xref: /openbmc/linux/arch/sparc/kernel/leon_kernel.c (revision 12eb4683)
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 unsigned int sparc_leon_eirq;
42 #define LEON_IMASK(cpu) (&leon3_irqctrl_regs->mask[cpu])
43 #define LEON_IACK (&leon3_irqctrl_regs->iclear)
44 #define LEON_DO_ACK_HW 1
45 
46 /* Return the last ACKed IRQ by the Extended IRQ controller. It has already
47  * been (automatically) ACKed when the CPU takes the trap.
48  */
49 static inline unsigned int leon_eirq_get(int cpu)
50 {
51 	return LEON3_BYPASS_LOAD_PA(&leon3_irqctrl_regs->intid[cpu]) & 0x1f;
52 }
53 
54 /* Handle one or multiple IRQs from the extended interrupt controller */
55 static void leon_handle_ext_irq(unsigned int irq, struct irq_desc *desc)
56 {
57 	unsigned int eirq;
58 	struct irq_bucket *p;
59 	int cpu = sparc_leon3_cpuid();
60 
61 	eirq = leon_eirq_get(cpu);
62 	p = irq_map[eirq];
63 	if ((eirq & 0x10) && p && p->irq) /* bit4 tells if IRQ happened */
64 		generic_handle_irq(p->irq);
65 }
66 
67 /* The extended IRQ controller has been found, this function registers it */
68 void leon_eirq_setup(unsigned int eirq)
69 {
70 	unsigned long mask, oldmask;
71 	unsigned int veirq;
72 
73 	if (eirq < 1 || eirq > 0xf) {
74 		printk(KERN_ERR "LEON EXT IRQ NUMBER BAD: %d\n", eirq);
75 		return;
76 	}
77 
78 	veirq = leon_build_device_irq(eirq, leon_handle_ext_irq, "extirq", 0);
79 
80 	/*
81 	 * Unmask the Extended IRQ, the IRQs routed through the Ext-IRQ
82 	 * controller have a mask-bit of their own, so this is safe.
83 	 */
84 	irq_link(veirq);
85 	mask = 1 << eirq;
86 	oldmask = LEON3_BYPASS_LOAD_PA(LEON_IMASK(boot_cpu_id));
87 	LEON3_BYPASS_STORE_PA(LEON_IMASK(boot_cpu_id), (oldmask | mask));
88 	sparc_leon_eirq = eirq;
89 }
90 
91 unsigned long leon_get_irqmask(unsigned int irq)
92 {
93 	unsigned long mask;
94 
95 	if (!irq || ((irq > 0xf) && !sparc_leon_eirq)
96 	    || ((irq > 0x1f) && sparc_leon_eirq)) {
97 		printk(KERN_ERR
98 		       "leon_get_irqmask: false irq number: %d\n", irq);
99 		mask = 0;
100 	} else {
101 		mask = LEON_HARD_INT(irq);
102 	}
103 	return mask;
104 }
105 
106 #ifdef CONFIG_SMP
107 static int irq_choose_cpu(const struct cpumask *affinity)
108 {
109 	cpumask_t mask;
110 
111 	cpumask_and(&mask, cpu_online_mask, affinity);
112 	if (cpumask_equal(&mask, cpu_online_mask) || cpumask_empty(&mask))
113 		return boot_cpu_id;
114 	else
115 		return cpumask_first(&mask);
116 }
117 #else
118 #define irq_choose_cpu(affinity) boot_cpu_id
119 #endif
120 
121 static int leon_set_affinity(struct irq_data *data, const struct cpumask *dest,
122 			     bool force)
123 {
124 	unsigned long mask, oldmask, flags;
125 	int oldcpu, newcpu;
126 
127 	mask = (unsigned long)data->chip_data;
128 	oldcpu = irq_choose_cpu(data->affinity);
129 	newcpu = irq_choose_cpu(dest);
130 
131 	if (oldcpu == newcpu)
132 		goto out;
133 
134 	/* unmask on old CPU first before enabling on the selected CPU */
135 	spin_lock_irqsave(&leon_irq_lock, flags);
136 	oldmask = LEON3_BYPASS_LOAD_PA(LEON_IMASK(oldcpu));
137 	LEON3_BYPASS_STORE_PA(LEON_IMASK(oldcpu), (oldmask & ~mask));
138 	oldmask = LEON3_BYPASS_LOAD_PA(LEON_IMASK(newcpu));
139 	LEON3_BYPASS_STORE_PA(LEON_IMASK(newcpu), (oldmask | mask));
140 	spin_unlock_irqrestore(&leon_irq_lock, flags);
141 out:
142 	return IRQ_SET_MASK_OK;
143 }
144 
145 static void leon_unmask_irq(struct irq_data *data)
146 {
147 	unsigned long mask, oldmask, flags;
148 	int cpu;
149 
150 	mask = (unsigned long)data->chip_data;
151 	cpu = irq_choose_cpu(data->affinity);
152 	spin_lock_irqsave(&leon_irq_lock, flags);
153 	oldmask = LEON3_BYPASS_LOAD_PA(LEON_IMASK(cpu));
154 	LEON3_BYPASS_STORE_PA(LEON_IMASK(cpu), (oldmask | mask));
155 	spin_unlock_irqrestore(&leon_irq_lock, flags);
156 }
157 
158 static void leon_mask_irq(struct irq_data *data)
159 {
160 	unsigned long mask, oldmask, flags;
161 	int cpu;
162 
163 	mask = (unsigned long)data->chip_data;
164 	cpu = irq_choose_cpu(data->affinity);
165 	spin_lock_irqsave(&leon_irq_lock, flags);
166 	oldmask = LEON3_BYPASS_LOAD_PA(LEON_IMASK(cpu));
167 	LEON3_BYPASS_STORE_PA(LEON_IMASK(cpu), (oldmask & ~mask));
168 	spin_unlock_irqrestore(&leon_irq_lock, flags);
169 }
170 
171 static unsigned int leon_startup_irq(struct irq_data *data)
172 {
173 	irq_link(data->irq);
174 	leon_unmask_irq(data);
175 	return 0;
176 }
177 
178 static void leon_shutdown_irq(struct irq_data *data)
179 {
180 	leon_mask_irq(data);
181 	irq_unlink(data->irq);
182 }
183 
184 /* Used by external level sensitive IRQ handlers on the LEON: ACK IRQ ctrl */
185 static void leon_eoi_irq(struct irq_data *data)
186 {
187 	unsigned long mask = (unsigned long)data->chip_data;
188 
189 	if (mask & LEON_DO_ACK_HW)
190 		LEON3_BYPASS_STORE_PA(LEON_IACK, mask & ~LEON_DO_ACK_HW);
191 }
192 
193 static struct irq_chip leon_irq = {
194 	.name			= "leon",
195 	.irq_startup		= leon_startup_irq,
196 	.irq_shutdown		= leon_shutdown_irq,
197 	.irq_mask		= leon_mask_irq,
198 	.irq_unmask		= leon_unmask_irq,
199 	.irq_eoi		= leon_eoi_irq,
200 	.irq_set_affinity	= leon_set_affinity,
201 };
202 
203 /*
204  * Build a LEON IRQ for the edge triggered LEON IRQ controller:
205  *  Edge (normal) IRQ           - handle_simple_irq, ack=DONT-CARE, never ack
206  *  Level IRQ (PCI|Level-GPIO)  - handle_fasteoi_irq, ack=1, ack after ISR
207  *  Per-CPU Edge                - handle_percpu_irq, ack=0
208  */
209 unsigned int leon_build_device_irq(unsigned int real_irq,
210 				    irq_flow_handler_t flow_handler,
211 				    const char *name, int do_ack)
212 {
213 	unsigned int irq;
214 	unsigned long mask;
215 	struct irq_desc *desc;
216 
217 	irq = 0;
218 	mask = leon_get_irqmask(real_irq);
219 	if (mask == 0)
220 		goto out;
221 
222 	irq = irq_alloc(real_irq, real_irq);
223 	if (irq == 0)
224 		goto out;
225 
226 	if (do_ack)
227 		mask |= LEON_DO_ACK_HW;
228 
229 	desc = irq_to_desc(irq);
230 	if (!desc || !desc->handle_irq || desc->handle_irq == handle_bad_irq) {
231 		irq_set_chip_and_handler_name(irq, &leon_irq,
232 					      flow_handler, name);
233 		irq_set_chip_data(irq, (void *)mask);
234 	}
235 
236 out:
237 	return irq;
238 }
239 
240 static unsigned int _leon_build_device_irq(struct platform_device *op,
241 					   unsigned int real_irq)
242 {
243 	return leon_build_device_irq(real_irq, handle_simple_irq, "edge", 0);
244 }
245 
246 void leon_update_virq_handling(unsigned int virq,
247 			      irq_flow_handler_t flow_handler,
248 			      const char *name, int do_ack)
249 {
250 	unsigned long mask = (unsigned long)irq_get_chip_data(virq);
251 
252 	mask &= ~LEON_DO_ACK_HW;
253 	if (do_ack)
254 		mask |= LEON_DO_ACK_HW;
255 
256 	irq_set_chip_and_handler_name(virq, &leon_irq,
257 				      flow_handler, name);
258 	irq_set_chip_data(virq, (void *)mask);
259 }
260 
261 static u32 leon_cycles_offset(void)
262 {
263 	u32 rld, val, off;
264 	rld = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].rld);
265 	val = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].val);
266 	off = rld - val;
267 	return rld - val;
268 }
269 
270 #ifdef CONFIG_SMP
271 
272 /* smp clockevent irq */
273 irqreturn_t leon_percpu_timer_ce_interrupt(int irq, void *unused)
274 {
275 	struct clock_event_device *ce;
276 	int cpu = smp_processor_id();
277 
278 	leon_clear_profile_irq(cpu);
279 
280 	if (cpu == boot_cpu_id)
281 		timer_interrupt(irq, NULL);
282 
283 	ce = &per_cpu(sparc32_clockevent, cpu);
284 
285 	irq_enter();
286 	if (ce->event_handler)
287 		ce->event_handler(ce);
288 	irq_exit();
289 
290 	return IRQ_HANDLED;
291 }
292 
293 #endif /* CONFIG_SMP */
294 
295 void __init leon_init_timers(void)
296 {
297 	int irq, eirq;
298 	struct device_node *rootnp, *np, *nnp;
299 	struct property *pp;
300 	int len;
301 	int icsel;
302 	int ampopts;
303 	int err;
304 	u32 config;
305 
306 	sparc_config.get_cycles_offset = leon_cycles_offset;
307 	sparc_config.cs_period = 1000000 / HZ;
308 	sparc_config.features |= FEAT_L10_CLOCKSOURCE;
309 
310 #ifndef CONFIG_SMP
311 	sparc_config.features |= FEAT_L10_CLOCKEVENT;
312 #endif
313 
314 	leondebug_irq_disable = 0;
315 	leon_debug_irqout = 0;
316 	master_l10_counter = (unsigned int *)&dummy_master_l10_counter;
317 	dummy_master_l10_counter = 0;
318 
319 	rootnp = of_find_node_by_path("/ambapp0");
320 	if (!rootnp)
321 		goto bad;
322 
323 	/* Find System ID: GRLIB build ID and optional CHIP ID */
324 	pp = of_find_property(rootnp, "systemid", &len);
325 	if (pp)
326 		amba_system_id = *(unsigned long *)pp->value;
327 
328 	/* Find IRQMP IRQ Controller Registers base adr otherwise bail out */
329 	np = of_find_node_by_name(rootnp, "GAISLER_IRQMP");
330 	if (!np) {
331 		np = of_find_node_by_name(rootnp, "01_00d");
332 		if (!np)
333 			goto bad;
334 	}
335 	pp = of_find_property(np, "reg", &len);
336 	if (!pp)
337 		goto bad;
338 	leon3_irqctrl_regs = *(struct leon3_irqctrl_regs_map **)pp->value;
339 
340 	/* Find GPTIMER Timer Registers base address otherwise bail out. */
341 	nnp = rootnp;
342 	do {
343 		np = of_find_node_by_name(nnp, "GAISLER_GPTIMER");
344 		if (!np) {
345 			np = of_find_node_by_name(nnp, "01_011");
346 			if (!np)
347 				goto bad;
348 		}
349 
350 		ampopts = 0;
351 		pp = of_find_property(np, "ampopts", &len);
352 		if (pp) {
353 			ampopts = *(int *)pp->value;
354 			if (ampopts == 0) {
355 				/* Skip this instance, resource already
356 				 * allocated by other OS */
357 				nnp = np;
358 				continue;
359 			}
360 		}
361 
362 		/* Select Timer-Instance on Timer Core. Default is zero */
363 		leon3_gptimer_idx = ampopts & 0x7;
364 
365 		pp = of_find_property(np, "reg", &len);
366 		if (pp)
367 			leon3_gptimer_regs = *(struct leon3_gptimer_regs_map **)
368 						pp->value;
369 		pp = of_find_property(np, "interrupts", &len);
370 		if (pp)
371 			leon3_gptimer_irq = *(unsigned int *)pp->value;
372 	} while (0);
373 
374 	if (!(leon3_gptimer_regs && leon3_irqctrl_regs && leon3_gptimer_irq))
375 		goto bad;
376 
377 	LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].val, 0);
378 	LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].rld,
379 				(((1000000 / HZ) - 1)));
380 	LEON3_BYPASS_STORE_PA(
381 			&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl, 0);
382 
383 	/*
384 	 * The IRQ controller may (if implemented) consist of multiple
385 	 * IRQ controllers, each mapped on a 4Kb boundary.
386 	 * Each CPU may be routed to different IRQCTRLs, however
387 	 * we assume that all CPUs (in SMP system) is routed to the
388 	 * same IRQ Controller, and for non-SMP only one IRQCTRL is
389 	 * accessed anyway.
390 	 * In AMP systems, Linux must run on CPU0 for the time being.
391 	 */
392 	icsel = LEON3_BYPASS_LOAD_PA(&leon3_irqctrl_regs->icsel[boot_cpu_id/8]);
393 	icsel = (icsel >> ((7 - (boot_cpu_id&0x7)) * 4)) & 0xf;
394 	leon3_irqctrl_regs += icsel;
395 
396 	/* Mask all IRQs on boot-cpu IRQ controller */
397 	LEON3_BYPASS_STORE_PA(&leon3_irqctrl_regs->mask[boot_cpu_id], 0);
398 
399 	/* Probe extended IRQ controller */
400 	eirq = (LEON3_BYPASS_LOAD_PA(&leon3_irqctrl_regs->mpstatus)
401 		>> 16) & 0xf;
402 	if (eirq != 0)
403 		leon_eirq_setup(eirq);
404 
405 #ifdef CONFIG_SMP
406 	{
407 		unsigned long flags;
408 
409 		/*
410 		 * In SMP, sun4m adds a IPI handler to IRQ trap handler that
411 		 * LEON never must take, sun4d and LEON overwrites the branch
412 		 * with a NOP.
413 		 */
414 		local_irq_save(flags);
415 		patchme_maybe_smp_msg[0] = 0x01000000; /* NOP out the branch */
416 		local_ops->cache_all();
417 		local_irq_restore(flags);
418 	}
419 #endif
420 
421 	config = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->config);
422 	if (config & (1 << LEON3_GPTIMER_SEPIRQ))
423 		leon3_gptimer_irq += leon3_gptimer_idx;
424 	else if ((config & LEON3_GPTIMER_TIMERS) > 1)
425 		pr_warn("GPTIMER uses shared irqs, using other timers of the same core will fail.\n");
426 
427 #ifdef CONFIG_SMP
428 	/* Install per-cpu IRQ handler for broadcasted ticker */
429 	irq = leon_build_device_irq(leon3_gptimer_irq, handle_percpu_irq,
430 				    "per-cpu", 0);
431 	err = request_irq(irq, leon_percpu_timer_ce_interrupt,
432 			  IRQF_PERCPU | IRQF_TIMER, "timer", NULL);
433 #else
434 	irq = _leon_build_device_irq(NULL, leon3_gptimer_irq);
435 	err = request_irq(irq, timer_interrupt, IRQF_TIMER, "timer", NULL);
436 #endif
437 	if (err) {
438 		pr_err("Unable to attach timer IRQ%d\n", irq);
439 		prom_halt();
440 	}
441 	LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl,
442 			      LEON3_GPTIMER_EN |
443 			      LEON3_GPTIMER_RL |
444 			      LEON3_GPTIMER_LD |
445 			      LEON3_GPTIMER_IRQEN);
446 	return;
447 bad:
448 	printk(KERN_ERR "No Timer/irqctrl found\n");
449 	BUG();
450 	return;
451 }
452 
453 static void leon_clear_clock_irq(void)
454 {
455 }
456 
457 static void leon_load_profile_irq(int cpu, unsigned int limit)
458 {
459 }
460 
461 void __init leon_trans_init(struct device_node *dp)
462 {
463 	if (strcmp(dp->type, "cpu") == 0 && strcmp(dp->name, "<NULL>") == 0) {
464 		struct property *p;
465 		p = of_find_property(dp, "mid", (void *)0);
466 		if (p) {
467 			int mid;
468 			dp->name = prom_early_alloc(5 + 1);
469 			memcpy(&mid, p->value, p->length);
470 			sprintf((char *)dp->name, "cpu%.2d", mid);
471 		}
472 	}
473 }
474 
475 #ifdef CONFIG_SMP
476 void leon_clear_profile_irq(int cpu)
477 {
478 }
479 
480 void leon_enable_irq_cpu(unsigned int irq_nr, unsigned int cpu)
481 {
482 	unsigned long mask, flags, *addr;
483 	mask = leon_get_irqmask(irq_nr);
484 	spin_lock_irqsave(&leon_irq_lock, flags);
485 	addr = (unsigned long *)LEON_IMASK(cpu);
486 	LEON3_BYPASS_STORE_PA(addr, (LEON3_BYPASS_LOAD_PA(addr) | mask));
487 	spin_unlock_irqrestore(&leon_irq_lock, flags);
488 }
489 
490 #endif
491 
492 void __init leon_init_IRQ(void)
493 {
494 	sparc_config.init_timers      = leon_init_timers;
495 	sparc_config.build_device_irq = _leon_build_device_irq;
496 	sparc_config.clock_rate       = 1000000;
497 	sparc_config.clear_clock_irq  = leon_clear_clock_irq;
498 	sparc_config.load_profile_irq = leon_load_profile_irq;
499 }
500