xref: /openbmc/linux/drivers/irqchip/irq-armada-370-xp.c (revision 1a4e39c2e5ca2eb494a53ecd73055562f690bca0)
1 /*
2  * Marvell Armada 370 and Armada XP SoC IRQ handling
3  *
4  * Copyright (C) 2012 Marvell
5  *
6  * Lior Amsalem <alior@marvell.com>
7  * Gregory CLEMENT <gregory.clement@free-electrons.com>
8  * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
9  * Ben Dooks <ben.dooks@codethink.co.uk>
10  *
11  * This file is licensed under the terms of the GNU General Public
12  * License version 2.  This program is licensed "as is" without any
13  * warranty of any kind, whether express or implied.
14  */
15 
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/init.h>
19 #include <linux/irq.h>
20 #include <linux/interrupt.h>
21 #include <linux/irqchip/chained_irq.h>
22 #include <linux/cpu.h>
23 #include <linux/io.h>
24 #include <linux/of_address.h>
25 #include <linux/of_irq.h>
26 #include <linux/of_pci.h>
27 #include <linux/irqdomain.h>
28 #include <linux/slab.h>
29 #include <linux/msi.h>
30 #include <asm/mach/arch.h>
31 #include <asm/exception.h>
32 #include <asm/smp_plat.h>
33 #include <asm/mach/irq.h>
34 
35 #include "irqchip.h"
36 
37 /* Interrupt Controller Registers Map */
38 #define ARMADA_370_XP_INT_SET_MASK_OFFS		(0x48)
39 #define ARMADA_370_XP_INT_CLEAR_MASK_OFFS	(0x4C)
40 
41 #define ARMADA_370_XP_INT_CONTROL		(0x00)
42 #define ARMADA_370_XP_INT_SET_ENABLE_OFFS	(0x30)
43 #define ARMADA_370_XP_INT_CLEAR_ENABLE_OFFS	(0x34)
44 #define ARMADA_370_XP_INT_SOURCE_CTL(irq)	(0x100 + irq*4)
45 #define ARMADA_370_XP_INT_SOURCE_CPU_MASK	0xF
46 #define ARMADA_370_XP_INT_IRQ_FIQ_MASK(cpuid)	((BIT(0) | BIT(8)) << cpuid)
47 
48 #define ARMADA_370_XP_CPU_INTACK_OFFS		(0x44)
49 #define ARMADA_375_PPI_CAUSE			(0x10)
50 
51 #define ARMADA_370_XP_SW_TRIG_INT_OFFS           (0x4)
52 #define ARMADA_370_XP_IN_DRBEL_MSK_OFFS          (0xc)
53 #define ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS        (0x8)
54 
55 #define ARMADA_370_XP_MAX_PER_CPU_IRQS		(28)
56 
57 #define ARMADA_370_XP_TIMER0_PER_CPU_IRQ	(5)
58 
59 #define IPI_DOORBELL_START                      (0)
60 #define IPI_DOORBELL_END                        (8)
61 #define IPI_DOORBELL_MASK                       0xFF
62 #define PCI_MSI_DOORBELL_START                  (16)
63 #define PCI_MSI_DOORBELL_NR                     (16)
64 #define PCI_MSI_DOORBELL_END                    (32)
65 #define PCI_MSI_DOORBELL_MASK                   0xFFFF0000
66 
67 static void __iomem *per_cpu_int_base;
68 static void __iomem *main_int_base;
69 static struct irq_domain *armada_370_xp_mpic_domain;
70 #ifdef CONFIG_PCI_MSI
71 static struct irq_domain *armada_370_xp_msi_domain;
72 static DECLARE_BITMAP(msi_used, PCI_MSI_DOORBELL_NR);
73 static DEFINE_MUTEX(msi_used_lock);
74 static phys_addr_t msi_doorbell_addr;
75 #endif
76 
77 /*
78  * In SMP mode:
79  * For shared global interrupts, mask/unmask global enable bit
80  * For CPU interrupts, mask/unmask the calling CPU's bit
81  */
82 static void armada_370_xp_irq_mask(struct irq_data *d)
83 {
84 	irq_hw_number_t hwirq = irqd_to_hwirq(d);
85 
86 	if (hwirq != ARMADA_370_XP_TIMER0_PER_CPU_IRQ)
87 		writel(hwirq, main_int_base +
88 				ARMADA_370_XP_INT_CLEAR_ENABLE_OFFS);
89 	else
90 		writel(hwirq, per_cpu_int_base +
91 				ARMADA_370_XP_INT_SET_MASK_OFFS);
92 }
93 
94 static void armada_370_xp_irq_unmask(struct irq_data *d)
95 {
96 	irq_hw_number_t hwirq = irqd_to_hwirq(d);
97 
98 	if (hwirq != ARMADA_370_XP_TIMER0_PER_CPU_IRQ)
99 		writel(hwirq, main_int_base +
100 				ARMADA_370_XP_INT_SET_ENABLE_OFFS);
101 	else
102 		writel(hwirq, per_cpu_int_base +
103 				ARMADA_370_XP_INT_CLEAR_MASK_OFFS);
104 }
105 
106 #ifdef CONFIG_PCI_MSI
107 
108 static int armada_370_xp_alloc_msi(void)
109 {
110 	int hwirq;
111 
112 	mutex_lock(&msi_used_lock);
113 	hwirq = find_first_zero_bit(&msi_used, PCI_MSI_DOORBELL_NR);
114 	if (hwirq >= PCI_MSI_DOORBELL_NR)
115 		hwirq = -ENOSPC;
116 	else
117 		set_bit(hwirq, msi_used);
118 	mutex_unlock(&msi_used_lock);
119 
120 	return hwirq;
121 }
122 
123 static void armada_370_xp_free_msi(int hwirq)
124 {
125 	mutex_lock(&msi_used_lock);
126 	if (!test_bit(hwirq, msi_used))
127 		pr_err("trying to free unused MSI#%d\n", hwirq);
128 	else
129 		clear_bit(hwirq, msi_used);
130 	mutex_unlock(&msi_used_lock);
131 }
132 
133 static int armada_370_xp_setup_msi_irq(struct msi_chip *chip,
134 				       struct pci_dev *pdev,
135 				       struct msi_desc *desc)
136 {
137 	struct msi_msg msg;
138 	int virq, hwirq;
139 
140 	/* We support MSI, but not MSI-X */
141 	if (desc->msi_attrib.is_msix)
142 		return -EINVAL;
143 
144 	hwirq = armada_370_xp_alloc_msi();
145 	if (hwirq < 0)
146 		return hwirq;
147 
148 	virq = irq_create_mapping(armada_370_xp_msi_domain, hwirq);
149 	if (!virq) {
150 		armada_370_xp_free_msi(hwirq);
151 		return -EINVAL;
152 	}
153 
154 	irq_set_msi_desc(virq, desc);
155 
156 	msg.address_lo = msi_doorbell_addr;
157 	msg.address_hi = 0;
158 	msg.data = 0xf00 | (hwirq + 16);
159 
160 	write_msi_msg(virq, &msg);
161 	return 0;
162 }
163 
164 static void armada_370_xp_teardown_msi_irq(struct msi_chip *chip,
165 					   unsigned int irq)
166 {
167 	struct irq_data *d = irq_get_irq_data(irq);
168 	unsigned long hwirq = d->hwirq;
169 
170 	irq_dispose_mapping(irq);
171 	armada_370_xp_free_msi(hwirq);
172 }
173 
174 static struct irq_chip armada_370_xp_msi_irq_chip = {
175 	.name = "armada_370_xp_msi_irq",
176 	.irq_enable = unmask_msi_irq,
177 	.irq_disable = mask_msi_irq,
178 	.irq_mask = mask_msi_irq,
179 	.irq_unmask = unmask_msi_irq,
180 };
181 
182 static int armada_370_xp_msi_map(struct irq_domain *domain, unsigned int virq,
183 				 irq_hw_number_t hw)
184 {
185 	irq_set_chip_and_handler(virq, &armada_370_xp_msi_irq_chip,
186 				 handle_simple_irq);
187 	set_irq_flags(virq, IRQF_VALID);
188 
189 	return 0;
190 }
191 
192 static const struct irq_domain_ops armada_370_xp_msi_irq_ops = {
193 	.map = armada_370_xp_msi_map,
194 };
195 
196 static int armada_370_xp_msi_init(struct device_node *node,
197 				  phys_addr_t main_int_phys_base)
198 {
199 	struct msi_chip *msi_chip;
200 	u32 reg;
201 	int ret;
202 
203 	msi_doorbell_addr = main_int_phys_base +
204 		ARMADA_370_XP_SW_TRIG_INT_OFFS;
205 
206 	msi_chip = kzalloc(sizeof(*msi_chip), GFP_KERNEL);
207 	if (!msi_chip)
208 		return -ENOMEM;
209 
210 	msi_chip->setup_irq = armada_370_xp_setup_msi_irq;
211 	msi_chip->teardown_irq = armada_370_xp_teardown_msi_irq;
212 	msi_chip->of_node = node;
213 
214 	armada_370_xp_msi_domain =
215 		irq_domain_add_linear(NULL, PCI_MSI_DOORBELL_NR,
216 				      &armada_370_xp_msi_irq_ops,
217 				      NULL);
218 	if (!armada_370_xp_msi_domain) {
219 		kfree(msi_chip);
220 		return -ENOMEM;
221 	}
222 
223 	ret = of_pci_msi_chip_add(msi_chip);
224 	if (ret < 0) {
225 		irq_domain_remove(armada_370_xp_msi_domain);
226 		kfree(msi_chip);
227 		return ret;
228 	}
229 
230 	reg = readl(per_cpu_int_base + ARMADA_370_XP_IN_DRBEL_MSK_OFFS)
231 		| PCI_MSI_DOORBELL_MASK;
232 
233 	writel(reg, per_cpu_int_base +
234 	       ARMADA_370_XP_IN_DRBEL_MSK_OFFS);
235 
236 	/* Unmask IPI interrupt */
237 	writel(1, per_cpu_int_base + ARMADA_370_XP_INT_CLEAR_MASK_OFFS);
238 
239 	return 0;
240 }
241 #else
242 static inline int armada_370_xp_msi_init(struct device_node *node,
243 					 phys_addr_t main_int_phys_base)
244 {
245 	return 0;
246 }
247 #endif
248 
249 #ifdef CONFIG_SMP
250 static DEFINE_RAW_SPINLOCK(irq_controller_lock);
251 
252 static int armada_xp_set_affinity(struct irq_data *d,
253 				  const struct cpumask *mask_val, bool force)
254 {
255 	irq_hw_number_t hwirq = irqd_to_hwirq(d);
256 	unsigned long reg, mask;
257 	int cpu;
258 
259 	/* Select a single core from the affinity mask which is online */
260 	cpu = cpumask_any_and(mask_val, cpu_online_mask);
261 	mask = 1UL << cpu_logical_map(cpu);
262 
263 	raw_spin_lock(&irq_controller_lock);
264 	reg = readl(main_int_base + ARMADA_370_XP_INT_SOURCE_CTL(hwirq));
265 	reg = (reg & (~ARMADA_370_XP_INT_SOURCE_CPU_MASK)) | mask;
266 	writel(reg, main_int_base + ARMADA_370_XP_INT_SOURCE_CTL(hwirq));
267 	raw_spin_unlock(&irq_controller_lock);
268 
269 	return 0;
270 }
271 #endif
272 
273 static struct irq_chip armada_370_xp_irq_chip = {
274 	.name		= "armada_370_xp_irq",
275 	.irq_mask       = armada_370_xp_irq_mask,
276 	.irq_mask_ack   = armada_370_xp_irq_mask,
277 	.irq_unmask     = armada_370_xp_irq_unmask,
278 #ifdef CONFIG_SMP
279 	.irq_set_affinity = armada_xp_set_affinity,
280 #endif
281 };
282 
283 static int armada_370_xp_mpic_irq_map(struct irq_domain *h,
284 				      unsigned int virq, irq_hw_number_t hw)
285 {
286 	armada_370_xp_irq_mask(irq_get_irq_data(virq));
287 	if (hw != ARMADA_370_XP_TIMER0_PER_CPU_IRQ)
288 		writel(hw, per_cpu_int_base +
289 			ARMADA_370_XP_INT_CLEAR_MASK_OFFS);
290 	else
291 		writel(hw, main_int_base + ARMADA_370_XP_INT_SET_ENABLE_OFFS);
292 	irq_set_status_flags(virq, IRQ_LEVEL);
293 
294 	if (hw == ARMADA_370_XP_TIMER0_PER_CPU_IRQ) {
295 		irq_set_percpu_devid(virq);
296 		irq_set_chip_and_handler(virq, &armada_370_xp_irq_chip,
297 					handle_percpu_devid_irq);
298 
299 	} else {
300 		irq_set_chip_and_handler(virq, &armada_370_xp_irq_chip,
301 					handle_level_irq);
302 	}
303 	set_irq_flags(virq, IRQF_VALID | IRQF_PROBE);
304 
305 	return 0;
306 }
307 
308 #ifdef CONFIG_SMP
309 static void armada_mpic_send_doorbell(const struct cpumask *mask,
310 				      unsigned int irq)
311 {
312 	int cpu;
313 	unsigned long map = 0;
314 
315 	/* Convert our logical CPU mask into a physical one. */
316 	for_each_cpu(cpu, mask)
317 		map |= 1 << cpu_logical_map(cpu);
318 
319 	/*
320 	 * Ensure that stores to Normal memory are visible to the
321 	 * other CPUs before issuing the IPI.
322 	 */
323 	dsb();
324 
325 	/* submit softirq */
326 	writel((map << 8) | irq, main_int_base +
327 		ARMADA_370_XP_SW_TRIG_INT_OFFS);
328 }
329 
330 static void armada_xp_mpic_smp_cpu_init(void)
331 {
332 	u32 control;
333 	int nr_irqs, i;
334 
335 	control = readl(main_int_base + ARMADA_370_XP_INT_CONTROL);
336 	nr_irqs = (control >> 2) & 0x3ff;
337 
338 	for (i = 0; i < nr_irqs; i++)
339 		writel(i, per_cpu_int_base + ARMADA_370_XP_INT_SET_MASK_OFFS);
340 
341 	/* Clear pending IPIs */
342 	writel(0, per_cpu_int_base + ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS);
343 
344 	/* Enable first 8 IPIs */
345 	writel(IPI_DOORBELL_MASK, per_cpu_int_base +
346 		ARMADA_370_XP_IN_DRBEL_MSK_OFFS);
347 
348 	/* Unmask IPI interrupt */
349 	writel(0, per_cpu_int_base + ARMADA_370_XP_INT_CLEAR_MASK_OFFS);
350 }
351 
352 static int armada_xp_mpic_secondary_init(struct notifier_block *nfb,
353 					 unsigned long action, void *hcpu)
354 {
355 	if (action == CPU_STARTING || action == CPU_STARTING_FROZEN)
356 		armada_xp_mpic_smp_cpu_init();
357 	return NOTIFY_OK;
358 }
359 
360 static struct notifier_block armada_370_xp_mpic_cpu_notifier = {
361 	.notifier_call = armada_xp_mpic_secondary_init,
362 	.priority = 100,
363 };
364 
365 #endif /* CONFIG_SMP */
366 
367 static struct irq_domain_ops armada_370_xp_mpic_irq_ops = {
368 	.map = armada_370_xp_mpic_irq_map,
369 	.xlate = irq_domain_xlate_onecell,
370 };
371 
372 #ifdef CONFIG_PCI_MSI
373 static void armada_370_xp_handle_msi_irq(struct pt_regs *regs, bool is_chained)
374 {
375 	u32 msimask, msinr;
376 
377 	msimask = readl_relaxed(per_cpu_int_base +
378 				ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS)
379 		& PCI_MSI_DOORBELL_MASK;
380 
381 	writel(~msimask, per_cpu_int_base +
382 	       ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS);
383 
384 	for (msinr = PCI_MSI_DOORBELL_START;
385 	     msinr < PCI_MSI_DOORBELL_END; msinr++) {
386 		int irq;
387 
388 		if (!(msimask & BIT(msinr)))
389 			continue;
390 
391 		if (is_chained) {
392 			irq = irq_find_mapping(armada_370_xp_msi_domain,
393 					       msinr - 16);
394 			generic_handle_irq(irq);
395 		} else {
396 			irq = msinr - 16;
397 			handle_domain_irq(armada_370_xp_msi_domain,
398 					  irq, regs);
399 		}
400 	}
401 }
402 #else
403 static void armada_370_xp_handle_msi_irq(struct pt_regs *r, bool b) {}
404 #endif
405 
406 static void armada_370_xp_mpic_handle_cascade_irq(unsigned int irq,
407 						  struct irq_desc *desc)
408 {
409 	struct irq_chip *chip = irq_get_chip(irq);
410 	unsigned long irqmap, irqn, irqsrc, cpuid;
411 	unsigned int cascade_irq;
412 
413 	chained_irq_enter(chip, desc);
414 
415 	irqmap = readl_relaxed(per_cpu_int_base + ARMADA_375_PPI_CAUSE);
416 	cpuid = cpu_logical_map(smp_processor_id());
417 
418 	for_each_set_bit(irqn, &irqmap, BITS_PER_LONG) {
419 		irqsrc = readl_relaxed(main_int_base +
420 				       ARMADA_370_XP_INT_SOURCE_CTL(irqn));
421 
422 		/* Check if the interrupt is not masked on current CPU.
423 		 * Test IRQ (0-1) and FIQ (8-9) mask bits.
424 		 */
425 		if (!(irqsrc & ARMADA_370_XP_INT_IRQ_FIQ_MASK(cpuid)))
426 			continue;
427 
428 		if (irqn == 1) {
429 			armada_370_xp_handle_msi_irq(NULL, true);
430 			continue;
431 		}
432 
433 		cascade_irq = irq_find_mapping(armada_370_xp_mpic_domain, irqn);
434 		generic_handle_irq(cascade_irq);
435 	}
436 
437 	chained_irq_exit(chip, desc);
438 }
439 
440 static void __exception_irq_entry
441 armada_370_xp_handle_irq(struct pt_regs *regs)
442 {
443 	u32 irqstat, irqnr;
444 
445 	do {
446 		irqstat = readl_relaxed(per_cpu_int_base +
447 					ARMADA_370_XP_CPU_INTACK_OFFS);
448 		irqnr = irqstat & 0x3FF;
449 
450 		if (irqnr > 1022)
451 			break;
452 
453 		if (irqnr > 1) {
454 			handle_domain_irq(armada_370_xp_mpic_domain,
455 					  irqnr, regs);
456 			continue;
457 		}
458 
459 		/* MSI handling */
460 		if (irqnr == 1)
461 			armada_370_xp_handle_msi_irq(regs, false);
462 
463 #ifdef CONFIG_SMP
464 		/* IPI Handling */
465 		if (irqnr == 0) {
466 			u32 ipimask, ipinr;
467 
468 			ipimask = readl_relaxed(per_cpu_int_base +
469 						ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS)
470 				& IPI_DOORBELL_MASK;
471 
472 			writel(~ipimask, per_cpu_int_base +
473 				ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS);
474 
475 			/* Handle all pending doorbells */
476 			for (ipinr = IPI_DOORBELL_START;
477 			     ipinr < IPI_DOORBELL_END; ipinr++) {
478 				if (ipimask & (0x1 << ipinr))
479 					handle_IPI(ipinr, regs);
480 			}
481 			continue;
482 		}
483 #endif
484 
485 	} while (1);
486 }
487 
488 static int __init armada_370_xp_mpic_of_init(struct device_node *node,
489 					     struct device_node *parent)
490 {
491 	struct resource main_int_res, per_cpu_int_res;
492 	int parent_irq, nr_irqs, i;
493 	u32 control;
494 
495 	BUG_ON(of_address_to_resource(node, 0, &main_int_res));
496 	BUG_ON(of_address_to_resource(node, 1, &per_cpu_int_res));
497 
498 	BUG_ON(!request_mem_region(main_int_res.start,
499 				   resource_size(&main_int_res),
500 				   node->full_name));
501 	BUG_ON(!request_mem_region(per_cpu_int_res.start,
502 				   resource_size(&per_cpu_int_res),
503 				   node->full_name));
504 
505 	main_int_base = ioremap(main_int_res.start,
506 				resource_size(&main_int_res));
507 	BUG_ON(!main_int_base);
508 
509 	per_cpu_int_base = ioremap(per_cpu_int_res.start,
510 				   resource_size(&per_cpu_int_res));
511 	BUG_ON(!per_cpu_int_base);
512 
513 	control = readl(main_int_base + ARMADA_370_XP_INT_CONTROL);
514 	nr_irqs = (control >> 2) & 0x3ff;
515 
516 	for (i = 0; i < nr_irqs; i++)
517 		writel(i, main_int_base + ARMADA_370_XP_INT_CLEAR_ENABLE_OFFS);
518 
519 	armada_370_xp_mpic_domain =
520 		irq_domain_add_linear(node, nr_irqs,
521 				&armada_370_xp_mpic_irq_ops, NULL);
522 
523 	BUG_ON(!armada_370_xp_mpic_domain);
524 
525 #ifdef CONFIG_SMP
526 	armada_xp_mpic_smp_cpu_init();
527 #endif
528 
529 	armada_370_xp_msi_init(node, main_int_res.start);
530 
531 	parent_irq = irq_of_parse_and_map(node, 0);
532 	if (parent_irq <= 0) {
533 		irq_set_default_host(armada_370_xp_mpic_domain);
534 		set_handle_irq(armada_370_xp_handle_irq);
535 #ifdef CONFIG_SMP
536 		set_smp_cross_call(armada_mpic_send_doorbell);
537 		register_cpu_notifier(&armada_370_xp_mpic_cpu_notifier);
538 #endif
539 	} else {
540 		irq_set_chained_handler(parent_irq,
541 					armada_370_xp_mpic_handle_cascade_irq);
542 	}
543 
544 	return 0;
545 }
546 
547 IRQCHIP_DECLARE(armada_370_xp_mpic, "marvell,mpic", armada_370_xp_mpic_of_init);
548