xref: /linux/arch/sparc/kernel/leon_kernel.c (revision af8e51644a70f612974a6e767fa7d896d3c23f88)
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/interrupt.h>
12 #include <linux/clocksource.h>
13 #include <linux/clockchips.h>
14 
15 #include <asm/oplib.h>
16 #include <asm/timer.h>
17 #include <asm/prom.h>
18 #include <asm/leon.h>
19 #include <asm/leon_amba.h>
20 #include <asm/traps.h>
21 #include <asm/cacheflush.h>
22 #include <asm/smp.h>
23 #include <asm/setup.h>
24 
25 #include "kernel.h"
26 #include "prom.h"
27 #include "irq.h"
28 
29 struct leon3_irqctrl_regs_map *leon3_irqctrl_regs; /* interrupt controller base address */
30 struct leon3_gptimer_regs_map *leon3_gptimer_regs; /* timer controller base address */
31 
32 int leondebug_irq_disable;
33 int leon_debug_irqout;
34 static volatile u32 dummy_master_l10_counter;
35 unsigned long amba_system_id;
36 static DEFINE_SPINLOCK(leon_irq_lock);
37 
38 static unsigned long leon3_gptimer_idx; /* Timer Index (0..6) within Timer Core */
39 static unsigned long leon3_gptimer_ackmask; /* For clearing pending bit */
40 unsigned long leon3_gptimer_irq; /* interrupt controller irq number */
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(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 static 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 	unsigned int cpu = cpumask_first_and(affinity, cpu_online_mask);
110 
111 	if (cpumask_subset(cpu_online_mask, affinity) || cpu >= nr_cpu_ids)
112 		return boot_cpu_id;
113 	else
114 		return cpu;
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(irq_data_get_affinity_mask(data));
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(irq_data_get_affinity_mask(data));
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(irq_data_get_affinity_mask(data));
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=DON'T-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 	struct irq_desc *desc;
215 
216 	irq = 0;
217 	mask = leon_get_irqmask(real_irq);
218 	if (mask == 0)
219 		goto out;
220 
221 	irq = irq_alloc(real_irq, real_irq);
222 	if (irq == 0)
223 		goto out;
224 
225 	if (do_ack)
226 		mask |= LEON_DO_ACK_HW;
227 
228 	desc = irq_to_desc(irq);
229 	if (!desc || !desc->handle_irq || desc->handle_irq == handle_bad_irq) {
230 		irq_set_chip_and_handler_name(irq, &leon_irq,
231 					      flow_handler, name);
232 		irq_set_chip_data(irq, (void *)mask);
233 	}
234 
235 out:
236 	return irq;
237 }
238 
239 static unsigned int _leon_build_device_irq(struct platform_device *op,
240 					   unsigned int real_irq)
241 {
242 	return leon_build_device_irq(real_irq, handle_simple_irq, "edge", 0);
243 }
244 
245 void leon_update_virq_handling(unsigned int virq,
246 			      irq_flow_handler_t flow_handler,
247 			      const char *name, int do_ack)
248 {
249 	unsigned long mask = (unsigned long)irq_get_chip_data(virq);
250 
251 	mask &= ~LEON_DO_ACK_HW;
252 	if (do_ack)
253 		mask |= LEON_DO_ACK_HW;
254 
255 	irq_set_chip_and_handler_name(virq, &leon_irq,
256 				      flow_handler, name);
257 	irq_set_chip_data(virq, (void *)mask);
258 }
259 
260 static u32 leon_cycles_offset(void)
261 {
262 	u32 rld, val, ctrl, off;
263 
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 	ctrl = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl);
267 	if (LEON3_GPTIMER_CTRL_ISPENDING(ctrl)) {
268 		val = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].val);
269 		off = 2 * rld - val;
270 	} else {
271 		off = rld - val;
272 	}
273 
274 	return off;
275 }
276 
277 #ifdef CONFIG_SMP
278 
279 /* smp clockevent irq */
280 static irqreturn_t leon_percpu_timer_ce_interrupt(int irq, void *unused)
281 {
282 	struct clock_event_device *ce;
283 	int cpu = smp_processor_id();
284 
285 	leon_clear_profile_irq(cpu);
286 
287 	if (cpu == boot_cpu_id)
288 		timer_interrupt(irq, NULL);
289 
290 	ce = &per_cpu(sparc32_clockevent, cpu);
291 
292 	irq_enter();
293 	if (ce->event_handler)
294 		ce->event_handler(ce);
295 	irq_exit();
296 
297 	return IRQ_HANDLED;
298 }
299 
300 #endif /* CONFIG_SMP */
301 
302 void __init leon_init_timers(void)
303 {
304 	int irq, eirq;
305 	struct device_node *rootnp, *np, *nnp;
306 	struct property *pp;
307 	int len;
308 	int icsel;
309 	int ampopts;
310 	int err;
311 	u32 config;
312 	u32 ctrl;
313 
314 	sparc_config.get_cycles_offset = leon_cycles_offset;
315 	sparc_config.cs_period = 1000000 / HZ;
316 	sparc_config.features |= FEAT_L10_CLOCKSOURCE;
317 
318 #ifndef CONFIG_SMP
319 	sparc_config.features |= FEAT_L10_CLOCKEVENT;
320 #endif
321 
322 	leondebug_irq_disable = 0;
323 	leon_debug_irqout = 0;
324 	master_l10_counter = (u32 __iomem *)&dummy_master_l10_counter;
325 	dummy_master_l10_counter = 0;
326 
327 	rootnp = of_find_node_by_path("/ambapp0");
328 	if (!rootnp)
329 		goto bad;
330 
331 	/* Find System ID: GRLIB build ID and optional CHIP ID */
332 	pp = of_find_property(rootnp, "systemid", &len);
333 	if (pp)
334 		amba_system_id = *(unsigned long *)pp->value;
335 
336 	/* Find IRQMP IRQ Controller Registers base adr otherwise bail out */
337 	np = of_find_node_by_name(rootnp, "GAISLER_IRQMP");
338 	if (!np) {
339 		np = of_find_node_by_name(rootnp, "01_00d");
340 		if (!np)
341 			goto bad;
342 	}
343 	pp = of_find_property(np, "reg", &len);
344 	if (!pp)
345 		goto bad;
346 	leon3_irqctrl_regs = *(struct leon3_irqctrl_regs_map **)pp->value;
347 
348 	/* Find GPTIMER Timer Registers base address otherwise bail out. */
349 	nnp = rootnp;
350 
351 retry:
352 	np = of_find_node_by_name(nnp, "GAISLER_GPTIMER");
353 	if (!np) {
354 		np = of_find_node_by_name(nnp, "01_011");
355 		if (!np)
356 			goto bad;
357 	}
358 
359 	ampopts = 0;
360 	pp = of_find_property(np, "ampopts", &len);
361 	if (pp) {
362 		ampopts = *(int *)pp->value;
363 		if (ampopts == 0) {
364 			/* Skip this instance, resource already
365 			 * allocated by other OS */
366 			nnp = np;
367 			goto retry;
368 		}
369 	}
370 
371 	/* Select Timer-Instance on Timer Core. Default is zero */
372 	leon3_gptimer_idx = ampopts & 0x7;
373 
374 	pp = of_find_property(np, "reg", &len);
375 	if (pp)
376 		leon3_gptimer_regs = *(struct leon3_gptimer_regs_map **)
377 					pp->value;
378 	pp = of_find_property(np, "interrupts", &len);
379 	if (pp)
380 		leon3_gptimer_irq = *(unsigned int *)pp->value;
381 
382 	if (!(leon3_gptimer_regs && leon3_irqctrl_regs && leon3_gptimer_irq))
383 		goto bad;
384 
385 	ctrl = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl);
386 	LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl,
387 			      ctrl | LEON3_GPTIMER_CTRL_PENDING);
388 	ctrl = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl);
389 
390 	if ((ctrl & LEON3_GPTIMER_CTRL_PENDING) != 0)
391 		leon3_gptimer_ackmask = ~LEON3_GPTIMER_CTRL_PENDING;
392 	else
393 		leon3_gptimer_ackmask = ~0;
394 
395 	LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].val, 0);
396 	LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].rld,
397 				(((1000000 / HZ) - 1)));
398 	LEON3_BYPASS_STORE_PA(
399 			&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl, 0);
400 
401 	/*
402 	 * The IRQ controller may (if implemented) consist of multiple
403 	 * IRQ controllers, each mapped on a 4Kb boundary.
404 	 * Each CPU may be routed to different IRQCTRLs, however
405 	 * we assume that all CPUs (in SMP system) is routed to the
406 	 * same IRQ Controller, and for non-SMP only one IRQCTRL is
407 	 * accessed anyway.
408 	 * In AMP systems, Linux must run on CPU0 for the time being.
409 	 */
410 	icsel = LEON3_BYPASS_LOAD_PA(&leon3_irqctrl_regs->icsel[boot_cpu_id/8]);
411 	icsel = (icsel >> ((7 - (boot_cpu_id&0x7)) * 4)) & 0xf;
412 	leon3_irqctrl_regs += icsel;
413 
414 	/* Mask all IRQs on boot-cpu IRQ controller */
415 	LEON3_BYPASS_STORE_PA(&leon3_irqctrl_regs->mask[boot_cpu_id], 0);
416 
417 	/* Probe extended IRQ controller */
418 	eirq = (LEON3_BYPASS_LOAD_PA(&leon3_irqctrl_regs->mpstatus)
419 		>> 16) & 0xf;
420 	if (eirq != 0)
421 		leon_eirq_setup(eirq);
422 
423 #ifdef CONFIG_SMP
424 	{
425 		unsigned long flags;
426 
427 		/*
428 		 * In SMP, sun4m adds a IPI handler to IRQ trap handler that
429 		 * LEON never must take, sun4d and LEON overwrites the branch
430 		 * with a NOP.
431 		 */
432 		local_irq_save(flags);
433 		patchme_maybe_smp_msg[0] = 0x01000000; /* NOP out the branch */
434 		local_ops->cache_all();
435 		local_irq_restore(flags);
436 	}
437 #endif
438 
439 	config = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->config);
440 	if (config & (1 << LEON3_GPTIMER_SEPIRQ))
441 		leon3_gptimer_irq += leon3_gptimer_idx;
442 	else if ((config & LEON3_GPTIMER_TIMERS) > 1)
443 		pr_warn("GPTIMER uses shared irqs, using other timers of the same core will fail.\n");
444 
445 #ifdef CONFIG_SMP
446 	/* Install per-cpu IRQ handler for broadcasted ticker */
447 	irq = leon_build_device_irq(leon3_gptimer_irq, handle_percpu_irq,
448 				    "per-cpu", 0);
449 	err = request_irq(irq, leon_percpu_timer_ce_interrupt,
450 			  IRQF_PERCPU | IRQF_TIMER, "timer", NULL);
451 #else
452 	irq = _leon_build_device_irq(NULL, leon3_gptimer_irq);
453 	err = request_irq(irq, timer_interrupt, IRQF_TIMER, "timer", NULL);
454 #endif
455 	if (err) {
456 		pr_err("Unable to attach timer IRQ%d\n", irq);
457 		prom_halt();
458 	}
459 	LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl,
460 			      LEON3_GPTIMER_EN |
461 			      LEON3_GPTIMER_RL |
462 			      LEON3_GPTIMER_LD |
463 			      LEON3_GPTIMER_IRQEN);
464 	return;
465 bad:
466 	printk(KERN_ERR "No Timer/irqctrl found\n");
467 	BUG();
468 	return;
469 }
470 
471 static void leon_clear_clock_irq(void)
472 {
473 	u32 ctrl;
474 
475 	ctrl = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl);
476 	LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl,
477 			      ctrl & leon3_gptimer_ackmask);
478 }
479 
480 static void leon_load_profile_irq(int cpu, unsigned int limit)
481 {
482 }
483 
484 #ifdef CONFIG_SMP
485 void leon_clear_profile_irq(int cpu)
486 {
487 }
488 
489 void leon_enable_irq_cpu(unsigned int irq_nr, unsigned int cpu)
490 {
491 	unsigned long mask, flags, *addr;
492 	mask = leon_get_irqmask(irq_nr);
493 	spin_lock_irqsave(&leon_irq_lock, flags);
494 	addr = (unsigned long *)LEON_IMASK(cpu);
495 	LEON3_BYPASS_STORE_PA(addr, (LEON3_BYPASS_LOAD_PA(addr) | mask));
496 	spin_unlock_irqrestore(&leon_irq_lock, flags);
497 }
498 
499 #endif
500 
501 void __init leon_init_IRQ(void)
502 {
503 	sparc_config.init_timers      = leon_init_timers;
504 	sparc_config.build_device_irq = _leon_build_device_irq;
505 	sparc_config.clock_rate       = 1000000;
506 	sparc_config.clear_clock_irq  = leon_clear_clock_irq;
507 	sparc_config.load_profile_irq = leon_load_profile_irq;
508 }
509