arch/powerpc/platforms/cell/interrupt.c

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