1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2015 Broadcom Corporation
4  */
5 
6 #include <linux/interrupt.h>
7 #include <linux/irqchip/chained_irq.h>
8 #include <linux/irqdomain.h>
9 #include <linux/msi.h>
10 #include <linux/of_irq.h>
11 #include <linux/of_pci.h>
12 #include <linux/pci.h>
13 
14 #include "pcie-iproc.h"
15 
16 #define IPROC_MSI_INTR_EN_SHIFT        11
17 #define IPROC_MSI_INTR_EN              BIT(IPROC_MSI_INTR_EN_SHIFT)
18 #define IPROC_MSI_INT_N_EVENT_SHIFT    1
19 #define IPROC_MSI_INT_N_EVENT          BIT(IPROC_MSI_INT_N_EVENT_SHIFT)
20 #define IPROC_MSI_EQ_EN_SHIFT          0
21 #define IPROC_MSI_EQ_EN                BIT(IPROC_MSI_EQ_EN_SHIFT)
22 
23 #define IPROC_MSI_EQ_MASK              0x3f
24 
25 /* Max number of GIC interrupts */
26 #define NR_HW_IRQS                     6
27 
28 /* Number of entries in each event queue */
29 #define EQ_LEN                         64
30 
31 /* Size of each event queue memory region */
32 #define EQ_MEM_REGION_SIZE             SZ_4K
33 
34 /* Size of each MSI address region */
35 #define MSI_MEM_REGION_SIZE            SZ_4K
36 
37 enum iproc_msi_reg {
38 	IPROC_MSI_EQ_PAGE = 0,
39 	IPROC_MSI_EQ_PAGE_UPPER,
40 	IPROC_MSI_PAGE,
41 	IPROC_MSI_PAGE_UPPER,
42 	IPROC_MSI_CTRL,
43 	IPROC_MSI_EQ_HEAD,
44 	IPROC_MSI_EQ_TAIL,
45 	IPROC_MSI_INTS_EN,
46 	IPROC_MSI_REG_SIZE,
47 };
48 
49 struct iproc_msi;
50 
51 /**
52  * iProc MSI group
53  *
54  * One MSI group is allocated per GIC interrupt, serviced by one iProc MSI
55  * event queue.
56  *
57  * @msi: pointer to iProc MSI data
58  * @gic_irq: GIC interrupt
59  * @eq: Event queue number
60  */
61 struct iproc_msi_grp {
62 	struct iproc_msi *msi;
63 	int gic_irq;
64 	unsigned int eq;
65 };
66 
67 /**
68  * iProc event queue based MSI
69  *
70  * Only meant to be used on platforms without MSI support integrated into the
71  * GIC.
72  *
73  * @pcie: pointer to iProc PCIe data
74  * @reg_offsets: MSI register offsets
75  * @grps: MSI groups
76  * @nr_irqs: number of total interrupts connected to GIC
77  * @nr_cpus: number of toal CPUs
78  * @has_inten_reg: indicates the MSI interrupt enable register needs to be
79  * set explicitly (required for some legacy platforms)
80  * @bitmap: MSI vector bitmap
81  * @bitmap_lock: lock to protect access to the MSI bitmap
82  * @nr_msi_vecs: total number of MSI vectors
83  * @inner_domain: inner IRQ domain
84  * @msi_domain: MSI IRQ domain
85  * @nr_eq_region: required number of 4K aligned memory region for MSI event
86  * queues
87  * @nr_msi_region: required number of 4K aligned address region for MSI posted
88  * writes
89  * @eq_cpu: pointer to allocated memory region for MSI event queues
90  * @eq_dma: DMA address of MSI event queues
91  * @msi_addr: MSI address
92  */
93 struct iproc_msi {
94 	struct iproc_pcie *pcie;
95 	const u16 (*reg_offsets)[IPROC_MSI_REG_SIZE];
96 	struct iproc_msi_grp *grps;
97 	int nr_irqs;
98 	int nr_cpus;
99 	bool has_inten_reg;
100 	unsigned long *bitmap;
101 	struct mutex bitmap_lock;
102 	unsigned int nr_msi_vecs;
103 	struct irq_domain *inner_domain;
104 	struct irq_domain *msi_domain;
105 	unsigned int nr_eq_region;
106 	unsigned int nr_msi_region;
107 	void *eq_cpu;
108 	dma_addr_t eq_dma;
109 	phys_addr_t msi_addr;
110 };
111 
112 static const u16 iproc_msi_reg_paxb[NR_HW_IRQS][IPROC_MSI_REG_SIZE] = {
113 	{ 0x200, 0x2c0, 0x204, 0x2c4, 0x210, 0x250, 0x254, 0x208 },
114 	{ 0x200, 0x2c0, 0x204, 0x2c4, 0x214, 0x258, 0x25c, 0x208 },
115 	{ 0x200, 0x2c0, 0x204, 0x2c4, 0x218, 0x260, 0x264, 0x208 },
116 	{ 0x200, 0x2c0, 0x204, 0x2c4, 0x21c, 0x268, 0x26c, 0x208 },
117 	{ 0x200, 0x2c0, 0x204, 0x2c4, 0x220, 0x270, 0x274, 0x208 },
118 	{ 0x200, 0x2c0, 0x204, 0x2c4, 0x224, 0x278, 0x27c, 0x208 },
119 };
120 
121 static const u16 iproc_msi_reg_paxc[NR_HW_IRQS][IPROC_MSI_REG_SIZE] = {
122 	{ 0xc00, 0xc04, 0xc08, 0xc0c, 0xc40, 0xc50, 0xc60 },
123 	{ 0xc10, 0xc14, 0xc18, 0xc1c, 0xc44, 0xc54, 0xc64 },
124 	{ 0xc20, 0xc24, 0xc28, 0xc2c, 0xc48, 0xc58, 0xc68 },
125 	{ 0xc30, 0xc34, 0xc38, 0xc3c, 0xc4c, 0xc5c, 0xc6c },
126 };
127 
128 static inline u32 iproc_msi_read_reg(struct iproc_msi *msi,
129 				     enum iproc_msi_reg reg,
130 				     unsigned int eq)
131 {
132 	struct iproc_pcie *pcie = msi->pcie;
133 
134 	return readl_relaxed(pcie->base + msi->reg_offsets[eq][reg]);
135 }
136 
137 static inline void iproc_msi_write_reg(struct iproc_msi *msi,
138 				       enum iproc_msi_reg reg,
139 				       int eq, u32 val)
140 {
141 	struct iproc_pcie *pcie = msi->pcie;
142 
143 	writel_relaxed(val, pcie->base + msi->reg_offsets[eq][reg]);
144 }
145 
146 static inline u32 hwirq_to_group(struct iproc_msi *msi, unsigned long hwirq)
147 {
148 	return (hwirq % msi->nr_irqs);
149 }
150 
151 static inline unsigned int iproc_msi_addr_offset(struct iproc_msi *msi,
152 						 unsigned long hwirq)
153 {
154 	if (msi->nr_msi_region > 1)
155 		return hwirq_to_group(msi, hwirq) * MSI_MEM_REGION_SIZE;
156 	else
157 		return hwirq_to_group(msi, hwirq) * sizeof(u32);
158 }
159 
160 static inline unsigned int iproc_msi_eq_offset(struct iproc_msi *msi, u32 eq)
161 {
162 	if (msi->nr_eq_region > 1)
163 		return eq * EQ_MEM_REGION_SIZE;
164 	else
165 		return eq * EQ_LEN * sizeof(u32);
166 }
167 
168 static struct irq_chip iproc_msi_irq_chip = {
169 	.name = "iProc-MSI",
170 };
171 
172 static struct msi_domain_info iproc_msi_domain_info = {
173 	.flags = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
174 		MSI_FLAG_MULTI_PCI_MSI | MSI_FLAG_PCI_MSIX,
175 	.chip = &iproc_msi_irq_chip,
176 };
177 
178 /*
179  * In iProc PCIe core, each MSI group is serviced by a GIC interrupt and a
180  * dedicated event queue.  Each MSI group can support up to 64 MSI vectors.
181  *
182  * The number of MSI groups varies between different iProc SoCs.  The total
183  * number of CPU cores also varies.  To support MSI IRQ affinity, we
184  * distribute GIC interrupts across all available CPUs.  MSI vector is moved
185  * from one GIC interrupt to another to steer to the target CPU.
186  *
187  * Assuming:
188  * - the number of MSI groups is M
189  * - the number of CPU cores is N
190  * - M is always a multiple of N
191  *
192  * Total number of raw MSI vectors = M * 64
193  * Total number of supported MSI vectors = (M * 64) / N
194  */
195 static inline int hwirq_to_cpu(struct iproc_msi *msi, unsigned long hwirq)
196 {
197 	return (hwirq % msi->nr_cpus);
198 }
199 
200 static inline unsigned long hwirq_to_canonical_hwirq(struct iproc_msi *msi,
201 						     unsigned long hwirq)
202 {
203 	return (hwirq - hwirq_to_cpu(msi, hwirq));
204 }
205 
206 static int iproc_msi_irq_set_affinity(struct irq_data *data,
207 				      const struct cpumask *mask, bool force)
208 {
209 	struct iproc_msi *msi = irq_data_get_irq_chip_data(data);
210 	int target_cpu = cpumask_first(mask);
211 	int curr_cpu;
212 
213 	curr_cpu = hwirq_to_cpu(msi, data->hwirq);
214 	if (curr_cpu == target_cpu)
215 		return IRQ_SET_MASK_OK_DONE;
216 
217 	/* steer MSI to the target CPU */
218 	data->hwirq = hwirq_to_canonical_hwirq(msi, data->hwirq) + target_cpu;
219 
220 	return IRQ_SET_MASK_OK;
221 }
222 
223 static void iproc_msi_irq_compose_msi_msg(struct irq_data *data,
224 					  struct msi_msg *msg)
225 {
226 	struct iproc_msi *msi = irq_data_get_irq_chip_data(data);
227 	dma_addr_t addr;
228 
229 	addr = msi->msi_addr + iproc_msi_addr_offset(msi, data->hwirq);
230 	msg->address_lo = lower_32_bits(addr);
231 	msg->address_hi = upper_32_bits(addr);
232 	msg->data = data->hwirq << 5;
233 }
234 
235 static struct irq_chip iproc_msi_bottom_irq_chip = {
236 	.name = "MSI",
237 	.irq_set_affinity = iproc_msi_irq_set_affinity,
238 	.irq_compose_msi_msg = iproc_msi_irq_compose_msi_msg,
239 };
240 
241 static int iproc_msi_irq_domain_alloc(struct irq_domain *domain,
242 				      unsigned int virq, unsigned int nr_irqs,
243 				      void *args)
244 {
245 	struct iproc_msi *msi = domain->host_data;
246 	int hwirq, i;
247 
248 	mutex_lock(&msi->bitmap_lock);
249 
250 	/* Allocate 'nr_cpus' number of MSI vectors each time */
251 	hwirq = bitmap_find_next_zero_area(msi->bitmap, msi->nr_msi_vecs, 0,
252 					   msi->nr_cpus, 0);
253 	if (hwirq < msi->nr_msi_vecs) {
254 		bitmap_set(msi->bitmap, hwirq, msi->nr_cpus);
255 	} else {
256 		mutex_unlock(&msi->bitmap_lock);
257 		return -ENOSPC;
258 	}
259 
260 	mutex_unlock(&msi->bitmap_lock);
261 
262 	for (i = 0; i < nr_irqs; i++) {
263 		irq_domain_set_info(domain, virq + i, hwirq + i,
264 				    &iproc_msi_bottom_irq_chip,
265 				    domain->host_data, handle_simple_irq,
266 				    NULL, NULL);
267 	}
268 
269 	return hwirq;
270 }
271 
272 static void iproc_msi_irq_domain_free(struct irq_domain *domain,
273 				      unsigned int virq, unsigned int nr_irqs)
274 {
275 	struct irq_data *data = irq_domain_get_irq_data(domain, virq);
276 	struct iproc_msi *msi = irq_data_get_irq_chip_data(data);
277 	unsigned int hwirq;
278 
279 	mutex_lock(&msi->bitmap_lock);
280 
281 	hwirq = hwirq_to_canonical_hwirq(msi, data->hwirq);
282 	bitmap_clear(msi->bitmap, hwirq, msi->nr_cpus);
283 
284 	mutex_unlock(&msi->bitmap_lock);
285 
286 	irq_domain_free_irqs_parent(domain, virq, nr_irqs);
287 }
288 
289 static const struct irq_domain_ops msi_domain_ops = {
290 	.alloc = iproc_msi_irq_domain_alloc,
291 	.free = iproc_msi_irq_domain_free,
292 };
293 
294 static inline u32 decode_msi_hwirq(struct iproc_msi *msi, u32 eq, u32 head)
295 {
296 	u32 *msg, hwirq;
297 	unsigned int offs;
298 
299 	offs = iproc_msi_eq_offset(msi, eq) + head * sizeof(u32);
300 	msg = (u32 *)(msi->eq_cpu + offs);
301 	hwirq = readl(msg);
302 	hwirq = (hwirq >> 5) + (hwirq & 0x1f);
303 
304 	/*
305 	 * Since we have multiple hwirq mapped to a single MSI vector,
306 	 * now we need to derive the hwirq at CPU0.  It can then be used to
307 	 * mapped back to virq.
308 	 */
309 	return hwirq_to_canonical_hwirq(msi, hwirq);
310 }
311 
312 static void iproc_msi_handler(struct irq_desc *desc)
313 {
314 	struct irq_chip *chip = irq_desc_get_chip(desc);
315 	struct iproc_msi_grp *grp;
316 	struct iproc_msi *msi;
317 	u32 eq, head, tail, nr_events;
318 	unsigned long hwirq;
319 	int virq;
320 
321 	chained_irq_enter(chip, desc);
322 
323 	grp = irq_desc_get_handler_data(desc);
324 	msi = grp->msi;
325 	eq = grp->eq;
326 
327 	/*
328 	 * iProc MSI event queue is tracked by head and tail pointers.  Head
329 	 * pointer indicates the next entry (MSI data) to be consumed by SW in
330 	 * the queue and needs to be updated by SW.  iProc MSI core uses the
331 	 * tail pointer as the next data insertion point.
332 	 *
333 	 * Entries between head and tail pointers contain valid MSI data.  MSI
334 	 * data is guaranteed to be in the event queue memory before the tail
335 	 * pointer is updated by the iProc MSI core.
336 	 */
337 	head = iproc_msi_read_reg(msi, IPROC_MSI_EQ_HEAD,
338 				  eq) & IPROC_MSI_EQ_MASK;
339 	do {
340 		tail = iproc_msi_read_reg(msi, IPROC_MSI_EQ_TAIL,
341 					  eq) & IPROC_MSI_EQ_MASK;
342 
343 		/*
344 		 * Figure out total number of events (MSI data) to be
345 		 * processed.
346 		 */
347 		nr_events = (tail < head) ?
348 			(EQ_LEN - (head - tail)) : (tail - head);
349 		if (!nr_events)
350 			break;
351 
352 		/* process all outstanding events */
353 		while (nr_events--) {
354 			hwirq = decode_msi_hwirq(msi, eq, head);
355 			virq = irq_find_mapping(msi->inner_domain, hwirq);
356 			generic_handle_irq(virq);
357 
358 			head++;
359 			head %= EQ_LEN;
360 		}
361 
362 		/*
363 		 * Now all outstanding events have been processed.  Update the
364 		 * head pointer.
365 		 */
366 		iproc_msi_write_reg(msi, IPROC_MSI_EQ_HEAD, eq, head);
367 
368 		/*
369 		 * Now go read the tail pointer again to see if there are new
370 		 * oustanding events that came in during the above window.
371 		 */
372 	} while (true);
373 
374 	chained_irq_exit(chip, desc);
375 }
376 
377 static void iproc_msi_enable(struct iproc_msi *msi)
378 {
379 	int i, eq;
380 	u32 val;
381 
382 	/* Program memory region for each event queue */
383 	for (i = 0; i < msi->nr_eq_region; i++) {
384 		dma_addr_t addr = msi->eq_dma + (i * EQ_MEM_REGION_SIZE);
385 
386 		iproc_msi_write_reg(msi, IPROC_MSI_EQ_PAGE, i,
387 				    lower_32_bits(addr));
388 		iproc_msi_write_reg(msi, IPROC_MSI_EQ_PAGE_UPPER, i,
389 				    upper_32_bits(addr));
390 	}
391 
392 	/* Program address region for MSI posted writes */
393 	for (i = 0; i < msi->nr_msi_region; i++) {
394 		phys_addr_t addr = msi->msi_addr + (i * MSI_MEM_REGION_SIZE);
395 
396 		iproc_msi_write_reg(msi, IPROC_MSI_PAGE, i,
397 				    lower_32_bits(addr));
398 		iproc_msi_write_reg(msi, IPROC_MSI_PAGE_UPPER, i,
399 				    upper_32_bits(addr));
400 	}
401 
402 	for (eq = 0; eq < msi->nr_irqs; eq++) {
403 		/* Enable MSI event queue */
404 		val = IPROC_MSI_INTR_EN | IPROC_MSI_INT_N_EVENT |
405 			IPROC_MSI_EQ_EN;
406 		iproc_msi_write_reg(msi, IPROC_MSI_CTRL, eq, val);
407 
408 		/*
409 		 * Some legacy platforms require the MSI interrupt enable
410 		 * register to be set explicitly.
411 		 */
412 		if (msi->has_inten_reg) {
413 			val = iproc_msi_read_reg(msi, IPROC_MSI_INTS_EN, eq);
414 			val |= BIT(eq);
415 			iproc_msi_write_reg(msi, IPROC_MSI_INTS_EN, eq, val);
416 		}
417 	}
418 }
419 
420 static void iproc_msi_disable(struct iproc_msi *msi)
421 {
422 	u32 eq, val;
423 
424 	for (eq = 0; eq < msi->nr_irqs; eq++) {
425 		if (msi->has_inten_reg) {
426 			val = iproc_msi_read_reg(msi, IPROC_MSI_INTS_EN, eq);
427 			val &= ~BIT(eq);
428 			iproc_msi_write_reg(msi, IPROC_MSI_INTS_EN, eq, val);
429 		}
430 
431 		val = iproc_msi_read_reg(msi, IPROC_MSI_CTRL, eq);
432 		val &= ~(IPROC_MSI_INTR_EN | IPROC_MSI_INT_N_EVENT |
433 			 IPROC_MSI_EQ_EN);
434 		iproc_msi_write_reg(msi, IPROC_MSI_CTRL, eq, val);
435 	}
436 }
437 
438 static int iproc_msi_alloc_domains(struct device_node *node,
439 				   struct iproc_msi *msi)
440 {
441 	msi->inner_domain = irq_domain_add_linear(NULL, msi->nr_msi_vecs,
442 						  &msi_domain_ops, msi);
443 	if (!msi->inner_domain)
444 		return -ENOMEM;
445 
446 	msi->msi_domain = pci_msi_create_irq_domain(of_node_to_fwnode(node),
447 						    &iproc_msi_domain_info,
448 						    msi->inner_domain);
449 	if (!msi->msi_domain) {
450 		irq_domain_remove(msi->inner_domain);
451 		return -ENOMEM;
452 	}
453 
454 	return 0;
455 }
456 
457 static void iproc_msi_free_domains(struct iproc_msi *msi)
458 {
459 	if (msi->msi_domain)
460 		irq_domain_remove(msi->msi_domain);
461 
462 	if (msi->inner_domain)
463 		irq_domain_remove(msi->inner_domain);
464 }
465 
466 static void iproc_msi_irq_free(struct iproc_msi *msi, unsigned int cpu)
467 {
468 	int i;
469 
470 	for (i = cpu; i < msi->nr_irqs; i += msi->nr_cpus) {
471 		irq_set_chained_handler_and_data(msi->grps[i].gic_irq,
472 						 NULL, NULL);
473 	}
474 }
475 
476 static int iproc_msi_irq_setup(struct iproc_msi *msi, unsigned int cpu)
477 {
478 	int i, ret;
479 	cpumask_var_t mask;
480 	struct iproc_pcie *pcie = msi->pcie;
481 
482 	for (i = cpu; i < msi->nr_irqs; i += msi->nr_cpus) {
483 		irq_set_chained_handler_and_data(msi->grps[i].gic_irq,
484 						 iproc_msi_handler,
485 						 &msi->grps[i]);
486 		/* Dedicate GIC interrupt to each CPU core */
487 		if (alloc_cpumask_var(&mask, GFP_KERNEL)) {
488 			cpumask_clear(mask);
489 			cpumask_set_cpu(cpu, mask);
490 			ret = irq_set_affinity(msi->grps[i].gic_irq, mask);
491 			if (ret)
492 				dev_err(pcie->dev,
493 					"failed to set affinity for IRQ%d\n",
494 					msi->grps[i].gic_irq);
495 			free_cpumask_var(mask);
496 		} else {
497 			dev_err(pcie->dev, "failed to alloc CPU mask\n");
498 			ret = -EINVAL;
499 		}
500 
501 		if (ret) {
502 			/* Free all configured/unconfigured IRQs */
503 			iproc_msi_irq_free(msi, cpu);
504 			return ret;
505 		}
506 	}
507 
508 	return 0;
509 }
510 
511 int iproc_msi_init(struct iproc_pcie *pcie, struct device_node *node)
512 {
513 	struct iproc_msi *msi;
514 	int i, ret;
515 	unsigned int cpu;
516 
517 	if (!of_device_is_compatible(node, "brcm,iproc-msi"))
518 		return -ENODEV;
519 
520 	if (!of_find_property(node, "msi-controller", NULL))
521 		return -ENODEV;
522 
523 	if (pcie->msi)
524 		return -EBUSY;
525 
526 	msi = devm_kzalloc(pcie->dev, sizeof(*msi), GFP_KERNEL);
527 	if (!msi)
528 		return -ENOMEM;
529 
530 	msi->pcie = pcie;
531 	pcie->msi = msi;
532 	msi->msi_addr = pcie->base_addr;
533 	mutex_init(&msi->bitmap_lock);
534 	msi->nr_cpus = num_possible_cpus();
535 
536 	msi->nr_irqs = of_irq_count(node);
537 	if (!msi->nr_irqs) {
538 		dev_err(pcie->dev, "found no MSI GIC interrupt\n");
539 		return -ENODEV;
540 	}
541 
542 	if (msi->nr_irqs > NR_HW_IRQS) {
543 		dev_warn(pcie->dev, "too many MSI GIC interrupts defined %d\n",
544 			 msi->nr_irqs);
545 		msi->nr_irqs = NR_HW_IRQS;
546 	}
547 
548 	if (msi->nr_irqs < msi->nr_cpus) {
549 		dev_err(pcie->dev,
550 			"not enough GIC interrupts for MSI affinity\n");
551 		return -EINVAL;
552 	}
553 
554 	if (msi->nr_irqs % msi->nr_cpus != 0) {
555 		msi->nr_irqs -= msi->nr_irqs % msi->nr_cpus;
556 		dev_warn(pcie->dev, "Reducing number of interrupts to %d\n",
557 			 msi->nr_irqs);
558 	}
559 
560 	switch (pcie->type) {
561 	case IPROC_PCIE_PAXB_BCMA:
562 	case IPROC_PCIE_PAXB:
563 		msi->reg_offsets = iproc_msi_reg_paxb;
564 		msi->nr_eq_region = 1;
565 		msi->nr_msi_region = 1;
566 		break;
567 	case IPROC_PCIE_PAXC:
568 		msi->reg_offsets = iproc_msi_reg_paxc;
569 		msi->nr_eq_region = msi->nr_irqs;
570 		msi->nr_msi_region = msi->nr_irqs;
571 		break;
572 	default:
573 		dev_err(pcie->dev, "incompatible iProc PCIe interface\n");
574 		return -EINVAL;
575 	}
576 
577 	if (of_find_property(node, "brcm,pcie-msi-inten", NULL))
578 		msi->has_inten_reg = true;
579 
580 	msi->nr_msi_vecs = msi->nr_irqs * EQ_LEN;
581 	msi->bitmap = devm_kcalloc(pcie->dev, BITS_TO_LONGS(msi->nr_msi_vecs),
582 				   sizeof(*msi->bitmap), GFP_KERNEL);
583 	if (!msi->bitmap)
584 		return -ENOMEM;
585 
586 	msi->grps = devm_kcalloc(pcie->dev, msi->nr_irqs, sizeof(*msi->grps),
587 				 GFP_KERNEL);
588 	if (!msi->grps)
589 		return -ENOMEM;
590 
591 	for (i = 0; i < msi->nr_irqs; i++) {
592 		unsigned int irq = irq_of_parse_and_map(node, i);
593 
594 		if (!irq) {
595 			dev_err(pcie->dev, "unable to parse/map interrupt\n");
596 			ret = -ENODEV;
597 			goto free_irqs;
598 		}
599 		msi->grps[i].gic_irq = irq;
600 		msi->grps[i].msi = msi;
601 		msi->grps[i].eq = i;
602 	}
603 
604 	/* Reserve memory for event queue and make sure memories are zeroed */
605 	msi->eq_cpu = dma_zalloc_coherent(pcie->dev,
606 					  msi->nr_eq_region * EQ_MEM_REGION_SIZE,
607 					  &msi->eq_dma, GFP_KERNEL);
608 	if (!msi->eq_cpu) {
609 		ret = -ENOMEM;
610 		goto free_irqs;
611 	}
612 
613 	ret = iproc_msi_alloc_domains(node, msi);
614 	if (ret) {
615 		dev_err(pcie->dev, "failed to create MSI domains\n");
616 		goto free_eq_dma;
617 	}
618 
619 	for_each_online_cpu(cpu) {
620 		ret = iproc_msi_irq_setup(msi, cpu);
621 		if (ret)
622 			goto free_msi_irq;
623 	}
624 
625 	iproc_msi_enable(msi);
626 
627 	return 0;
628 
629 free_msi_irq:
630 	for_each_online_cpu(cpu)
631 		iproc_msi_irq_free(msi, cpu);
632 	iproc_msi_free_domains(msi);
633 
634 free_eq_dma:
635 	dma_free_coherent(pcie->dev, msi->nr_eq_region * EQ_MEM_REGION_SIZE,
636 			  msi->eq_cpu, msi->eq_dma);
637 
638 free_irqs:
639 	for (i = 0; i < msi->nr_irqs; i++) {
640 		if (msi->grps[i].gic_irq)
641 			irq_dispose_mapping(msi->grps[i].gic_irq);
642 	}
643 	pcie->msi = NULL;
644 	return ret;
645 }
646 EXPORT_SYMBOL(iproc_msi_init);
647 
648 void iproc_msi_exit(struct iproc_pcie *pcie)
649 {
650 	struct iproc_msi *msi = pcie->msi;
651 	unsigned int i, cpu;
652 
653 	if (!msi)
654 		return;
655 
656 	iproc_msi_disable(msi);
657 
658 	for_each_online_cpu(cpu)
659 		iproc_msi_irq_free(msi, cpu);
660 
661 	iproc_msi_free_domains(msi);
662 
663 	dma_free_coherent(pcie->dev, msi->nr_eq_region * EQ_MEM_REGION_SIZE,
664 			  msi->eq_cpu, msi->eq_dma);
665 
666 	for (i = 0; i < msi->nr_irqs; i++) {
667 		if (msi->grps[i].gic_irq)
668 			irq_dispose_mapping(msi->grps[i].gic_irq);
669 	}
670 }
671 EXPORT_SYMBOL(iproc_msi_exit);
672