1 /*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 2013 Cavium, Inc.
7 */
8
9 #include <linux/interrupt.h>
10 #include <linux/cpumask.h>
11 #include <linux/kernel.h>
12 #include <linux/mutex.h>
13
14 #include <asm/io.h>
15
16 #define MBOX_BITS_PER_CPU 2
17
cpunum_for_cpu(int cpu)18 static int cpunum_for_cpu(int cpu)
19 {
20 #ifdef CONFIG_SMP
21 return cpu_logical_map(cpu);
22 #else
23 return get_ebase_cpunum();
24 #endif
25 }
26
27 struct core_chip_data {
28 struct mutex core_irq_mutex;
29 bool current_en;
30 bool desired_en;
31 u8 bit;
32 };
33
34 static struct core_chip_data irq_core_chip_data[8];
35
irq_core_ack(struct irq_data * data)36 static void irq_core_ack(struct irq_data *data)
37 {
38 struct core_chip_data *cd = irq_data_get_irq_chip_data(data);
39 unsigned int bit = cd->bit;
40
41 /*
42 * We don't need to disable IRQs to make these atomic since
43 * they are already disabled earlier in the low level
44 * interrupt code.
45 */
46 clear_c0_status(0x100 << bit);
47 /* The two user interrupts must be cleared manually. */
48 if (bit < 2)
49 clear_c0_cause(0x100 << bit);
50 }
51
irq_core_eoi(struct irq_data * data)52 static void irq_core_eoi(struct irq_data *data)
53 {
54 struct core_chip_data *cd = irq_data_get_irq_chip_data(data);
55
56 /*
57 * We don't need to disable IRQs to make these atomic since
58 * they are already disabled earlier in the low level
59 * interrupt code.
60 */
61 set_c0_status(0x100 << cd->bit);
62 }
63
irq_core_set_enable_local(void * arg)64 static void irq_core_set_enable_local(void *arg)
65 {
66 struct irq_data *data = arg;
67 struct core_chip_data *cd = irq_data_get_irq_chip_data(data);
68 unsigned int mask = 0x100 << cd->bit;
69
70 /*
71 * Interrupts are already disabled, so these are atomic.
72 */
73 if (cd->desired_en)
74 set_c0_status(mask);
75 else
76 clear_c0_status(mask);
77
78 }
79
irq_core_disable(struct irq_data * data)80 static void irq_core_disable(struct irq_data *data)
81 {
82 struct core_chip_data *cd = irq_data_get_irq_chip_data(data);
83 cd->desired_en = false;
84 }
85
irq_core_enable(struct irq_data * data)86 static void irq_core_enable(struct irq_data *data)
87 {
88 struct core_chip_data *cd = irq_data_get_irq_chip_data(data);
89 cd->desired_en = true;
90 }
91
irq_core_bus_lock(struct irq_data * data)92 static void irq_core_bus_lock(struct irq_data *data)
93 {
94 struct core_chip_data *cd = irq_data_get_irq_chip_data(data);
95
96 mutex_lock(&cd->core_irq_mutex);
97 }
98
irq_core_bus_sync_unlock(struct irq_data * data)99 static void irq_core_bus_sync_unlock(struct irq_data *data)
100 {
101 struct core_chip_data *cd = irq_data_get_irq_chip_data(data);
102
103 if (cd->desired_en != cd->current_en) {
104 on_each_cpu(irq_core_set_enable_local, data, 1);
105 cd->current_en = cd->desired_en;
106 }
107
108 mutex_unlock(&cd->core_irq_mutex);
109 }
110
111 static struct irq_chip irq_chip_core = {
112 .name = "Core",
113 .irq_enable = irq_core_enable,
114 .irq_disable = irq_core_disable,
115 .irq_ack = irq_core_ack,
116 .irq_eoi = irq_core_eoi,
117 .irq_bus_lock = irq_core_bus_lock,
118 .irq_bus_sync_unlock = irq_core_bus_sync_unlock,
119
120 .irq_cpu_online = irq_core_eoi,
121 .irq_cpu_offline = irq_core_ack,
122 .flags = IRQCHIP_ONOFFLINE_ENABLED,
123 };
124
irq_init_core(void)125 static void __init irq_init_core(void)
126 {
127 int i;
128 int irq;
129 struct core_chip_data *cd;
130
131 /* Start with a clean slate */
132 clear_c0_status(ST0_IM);
133 clear_c0_cause(CAUSEF_IP0 | CAUSEF_IP1);
134
135 for (i = 0; i < ARRAY_SIZE(irq_core_chip_data); i++) {
136 cd = irq_core_chip_data + i;
137 cd->current_en = false;
138 cd->desired_en = false;
139 cd->bit = i;
140 mutex_init(&cd->core_irq_mutex);
141
142 irq = MIPS_CPU_IRQ_BASE + i;
143
144 switch (i) {
145 case 0: /* SW0 */
146 case 1: /* SW1 */
147 case 5: /* IP5 */
148 case 6: /* IP6 */
149 case 7: /* IP7 */
150 irq_set_chip_data(irq, cd);
151 irq_set_chip_and_handler(irq, &irq_chip_core,
152 handle_percpu_irq);
153 break;
154 default:
155 break;
156 }
157 }
158 }
159
160 static void __iomem *mips_irq_chip;
161 #define MIPS_IRQ_CHIP_NUM_BITS 0
162 #define MIPS_IRQ_CHIP_REGS 8
163
164 static int mips_irq_cpu_stride;
165 static int mips_irq_chip_reg_raw;
166 static int mips_irq_chip_reg_src;
167 static int mips_irq_chip_reg_en;
168 static int mips_irq_chip_reg_raw_w1s;
169 static int mips_irq_chip_reg_raw_w1c;
170 static int mips_irq_chip_reg_en_w1s;
171 static int mips_irq_chip_reg_en_w1c;
172
irq_pci_enable(struct irq_data * data)173 static void irq_pci_enable(struct irq_data *data)
174 {
175 u32 mask = 1u << data->irq;
176
177 __raw_writel(mask, mips_irq_chip + mips_irq_chip_reg_en_w1s);
178 }
179
irq_pci_disable(struct irq_data * data)180 static void irq_pci_disable(struct irq_data *data)
181 {
182 u32 mask = 1u << data->irq;
183
184 __raw_writel(mask, mips_irq_chip + mips_irq_chip_reg_en_w1c);
185 }
186
irq_pci_ack(struct irq_data * data)187 static void irq_pci_ack(struct irq_data *data)
188 {
189 }
190
irq_pci_mask(struct irq_data * data)191 static void irq_pci_mask(struct irq_data *data)
192 {
193 u32 mask = 1u << data->irq;
194
195 __raw_writel(mask, mips_irq_chip + mips_irq_chip_reg_en_w1c);
196 }
197
irq_pci_unmask(struct irq_data * data)198 static void irq_pci_unmask(struct irq_data *data)
199 {
200 u32 mask = 1u << data->irq;
201
202 __raw_writel(mask, mips_irq_chip + mips_irq_chip_reg_en_w1s);
203 }
204
205 static struct irq_chip irq_chip_pci = {
206 .name = "PCI",
207 .irq_enable = irq_pci_enable,
208 .irq_disable = irq_pci_disable,
209 .irq_ack = irq_pci_ack,
210 .irq_mask = irq_pci_mask,
211 .irq_unmask = irq_pci_unmask,
212 };
213
irq_mbox_all(struct irq_data * data,void __iomem * base)214 static void irq_mbox_all(struct irq_data *data, void __iomem *base)
215 {
216 int cpu;
217 unsigned int mbox = data->irq - MIPS_IRQ_MBOX0;
218 u32 mask;
219
220 WARN_ON(mbox >= MBOX_BITS_PER_CPU);
221
222 for_each_online_cpu(cpu) {
223 unsigned int cpuid = cpunum_for_cpu(cpu);
224 mask = 1 << (cpuid * MBOX_BITS_PER_CPU + mbox);
225 __raw_writel(mask, base + (cpuid * mips_irq_cpu_stride));
226 }
227 }
228
irq_mbox_enable(struct irq_data * data)229 static void irq_mbox_enable(struct irq_data *data)
230 {
231 irq_mbox_all(data, mips_irq_chip + mips_irq_chip_reg_en_w1s + sizeof(u32));
232 }
233
irq_mbox_disable(struct irq_data * data)234 static void irq_mbox_disable(struct irq_data *data)
235 {
236 irq_mbox_all(data, mips_irq_chip + mips_irq_chip_reg_en_w1c + sizeof(u32));
237 }
238
irq_mbox_ack(struct irq_data * data)239 static void irq_mbox_ack(struct irq_data *data)
240 {
241 u32 mask;
242 unsigned int mbox = data->irq - MIPS_IRQ_MBOX0;
243
244 WARN_ON(mbox >= MBOX_BITS_PER_CPU);
245
246 mask = 1 << (get_ebase_cpunum() * MBOX_BITS_PER_CPU + mbox);
247 __raw_writel(mask, mips_irq_chip + mips_irq_chip_reg_raw_w1c + sizeof(u32));
248 }
249
irq_mbox_ipi(int cpu,unsigned int actions)250 void irq_mbox_ipi(int cpu, unsigned int actions)
251 {
252 unsigned int cpuid = cpunum_for_cpu(cpu);
253 u32 mask;
254
255 WARN_ON(actions >= (1 << MBOX_BITS_PER_CPU));
256
257 mask = actions << (cpuid * MBOX_BITS_PER_CPU);
258 __raw_writel(mask, mips_irq_chip + mips_irq_chip_reg_raw_w1s + sizeof(u32));
259 }
260
irq_mbox_cpu_onoffline(struct irq_data * data,void __iomem * base)261 static void irq_mbox_cpu_onoffline(struct irq_data *data, void __iomem *base)
262 {
263 unsigned int mbox = data->irq - MIPS_IRQ_MBOX0;
264 unsigned int cpuid = get_ebase_cpunum();
265 u32 mask;
266
267 WARN_ON(mbox >= MBOX_BITS_PER_CPU);
268
269 mask = 1 << (cpuid * MBOX_BITS_PER_CPU + mbox);
270 __raw_writel(mask, base + (cpuid * mips_irq_cpu_stride));
271
272 }
273
irq_mbox_cpu_online(struct irq_data * data)274 static void irq_mbox_cpu_online(struct irq_data *data)
275 {
276 irq_mbox_cpu_onoffline(data, mips_irq_chip + mips_irq_chip_reg_en_w1s + sizeof(u32));
277 }
278
irq_mbox_cpu_offline(struct irq_data * data)279 static void irq_mbox_cpu_offline(struct irq_data *data)
280 {
281 irq_mbox_cpu_onoffline(data, mips_irq_chip + mips_irq_chip_reg_en_w1c + sizeof(u32));
282 }
283
284 static struct irq_chip irq_chip_mbox = {
285 .name = "MBOX",
286 .irq_enable = irq_mbox_enable,
287 .irq_disable = irq_mbox_disable,
288 .irq_ack = irq_mbox_ack,
289 .irq_cpu_online = irq_mbox_cpu_online,
290 .irq_cpu_offline = irq_mbox_cpu_offline,
291 .flags = IRQCHIP_ONOFFLINE_ENABLED,
292 };
293
irq_pci_init(void)294 static void __init irq_pci_init(void)
295 {
296 int i, stride;
297 u32 num_bits;
298
299 mips_irq_chip = ioremap(0x1e010000, 4096);
300
301 num_bits = __raw_readl(mips_irq_chip + MIPS_IRQ_CHIP_NUM_BITS);
302 stride = 8 * (1 + ((num_bits - 1) / 64));
303
304
305 pr_notice("mips_irq_chip: %u bits, reg stride: %d\n", num_bits, stride);
306 mips_irq_chip_reg_raw = MIPS_IRQ_CHIP_REGS + 0 * stride;
307 mips_irq_chip_reg_raw_w1s = MIPS_IRQ_CHIP_REGS + 1 * stride;
308 mips_irq_chip_reg_raw_w1c = MIPS_IRQ_CHIP_REGS + 2 * stride;
309 mips_irq_chip_reg_src = MIPS_IRQ_CHIP_REGS + 3 * stride;
310 mips_irq_chip_reg_en = MIPS_IRQ_CHIP_REGS + 4 * stride;
311 mips_irq_chip_reg_en_w1s = MIPS_IRQ_CHIP_REGS + 5 * stride;
312 mips_irq_chip_reg_en_w1c = MIPS_IRQ_CHIP_REGS + 6 * stride;
313 mips_irq_cpu_stride = stride * 4;
314
315 for (i = 0; i < 4; i++)
316 irq_set_chip_and_handler(i + MIPS_IRQ_PCIA, &irq_chip_pci, handle_level_irq);
317
318 for (i = 0; i < 2; i++)
319 irq_set_chip_and_handler(i + MIPS_IRQ_MBOX0, &irq_chip_mbox, handle_percpu_irq);
320
321
322 set_c0_status(STATUSF_IP2);
323 }
324
irq_pci_dispatch(void)325 static void irq_pci_dispatch(void)
326 {
327 unsigned int cpuid = get_ebase_cpunum();
328 u32 en;
329
330 en = __raw_readl(mips_irq_chip + mips_irq_chip_reg_src +
331 (cpuid * mips_irq_cpu_stride));
332
333 if (!en) {
334 en = __raw_readl(mips_irq_chip + mips_irq_chip_reg_src + (cpuid * mips_irq_cpu_stride) + sizeof(u32));
335 en = (en >> (2 * cpuid)) & 3;
336
337 if (!en)
338 spurious_interrupt();
339 else
340 do_IRQ(__ffs(en) + MIPS_IRQ_MBOX0); /* MBOX type */
341 } else {
342 do_IRQ(__ffs(en));
343 }
344 }
345
346
arch_init_irq(void)347 void __init arch_init_irq(void)
348 {
349 irq_init_core();
350 irq_pci_init();
351 }
352
plat_irq_dispatch(void)353 asmlinkage void plat_irq_dispatch(void)
354 {
355 unsigned int pending = read_c0_cause() & read_c0_status() & ST0_IM;
356 int ip;
357
358 if (unlikely(!pending)) {
359 spurious_interrupt();
360 return;
361 }
362
363 ip = ffs(pending) - 1 - STATUSB_IP0;
364 if (ip == 2)
365 irq_pci_dispatch();
366 else
367 do_IRQ(MIPS_CPU_IRQ_BASE + ip);
368 }
369