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1/*
2 * Broadcom BCM7038 style Level 1 interrupt controller driver
3 *
4 * Copyright (C) 2014 Broadcom Corporation
5 * Author: Kevin Cernekee
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
14#include <linux/bitops.h>
15#include <linux/kernel.h>
16#include <linux/init.h>
17#include <linux/interrupt.h>
18#include <linux/io.h>
19#include <linux/ioport.h>
20#include <linux/irq.h>
21#include <linux/irqdomain.h>
22#include <linux/module.h>
23#include <linux/of.h>
24#include <linux/of_irq.h>
25#include <linux/of_address.h>
26#include <linux/of_platform.h>
27#include <linux/platform_device.h>
28#include <linux/slab.h>
29#include <linux/smp.h>
30#include <linux/types.h>
31#include <linux/irqchip.h>
32#include <linux/irqchip/chained_irq.h>
33
34#define IRQS_PER_WORD 32
35#define REG_BYTES_PER_IRQ_WORD (sizeof(u32) * 4)
36#define MAX_WORDS 8
37
38struct bcm7038_l1_cpu;
39
40struct bcm7038_l1_chip {
41 raw_spinlock_t lock;
42 unsigned int n_words;
43 struct irq_domain *domain;
44 struct bcm7038_l1_cpu *cpus[NR_CPUS];
45 u8 affinity[MAX_WORDS * IRQS_PER_WORD];
46};
47
48struct bcm7038_l1_cpu {
49 void __iomem *map_base;
50 u32 mask_cache[0];
51};
52
53/*
54 * STATUS/MASK_STATUS/MASK_SET/MASK_CLEAR are packed one right after another:
55 *
56 * 7038:
57 * 0x1000_1400: W0_STATUS
58 * 0x1000_1404: W1_STATUS
59 * 0x1000_1408: W0_MASK_STATUS
60 * 0x1000_140c: W1_MASK_STATUS
61 * 0x1000_1410: W0_MASK_SET
62 * 0x1000_1414: W1_MASK_SET
63 * 0x1000_1418: W0_MASK_CLEAR
64 * 0x1000_141c: W1_MASK_CLEAR
65 *
66 * 7445:
67 * 0xf03e_1500: W0_STATUS
68 * 0xf03e_1504: W1_STATUS
69 * 0xf03e_1508: W2_STATUS
70 * 0xf03e_150c: W3_STATUS
71 * 0xf03e_1510: W4_STATUS
72 * 0xf03e_1514: W0_MASK_STATUS
73 * 0xf03e_1518: W1_MASK_STATUS
74 * [...]
75 */
76
77static inline unsigned int reg_status(struct bcm7038_l1_chip *intc,
78 unsigned int word)
79{
80 return (0 * intc->n_words + word) * sizeof(u32);
81}
82
83static inline unsigned int reg_mask_status(struct bcm7038_l1_chip *intc,
84 unsigned int word)
85{
86 return (1 * intc->n_words + word) * sizeof(u32);
87}
88
89static inline unsigned int reg_mask_set(struct bcm7038_l1_chip *intc,
90 unsigned int word)
91{
92 return (2 * intc->n_words + word) * sizeof(u32);
93}
94
95static inline unsigned int reg_mask_clr(struct bcm7038_l1_chip *intc,
96 unsigned int word)
97{
98 return (3 * intc->n_words + word) * sizeof(u32);
99}
100
101static inline u32 l1_readl(void __iomem *reg)
102{
103 if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
104 return ioread32be(reg);
105 else
106 return readl(reg);
107}
108
109static inline void l1_writel(u32 val, void __iomem *reg)
110{
111 if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
112 iowrite32be(val, reg);
113 else
114 writel(val, reg);
115}
116
117static void bcm7038_l1_irq_handle(struct irq_desc *desc)
118{
119 struct bcm7038_l1_chip *intc = irq_desc_get_handler_data(desc);
120 struct bcm7038_l1_cpu *cpu;
121 struct irq_chip *chip = irq_desc_get_chip(desc);
122 unsigned int idx;
123
124#ifdef CONFIG_SMP
125 cpu = intc->cpus[cpu_logical_map(smp_processor_id())];
126#else
127 cpu = intc->cpus[0];
128#endif
129
130 chained_irq_enter(chip, desc);
131
132 for (idx = 0; idx < intc->n_words; idx++) {
133 int base = idx * IRQS_PER_WORD;
134 unsigned long pending, flags;
135 int hwirq;
136
137 raw_spin_lock_irqsave(&intc->lock, flags);
138 pending = l1_readl(cpu->map_base + reg_status(intc, idx)) &
139 ~cpu->mask_cache[idx];
140 raw_spin_unlock_irqrestore(&intc->lock, flags);
141
142 for_each_set_bit(hwirq, &pending, IRQS_PER_WORD) {
143 generic_handle_irq(irq_find_mapping(intc->domain,
144 base + hwirq));
145 }
146 }
147
148 chained_irq_exit(chip, desc);
149}
150
151static void __bcm7038_l1_unmask(struct irq_data *d, unsigned int cpu_idx)
152{
153 struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
154 u32 word = d->hwirq / IRQS_PER_WORD;
155 u32 mask = BIT(d->hwirq % IRQS_PER_WORD);
156
157 intc->cpus[cpu_idx]->mask_cache[word] &= ~mask;
158 l1_writel(mask, intc->cpus[cpu_idx]->map_base +
159 reg_mask_clr(intc, word));
160}
161
162static void __bcm7038_l1_mask(struct irq_data *d, unsigned int cpu_idx)
163{
164 struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
165 u32 word = d->hwirq / IRQS_PER_WORD;
166 u32 mask = BIT(d->hwirq % IRQS_PER_WORD);
167
168 intc->cpus[cpu_idx]->mask_cache[word] |= mask;
169 l1_writel(mask, intc->cpus[cpu_idx]->map_base +
170 reg_mask_set(intc, word));
171}
172
173static void bcm7038_l1_unmask(struct irq_data *d)
174{
175 struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
176 unsigned long flags;
177
178 raw_spin_lock_irqsave(&intc->lock, flags);
179 __bcm7038_l1_unmask(d, intc->affinity[d->hwirq]);
180 raw_spin_unlock_irqrestore(&intc->lock, flags);
181}
182
183static void bcm7038_l1_mask(struct irq_data *d)
184{
185 struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
186 unsigned long flags;
187
188 raw_spin_lock_irqsave(&intc->lock, flags);
189 __bcm7038_l1_mask(d, intc->affinity[d->hwirq]);
190 raw_spin_unlock_irqrestore(&intc->lock, flags);
191}
192
193static int bcm7038_l1_set_affinity(struct irq_data *d,
194 const struct cpumask *dest,
195 bool force)
196{
197 struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
198 unsigned long flags;
199 irq_hw_number_t hw = d->hwirq;
200 u32 word = hw / IRQS_PER_WORD;
201 u32 mask = BIT(hw % IRQS_PER_WORD);
202 unsigned int first_cpu = cpumask_any_and(dest, cpu_online_mask);
203 bool was_disabled;
204
205 raw_spin_lock_irqsave(&intc->lock, flags);
206
207 was_disabled = !!(intc->cpus[intc->affinity[hw]]->mask_cache[word] &
208 mask);
209 __bcm7038_l1_mask(d, intc->affinity[hw]);
210 intc->affinity[hw] = first_cpu;
211 if (!was_disabled)
212 __bcm7038_l1_unmask(d, first_cpu);
213
214 raw_spin_unlock_irqrestore(&intc->lock, flags);
215 irq_data_update_effective_affinity(d, cpumask_of(first_cpu));
216
217 return 0;
218}
219
220static void bcm7038_l1_cpu_offline(struct irq_data *d)
221{
222 struct cpumask *mask = irq_data_get_affinity_mask(d);
223 int cpu = smp_processor_id();
224 cpumask_t new_affinity;
225
226 /* This CPU was not on the affinity mask */
227 if (!cpumask_test_cpu(cpu, mask))
228 return;
229
230 if (cpumask_weight(mask) > 1) {
231 /*
232 * Multiple CPU affinity, remove this CPU from the affinity
233 * mask
234 */
235 cpumask_copy(&new_affinity, mask);
236 cpumask_clear_cpu(cpu, &new_affinity);
237 } else {
238 /* Only CPU, put on the lowest online CPU */
239 cpumask_clear(&new_affinity);
240 cpumask_set_cpu(cpumask_first(cpu_online_mask), &new_affinity);
241 }
242 irq_set_affinity_locked(d, &new_affinity, false);
243}
244
245static int __init bcm7038_l1_init_one(struct device_node *dn,
246 unsigned int idx,
247 struct bcm7038_l1_chip *intc)
248{
249 struct resource res;
250 resource_size_t sz;
251 struct bcm7038_l1_cpu *cpu;
252 unsigned int i, n_words, parent_irq;
253
254 if (of_address_to_resource(dn, idx, &res))
255 return -EINVAL;
256 sz = resource_size(&res);
257 n_words = sz / REG_BYTES_PER_IRQ_WORD;
258
259 if (n_words > MAX_WORDS)
260 return -EINVAL;
261 else if (!intc->n_words)
262 intc->n_words = n_words;
263 else if (intc->n_words != n_words)
264 return -EINVAL;
265
266 cpu = intc->cpus[idx] = kzalloc(sizeof(*cpu) + n_words * sizeof(u32),
267 GFP_KERNEL);
268 if (!cpu)
269 return -ENOMEM;
270
271 cpu->map_base = ioremap(res.start, sz);
272 if (!cpu->map_base)
273 return -ENOMEM;
274
275 for (i = 0; i < n_words; i++) {
276 l1_writel(0xffffffff, cpu->map_base + reg_mask_set(intc, i));
277 cpu->mask_cache[i] = 0xffffffff;
278 }
279
280 parent_irq = irq_of_parse_and_map(dn, idx);
281 if (!parent_irq) {
282 pr_err("failed to map parent interrupt %d\n", parent_irq);
283 return -EINVAL;
284 }
285 irq_set_chained_handler_and_data(parent_irq, bcm7038_l1_irq_handle,
286 intc);
287
288 return 0;
289}
290
291static struct irq_chip bcm7038_l1_irq_chip = {
292 .name = "bcm7038-l1",
293 .irq_mask = bcm7038_l1_mask,
294 .irq_unmask = bcm7038_l1_unmask,
295 .irq_set_affinity = bcm7038_l1_set_affinity,
296 .irq_cpu_offline = bcm7038_l1_cpu_offline,
297};
298
299static int bcm7038_l1_map(struct irq_domain *d, unsigned int virq,
300 irq_hw_number_t hw_irq)
301{
302 irq_set_chip_and_handler(virq, &bcm7038_l1_irq_chip, handle_level_irq);
303 irq_set_chip_data(virq, d->host_data);
304 irqd_set_single_target(irq_desc_get_irq_data(irq_to_desc(virq)));
305 return 0;
306}
307
308static const struct irq_domain_ops bcm7038_l1_domain_ops = {
309 .xlate = irq_domain_xlate_onecell,
310 .map = bcm7038_l1_map,
311};
312
313int __init bcm7038_l1_of_init(struct device_node *dn,
314 struct device_node *parent)
315{
316 struct bcm7038_l1_chip *intc;
317 int idx, ret;
318
319 intc = kzalloc(sizeof(*intc), GFP_KERNEL);
320 if (!intc)
321 return -ENOMEM;
322
323 raw_spin_lock_init(&intc->lock);
324 for_each_possible_cpu(idx) {
325 ret = bcm7038_l1_init_one(dn, idx, intc);
326 if (ret < 0) {
327 if (idx)
328 break;
329 pr_err("failed to remap intc L1 registers\n");
330 goto out_free;
331 }
332 }
333
334 intc->domain = irq_domain_add_linear(dn, IRQS_PER_WORD * intc->n_words,
335 &bcm7038_l1_domain_ops,
336 intc);
337 if (!intc->domain) {
338 ret = -ENOMEM;
339 goto out_unmap;
340 }
341
342 return 0;
343
344out_unmap:
345 for_each_possible_cpu(idx) {
346 struct bcm7038_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 }
354out_free:
355 kfree(intc);
356 return ret;
357}
358
359IRQCHIP_DECLARE(bcm7038_l1, "brcm,bcm7038-l1-intc", bcm7038_l1_of_init);