xref: /linux/arch/sparc/kernel/leon_kernel.c (revision c79c3c34f75d72a066e292b10aa50fc758c97c89)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2009 Daniel Hellstrom (daniel@gaisler.com) Aeroflex Gaisler AB
4  * Copyright (C) 2009 Konrad Eisele (konrad@gaisler.com) Aeroflex Gaisler AB
5  */
6 
7 #include <linux/kernel.h>
8 #include <linux/errno.h>
9 #include <linux/mutex.h>
10 #include <linux/of.h>
11 #include <linux/of_platform.h>
12 #include <linux/interrupt.h>
13 #include <linux/of_device.h>
14 #include <linux/clocksource.h>
15 #include <linux/clockchips.h>
16 
17 #include <asm/oplib.h>
18 #include <asm/timer.h>
19 #include <asm/prom.h>
20 #include <asm/leon.h>
21 #include <asm/leon_amba.h>
22 #include <asm/traps.h>
23 #include <asm/cacheflush.h>
24 #include <asm/smp.h>
25 #include <asm/setup.h>
26 
27 #include "kernel.h"
28 #include "prom.h"
29 #include "irq.h"
30 
31 struct leon3_irqctrl_regs_map *leon3_irqctrl_regs; /* interrupt controller base address */
32 struct leon3_gptimer_regs_map *leon3_gptimer_regs; /* timer controller base address */
33 
34 int leondebug_irq_disable;
35 int leon_debug_irqout;
36 static volatile u32 dummy_master_l10_counter;
37 unsigned long amba_system_id;
38 static DEFINE_SPINLOCK(leon_irq_lock);
39 
40 static unsigned long leon3_gptimer_idx; /* Timer Index (0..6) within Timer Core */
41 static unsigned long leon3_gptimer_ackmask; /* For clearing pending bit */
42 unsigned long leon3_gptimer_irq; /* interrupt controller irq number */
43 unsigned int sparc_leon_eirq;
44 #define LEON_IMASK(cpu) (&leon3_irqctrl_regs->mask[cpu])
45 #define LEON_IACK (&leon3_irqctrl_regs->iclear)
46 #define LEON_DO_ACK_HW 1
47 
48 /* Return the last ACKed IRQ by the Extended IRQ controller. It has already
49  * been (automatically) ACKed when the CPU takes the trap.
50  */
51 static inline unsigned int leon_eirq_get(int cpu)
52 {
53 	return LEON3_BYPASS_LOAD_PA(&leon3_irqctrl_regs->intid[cpu]) & 0x1f;
54 }
55 
56 /* Handle one or multiple IRQs from the extended interrupt controller */
57 static void leon_handle_ext_irq(struct irq_desc *desc)
58 {
59 	unsigned int eirq;
60 	struct irq_bucket *p;
61 	int cpu = sparc_leon3_cpuid();
62 
63 	eirq = leon_eirq_get(cpu);
64 	p = irq_map[eirq];
65 	if ((eirq & 0x10) && p && p->irq) /* bit4 tells if IRQ happened */
66 		generic_handle_irq(p->irq);
67 }
68 
69 /* The extended IRQ controller has been found, this function registers it */
70 static void leon_eirq_setup(unsigned int eirq)
71 {
72 	unsigned long mask, oldmask;
73 	unsigned int veirq;
74 
75 	if (eirq < 1 || eirq > 0xf) {
76 		printk(KERN_ERR "LEON EXT IRQ NUMBER BAD: %d\n", eirq);
77 		return;
78 	}
79 
80 	veirq = leon_build_device_irq(eirq, leon_handle_ext_irq, "extirq", 0);
81 
82 	/*
83 	 * Unmask the Extended IRQ, the IRQs routed through the Ext-IRQ
84 	 * controller have a mask-bit of their own, so this is safe.
85 	 */
86 	irq_link(veirq);
87 	mask = 1 << eirq;
88 	oldmask = LEON3_BYPASS_LOAD_PA(LEON_IMASK(boot_cpu_id));
89 	LEON3_BYPASS_STORE_PA(LEON_IMASK(boot_cpu_id), (oldmask | mask));
90 	sparc_leon_eirq = eirq;
91 }
92 
93 unsigned long leon_get_irqmask(unsigned int irq)
94 {
95 	unsigned long mask;
96 
97 	if (!irq || ((irq > 0xf) && !sparc_leon_eirq)
98 	    || ((irq > 0x1f) && sparc_leon_eirq)) {
99 		printk(KERN_ERR
100 		       "leon_get_irqmask: false irq number: %d\n", irq);
101 		mask = 0;
102 	} else {
103 		mask = LEON_HARD_INT(irq);
104 	}
105 	return mask;
106 }
107 
108 #ifdef CONFIG_SMP
109 static int irq_choose_cpu(const struct cpumask *affinity)
110 {
111 	cpumask_t mask;
112 
113 	cpumask_and(&mask, cpu_online_mask, affinity);
114 	if (cpumask_equal(&mask, cpu_online_mask) || cpumask_empty(&mask))
115 		return boot_cpu_id;
116 	else
117 		return cpumask_first(&mask);
118 }
119 #else
120 #define irq_choose_cpu(affinity) boot_cpu_id
121 #endif
122 
123 static int leon_set_affinity(struct irq_data *data, const struct cpumask *dest,
124 			     bool force)
125 {
126 	unsigned long mask, oldmask, flags;
127 	int oldcpu, newcpu;
128 
129 	mask = (unsigned long)data->chip_data;
130 	oldcpu = irq_choose_cpu(irq_data_get_affinity_mask(data));
131 	newcpu = irq_choose_cpu(dest);
132 
133 	if (oldcpu == newcpu)
134 		goto out;
135 
136 	/* unmask on old CPU first before enabling on the selected CPU */
137 	spin_lock_irqsave(&leon_irq_lock, flags);
138 	oldmask = LEON3_BYPASS_LOAD_PA(LEON_IMASK(oldcpu));
139 	LEON3_BYPASS_STORE_PA(LEON_IMASK(oldcpu), (oldmask & ~mask));
140 	oldmask = LEON3_BYPASS_LOAD_PA(LEON_IMASK(newcpu));
141 	LEON3_BYPASS_STORE_PA(LEON_IMASK(newcpu), (oldmask | mask));
142 	spin_unlock_irqrestore(&leon_irq_lock, flags);
143 out:
144 	return IRQ_SET_MASK_OK;
145 }
146 
147 static void leon_unmask_irq(struct irq_data *data)
148 {
149 	unsigned long mask, oldmask, flags;
150 	int cpu;
151 
152 	mask = (unsigned long)data->chip_data;
153 	cpu = irq_choose_cpu(irq_data_get_affinity_mask(data));
154 	spin_lock_irqsave(&leon_irq_lock, flags);
155 	oldmask = LEON3_BYPASS_LOAD_PA(LEON_IMASK(cpu));
156 	LEON3_BYPASS_STORE_PA(LEON_IMASK(cpu), (oldmask | mask));
157 	spin_unlock_irqrestore(&leon_irq_lock, flags);
158 }
159 
160 static void leon_mask_irq(struct irq_data *data)
161 {
162 	unsigned long mask, oldmask, flags;
163 	int cpu;
164 
165 	mask = (unsigned long)data->chip_data;
166 	cpu = irq_choose_cpu(irq_data_get_affinity_mask(data));
167 	spin_lock_irqsave(&leon_irq_lock, flags);
168 	oldmask = LEON3_BYPASS_LOAD_PA(LEON_IMASK(cpu));
169 	LEON3_BYPASS_STORE_PA(LEON_IMASK(cpu), (oldmask & ~mask));
170 	spin_unlock_irqrestore(&leon_irq_lock, flags);
171 }
172 
173 static unsigned int leon_startup_irq(struct irq_data *data)
174 {
175 	irq_link(data->irq);
176 	leon_unmask_irq(data);
177 	return 0;
178 }
179 
180 static void leon_shutdown_irq(struct irq_data *data)
181 {
182 	leon_mask_irq(data);
183 	irq_unlink(data->irq);
184 }
185 
186 /* Used by external level sensitive IRQ handlers on the LEON: ACK IRQ ctrl */
187 static void leon_eoi_irq(struct irq_data *data)
188 {
189 	unsigned long mask = (unsigned long)data->chip_data;
190 
191 	if (mask & LEON_DO_ACK_HW)
192 		LEON3_BYPASS_STORE_PA(LEON_IACK, mask & ~LEON_DO_ACK_HW);
193 }
194 
195 static struct irq_chip leon_irq = {
196 	.name			= "leon",
197 	.irq_startup		= leon_startup_irq,
198 	.irq_shutdown		= leon_shutdown_irq,
199 	.irq_mask		= leon_mask_irq,
200 	.irq_unmask		= leon_unmask_irq,
201 	.irq_eoi		= leon_eoi_irq,
202 	.irq_set_affinity	= leon_set_affinity,
203 };
204 
205 /*
206  * Build a LEON IRQ for the edge triggered LEON IRQ controller:
207  *  Edge (normal) IRQ           - handle_simple_irq, ack=DON'T-CARE, never ack
208  *  Level IRQ (PCI|Level-GPIO)  - handle_fasteoi_irq, ack=1, ack after ISR
209  *  Per-CPU Edge                - handle_percpu_irq, ack=0
210  */
211 unsigned int leon_build_device_irq(unsigned int real_irq,
212 				    irq_flow_handler_t flow_handler,
213 				    const char *name, int do_ack)
214 {
215 	unsigned int irq;
216 	unsigned long mask;
217 	struct irq_desc *desc;
218 
219 	irq = 0;
220 	mask = leon_get_irqmask(real_irq);
221 	if (mask == 0)
222 		goto out;
223 
224 	irq = irq_alloc(real_irq, real_irq);
225 	if (irq == 0)
226 		goto out;
227 
228 	if (do_ack)
229 		mask |= LEON_DO_ACK_HW;
230 
231 	desc = irq_to_desc(irq);
232 	if (!desc || !desc->handle_irq || desc->handle_irq == handle_bad_irq) {
233 		irq_set_chip_and_handler_name(irq, &leon_irq,
234 					      flow_handler, name);
235 		irq_set_chip_data(irq, (void *)mask);
236 	}
237 
238 out:
239 	return irq;
240 }
241 
242 static unsigned int _leon_build_device_irq(struct platform_device *op,
243 					   unsigned int real_irq)
244 {
245 	return leon_build_device_irq(real_irq, handle_simple_irq, "edge", 0);
246 }
247 
248 void leon_update_virq_handling(unsigned int virq,
249 			      irq_flow_handler_t flow_handler,
250 			      const char *name, int do_ack)
251 {
252 	unsigned long mask = (unsigned long)irq_get_chip_data(virq);
253 
254 	mask &= ~LEON_DO_ACK_HW;
255 	if (do_ack)
256 		mask |= LEON_DO_ACK_HW;
257 
258 	irq_set_chip_and_handler_name(virq, &leon_irq,
259 				      flow_handler, name);
260 	irq_set_chip_data(virq, (void *)mask);
261 }
262 
263 static u32 leon_cycles_offset(void)
264 {
265 	u32 rld, val, ctrl, off;
266 
267 	rld = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].rld);
268 	val = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].val);
269 	ctrl = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl);
270 	if (LEON3_GPTIMER_CTRL_ISPENDING(ctrl)) {
271 		val = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].val);
272 		off = 2 * rld - val;
273 	} else {
274 		off = rld - val;
275 	}
276 
277 	return off;
278 }
279 
280 #ifdef CONFIG_SMP
281 
282 /* smp clockevent irq */
283 static irqreturn_t leon_percpu_timer_ce_interrupt(int irq, void *unused)
284 {
285 	struct clock_event_device *ce;
286 	int cpu = smp_processor_id();
287 
288 	leon_clear_profile_irq(cpu);
289 
290 	if (cpu == boot_cpu_id)
291 		timer_interrupt(irq, NULL);
292 
293 	ce = &per_cpu(sparc32_clockevent, cpu);
294 
295 	irq_enter();
296 	if (ce->event_handler)
297 		ce->event_handler(ce);
298 	irq_exit();
299 
300 	return IRQ_HANDLED;
301 }
302 
303 #endif /* CONFIG_SMP */
304 
305 void __init leon_init_timers(void)
306 {
307 	int irq, eirq;
308 	struct device_node *rootnp, *np, *nnp;
309 	struct property *pp;
310 	int len;
311 	int icsel;
312 	int ampopts;
313 	int err;
314 	u32 config;
315 	u32 ctrl;
316 
317 	sparc_config.get_cycles_offset = leon_cycles_offset;
318 	sparc_config.cs_period = 1000000 / HZ;
319 	sparc_config.features |= FEAT_L10_CLOCKSOURCE;
320 
321 #ifndef CONFIG_SMP
322 	sparc_config.features |= FEAT_L10_CLOCKEVENT;
323 #endif
324 
325 	leondebug_irq_disable = 0;
326 	leon_debug_irqout = 0;
327 	master_l10_counter = (u32 __iomem *)&dummy_master_l10_counter;
328 	dummy_master_l10_counter = 0;
329 
330 	rootnp = of_find_node_by_path("/ambapp0");
331 	if (!rootnp)
332 		goto bad;
333 
334 	/* Find System ID: GRLIB build ID and optional CHIP ID */
335 	pp = of_find_property(rootnp, "systemid", &len);
336 	if (pp)
337 		amba_system_id = *(unsigned long *)pp->value;
338 
339 	/* Find IRQMP IRQ Controller Registers base adr otherwise bail out */
340 	np = of_find_node_by_name(rootnp, "GAISLER_IRQMP");
341 	if (!np) {
342 		np = of_find_node_by_name(rootnp, "01_00d");
343 		if (!np)
344 			goto bad;
345 	}
346 	pp = of_find_property(np, "reg", &len);
347 	if (!pp)
348 		goto bad;
349 	leon3_irqctrl_regs = *(struct leon3_irqctrl_regs_map **)pp->value;
350 
351 	/* Find GPTIMER Timer Registers base address otherwise bail out. */
352 	nnp = rootnp;
353 
354 retry:
355 	np = of_find_node_by_name(nnp, "GAISLER_GPTIMER");
356 	if (!np) {
357 		np = of_find_node_by_name(nnp, "01_011");
358 		if (!np)
359 			goto bad;
360 	}
361 
362 	ampopts = 0;
363 	pp = of_find_property(np, "ampopts", &len);
364 	if (pp) {
365 		ampopts = *(int *)pp->value;
366 		if (ampopts == 0) {
367 			/* Skip this instance, resource already
368 			 * allocated by other OS */
369 			nnp = np;
370 			goto retry;
371 		}
372 	}
373 
374 	/* Select Timer-Instance on Timer Core. Default is zero */
375 	leon3_gptimer_idx = ampopts & 0x7;
376 
377 	pp = of_find_property(np, "reg", &len);
378 	if (pp)
379 		leon3_gptimer_regs = *(struct leon3_gptimer_regs_map **)
380 					pp->value;
381 	pp = of_find_property(np, "interrupts", &len);
382 	if (pp)
383 		leon3_gptimer_irq = *(unsigned int *)pp->value;
384 
385 	if (!(leon3_gptimer_regs && leon3_irqctrl_regs && leon3_gptimer_irq))
386 		goto bad;
387 
388 	ctrl = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl);
389 	LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl,
390 			      ctrl | LEON3_GPTIMER_CTRL_PENDING);
391 	ctrl = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl);
392 
393 	if ((ctrl & LEON3_GPTIMER_CTRL_PENDING) != 0)
394 		leon3_gptimer_ackmask = ~LEON3_GPTIMER_CTRL_PENDING;
395 	else
396 		leon3_gptimer_ackmask = ~0;
397 
398 	LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].val, 0);
399 	LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].rld,
400 				(((1000000 / HZ) - 1)));
401 	LEON3_BYPASS_STORE_PA(
402 			&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl, 0);
403 
404 	/*
405 	 * The IRQ controller may (if implemented) consist of multiple
406 	 * IRQ controllers, each mapped on a 4Kb boundary.
407 	 * Each CPU may be routed to different IRQCTRLs, however
408 	 * we assume that all CPUs (in SMP system) is routed to the
409 	 * same IRQ Controller, and for non-SMP only one IRQCTRL is
410 	 * accessed anyway.
411 	 * In AMP systems, Linux must run on CPU0 for the time being.
412 	 */
413 	icsel = LEON3_BYPASS_LOAD_PA(&leon3_irqctrl_regs->icsel[boot_cpu_id/8]);
414 	icsel = (icsel >> ((7 - (boot_cpu_id&0x7)) * 4)) & 0xf;
415 	leon3_irqctrl_regs += icsel;
416 
417 	/* Mask all IRQs on boot-cpu IRQ controller */
418 	LEON3_BYPASS_STORE_PA(&leon3_irqctrl_regs->mask[boot_cpu_id], 0);
419 
420 	/* Probe extended IRQ controller */
421 	eirq = (LEON3_BYPASS_LOAD_PA(&leon3_irqctrl_regs->mpstatus)
422 		>> 16) & 0xf;
423 	if (eirq != 0)
424 		leon_eirq_setup(eirq);
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 	config = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->config);
443 	if (config & (1 << LEON3_GPTIMER_SEPIRQ))
444 		leon3_gptimer_irq += leon3_gptimer_idx;
445 	else if ((config & LEON3_GPTIMER_TIMERS) > 1)
446 		pr_warn("GPTIMER uses shared irqs, using other timers of the same core will fail.\n");
447 
448 #ifdef CONFIG_SMP
449 	/* Install per-cpu IRQ handler for broadcasted ticker */
450 	irq = leon_build_device_irq(leon3_gptimer_irq, handle_percpu_irq,
451 				    "per-cpu", 0);
452 	err = request_irq(irq, leon_percpu_timer_ce_interrupt,
453 			  IRQF_PERCPU | IRQF_TIMER, "timer", NULL);
454 #else
455 	irq = _leon_build_device_irq(NULL, leon3_gptimer_irq);
456 	err = request_irq(irq, timer_interrupt, IRQF_TIMER, "timer", NULL);
457 #endif
458 	if (err) {
459 		pr_err("Unable to attach timer IRQ%d\n", irq);
460 		prom_halt();
461 	}
462 	LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl,
463 			      LEON3_GPTIMER_EN |
464 			      LEON3_GPTIMER_RL |
465 			      LEON3_GPTIMER_LD |
466 			      LEON3_GPTIMER_IRQEN);
467 	return;
468 bad:
469 	printk(KERN_ERR "No Timer/irqctrl found\n");
470 	BUG();
471 	return;
472 }
473 
474 static void leon_clear_clock_irq(void)
475 {
476 	u32 ctrl;
477 
478 	ctrl = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl);
479 	LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl,
480 			      ctrl & leon3_gptimer_ackmask);
481 }
482 
483 static void leon_load_profile_irq(int cpu, unsigned int limit)
484 {
485 }
486 
487 #ifdef CONFIG_SMP
488 void leon_clear_profile_irq(int cpu)
489 {
490 }
491 
492 void leon_enable_irq_cpu(unsigned int irq_nr, unsigned int cpu)
493 {
494 	unsigned long mask, flags, *addr;
495 	mask = leon_get_irqmask(irq_nr);
496 	spin_lock_irqsave(&leon_irq_lock, flags);
497 	addr = (unsigned long *)LEON_IMASK(cpu);
498 	LEON3_BYPASS_STORE_PA(addr, (LEON3_BYPASS_LOAD_PA(addr) | mask));
499 	spin_unlock_irqrestore(&leon_irq_lock, flags);
500 }
501 
502 #endif
503 
504 void __init leon_init_IRQ(void)
505 {
506 	sparc_config.init_timers      = leon_init_timers;
507 	sparc_config.build_device_irq = _leon_build_device_irq;
508 	sparc_config.clock_rate       = 1000000;
509 	sparc_config.clear_clock_irq  = leon_clear_clock_irq;
510 	sparc_config.load_profile_irq = leon_load_profile_irq;
511 }
512