int cpu = smp_processor_id();
272 
273 	leon_clear_profile_irq(cpu);
274 
275 	ce = &per_cpu(sparc32_clockevent, cpu);
276 
277 	irq_enter();
278 	if (ce->event_handler)
279 		ce->event_handler(ce);
280 	irq_exit();
281 
282 	return IRQ_HANDLED;
283 }
284 
285 #endif /* CONFIG_SMP */
286 
287 void __init leon_init_timers(void)
288 {
289 	int irq, eirq;
290 	struct device_node *rootnp, *np, *nnp;
291 	struct property *pp;
292 	int len;
293 	int icsel;
294 	int ampopts;
295 	int err;
296 
297 	sparc_config.get_cycles_offset = leon_cycles_offset;
298 	sparc_config.cs_period = 1000000 / HZ;
299 	sparc_config.features |= FEAT_L10_CLOCKSOURCE;
300 
301 #ifndef CONFIG_SMP
302 	sparc_config.features |= FEAT_L10_CLOCKEVENT;
303 #endif
304 
305 	leondebug_irq_disable = 0;
306 	leon_debug_irqout = 0;
307 	master_l10_counter = (unsigned int *)&dummy_master_l10_counter;
308 	dummy_master_l10_counter = 0;
309 
310 	rootnp = of_find_node_by_path("/ambapp0");
311 	if (!rootnp)
312 		goto bad;
313 
314 	/* Find System ID: GRLIB build ID and optional CHIP ID */
315 	pp = of_find_property(rootnp, "systemid", &len);
316 	if (pp)
317 		amba_system_id = *(unsigned long *)pp->value;
318 
319 	/* Find IRQMP IRQ Controller Registers base adr otherwise bail out */
320 	np = of_find_node_by_name(rootnp, "GAISLER_IRQMP");
321 	if (!np) {
322 		np = of_find_node_by_name(rootnp, "01_00d");
323 		if (!np)
324 			goto bad;
325 	}
326 	pp = of_find_property(np, "reg", &len);
327 	if (!pp)
328 		goto bad;
329 	leon3_irqctrl_regs = *(struct leon3_irqctrl_regs_map **)pp->value;
330 
331 	/* Find GPTIMER Timer Registers base address otherwise bail out. */
332 	nnp = rootnp;
333 	do {
334 		np = of_find_node_by_name(nnp, "GAISLER_GPTIMER");
335 		if (!np) {
336 			np = of_find_node_by_name(nnp, "01_011");
337 			if (!np)
338 				goto bad;
339 		}
340 
341 		ampopts = 0;
342 		pp = of_find_property(np, "ampopts", &len);
343 		if (pp) {
344 			ampopts = *(int *)pp->value;
345 			if (ampopts == 0) {
346 				/* Skip this instance, resource already
347 				 * allocated by other OS */
348 				nnp = np;
349 				continue;
350 			}
351 		}
352 
353 		/* Select Timer-Instance on Timer Core. Default is zero */
354 		leon3_gptimer_idx = ampopts & 0x7;
355 
356 		pp = of_find_property(np, "reg", &len);
357 		if (pp)
358 			leon3_gptimer_regs = *(struct leon3_gptimer_regs_map **)
359 						pp->value;
360 		pp = of_find_property(np, "interrupts", &len);
361 		if (pp)
362 			leon3_gptimer_irq = *(unsigned int *)pp->value;
363 	} while (0);
364 
365 	if (!(leon3_gptimer_regs && leon3_irqctrl_regs && leon3_gptimer_irq))
366 		goto bad;
367 
368 	LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].val, 0);
369 	LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].rld,
370 				(((1000000 / HZ) - 1)));
371 	LEON3_BYPASS_STORE_PA(
372 			&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl, 0);
373 
374 #ifdef CONFIG_SMP
375 	leon3_ticker_irq = leon3_gptimer_irq + 1 + leon3_gptimer_idx;
376 
377 	if (!(LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->config) &
378 	      (1<<LEON3_GPTIMER_SEPIRQ))) {
379 		printk(KERN_ERR "timer not configured with separate irqs\n");
380 		BUG();
381 	}
382 
383 	LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx+1].val,
384 				0);
385 	LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx+1].rld,
386 				(((1000000/HZ) - 1)));
387 	LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx+1].ctrl,
388 				0);
389 #endif
390 
391 	/*
392 	 * The IRQ controller may (if implemented) consist of multiple
393 	 * IRQ controllers, each mapped on a 4Kb boundary.
394 	 * Each CPU may be routed to different IRQCTRLs, however
395 	 * we assume that all CPUs (in SMP system) is routed to the
396 	 * same IRQ Controller, and for non-SMP only one IRQCTRL is
397 	 * accessed anyway.
398 	 * In AMP systems, Linux must run on CPU0 for the time being.
399 	 */
400 	icsel = LEON3_BYPASS_LOAD_PA(&leon3_irqctrl_regs->icsel[boot_cpu_id/8]);
401 	icsel = (icsel >> ((7 - (boot_cpu_id&0x7)) * 4)) & 0xf;
402 	leon3_irqctrl_regs += icsel;
403 
404 	/* Mask all IRQs on boot-cpu IRQ controller */
405 	LEON3_BYPASS_STORE_PA(&leon3_irqctrl_regs->mask[boot_cpu_id], 0);
406 
407 	/* Probe extended IRQ controller */
408 	eirq = (LEON3_BYPASS_LOAD_PA(&leon3_irqctrl_regs->mpstatus)
409 		>> 16) & 0xf;
410 	if (eirq != 0)
411 		leon_eirq_setup(eirq);
412 
413 	irq = _leon_build_device_irq(NULL, leon3_gptimer_irq+leon3_gptimer_idx);
414 	err = request_irq(irq, timer_interrupt, IRQF_TIMER, "timer", NULL);
415 	if (err) {
416 		printk(KERN_ERR "unable to attach timer IRQ%d\n", irq);
417 		prom_halt();
418 	}
419 
420 #ifdef CONFIG_SMP
421 	{
422 		unsigned long flags;
423 
424 		/*
425 		 * In SMP, sun4m adds a IPI handler to IRQ trap handler that
426 		 * LEON never must take, sun4d and LEON overwrites the branch
427 		 * with a NOP.
428 		 */
429 		local_irq_save(flags);
430 		patchme_maybe_smp_msg[0] = 0x01000000; /* NOP out the branch */
431 		local_ops->cache_all();
432 		local_irq_restore(flags);
433 	}
434 #endif
435 
436 	LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl,
437 			      LEON3_GPTIMER_EN |
438 			      LEON3_GPTIMER_RL |
439 			      LEON3_GPTIMER_LD |
440 			      LEON3_GPTIMER_IRQEN);
441 
442 #ifdef CONFIG_SMP
443 	/* Install per-cpu IRQ handler for broadcasted ticker */
444 	irq = leon_build_device_irq(leon3_ticker_irq, handle_percpu_irq,
445 				    "per-cpu", 0);
446 	err = request_irq(irq, leon_percpu_timer_ce_interrupt,
447 			  IRQF_PERCPU | IRQF_TIMER, "ticker",
448 			  NULL);
449 	if (err) {
450 		printk(KERN_ERR "unable to attach ticker IRQ%d\n", irq);
451 		prom_halt();
452 	}
453 
454 	LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx+1].ctrl,
455 			      LEON3_GPTIMER_EN |
456 			      LEON3_GPTIMER_RL |
457 			      LEON3_GPTIMER_LD |
458 			      LEON3_GPTIMER_IRQEN);
459 #endif
460 	return;
461 bad:
462 	printk(KERN_ERR "No Timer/irqctrl found\n");
463 	BUG();
464 	return;
465 }
466 
467 static void leon_clear_clock_irq(void)
468 {
469 }
470 
471 static void leon_load_profile_irq(int cpu, unsigned int limit)
472 {
473 }
474 
475 void __init leon_trans_init(struct device_node *dp)
476 {
477 	if (strcmp(dp->type, "cpu") == 0 && strcmp(dp->name, "<NULL>") == 0) {
478 		struct property *p;
479 		p = of_find_property(dp, "mid", (void *)0);
480 		if (p) {
481 			int mid;
482 			dp->name = prom_early_alloc(5 + 1);
483 			memcpy(&mid, p->value, p->length);
484 			sprintf((char *)dp->name, "cpu%.2d", mid);
485 		}
486 	}
487 }
488 
489 #ifdef CONFIG_SMP
490 void leon_clear_profile_irq(int cpu)
491 {
492 }
493 
494 void leon_enable_irq_cpu(unsigned int irq_nr, unsigned int cpu)
495 {
496 	unsigned long mask, flags, *addr;
497 	mask = leon_get_irqmask(irq_nr);
498 	spin_lock_irqsave(&leon_irq_lock, flags);
499 	addr = (unsigned long *)LEON_IMASK(cpu);
500 	LEON3_BYPASS_STORE_PA(addr, (LEON3_BYPASS_LOAD_PA(addr) | mask));
501 	spin_unlock_irqrestore(&leon_irq_lock, flags);
502 }
503 
504 #endif
505 
506 void __init leon_init_IRQ(void)
507 {
508 	sparc_config.init_timers      = leon_init_timers;
509 	sparc_config.build_device_irq = _leon_build_device_irq;
510 	sparc_config.clock_rate       = 1000000;
511 	sparc_config.clear_clock_irq  = leon_clear_clock_irq;
512 	sparc_config.load_profile_irq = leon_load_profile_irq;
513 }
514