1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Broadcom BCM6345 style Level 1 interrupt controller driver
4 *
5 * Copyright (C) 2014 Broadcom Corporation
6 * Copyright 2015 Simon Arlott
7 *
8 * This is based on the BCM7038 (which supports SMP) but with a single
9 * enable register instead of separate mask/set/clear registers.
10 *
11 * The BCM3380 has a similar mask/status register layout, but each pair
12 * of words is at separate locations (and SMP is not supported).
13 *
14 * ENABLE/STATUS words are packed next to each other for each CPU:
15 *
16 * BCM6368:
17 * 0x1000_0020: CPU0_W0_ENABLE
18 * 0x1000_0024: CPU0_W1_ENABLE
19 * 0x1000_0028: CPU0_W0_STATUS IRQs 31-63
20 * 0x1000_002c: CPU0_W1_STATUS IRQs 0-31
21 * 0x1000_0030: CPU1_W0_ENABLE
22 * 0x1000_0034: CPU1_W1_ENABLE
23 * 0x1000_0038: CPU1_W0_STATUS IRQs 31-63
24 * 0x1000_003c: CPU1_W1_STATUS IRQs 0-31
25 *
26 * BCM63168:
27 * 0x1000_0020: CPU0_W0_ENABLE
28 * 0x1000_0024: CPU0_W1_ENABLE
29 * 0x1000_0028: CPU0_W2_ENABLE
30 * 0x1000_002c: CPU0_W3_ENABLE
31 * 0x1000_0030: CPU0_W0_STATUS IRQs 96-127
32 * 0x1000_0034: CPU0_W1_STATUS IRQs 64-95
33 * 0x1000_0038: CPU0_W2_STATUS IRQs 32-63
34 * 0x1000_003c: CPU0_W3_STATUS IRQs 0-31
35 * 0x1000_0040: CPU1_W0_ENABLE
36 * 0x1000_0044: CPU1_W1_ENABLE
37 * 0x1000_0048: CPU1_W2_ENABLE
38 * 0x1000_004c: CPU1_W3_ENABLE
39 * 0x1000_0050: CPU1_W0_STATUS IRQs 96-127
40 * 0x1000_0054: CPU1_W1_STATUS IRQs 64-95
41 * 0x1000_0058: CPU1_W2_STATUS IRQs 32-63
42 * 0x1000_005c: CPU1_W3_STATUS IRQs 0-31
43 *
44 * IRQs are numbered in CPU native endian order
45 * (which is big-endian in these examples)
46 */
47
48 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
49
50 #include <linux/bitops.h>
51 #include <linux/cpumask.h>
52 #include <linux/kernel.h>
53 #include <linux/init.h>
54 #include <linux/interrupt.h>
55 #include <linux/io.h>
56 #include <linux/ioport.h>
57 #include <linux/irq.h>
58 #include <linux/irqdomain.h>
59 #include <linux/module.h>
60 #include <linux/of.h>
61 #include <linux/of_irq.h>
62 #include <linux/of_address.h>
63 #include <linux/of_platform.h>
64 #include <linux/platform_device.h>
65 #include <linux/slab.h>
66 #include <linux/smp.h>
67 #include <linux/types.h>
68 #include <linux/irqchip.h>
69 #include <linux/irqchip/chained_irq.h>
70
71 #define IRQS_PER_WORD 32
72 #define REG_BYTES_PER_IRQ_WORD (sizeof(u32) * 2)
73
74 struct bcm6345_l1_cpu;
75
76 struct bcm6345_l1_chip {
77 raw_spinlock_t lock;
78 unsigned int n_words;
79 struct irq_domain *domain;
80 struct cpumask cpumask;
81 struct bcm6345_l1_cpu *cpus[NR_CPUS];
82 };
83
84 struct bcm6345_l1_cpu {
85 void __iomem *map_base;
86 unsigned int parent_irq;
87 u32 enable_cache[];
88 };
89
reg_enable(struct bcm6345_l1_chip * intc,unsigned int word)90 static inline unsigned int reg_enable(struct bcm6345_l1_chip *intc,
91 unsigned int word)
92 {
93 #ifdef __BIG_ENDIAN
94 return (1 * intc->n_words - word - 1) * sizeof(u32);
95 #else
96 return (0 * intc->n_words + word) * sizeof(u32);
97 #endif
98 }
99
reg_status(struct bcm6345_l1_chip * intc,unsigned int word)100 static inline unsigned int reg_status(struct bcm6345_l1_chip *intc,
101 unsigned int word)
102 {
103 #ifdef __BIG_ENDIAN
104 return (2 * intc->n_words - word - 1) * sizeof(u32);
105 #else
106 return (1 * intc->n_words + word) * sizeof(u32);
107 #endif
108 }
109
cpu_for_irq(struct bcm6345_l1_chip * intc,struct irq_data * d)110 static inline unsigned int cpu_for_irq(struct bcm6345_l1_chip *intc,
111 struct irq_data *d)
112 {
113 return cpumask_first_and(&intc->cpumask, irq_data_get_affinity_mask(d));
114 }
115
bcm6345_l1_irq_handle(struct irq_desc * desc)116 static void bcm6345_l1_irq_handle(struct irq_desc *desc)
117 {
118 struct bcm6345_l1_chip *intc = irq_desc_get_handler_data(desc);
119 struct bcm6345_l1_cpu *cpu;
120 struct irq_chip *chip = irq_desc_get_chip(desc);
121 unsigned int idx;
122
123 #ifdef CONFIG_SMP
124 cpu = intc->cpus[cpu_logical_map(smp_processor_id())];
125 #else
126 cpu = intc->cpus[0];
127 #endif
128
129 chained_irq_enter(chip, desc);
130
131 for (idx = 0; idx < intc->n_words; idx++) {
132 int base = idx * IRQS_PER_WORD;
133 unsigned long pending;
134 irq_hw_number_t hwirq;
135
136 pending = __raw_readl(cpu->map_base + reg_status(intc, idx));
137 pending &= __raw_readl(cpu->map_base + reg_enable(intc, idx));
138
139 for_each_set_bit(hwirq, &pending, IRQS_PER_WORD) {
140 if (generic_handle_domain_irq(intc->domain, base + hwirq))
141 spurious_interrupt();
142 }
143 }
144
145 chained_irq_exit(chip, desc);
146 }
147
__bcm6345_l1_unmask(struct irq_data * d)148 static inline void __bcm6345_l1_unmask(struct irq_data *d)
149 {
150 struct bcm6345_l1_chip *intc = irq_data_get_irq_chip_data(d);
151 u32 word = d->hwirq / IRQS_PER_WORD;
152 u32 mask = BIT(d->hwirq % IRQS_PER_WORD);
153 unsigned int cpu_idx = cpu_for_irq(intc, d);
154
155 intc->cpus[cpu_idx]->enable_cache[word] |= mask;
156 __raw_writel(intc->cpus[cpu_idx]->enable_cache[word],
157 intc->cpus[cpu_idx]->map_base + reg_enable(intc, word));
158 }
159
__bcm6345_l1_mask(struct irq_data * d)160 static inline void __bcm6345_l1_mask(struct irq_data *d)
161 {
162 struct bcm6345_l1_chip *intc = irq_data_get_irq_chip_data(d);
163 u32 word = d->hwirq / IRQS_PER_WORD;
164 u32 mask = BIT(d->hwirq % IRQS_PER_WORD);
165 unsigned int cpu_idx = cpu_for_irq(intc, d);
166
167 intc->cpus[cpu_idx]->enable_cache[word] &= ~mask;
168 __raw_writel(intc->cpus[cpu_idx]->enable_cache[word],
169 intc->cpus[cpu_idx]->map_base + reg_enable(intc, word));
170 }
171
bcm6345_l1_unmask(struct irq_data * d)172 static void bcm6345_l1_unmask(struct irq_data *d)
173 {
174 struct bcm6345_l1_chip *intc = irq_data_get_irq_chip_data(d);
175 unsigned long flags;
176
177 raw_spin_lock_irqsave(&intc->lock, flags);
178 __bcm6345_l1_unmask(d);
179 raw_spin_unlock_irqrestore(&intc->lock, flags);
180 }
181
bcm6345_l1_mask(struct irq_data * d)182 static void bcm6345_l1_mask(struct irq_data *d)
183 {
184 struct bcm6345_l1_chip *intc = irq_data_get_irq_chip_data(d);
185 unsigned long flags;
186
187 raw_spin_lock_irqsave(&intc->lock, flags);
188 __bcm6345_l1_mask(d);
189 raw_spin_unlock_irqrestore(&intc->lock, flags);
190 }
191
bcm6345_l1_set_affinity(struct irq_data * d,const struct cpumask * dest,bool force)192 static int bcm6345_l1_set_affinity(struct irq_data *d,
193 const struct cpumask *dest,
194 bool force)
195 {
196 struct bcm6345_l1_chip *intc = irq_data_get_irq_chip_data(d);
197 u32 word = d->hwirq / IRQS_PER_WORD;
198 u32 mask = BIT(d->hwirq % IRQS_PER_WORD);
199 unsigned int old_cpu = cpu_for_irq(intc, d);
200 unsigned int new_cpu;
201 struct cpumask valid;
202 unsigned long flags;
203 bool enabled;
204
205 if (!cpumask_and(&valid, &intc->cpumask, dest))
206 return -EINVAL;
207
208 new_cpu = cpumask_any_and(&valid, cpu_online_mask);
209 if (new_cpu >= nr_cpu_ids)
210 return -EINVAL;
211
212 dest = cpumask_of(new_cpu);
213
214 raw_spin_lock_irqsave(&intc->lock, flags);
215 if (old_cpu != new_cpu) {
216 enabled = intc->cpus[old_cpu]->enable_cache[word] & mask;
217 if (enabled)
218 __bcm6345_l1_mask(d);
219 cpumask_copy(irq_data_get_affinity_mask(d), dest);
220 if (enabled)
221 __bcm6345_l1_unmask(d);
222 } else {
223 cpumask_copy(irq_data_get_affinity_mask(d), dest);
224 }
225 raw_spin_unlock_irqrestore(&intc->lock, flags);
226
227 irq_data_update_effective_affinity(d, cpumask_of(new_cpu));
228
229 return IRQ_SET_MASK_OK_NOCOPY;
230 }
231
bcm6345_l1_init_one(struct device_node * dn,unsigned int idx,struct bcm6345_l1_chip * intc)232 static int __init bcm6345_l1_init_one(struct device_node *dn,
233 unsigned int idx,
234 struct bcm6345_l1_chip *intc)
235 {
236 struct resource res;
237 resource_size_t sz;
238 struct bcm6345_l1_cpu *cpu;
239 unsigned int i, n_words;
240
241 if (of_address_to_resource(dn, idx, &res))
242 return -EINVAL;
243 sz = resource_size(&res);
244 n_words = sz / REG_BYTES_PER_IRQ_WORD;
245
246 if (!intc->n_words)
247 intc->n_words = n_words;
248 else if (intc->n_words != n_words)
249 return -EINVAL;
250
251 cpu = intc->cpus[idx] = kzalloc(sizeof(*cpu) + n_words * sizeof(u32),
252 GFP_KERNEL);
253 if (!cpu)
254 return -ENOMEM;
255
256 cpu->map_base = ioremap(res.start, sz);
257 if (!cpu->map_base)
258 return -ENOMEM;
259
260 for (i = 0; i < n_words; i++) {
261 cpu->enable_cache[i] = 0;
262 __raw_writel(0, cpu->map_base + reg_enable(intc, i));
263 }
264
265 cpu->parent_irq = irq_of_parse_and_map(dn, idx);
266 if (!cpu->parent_irq) {
267 pr_err("failed to map parent interrupt %d\n", cpu->parent_irq);
268 return -EINVAL;
269 }
270 irq_set_chained_handler_and_data(cpu->parent_irq,
271 bcm6345_l1_irq_handle, intc);
272
273 return 0;
274 }
275
276 static struct irq_chip bcm6345_l1_irq_chip = {
277 .name = "bcm6345-l1",
278 .irq_mask = bcm6345_l1_mask,
279 .irq_unmask = bcm6345_l1_unmask,
280 .irq_set_affinity = bcm6345_l1_set_affinity,
281 };
282
bcm6345_l1_map(struct irq_domain * d,unsigned int virq,irq_hw_number_t hw_irq)283 static int bcm6345_l1_map(struct irq_domain *d, unsigned int virq,
284 irq_hw_number_t hw_irq)
285 {
286 irq_set_chip_and_handler(virq,
287 &bcm6345_l1_irq_chip, handle_percpu_irq);
288 irq_set_chip_data(virq, d->host_data);
289 irqd_set_single_target(irq_desc_get_irq_data(irq_to_desc(virq)));
290 return 0;
291 }
292
293 static const struct irq_domain_ops bcm6345_l1_domain_ops = {
294 .xlate = irq_domain_xlate_onecell,
295 .map = bcm6345_l1_map,
296 };
297
bcm6345_l1_of_init(struct device_node * dn,struct device_node * parent)298 static int __init bcm6345_l1_of_init(struct device_node *dn,
299 struct device_node *parent)
300 {
301 struct bcm6345_l1_chip *intc;
302 unsigned int idx;
303 int ret;
304
305 intc = kzalloc(sizeof(*intc), GFP_KERNEL);
306 if (!intc)
307 return -ENOMEM;
308
309 for_each_possible_cpu(idx) {
310 ret = bcm6345_l1_init_one(dn, idx, intc);
311 if (ret)
312 pr_err("failed to init intc L1 for cpu %d: %d\n",
313 idx, ret);
314 else
315 cpumask_set_cpu(idx, &intc->cpumask);
316 }
317
318 if (!cpumask_weight(&intc->cpumask)) {
319 ret = -ENODEV;
320 goto out_free;
321 }
322
323 raw_spin_lock_init(&intc->lock);
324
325 intc->domain = irq_domain_add_linear(dn, IRQS_PER_WORD * intc->n_words,
326 &bcm6345_l1_domain_ops,
327 intc);
328 if (!intc->domain) {
329 ret = -ENOMEM;
330 goto out_unmap;
331 }
332
333 pr_info("registered BCM6345 L1 intc (IRQs: %d)\n",
334 IRQS_PER_WORD * intc->n_words);
335 for_each_cpu(idx, &intc->cpumask) {
336 struct bcm6345_l1_cpu *cpu = intc->cpus[idx];
337
338 pr_info(" CPU%u at MMIO 0x%p (irq = %d)\n", idx,
339 cpu->map_base, cpu->parent_irq);
340 }
341
342 return 0;
343
344 out_unmap:
345 for_each_possible_cpu(idx) {
346 struct bcm6345_l1_cpu *cpu = intc->cpus[idx];
347
348 if (cpu) {
349 if (cpu->map_base)
350 iounmap(cpu->map_base);
351 kfree(cpu);
352 }
353 }
354 out_free:
355 kfree(intc);
356 return ret;
357 }
358
359 IRQCHIP_DECLARE(bcm6345_l1, "brcm,bcm6345-l1-intc", bcm6345_l1_of_init);
360