xref: /openbmc/linux/arch/sparc/kernel/leon_kernel.c (revision 4a44a19b)
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 volatile u32 dummy_master_l10_counter;
36 unsigned long amba_system_id;
37 static DEFINE_SPINLOCK(leon_irq_lock);
38 
39 static unsigned long leon3_gptimer_idx; /* Timer Index (0..6) within Timer Core */
40 static unsigned long leon3_gptimer_ackmask; /* For clearing pending bit */
41 unsigned long leon3_gptimer_irq; /* interrupt controller irq number */
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 static 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, ctrl, off;
265 
266 	rld = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].rld);
267 	val = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].val);
268 	ctrl = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl);
269 	if (LEON3_GPTIMER_CTRL_ISPENDING(ctrl)) {
270 		val = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].val);
271 		off = 2 * rld - val;
272 	} else {
273 		off = rld - val;
274 	}
275 
276 	return off;
277 }
278 
279 #ifdef CONFIG_SMP
280 
281 /* smp clockevent irq */
282 static irqreturn_t leon_percpu_timer_ce_interrupt(int irq, void *unused)
283 {
284 	struct clock_event_device *ce;
285 	int cpu = smp_processor_id();
286 
287 	leon_clear_profile_irq(cpu);
288 
289 	if (cpu == boot_cpu_id)
290 		timer_interrupt(irq, NULL);
291 
292 	ce = &per_cpu(sparc32_clockevent, cpu);
293 
294 	irq_enter();
295 	if (ce->event_handler)
296 		ce->event_handler(ce);
297 	irq_exit();
298 
299 	return IRQ_HANDLED;
300 }
301 
302 #endif /* CONFIG_SMP */
303 
304 void __init leon_init_timers(void)
305 {
306 	int irq, eirq;
307 	struct device_node *rootnp, *np, *nnp;
308 	struct property *pp;
309 	int len;
310 	int icsel;
311 	int ampopts;
312 	int err;
313 	u32 config;
314 	u32 ctrl;
315 
316 	sparc_config.get_cycles_offset = leon_cycles_offset;
317 	sparc_config.cs_period = 1000000 / HZ;
318 	sparc_config.features |= FEAT_L10_CLOCKSOURCE;
319 
320 #ifndef CONFIG_SMP
321 	sparc_config.features |= FEAT_L10_CLOCKEVENT;
322 #endif
323 
324 	leondebug_irq_disable = 0;
325 	leon_debug_irqout = 0;
326 	master_l10_counter = (u32 __iomem *)&dummy_master_l10_counter;
327 	dummy_master_l10_counter = 0;
328 
329 	rootnp = of_find_node_by_path("/ambapp0");
330 	if (!rootnp)
331 		goto bad;
332 
333 	/* Find System ID: GRLIB build ID and optional CHIP ID */
334 	pp = of_find_property(rootnp, "systemid", &len);
335 	if (pp)
336 		amba_system_id = *(unsigned long *)pp->value;
337 
338 	/* Find IRQMP IRQ Controller Registers base adr otherwise bail out */
339 	np = of_find_node_by_name(rootnp, "GAISLER_IRQMP");
340 	if (!np) {
341 		np = of_find_node_by_name(rootnp, "01_00d");
342 		if (!np)
343 			goto bad;
344 	}
345 	pp = of_find_property(np, "reg", &len);
346 	if (!pp)
347 		goto bad;
348 	leon3_irqctrl_regs = *(struct leon3_irqctrl_regs_map **)pp->value;
349 
350 	/* Find GPTIMER Timer Registers base address otherwise bail out. */
351 	nnp = rootnp;
352 	do {
353 		np = of_find_node_by_name(nnp, "GAISLER_GPTIMER");
354 		if (!np) {
355 			np = of_find_node_by_name(nnp, "01_011");
356 			if (!np)
357 				goto bad;
358 		}
359 
360 		ampopts = 0;
361 		pp = of_find_property(np, "ampopts", &len);
362 		if (pp) {
363 			ampopts = *(int *)pp->value;
364 			if (ampopts == 0) {
365 				/* Skip this instance, resource already
366 				 * allocated by other OS */
367 				nnp = np;
368 				continue;
369 			}
370 		}
371 
372 		/* Select Timer-Instance on Timer Core. Default is zero */
373 		leon3_gptimer_idx = ampopts & 0x7;
374 
375 		pp = of_find_property(np, "reg", &len);
376 		if (pp)
377 			leon3_gptimer_regs = *(struct leon3_gptimer_regs_map **)
378 						pp->value;
379 		pp = of_find_property(np, "interrupts", &len);
380 		if (pp)
381 			leon3_gptimer_irq = *(unsigned int *)pp->value;
382 	} while (0);
383 
384 	if (!(leon3_gptimer_regs && leon3_irqctrl_regs && leon3_gptimer_irq))
385 		goto bad;
386 
387 	ctrl = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl);
388 	LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl,
389 			      ctrl | LEON3_GPTIMER_CTRL_PENDING);
390 	ctrl = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl);
391 
392 	if ((ctrl & LEON3_GPTIMER_CTRL_PENDING) != 0)
393 		leon3_gptimer_ackmask = ~LEON3_GPTIMER_CTRL_PENDING;
394 	else
395 		leon3_gptimer_ackmask = ~0;
396 
397 	LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].val, 0);
398 	LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].rld,
399 				(((1000000 / HZ) - 1)));
400 	LEON3_BYPASS_STORE_PA(
401 			&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl, 0);
402 
403 	/*
404 	 * The IRQ controller may (if implemented) consist of multiple
405 	 * IRQ controllers, each mapped on a 4Kb boundary.
406 	 * Each CPU may be routed to different IRQCTRLs, however
407 	 * we assume that all CPUs (in SMP system) is routed to the
408 	 * same IRQ Controller, and for non-SMP only one IRQCTRL is
409 	 * accessed anyway.
410 	 * In AMP systems, Linux must run on CPU0 for the time being.
411 	 */
412 	icsel = LEON3_BYPASS_LOAD_PA(&leon3_irqctrl_regs->icsel[boot_cpu_id/8]);
413 	icsel = (icsel >> ((7 - (boot_cpu_id&0x7)) * 4)) & 0xf;
414 	leon3_irqctrl_regs += icsel;
415 
416 	/* Mask all IRQs on boot-cpu IRQ controller */
417 	LEON3_BYPASS_STORE_PA(&leon3_irqctrl_regs->mask[boot_cpu_id], 0);
418 
419 	/* Probe extended IRQ controller */
420 	eirq = (LEON3_BYPASS_LOAD_PA(&leon3_irqctrl_regs->mpstatus)
421 		>> 16) & 0xf;
422 	if (eirq != 0)
423 		leon_eirq_setup(eirq);
424 
425 #ifdef CONFIG_SMP
426 	{
427 		unsigned long flags;
428 
429 		/*
430 		 * In SMP, sun4m adds a IPI handler to IRQ trap handler that
431 		 * LEON never must take, sun4d and LEON overwrites the branch
432 		 * with a NOP.
433 		 */
434 		local_irq_save(flags);
435 		patchme_maybe_smp_msg[0] = 0x01000000; /* NOP out the branch */
436 		local_ops->cache_all();
437 		local_irq_restore(flags);
438 	}
439 #endif
440 
441 	config = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->config);
442 	if (config & (1 << LEON3_GPTIMER_SEPIRQ))
443 		leon3_gptimer_irq += leon3_gptimer_idx;
444 	else if ((config & LEON3_GPTIMER_TIMERS) > 1)
445 		pr_warn("GPTIMER uses shared irqs, using other timers of the same core will fail.\n");
446 
447 #ifdef CONFIG_SMP
448 	/* Install per-cpu IRQ handler for broadcasted ticker */
449 	irq = leon_build_device_irq(leon3_gptimer_irq, handle_percpu_irq,
450 				    "per-cpu", 0);
451 	err = request_irq(irq, leon_percpu_timer_ce_interrupt,
452 			  IRQF_PERCPU | IRQF_TIMER, "timer", NULL);
453 #else
454 	irq = _leon_build_device_irq(NULL, leon3_gptimer_irq);
455 	err = request_irq(irq, timer_interrupt, IRQF_TIMER, "timer", NULL);
456 #endif
457 	if (err) {
458 		pr_err("Unable to attach timer IRQ%d\n", irq);
459 		prom_halt();
460 	}
461 	LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl,
462 			      LEON3_GPTIMER_EN |
463 			      LEON3_GPTIMER_RL |
464 			      LEON3_GPTIMER_LD |
465 			      LEON3_GPTIMER_IRQEN);
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 	u32 ctrl;
476 
477 	ctrl = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl);
478 	LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl,
479 			      ctrl & leon3_gptimer_ackmask);
480 }
481 
482 static void leon_load_profile_irq(int cpu, unsigned int limit)
483 {
484 }
485 
486 void __init leon_trans_init(struct device_node *dp)
487 {
488 	if (strcmp(dp->type, "cpu") == 0 && strcmp(dp->name, "<NULL>") == 0) {
489 		struct property *p;
490 		p = of_find_property(dp, "mid", (void *)0);
491 		if (p) {
492 			int mid;
493 			dp->name = prom_early_alloc(5 + 1);
494 			memcpy(&mid, p->value, p->length);
495 			sprintf((char *)dp->name, "cpu%.2d", mid);
496 		}
497 	}
498 }
499 
500 #ifdef CONFIG_SMP
501 void leon_clear_profile_irq(int cpu)
502 {
503 }
504 
505 void leon_enable_irq_cpu(unsigned int irq_nr, unsigned int cpu)
506 {
507 	unsigned long mask, flags, *addr;
508 	mask = leon_get_irqmask(irq_nr);
509 	spin_lock_irqsave(&leon_irq_lock, flags);
510 	addr = (unsigned long *)LEON_IMASK(cpu);
511 	LEON3_BYPASS_STORE_PA(addr, (LEON3_BYPASS_LOAD_PA(addr) | mask));
512 	spin_unlock_irqrestore(&leon_irq_lock, flags);
513 }
514 
515 #endif
516 
517 void __init leon_init_IRQ(void)
518 {
519 	sparc_config.init_timers      = leon_init_timers;
520 	sparc_config.build_device_irq = _leon_build_device_irq;
521 	sparc_config.clock_rate       = 1000000;
522 	sparc_config.clear_clock_irq  = leon_clear_clock_irq;
523 	sparc_config.load_profile_irq = leon_load_profile_irq;
524 }
525