1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * ip27-irq.c: Highlevel interrupt handling for IP27 architecture.
4 *
5 * Copyright (C) 1999, 2000 Ralf Baechle (ralf@gnu.org)
6 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
7 * Copyright (C) 1999 - 2001 Kanoj Sarcar
8 */
9
10 #include <linux/interrupt.h>
11 #include <linux/irq.h>
12 #include <linux/irqdomain.h>
13 #include <linux/ioport.h>
14 #include <linux/kernel.h>
15 #include <linux/bitops.h>
16 #include <linux/sched.h>
17
18 #include <asm/io.h>
19 #include <asm/irq_cpu.h>
20 #include <asm/sn/addrs.h>
21 #include <asm/sn/agent.h>
22 #include <asm/sn/arch.h>
23 #include <asm/sn/intr.h>
24 #include <asm/sn/irq_alloc.h>
25
26 struct hub_irq_data {
27 u64 *irq_mask[2];
28 cpuid_t cpu;
29 };
30
31 static DECLARE_BITMAP(hub_irq_map, IP27_HUB_IRQ_COUNT);
32
33 static DEFINE_PER_CPU(unsigned long [2], irq_enable_mask);
34
alloc_level(void)35 static inline int alloc_level(void)
36 {
37 int level;
38
39 again:
40 level = find_first_zero_bit(hub_irq_map, IP27_HUB_IRQ_COUNT);
41 if (level >= IP27_HUB_IRQ_COUNT)
42 return -ENOSPC;
43
44 if (test_and_set_bit(level, hub_irq_map))
45 goto again;
46
47 return level;
48 }
49
enable_hub_irq(struct irq_data * d)50 static void enable_hub_irq(struct irq_data *d)
51 {
52 struct hub_irq_data *hd = irq_data_get_irq_chip_data(d);
53 unsigned long *mask = per_cpu(irq_enable_mask, hd->cpu);
54
55 set_bit(d->hwirq, mask);
56 __raw_writeq(mask[0], hd->irq_mask[0]);
57 __raw_writeq(mask[1], hd->irq_mask[1]);
58 }
59
disable_hub_irq(struct irq_data * d)60 static void disable_hub_irq(struct irq_data *d)
61 {
62 struct hub_irq_data *hd = irq_data_get_irq_chip_data(d);
63 unsigned long *mask = per_cpu(irq_enable_mask, hd->cpu);
64
65 clear_bit(d->hwirq, mask);
66 __raw_writeq(mask[0], hd->irq_mask[0]);
67 __raw_writeq(mask[1], hd->irq_mask[1]);
68 }
69
setup_hub_mask(struct hub_irq_data * hd,const struct cpumask * mask)70 static void setup_hub_mask(struct hub_irq_data *hd, const struct cpumask *mask)
71 {
72 nasid_t nasid;
73 int cpu;
74
75 cpu = cpumask_first_and(mask, cpu_online_mask);
76 if (cpu >= nr_cpu_ids)
77 cpu = cpumask_any(cpu_online_mask);
78
79 nasid = cpu_to_node(cpu);
80 hd->cpu = cpu;
81 if (!cputoslice(cpu)) {
82 hd->irq_mask[0] = REMOTE_HUB_PTR(nasid, PI_INT_MASK0_A);
83 hd->irq_mask[1] = REMOTE_HUB_PTR(nasid, PI_INT_MASK1_A);
84 } else {
85 hd->irq_mask[0] = REMOTE_HUB_PTR(nasid, PI_INT_MASK0_B);
86 hd->irq_mask[1] = REMOTE_HUB_PTR(nasid, PI_INT_MASK1_B);
87 }
88 }
89
set_affinity_hub_irq(struct irq_data * d,const struct cpumask * mask,bool force)90 static int set_affinity_hub_irq(struct irq_data *d, const struct cpumask *mask,
91 bool force)
92 {
93 struct hub_irq_data *hd = irq_data_get_irq_chip_data(d);
94
95 if (!hd)
96 return -EINVAL;
97
98 if (irqd_is_started(d))
99 disable_hub_irq(d);
100
101 setup_hub_mask(hd, mask);
102
103 if (irqd_is_started(d))
104 enable_hub_irq(d);
105
106 irq_data_update_effective_affinity(d, cpumask_of(hd->cpu));
107
108 return 0;
109 }
110
111 static struct irq_chip hub_irq_type = {
112 .name = "HUB",
113 .irq_mask = disable_hub_irq,
114 .irq_unmask = enable_hub_irq,
115 .irq_set_affinity = set_affinity_hub_irq,
116 };
117
hub_domain_alloc(struct irq_domain * domain,unsigned int virq,unsigned int nr_irqs,void * arg)118 static int hub_domain_alloc(struct irq_domain *domain, unsigned int virq,
119 unsigned int nr_irqs, void *arg)
120 {
121 struct irq_alloc_info *info = arg;
122 struct hub_irq_data *hd;
123 struct hub_data *hub;
124 struct irq_desc *desc;
125 int swlevel;
126
127 if (nr_irqs > 1 || !info)
128 return -EINVAL;
129
130 hd = kzalloc(sizeof(*hd), GFP_KERNEL);
131 if (!hd)
132 return -ENOMEM;
133
134 swlevel = alloc_level();
135 if (unlikely(swlevel < 0)) {
136 kfree(hd);
137 return -EAGAIN;
138 }
139 irq_domain_set_info(domain, virq, swlevel, &hub_irq_type, hd,
140 handle_level_irq, NULL, NULL);
141
142 /* use CPU connected to nearest hub */
143 hub = hub_data(info->nasid);
144 setup_hub_mask(hd, &hub->h_cpus);
145 info->nasid = cpu_to_node(hd->cpu);
146
147 /* Make sure it's not already pending when we connect it. */
148 REMOTE_HUB_CLR_INTR(info->nasid, swlevel);
149
150 desc = irq_to_desc(virq);
151 desc->irq_common_data.node = info->nasid;
152 cpumask_copy(desc->irq_common_data.affinity, &hub->h_cpus);
153
154 return 0;
155 }
156
hub_domain_free(struct irq_domain * domain,unsigned int virq,unsigned int nr_irqs)157 static void hub_domain_free(struct irq_domain *domain,
158 unsigned int virq, unsigned int nr_irqs)
159 {
160 struct irq_data *irqd;
161
162 if (nr_irqs > 1)
163 return;
164
165 irqd = irq_domain_get_irq_data(domain, virq);
166 if (irqd && irqd->chip_data)
167 kfree(irqd->chip_data);
168 }
169
170 static const struct irq_domain_ops hub_domain_ops = {
171 .alloc = hub_domain_alloc,
172 .free = hub_domain_free,
173 };
174
175 /*
176 * This code is unnecessarily complex, because we do
177 * intr enabling. Basically, once we grab the set of intrs we need
178 * to service, we must mask _all_ these interrupts; firstly, to make
179 * sure the same intr does not intr again, causing recursion that
180 * can lead to stack overflow. Secondly, we can not just mask the
181 * one intr we are do_IRQing, because the non-masked intrs in the
182 * first set might intr again, causing multiple servicings of the
183 * same intr. This effect is mostly seen for intercpu intrs.
184 * Kanoj 05.13.00
185 */
186
ip27_do_irq_mask0(struct irq_desc * desc)187 static void ip27_do_irq_mask0(struct irq_desc *desc)
188 {
189 cpuid_t cpu = smp_processor_id();
190 unsigned long *mask = per_cpu(irq_enable_mask, cpu);
191 struct irq_domain *domain;
192 u64 pend0;
193 int ret;
194
195 /* copied from Irix intpend0() */
196 pend0 = LOCAL_HUB_L(PI_INT_PEND0);
197
198 pend0 &= mask[0]; /* Pick intrs we should look at */
199 if (!pend0)
200 return;
201
202 #ifdef CONFIG_SMP
203 if (pend0 & (1UL << CPU_RESCHED_A_IRQ)) {
204 LOCAL_HUB_CLR_INTR(CPU_RESCHED_A_IRQ);
205 scheduler_ipi();
206 } else if (pend0 & (1UL << CPU_RESCHED_B_IRQ)) {
207 LOCAL_HUB_CLR_INTR(CPU_RESCHED_B_IRQ);
208 scheduler_ipi();
209 } else if (pend0 & (1UL << CPU_CALL_A_IRQ)) {
210 LOCAL_HUB_CLR_INTR(CPU_CALL_A_IRQ);
211 generic_smp_call_function_interrupt();
212 } else if (pend0 & (1UL << CPU_CALL_B_IRQ)) {
213 LOCAL_HUB_CLR_INTR(CPU_CALL_B_IRQ);
214 generic_smp_call_function_interrupt();
215 } else
216 #endif
217 {
218 domain = irq_desc_get_handler_data(desc);
219 ret = generic_handle_domain_irq(domain, __ffs(pend0));
220 if (ret)
221 spurious_interrupt();
222 }
223
224 LOCAL_HUB_L(PI_INT_PEND0);
225 }
226
ip27_do_irq_mask1(struct irq_desc * desc)227 static void ip27_do_irq_mask1(struct irq_desc *desc)
228 {
229 cpuid_t cpu = smp_processor_id();
230 unsigned long *mask = per_cpu(irq_enable_mask, cpu);
231 struct irq_domain *domain;
232 u64 pend1;
233 int ret;
234
235 /* copied from Irix intpend0() */
236 pend1 = LOCAL_HUB_L(PI_INT_PEND1);
237
238 pend1 &= mask[1]; /* Pick intrs we should look at */
239 if (!pend1)
240 return;
241
242 domain = irq_desc_get_handler_data(desc);
243 ret = generic_handle_domain_irq(domain, __ffs(pend1) + 64);
244 if (ret)
245 spurious_interrupt();
246
247 LOCAL_HUB_L(PI_INT_PEND1);
248 }
249
install_ipi(void)250 void install_ipi(void)
251 {
252 int cpu = smp_processor_id();
253 unsigned long *mask = per_cpu(irq_enable_mask, cpu);
254 int slice = LOCAL_HUB_L(PI_CPU_NUM);
255 int resched, call;
256
257 resched = CPU_RESCHED_A_IRQ + slice;
258 set_bit(resched, mask);
259 LOCAL_HUB_CLR_INTR(resched);
260
261 call = CPU_CALL_A_IRQ + slice;
262 set_bit(call, mask);
263 LOCAL_HUB_CLR_INTR(call);
264
265 if (slice == 0) {
266 LOCAL_HUB_S(PI_INT_MASK0_A, mask[0]);
267 LOCAL_HUB_S(PI_INT_MASK1_A, mask[1]);
268 } else {
269 LOCAL_HUB_S(PI_INT_MASK0_B, mask[0]);
270 LOCAL_HUB_S(PI_INT_MASK1_B, mask[1]);
271 }
272 }
273
arch_init_irq(void)274 void __init arch_init_irq(void)
275 {
276 struct irq_domain *domain;
277 struct fwnode_handle *fn;
278 int i;
279
280 mips_cpu_irq_init();
281
282 /*
283 * Some interrupts are reserved by hardware or by software convention.
284 * Mark these as reserved right away so they won't be used accidentally
285 * later.
286 */
287 for (i = 0; i <= CPU_CALL_B_IRQ; i++)
288 set_bit(i, hub_irq_map);
289
290 for (i = NI_BRDCAST_ERR_A; i <= MSC_PANIC_INTR; i++)
291 set_bit(i, hub_irq_map);
292
293 fn = irq_domain_alloc_named_fwnode("HUB");
294 WARN_ON(fn == NULL);
295 if (!fn)
296 return;
297 domain = irq_domain_create_linear(fn, IP27_HUB_IRQ_COUNT,
298 &hub_domain_ops, NULL);
299 WARN_ON(domain == NULL);
300 if (!domain)
301 return;
302
303 irq_set_default_host(domain);
304
305 irq_set_percpu_devid(IP27_HUB_PEND0_IRQ);
306 irq_set_chained_handler_and_data(IP27_HUB_PEND0_IRQ, ip27_do_irq_mask0,
307 domain);
308 irq_set_percpu_devid(IP27_HUB_PEND1_IRQ);
309 irq_set_chained_handler_and_data(IP27_HUB_PEND1_IRQ, ip27_do_irq_mask1,
310 domain);
311 }
312