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/ioport.h> 13 #include <linux/kernel.h> 14 #include <linux/bitops.h> 15 #include <linux/sched.h> 16 17 #include <asm/io.h> 18 #include <asm/irq_cpu.h> 19 #include <asm/sn/addrs.h> 20 #include <asm/sn/agent.h> 21 #include <asm/sn/arch.h> 22 #include <asm/sn/intr.h> 23 #include <asm/sn/irq_alloc.h> 24 25 struct hub_irq_data { 26 u64 *irq_mask[2]; 27 cpuid_t cpu; 28 }; 29 30 static DECLARE_BITMAP(hub_irq_map, IP27_HUB_IRQ_COUNT); 31 32 static DEFINE_PER_CPU(unsigned long [2], irq_enable_mask); 33 34 static inline int alloc_level(void) 35 { 36 int level; 37 38 again: 39 level = find_first_zero_bit(hub_irq_map, IP27_HUB_IRQ_COUNT); 40 if (level >= IP27_HUB_IRQ_COUNT) 41 return -ENOSPC; 42 43 if (test_and_set_bit(level, hub_irq_map)) 44 goto again; 45 46 return level; 47 } 48 49 static void enable_hub_irq(struct irq_data *d) 50 { 51 struct hub_irq_data *hd = irq_data_get_irq_chip_data(d); 52 unsigned long *mask = per_cpu(irq_enable_mask, hd->cpu); 53 54 set_bit(d->hwirq, mask); 55 __raw_writeq(mask[0], hd->irq_mask[0]); 56 __raw_writeq(mask[1], hd->irq_mask[1]); 57 } 58 59 static void disable_hub_irq(struct irq_data *d) 60 { 61 struct hub_irq_data *hd = irq_data_get_irq_chip_data(d); 62 unsigned long *mask = per_cpu(irq_enable_mask, hd->cpu); 63 64 clear_bit(d->hwirq, mask); 65 __raw_writeq(mask[0], hd->irq_mask[0]); 66 __raw_writeq(mask[1], hd->irq_mask[1]); 67 } 68 69 static void setup_hub_mask(struct hub_irq_data *hd, const struct cpumask *mask) 70 { 71 nasid_t nasid; 72 int cpu; 73 74 cpu = cpumask_first_and(mask, cpu_online_mask); 75 if (cpu >= nr_cpu_ids) 76 cpu = cpumask_any(cpu_online_mask); 77 78 nasid = cpu_to_node(cpu); 79 hd->cpu = cpu; 80 if (!cputoslice(cpu)) { 81 hd->irq_mask[0] = REMOTE_HUB_PTR(nasid, PI_INT_MASK0_A); 82 hd->irq_mask[1] = REMOTE_HUB_PTR(nasid, PI_INT_MASK1_A); 83 } else { 84 hd->irq_mask[0] = REMOTE_HUB_PTR(nasid, PI_INT_MASK0_B); 85 hd->irq_mask[1] = REMOTE_HUB_PTR(nasid, PI_INT_MASK1_B); 86 } 87 } 88 89 static int set_affinity_hub_irq(struct irq_data *d, const struct cpumask *mask, 90 bool force) 91 { 92 struct hub_irq_data *hd = irq_data_get_irq_chip_data(d); 93 94 if (!hd) 95 return -EINVAL; 96 97 if (irqd_is_started(d)) 98 disable_hub_irq(d); 99 100 setup_hub_mask(hd, mask); 101 102 if (irqd_is_started(d)) 103 enable_hub_irq(d); 104 105 irq_data_update_effective_affinity(d, cpumask_of(hd->cpu)); 106 107 return 0; 108 } 109 110 static struct irq_chip hub_irq_type = { 111 .name = "HUB", 112 .irq_mask = disable_hub_irq, 113 .irq_unmask = enable_hub_irq, 114 .irq_set_affinity = set_affinity_hub_irq, 115 }; 116 117 static int hub_domain_alloc(struct irq_domain *domain, unsigned int virq, 118 unsigned int nr_irqs, void *arg) 119 { 120 struct irq_alloc_info *info = arg; 121 struct hub_irq_data *hd; 122 struct hub_data *hub; 123 struct irq_desc *desc; 124 int swlevel; 125 126 if (nr_irqs > 1 || !info) 127 return -EINVAL; 128 129 hd = kzalloc(sizeof(*hd), GFP_KERNEL); 130 if (!hd) 131 return -ENOMEM; 132 133 swlevel = alloc_level(); 134 if (unlikely(swlevel < 0)) { 135 kfree(hd); 136 return -EAGAIN; 137 } 138 irq_domain_set_info(domain, virq, swlevel, &hub_irq_type, hd, 139 handle_level_irq, NULL, NULL); 140 141 /* use CPU connected to nearest hub */ 142 hub = hub_data(info->nasid); 143 setup_hub_mask(hd, &hub->h_cpus); 144 info->nasid = cpu_to_node(hd->cpu); 145 146 /* Make sure it's not already pending when we connect it. */ 147 REMOTE_HUB_CLR_INTR(info->nasid, swlevel); 148 149 desc = irq_to_desc(virq); 150 desc->irq_common_data.node = info->nasid; 151 cpumask_copy(desc->irq_common_data.affinity, &hub->h_cpus); 152 153 return 0; 154 } 155 156 static void hub_domain_free(struct irq_domain *domain, 157 unsigned int virq, unsigned int nr_irqs) 158 { 159 struct irq_data *irqd; 160 161 if (nr_irqs > 1) 162 return; 163 164 irqd = irq_domain_get_irq_data(domain, virq); 165 if (irqd && irqd->chip_data) 166 kfree(irqd->chip_data); 167 } 168 169 static const struct irq_domain_ops hub_domain_ops = { 170 .alloc = hub_domain_alloc, 171 .free = hub_domain_free, 172 }; 173 174 /* 175 * This code is unnecessarily complex, because we do 176 * intr enabling. Basically, once we grab the set of intrs we need 177 * to service, we must mask _all_ these interrupts; firstly, to make 178 * sure the same intr does not intr again, causing recursion that 179 * can lead to stack overflow. Secondly, we can not just mask the 180 * one intr we are do_IRQing, because the non-masked intrs in the 181 * first set might intr again, causing multiple servicings of the 182 * same intr. This effect is mostly seen for intercpu intrs. 183 * Kanoj 05.13.00 184 */ 185 186 static void ip27_do_irq_mask0(struct irq_desc *desc) 187 { 188 cpuid_t cpu = smp_processor_id(); 189 unsigned long *mask = per_cpu(irq_enable_mask, cpu); 190 struct irq_domain *domain; 191 u64 pend0; 192 int irq; 193 194 /* copied from Irix intpend0() */ 195 pend0 = LOCAL_HUB_L(PI_INT_PEND0); 196 197 pend0 &= mask[0]; /* Pick intrs we should look at */ 198 if (!pend0) 199 return; 200 201 #ifdef CONFIG_SMP 202 if (pend0 & (1UL << CPU_RESCHED_A_IRQ)) { 203 LOCAL_HUB_CLR_INTR(CPU_RESCHED_A_IRQ); 204 scheduler_ipi(); 205 } else if (pend0 & (1UL << CPU_RESCHED_B_IRQ)) { 206 LOCAL_HUB_CLR_INTR(CPU_RESCHED_B_IRQ); 207 scheduler_ipi(); 208 } else if (pend0 & (1UL << CPU_CALL_A_IRQ)) { 209 LOCAL_HUB_CLR_INTR(CPU_CALL_A_IRQ); 210 generic_smp_call_function_interrupt(); 211 } else if (pend0 & (1UL << CPU_CALL_B_IRQ)) { 212 LOCAL_HUB_CLR_INTR(CPU_CALL_B_IRQ); 213 generic_smp_call_function_interrupt(); 214 } else 215 #endif 216 { 217 domain = irq_desc_get_handler_data(desc); 218 irq = irq_linear_revmap(domain, __ffs(pend0)); 219 if (irq) 220 generic_handle_irq(irq); 221 else 222 spurious_interrupt(); 223 } 224 225 LOCAL_HUB_L(PI_INT_PEND0); 226 } 227 228 static void ip27_do_irq_mask1(struct irq_desc *desc) 229 { 230 cpuid_t cpu = smp_processor_id(); 231 unsigned long *mask = per_cpu(irq_enable_mask, cpu); 232 struct irq_domain *domain; 233 u64 pend1; 234 int irq; 235 236 /* copied from Irix intpend0() */ 237 pend1 = LOCAL_HUB_L(PI_INT_PEND1); 238 239 pend1 &= mask[1]; /* Pick intrs we should look at */ 240 if (!pend1) 241 return; 242 243 domain = irq_desc_get_handler_data(desc); 244 irq = irq_linear_revmap(domain, __ffs(pend1) + 64); 245 if (irq) 246 generic_handle_irq(irq); 247 else 248 spurious_interrupt(); 249 250 LOCAL_HUB_L(PI_INT_PEND1); 251 } 252 253 void install_ipi(void) 254 { 255 int cpu = smp_processor_id(); 256 unsigned long *mask = per_cpu(irq_enable_mask, cpu); 257 int slice = LOCAL_HUB_L(PI_CPU_NUM); 258 int resched, call; 259 260 resched = CPU_RESCHED_A_IRQ + slice; 261 set_bit(resched, mask); 262 LOCAL_HUB_CLR_INTR(resched); 263 264 call = CPU_CALL_A_IRQ + slice; 265 set_bit(call, mask); 266 LOCAL_HUB_CLR_INTR(call); 267 268 if (slice == 0) { 269 LOCAL_HUB_S(PI_INT_MASK0_A, mask[0]); 270 LOCAL_HUB_S(PI_INT_MASK1_A, mask[1]); 271 } else { 272 LOCAL_HUB_S(PI_INT_MASK0_B, mask[0]); 273 LOCAL_HUB_S(PI_INT_MASK1_B, mask[1]); 274 } 275 } 276 277 void __init arch_init_irq(void) 278 { 279 struct irq_domain *domain; 280 struct fwnode_handle *fn; 281 int i; 282 283 mips_cpu_irq_init(); 284 285 /* 286 * Some interrupts are reserved by hardware or by software convention. 287 * Mark these as reserved right away so they won't be used accidentally 288 * later. 289 */ 290 for (i = 0; i <= CPU_CALL_B_IRQ; i++) 291 set_bit(i, hub_irq_map); 292 293 for (i = NI_BRDCAST_ERR_A; i <= MSC_PANIC_INTR; i++) 294 set_bit(i, hub_irq_map); 295 296 fn = irq_domain_alloc_named_fwnode("HUB"); 297 WARN_ON(fn == NULL); 298 if (!fn) 299 return; 300 domain = irq_domain_create_linear(fn, IP27_HUB_IRQ_COUNT, 301 &hub_domain_ops, NULL); 302 WARN_ON(domain == NULL); 303 if (!domain) 304 return; 305 306 irq_set_default_host(domain); 307 308 irq_set_percpu_devid(IP27_HUB_PEND0_IRQ); 309 irq_set_chained_handler_and_data(IP27_HUB_PEND0_IRQ, ip27_do_irq_mask0, 310 domain); 311 irq_set_percpu_devid(IP27_HUB_PEND1_IRQ); 312 irq_set_chained_handler_and_data(IP27_HUB_PEND1_IRQ, ip27_do_irq_mask1, 313 domain); 314 } 315