1 /* 2 * Cell Internal Interrupt Controller 3 * 4 * Copyright (C) 2006 Benjamin Herrenschmidt (benh@kernel.crashing.org) 5 * IBM, Corp. 6 * 7 * (C) Copyright IBM Deutschland Entwicklung GmbH 2005 8 * 9 * Author: Arnd Bergmann <arndb@de.ibm.com> 10 * 11 * This program is free software; you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License as published by 13 * the Free Software Foundation; either version 2, or (at your option) 14 * any later version. 15 * 16 * This program is distributed in the hope that it will be useful, 17 * but WITHOUT ANY WARRANTY; without even the implied warranty of 18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 19 * GNU General Public License for more details. 20 * 21 * You should have received a copy of the GNU General Public License 22 * along with this program; if not, write to the Free Software 23 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 24 * 25 * TODO: 26 * - Fix various assumptions related to HW CPU numbers vs. linux CPU numbers 27 * vs node numbers in the setup code 28 * - Implement proper handling of maxcpus=1/2 (that is, routing of irqs from 29 * a non-active node to the active node) 30 */ 31 32 #include <linux/interrupt.h> 33 #include <linux/irq.h> 34 #include <linux/export.h> 35 #include <linux/percpu.h> 36 #include <linux/types.h> 37 #include <linux/ioport.h> 38 #include <linux/kernel_stat.h> 39 40 #include <asm/io.h> 41 #include <asm/pgtable.h> 42 #include <asm/prom.h> 43 #include <asm/ptrace.h> 44 #include <asm/machdep.h> 45 #include <asm/cell-regs.h> 46 47 #include "interrupt.h" 48 49 struct iic { 50 struct cbe_iic_thread_regs __iomem *regs; 51 u8 target_id; 52 u8 eoi_stack[16]; 53 int eoi_ptr; 54 struct device_node *node; 55 }; 56 57 static DEFINE_PER_CPU(struct iic, cpu_iic); 58 #define IIC_NODE_COUNT 2 59 static struct irq_domain *iic_host; 60 61 /* Convert between "pending" bits and hw irq number */ 62 static irq_hw_number_t iic_pending_to_hwnum(struct cbe_iic_pending_bits bits) 63 { 64 unsigned char unit = bits.source & 0xf; 65 unsigned char node = bits.source >> 4; 66 unsigned char class = bits.class & 3; 67 68 /* Decode IPIs */ 69 if (bits.flags & CBE_IIC_IRQ_IPI) 70 return IIC_IRQ_TYPE_IPI | (bits.prio >> 4); 71 else 72 return (node << IIC_IRQ_NODE_SHIFT) | (class << 4) | unit; 73 } 74 75 static void iic_mask(struct irq_data *d) 76 { 77 } 78 79 static void iic_unmask(struct irq_data *d) 80 { 81 } 82 83 static void iic_eoi(struct irq_data *d) 84 { 85 struct iic *iic = this_cpu_ptr(&cpu_iic); 86 out_be64(&iic->regs->prio, iic->eoi_stack[--iic->eoi_ptr]); 87 BUG_ON(iic->eoi_ptr < 0); 88 } 89 90 static struct irq_chip iic_chip = { 91 .name = "CELL-IIC", 92 .irq_mask = iic_mask, 93 .irq_unmask = iic_unmask, 94 .irq_eoi = iic_eoi, 95 }; 96 97 98 static void iic_ioexc_eoi(struct irq_data *d) 99 { 100 } 101 102 static void iic_ioexc_cascade(struct irq_desc *desc) 103 { 104 struct irq_chip *chip = irq_desc_get_chip(desc); 105 struct cbe_iic_regs __iomem *node_iic = 106 (void __iomem *)irq_desc_get_handler_data(desc); 107 unsigned int irq = irq_desc_get_irq(desc); 108 unsigned int base = (irq & 0xffffff00) | IIC_IRQ_TYPE_IOEXC; 109 unsigned long bits, ack; 110 int cascade; 111 112 for (;;) { 113 bits = in_be64(&node_iic->iic_is); 114 if (bits == 0) 115 break; 116 /* pre-ack edge interrupts */ 117 ack = bits & IIC_ISR_EDGE_MASK; 118 if (ack) 119 out_be64(&node_iic->iic_is, ack); 120 /* handle them */ 121 for (cascade = 63; cascade >= 0; cascade--) 122 if (bits & (0x8000000000000000UL >> cascade)) { 123 unsigned int cirq = 124 irq_linear_revmap(iic_host, 125 base | cascade); 126 if (cirq) 127 generic_handle_irq(cirq); 128 } 129 /* post-ack level interrupts */ 130 ack = bits & ~IIC_ISR_EDGE_MASK; 131 if (ack) 132 out_be64(&node_iic->iic_is, ack); 133 } 134 chip->irq_eoi(&desc->irq_data); 135 } 136 137 138 static struct irq_chip iic_ioexc_chip = { 139 .name = "CELL-IOEX", 140 .irq_mask = iic_mask, 141 .irq_unmask = iic_unmask, 142 .irq_eoi = iic_ioexc_eoi, 143 }; 144 145 /* Get an IRQ number from the pending state register of the IIC */ 146 static unsigned int iic_get_irq(void) 147 { 148 struct cbe_iic_pending_bits pending; 149 struct iic *iic; 150 unsigned int virq; 151 152 iic = this_cpu_ptr(&cpu_iic); 153 *(unsigned long *) &pending = 154 in_be64((u64 __iomem *) &iic->regs->pending_destr); 155 if (!(pending.flags & CBE_IIC_IRQ_VALID)) 156 return 0; 157 virq = irq_linear_revmap(iic_host, iic_pending_to_hwnum(pending)); 158 if (!virq) 159 return 0; 160 iic->eoi_stack[++iic->eoi_ptr] = pending.prio; 161 BUG_ON(iic->eoi_ptr > 15); 162 return virq; 163 } 164 165 void iic_setup_cpu(void) 166 { 167 out_be64(&this_cpu_ptr(&cpu_iic)->regs->prio, 0xff); 168 } 169 170 u8 iic_get_target_id(int cpu) 171 { 172 return per_cpu(cpu_iic, cpu).target_id; 173 } 174 175 EXPORT_SYMBOL_GPL(iic_get_target_id); 176 177 #ifdef CONFIG_SMP 178 179 /* Use the highest interrupt priorities for IPI */ 180 static inline int iic_msg_to_irq(int msg) 181 { 182 return IIC_IRQ_TYPE_IPI + 0xf - msg; 183 } 184 185 void iic_message_pass(int cpu, int msg) 186 { 187 out_be64(&per_cpu(cpu_iic, cpu).regs->generate, (0xf - msg) << 4); 188 } 189 190 static void iic_request_ipi(int msg) 191 { 192 int virq; 193 194 virq = irq_create_mapping(iic_host, iic_msg_to_irq(msg)); 195 if (!virq) { 196 printk(KERN_ERR 197 "iic: failed to map IPI %s\n", smp_ipi_name[msg]); 198 return; 199 } 200 201 /* 202 * If smp_request_message_ipi encounters an error it will notify 203 * the error. If a message is not needed it will return non-zero. 204 */ 205 if (smp_request_message_ipi(virq, msg)) 206 irq_dispose_mapping(virq); 207 } 208 209 void iic_request_IPIs(void) 210 { 211 iic_request_ipi(PPC_MSG_CALL_FUNCTION); 212 iic_request_ipi(PPC_MSG_RESCHEDULE); 213 iic_request_ipi(PPC_MSG_TICK_BROADCAST); 214 iic_request_ipi(PPC_MSG_NMI_IPI); 215 } 216 217 #endif /* CONFIG_SMP */ 218 219 220 static int iic_host_match(struct irq_domain *h, struct device_node *node, 221 enum irq_domain_bus_token bus_token) 222 { 223 return of_device_is_compatible(node, 224 "IBM,CBEA-Internal-Interrupt-Controller"); 225 } 226 227 static int iic_host_map(struct irq_domain *h, unsigned int virq, 228 irq_hw_number_t hw) 229 { 230 switch (hw & IIC_IRQ_TYPE_MASK) { 231 case IIC_IRQ_TYPE_IPI: 232 irq_set_chip_and_handler(virq, &iic_chip, handle_percpu_irq); 233 break; 234 case IIC_IRQ_TYPE_IOEXC: 235 irq_set_chip_and_handler(virq, &iic_ioexc_chip, 236 handle_edge_eoi_irq); 237 break; 238 default: 239 irq_set_chip_and_handler(virq, &iic_chip, handle_edge_eoi_irq); 240 } 241 return 0; 242 } 243 244 static int iic_host_xlate(struct irq_domain *h, struct device_node *ct, 245 const u32 *intspec, unsigned int intsize, 246 irq_hw_number_t *out_hwirq, unsigned int *out_flags) 247 248 { 249 unsigned int node, ext, unit, class; 250 const u32 *val; 251 252 if (!of_device_is_compatible(ct, 253 "IBM,CBEA-Internal-Interrupt-Controller")) 254 return -ENODEV; 255 if (intsize != 1) 256 return -ENODEV; 257 val = of_get_property(ct, "#interrupt-cells", NULL); 258 if (val == NULL || *val != 1) 259 return -ENODEV; 260 261 node = intspec[0] >> 24; 262 ext = (intspec[0] >> 16) & 0xff; 263 class = (intspec[0] >> 8) & 0xff; 264 unit = intspec[0] & 0xff; 265 266 /* Check if node is in supported range */ 267 if (node > 1) 268 return -EINVAL; 269 270 /* Build up interrupt number, special case for IO exceptions */ 271 *out_hwirq = (node << IIC_IRQ_NODE_SHIFT); 272 if (unit == IIC_UNIT_IIC && class == 1) 273 *out_hwirq |= IIC_IRQ_TYPE_IOEXC | ext; 274 else 275 *out_hwirq |= IIC_IRQ_TYPE_NORMAL | 276 (class << IIC_IRQ_CLASS_SHIFT) | unit; 277 278 /* Dummy flags, ignored by iic code */ 279 *out_flags = IRQ_TYPE_EDGE_RISING; 280 281 return 0; 282 } 283 284 static const struct irq_domain_ops iic_host_ops = { 285 .match = iic_host_match, 286 .map = iic_host_map, 287 .xlate = iic_host_xlate, 288 }; 289 290 static void __init init_one_iic(unsigned int hw_cpu, unsigned long addr, 291 struct device_node *node) 292 { 293 /* XXX FIXME: should locate the linux CPU number from the HW cpu 294 * number properly. We are lucky for now 295 */ 296 struct iic *iic = &per_cpu(cpu_iic, hw_cpu); 297 298 iic->regs = ioremap(addr, sizeof(struct cbe_iic_thread_regs)); 299 BUG_ON(iic->regs == NULL); 300 301 iic->target_id = ((hw_cpu & 2) << 3) | ((hw_cpu & 1) ? 0xf : 0xe); 302 iic->eoi_stack[0] = 0xff; 303 iic->node = of_node_get(node); 304 out_be64(&iic->regs->prio, 0); 305 306 printk(KERN_INFO "IIC for CPU %d target id 0x%x : %pOF\n", 307 hw_cpu, iic->target_id, node); 308 } 309 310 static int __init setup_iic(void) 311 { 312 struct device_node *dn; 313 struct resource r0, r1; 314 unsigned int node, cascade, found = 0; 315 struct cbe_iic_regs __iomem *node_iic; 316 const u32 *np; 317 318 for (dn = NULL; 319 (dn = of_find_node_by_name(dn,"interrupt-controller")) != NULL;) { 320 if (!of_device_is_compatible(dn, 321 "IBM,CBEA-Internal-Interrupt-Controller")) 322 continue; 323 np = of_get_property(dn, "ibm,interrupt-server-ranges", NULL); 324 if (np == NULL) { 325 printk(KERN_WARNING "IIC: CPU association not found\n"); 326 of_node_put(dn); 327 return -ENODEV; 328 } 329 if (of_address_to_resource(dn, 0, &r0) || 330 of_address_to_resource(dn, 1, &r1)) { 331 printk(KERN_WARNING "IIC: Can't resolve addresses\n"); 332 of_node_put(dn); 333 return -ENODEV; 334 } 335 found++; 336 init_one_iic(np[0], r0.start, dn); 337 init_one_iic(np[1], r1.start, dn); 338 339 /* Setup cascade for IO exceptions. XXX cleanup tricks to get 340 * node vs CPU etc... 341 * Note that we configure the IIC_IRR here with a hard coded 342 * priority of 1. We might want to improve that later. 343 */ 344 node = np[0] >> 1; 345 node_iic = cbe_get_cpu_iic_regs(np[0]); 346 cascade = node << IIC_IRQ_NODE_SHIFT; 347 cascade |= 1 << IIC_IRQ_CLASS_SHIFT; 348 cascade |= IIC_UNIT_IIC; 349 cascade = irq_create_mapping(iic_host, cascade); 350 if (!cascade) 351 continue; 352 /* 353 * irq_data is a generic pointer that gets passed back 354 * to us later, so the forced cast is fine. 355 */ 356 irq_set_handler_data(cascade, (void __force *)node_iic); 357 irq_set_chained_handler(cascade, iic_ioexc_cascade); 358 out_be64(&node_iic->iic_ir, 359 (1 << 12) /* priority */ | 360 (node << 4) /* dest node */ | 361 IIC_UNIT_THREAD_0 /* route them to thread 0 */); 362 /* Flush pending (make sure it triggers if there is 363 * anything pending 364 */ 365 out_be64(&node_iic->iic_is, 0xfffffffffffffffful); 366 } 367 368 if (found) 369 return 0; 370 else 371 return -ENODEV; 372 } 373 374 void __init iic_init_IRQ(void) 375 { 376 /* Setup an irq host data structure */ 377 iic_host = irq_domain_add_linear(NULL, IIC_SOURCE_COUNT, &iic_host_ops, 378 NULL); 379 BUG_ON(iic_host == NULL); 380 irq_set_default_host(iic_host); 381 382 /* Discover and initialize iics */ 383 if (setup_iic() < 0) 384 panic("IIC: Failed to initialize !\n"); 385 386 /* Set master interrupt handling function */ 387 ppc_md.get_irq = iic_get_irq; 388 389 /* Enable on current CPU */ 390 iic_setup_cpu(); 391 } 392 393 void iic_set_interrupt_routing(int cpu, int thread, int priority) 394 { 395 struct cbe_iic_regs __iomem *iic_regs = cbe_get_cpu_iic_regs(cpu); 396 u64 iic_ir = 0; 397 int node = cpu >> 1; 398 399 /* Set which node and thread will handle the next interrupt */ 400 iic_ir |= CBE_IIC_IR_PRIO(priority) | 401 CBE_IIC_IR_DEST_NODE(node); 402 if (thread == 0) 403 iic_ir |= CBE_IIC_IR_DEST_UNIT(CBE_IIC_IR_PT_0); 404 else 405 iic_ir |= CBE_IIC_IR_DEST_UNIT(CBE_IIC_IR_PT_1); 406 out_be64(&iic_regs->iic_ir, iic_ir); 407 } 408