1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Cell Internal Interrupt Controller 4 * 5 * Copyright (C) 2006 Benjamin Herrenschmidt (benh@kernel.crashing.org) 6 * IBM, Corp. 7 * 8 * (C) Copyright IBM Deutschland Entwicklung GmbH 2005 9 * 10 * Author: Arnd Bergmann <arndb@de.ibm.com> 11 * 12 * TODO: 13 * - Fix various assumptions related to HW CPU numbers vs. linux CPU numbers 14 * vs node numbers in the setup code 15 * - Implement proper handling of maxcpus=1/2 (that is, routing of irqs from 16 * a non-active node to the active node) 17 */ 18 19 #include <linux/interrupt.h> 20 #include <linux/irq.h> 21 #include <linux/export.h> 22 #include <linux/percpu.h> 23 #include <linux/types.h> 24 #include <linux/ioport.h> 25 #include <linux/kernel_stat.h> 26 #include <linux/pgtable.h> 27 28 #include <asm/io.h> 29 #include <asm/prom.h> 30 #include <asm/ptrace.h> 31 #include <asm/machdep.h> 32 #include <asm/cell-regs.h> 33 34 #include "interrupt.h" 35 36 struct iic { 37 struct cbe_iic_thread_regs __iomem *regs; 38 u8 target_id; 39 u8 eoi_stack[16]; 40 int eoi_ptr; 41 struct device_node *node; 42 }; 43 44 static DEFINE_PER_CPU(struct iic, cpu_iic); 45 #define IIC_NODE_COUNT 2 46 static struct irq_domain *iic_host; 47 48 /* Convert between "pending" bits and hw irq number */ 49 static irq_hw_number_t iic_pending_to_hwnum(struct cbe_iic_pending_bits bits) 50 { 51 unsigned char unit = bits.source & 0xf; 52 unsigned char node = bits.source >> 4; 53 unsigned char class = bits.class & 3; 54 55 /* Decode IPIs */ 56 if (bits.flags & CBE_IIC_IRQ_IPI) 57 return IIC_IRQ_TYPE_IPI | (bits.prio >> 4); 58 else 59 return (node << IIC_IRQ_NODE_SHIFT) | (class << 4) | unit; 60 } 61 62 static void iic_mask(struct irq_data *d) 63 { 64 } 65 66 static void iic_unmask(struct irq_data *d) 67 { 68 } 69 70 static void iic_eoi(struct irq_data *d) 71 { 72 struct iic *iic = this_cpu_ptr(&cpu_iic); 73 out_be64(&iic->regs->prio, iic->eoi_stack[--iic->eoi_ptr]); 74 BUG_ON(iic->eoi_ptr < 0); 75 } 76 77 static struct irq_chip iic_chip = { 78 .name = "CELL-IIC", 79 .irq_mask = iic_mask, 80 .irq_unmask = iic_unmask, 81 .irq_eoi = iic_eoi, 82 }; 83 84 85 static void iic_ioexc_eoi(struct irq_data *d) 86 { 87 } 88 89 static void iic_ioexc_cascade(struct irq_desc *desc) 90 { 91 struct irq_chip *chip = irq_desc_get_chip(desc); 92 struct cbe_iic_regs __iomem *node_iic = 93 (void __iomem *)irq_desc_get_handler_data(desc); 94 unsigned int irq = irq_desc_get_irq(desc); 95 unsigned int base = (irq & 0xffffff00) | IIC_IRQ_TYPE_IOEXC; 96 unsigned long bits, ack; 97 int cascade; 98 99 for (;;) { 100 bits = in_be64(&node_iic->iic_is); 101 if (bits == 0) 102 break; 103 /* pre-ack edge interrupts */ 104 ack = bits & IIC_ISR_EDGE_MASK; 105 if (ack) 106 out_be64(&node_iic->iic_is, ack); 107 /* handle them */ 108 for (cascade = 63; cascade >= 0; cascade--) 109 if (bits & (0x8000000000000000UL >> cascade)) 110 generic_handle_domain_irq(iic_host, 111 base | cascade); 112 /* post-ack level interrupts */ 113 ack = bits & ~IIC_ISR_EDGE_MASK; 114 if (ack) 115 out_be64(&node_iic->iic_is, ack); 116 } 117 chip->irq_eoi(&desc->irq_data); 118 } 119 120 121 static struct irq_chip iic_ioexc_chip = { 122 .name = "CELL-IOEX", 123 .irq_mask = iic_mask, 124 .irq_unmask = iic_unmask, 125 .irq_eoi = iic_ioexc_eoi, 126 }; 127 128 /* Get an IRQ number from the pending state register of the IIC */ 129 static unsigned int iic_get_irq(void) 130 { 131 struct cbe_iic_pending_bits pending; 132 struct iic *iic; 133 unsigned int virq; 134 135 iic = this_cpu_ptr(&cpu_iic); 136 *(unsigned long *) &pending = 137 in_be64((u64 __iomem *) &iic->regs->pending_destr); 138 if (!(pending.flags & CBE_IIC_IRQ_VALID)) 139 return 0; 140 virq = irq_linear_revmap(iic_host, iic_pending_to_hwnum(pending)); 141 if (!virq) 142 return 0; 143 iic->eoi_stack[++iic->eoi_ptr] = pending.prio; 144 BUG_ON(iic->eoi_ptr > 15); 145 return virq; 146 } 147 148 void iic_setup_cpu(void) 149 { 150 out_be64(&this_cpu_ptr(&cpu_iic)->regs->prio, 0xff); 151 } 152 153 u8 iic_get_target_id(int cpu) 154 { 155 return per_cpu(cpu_iic, cpu).target_id; 156 } 157 158 EXPORT_SYMBOL_GPL(iic_get_target_id); 159 160 #ifdef CONFIG_SMP 161 162 /* Use the highest interrupt priorities for IPI */ 163 static inline int iic_msg_to_irq(int msg) 164 { 165 return IIC_IRQ_TYPE_IPI + 0xf - msg; 166 } 167 168 void iic_message_pass(int cpu, int msg) 169 { 170 out_be64(&per_cpu(cpu_iic, cpu).regs->generate, (0xf - msg) << 4); 171 } 172 173 static void iic_request_ipi(int msg) 174 { 175 int virq; 176 177 virq = irq_create_mapping(iic_host, iic_msg_to_irq(msg)); 178 if (!virq) { 179 printk(KERN_ERR 180 "iic: failed to map IPI %s\n", smp_ipi_name[msg]); 181 return; 182 } 183 184 /* 185 * If smp_request_message_ipi encounters an error it will notify 186 * the error. If a message is not needed it will return non-zero. 187 */ 188 if (smp_request_message_ipi(virq, msg)) 189 irq_dispose_mapping(virq); 190 } 191 192 void iic_request_IPIs(void) 193 { 194 iic_request_ipi(PPC_MSG_CALL_FUNCTION); 195 iic_request_ipi(PPC_MSG_RESCHEDULE); 196 iic_request_ipi(PPC_MSG_TICK_BROADCAST); 197 iic_request_ipi(PPC_MSG_NMI_IPI); 198 } 199 200 #endif /* CONFIG_SMP */ 201 202 203 static int iic_host_match(struct irq_domain *h, struct device_node *node, 204 enum irq_domain_bus_token bus_token) 205 { 206 return of_device_is_compatible(node, 207 "IBM,CBEA-Internal-Interrupt-Controller"); 208 } 209 210 static int iic_host_map(struct irq_domain *h, unsigned int virq, 211 irq_hw_number_t hw) 212 { 213 switch (hw & IIC_IRQ_TYPE_MASK) { 214 case IIC_IRQ_TYPE_IPI: 215 irq_set_chip_and_handler(virq, &iic_chip, handle_percpu_irq); 216 break; 217 case IIC_IRQ_TYPE_IOEXC: 218 irq_set_chip_and_handler(virq, &iic_ioexc_chip, 219 handle_edge_eoi_irq); 220 break; 221 default: 222 irq_set_chip_and_handler(virq, &iic_chip, handle_edge_eoi_irq); 223 } 224 return 0; 225 } 226 227 static int iic_host_xlate(struct irq_domain *h, struct device_node *ct, 228 const u32 *intspec, unsigned int intsize, 229 irq_hw_number_t *out_hwirq, unsigned int *out_flags) 230 231 { 232 unsigned int node, ext, unit, class; 233 const u32 *val; 234 235 if (!of_device_is_compatible(ct, 236 "IBM,CBEA-Internal-Interrupt-Controller")) 237 return -ENODEV; 238 if (intsize != 1) 239 return -ENODEV; 240 val = of_get_property(ct, "#interrupt-cells", NULL); 241 if (val == NULL || *val != 1) 242 return -ENODEV; 243 244 node = intspec[0] >> 24; 245 ext = (intspec[0] >> 16) & 0xff; 246 class = (intspec[0] >> 8) & 0xff; 247 unit = intspec[0] & 0xff; 248 249 /* Check if node is in supported range */ 250 if (node > 1) 251 return -EINVAL; 252 253 /* Build up interrupt number, special case for IO exceptions */ 254 *out_hwirq = (node << IIC_IRQ_NODE_SHIFT); 255 if (unit == IIC_UNIT_IIC && class == 1) 256 *out_hwirq |= IIC_IRQ_TYPE_IOEXC | ext; 257 else 258 *out_hwirq |= IIC_IRQ_TYPE_NORMAL | 259 (class << IIC_IRQ_CLASS_SHIFT) | unit; 260 261 /* Dummy flags, ignored by iic code */ 262 *out_flags = IRQ_TYPE_EDGE_RISING; 263 264 return 0; 265 } 266 267 static const struct irq_domain_ops iic_host_ops = { 268 .match = iic_host_match, 269 .map = iic_host_map, 270 .xlate = iic_host_xlate, 271 }; 272 273 static void __init init_one_iic(unsigned int hw_cpu, unsigned long addr, 274 struct device_node *node) 275 { 276 /* XXX FIXME: should locate the linux CPU number from the HW cpu 277 * number properly. We are lucky for now 278 */ 279 struct iic *iic = &per_cpu(cpu_iic, hw_cpu); 280 281 iic->regs = ioremap(addr, sizeof(struct cbe_iic_thread_regs)); 282 BUG_ON(iic->regs == NULL); 283 284 iic->target_id = ((hw_cpu & 2) << 3) | ((hw_cpu & 1) ? 0xf : 0xe); 285 iic->eoi_stack[0] = 0xff; 286 iic->node = of_node_get(node); 287 out_be64(&iic->regs->prio, 0); 288 289 printk(KERN_INFO "IIC for CPU %d target id 0x%x : %pOF\n", 290 hw_cpu, iic->target_id, node); 291 } 292 293 static int __init setup_iic(void) 294 { 295 struct device_node *dn; 296 struct resource r0, r1; 297 unsigned int node, cascade, found = 0; 298 struct cbe_iic_regs __iomem *node_iic; 299 const u32 *np; 300 301 for_each_node_by_name(dn, "interrupt-controller") { 302 if (!of_device_is_compatible(dn, 303 "IBM,CBEA-Internal-Interrupt-Controller")) 304 continue; 305 np = of_get_property(dn, "ibm,interrupt-server-ranges", NULL); 306 if (np == NULL) { 307 printk(KERN_WARNING "IIC: CPU association not found\n"); 308 of_node_put(dn); 309 return -ENODEV; 310 } 311 if (of_address_to_resource(dn, 0, &r0) || 312 of_address_to_resource(dn, 1, &r1)) { 313 printk(KERN_WARNING "IIC: Can't resolve addresses\n"); 314 of_node_put(dn); 315 return -ENODEV; 316 } 317 found++; 318 init_one_iic(np[0], r0.start, dn); 319 init_one_iic(np[1], r1.start, dn); 320 321 /* Setup cascade for IO exceptions. XXX cleanup tricks to get 322 * node vs CPU etc... 323 * Note that we configure the IIC_IRR here with a hard coded 324 * priority of 1. We might want to improve that later. 325 */ 326 node = np[0] >> 1; 327 node_iic = cbe_get_cpu_iic_regs(np[0]); 328 cascade = node << IIC_IRQ_NODE_SHIFT; 329 cascade |= 1 << IIC_IRQ_CLASS_SHIFT; 330 cascade |= IIC_UNIT_IIC; 331 cascade = irq_create_mapping(iic_host, cascade); 332 if (!cascade) 333 continue; 334 /* 335 * irq_data is a generic pointer that gets passed back 336 * to us later, so the forced cast is fine. 337 */ 338 irq_set_handler_data(cascade, (void __force *)node_iic); 339 irq_set_chained_handler(cascade, iic_ioexc_cascade); 340 out_be64(&node_iic->iic_ir, 341 (1 << 12) /* priority */ | 342 (node << 4) /* dest node */ | 343 IIC_UNIT_THREAD_0 /* route them to thread 0 */); 344 /* Flush pending (make sure it triggers if there is 345 * anything pending 346 */ 347 out_be64(&node_iic->iic_is, 0xfffffffffffffffful); 348 } 349 350 if (found) 351 return 0; 352 else 353 return -ENODEV; 354 } 355 356 void __init iic_init_IRQ(void) 357 { 358 /* Setup an irq host data structure */ 359 iic_host = irq_domain_add_linear(NULL, IIC_SOURCE_COUNT, &iic_host_ops, 360 NULL); 361 BUG_ON(iic_host == NULL); 362 irq_set_default_host(iic_host); 363 364 /* Discover and initialize iics */ 365 if (setup_iic() < 0) 366 panic("IIC: Failed to initialize !\n"); 367 368 /* Set master interrupt handling function */ 369 ppc_md.get_irq = iic_get_irq; 370 371 /* Enable on current CPU */ 372 iic_setup_cpu(); 373 } 374 375 void iic_set_interrupt_routing(int cpu, int thread, int priority) 376 { 377 struct cbe_iic_regs __iomem *iic_regs = cbe_get_cpu_iic_regs(cpu); 378 u64 iic_ir = 0; 379 int node = cpu >> 1; 380 381 /* Set which node and thread will handle the next interrupt */ 382 iic_ir |= CBE_IIC_IR_PRIO(priority) | 383 CBE_IIC_IR_DEST_NODE(node); 384 if (thread == 0) 385 iic_ir |= CBE_IIC_IR_DEST_UNIT(CBE_IIC_IR_PT_0); 386 else 387 iic_ir |= CBE_IIC_IR_DEST_UNIT(CBE_IIC_IR_PT_1); 388 out_be64(&iic_regs->iic_ir, iic_ir); 389 } 390