arch/sparc/kernel/leon_kernel.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2009 Daniel Hellstrom (daniel@gaisler.com) Aeroflex Gaisler AB
   4  * Copyright (C) 2009 Konrad Eisele (konrad@gaisler.com) Aeroflex Gaisler AB
   5  */
   6
   7 #include <linux/kernel.h>
   8 #include <linux/errno.h>
   9 #include <linux/mutex.h>
  10 #include <linux/of.h>
  11 #include <linux/of_platform.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/of_device.h>
  14 #include <linux/clocksource.h>
  15 #include <linux/clockchips.h>
  16
  17 #include <asm/oplib.h>
  18 #include <asm/timer.h>
  19 #include <asm/prom.h>
  20 #include <asm/leon.h>
  21 #include <asm/leon_amba.h>
  22 #include <asm/traps.h>
  23 #include <asm/cacheflush.h>
  24 #include <asm/smp.h>
  25 #include <asm/setup.h>
  26
  27 #include "kernel.h"
  28 #include "prom.h"
  29 #include "irq.h"
  30
  31 struct leon3_irqctrl_regs_map *leon3_irqctrl_regs; /* interrupt controller base address */
  32 struct leon3_gptimer_regs_map *leon3_gptimer_regs; /* timer controller base address */
  33
  34 int leondebug_irq_disable;
  35 int leon_debug_irqout;
  36 static volatile u32 dummy_master_l10_counter;
  37 unsigned long amba_system_id;
  38 static DEFINE_SPINLOCK(leon_irq_lock);
  39
  40 static unsigned long leon3_gptimer_idx; /* Timer Index (0..6) within Timer Core */
  41 static unsigned long leon3_gptimer_ackmask; /* For clearing pending bit */
  42 unsigned long leon3_gptimer_irq; /* interrupt controller irq number */
  43 unsigned int sparc_leon_eirq;
  44 #define LEON_IMASK(cpu) (&leon3_irqctrl_regs->mask[cpu])
  45 #define LEON_IACK (&leon3_irqctrl_regs->iclear)
  46 #define LEON_DO_ACK_HW 1
  47
  48 /* Return the last ACKed IRQ by the Extended IRQ controller. It has already
  49  * been (automatically) ACKed when the CPU takes the trap.
  50  */
  51 static inline unsigned int leon_eirq_get(int cpu)
  52 {
  53         return LEON3_BYPASS_LOAD_PA(&leon3_irqctrl_regs->intid[cpu]) & 0x1f;
  54 }
  55
  56 /* Handle one or multiple IRQs from the extended interrupt controller */
  57 static void leon_handle_ext_irq(struct irq_desc *desc)
  58 {
  59         unsigned int eirq;
  60         struct irq_bucket *p;
  61         int cpu = sparc_leon3_cpuid();
  62
  63         eirq = leon_eirq_get(cpu);
  64         p = irq_map[eirq];
  65         if ((eirq & 0x10) && p && p->irq) /* bit4 tells if IRQ happened */
  66                 generic_handle_irq(p->irq);
  67 }
  68
  69 /* The extended IRQ controller has been found, this function registers it */
  70 static void leon_eirq_setup(unsigned int eirq)
  71 {
  72         unsigned long mask, oldmask;
  73         unsigned int veirq;
  74
  75         if (eirq < 1 || eirq > 0xf) {
  76                 printk(KERN_ERR "LEON EXT IRQ NUMBER BAD: %d\n", eirq);
  77                 return;
  78         }
  79
  80         veirq = leon_build_device_irq(eirq, leon_handle_ext_irq, "extirq", 0);
  81
  82         /*
  83          * Unmask the Extended IRQ, the IRQs routed through the Ext-IRQ
  84          * controller have a mask-bit of their own, so this is safe.
  85          */
  86         irq_link(veirq);
  87         mask = 1 << eirq;
  88         oldmask = LEON3_BYPASS_LOAD_PA(LEON_IMASK(boot_cpu_id));
  89         LEON3_BYPASS_STORE_PA(LEON_IMASK(boot_cpu_id), (oldmask | mask));
  90         sparc_leon_eirq = eirq;
  91 }
  92
  93 unsigned long leon_get_irqmask(unsigned int irq)
  94 {
  95         unsigned long mask;
  96
  97         if (!irq || ((irq > 0xf) && !sparc_leon_eirq)
  98             || ((irq > 0x1f) && sparc_leon_eirq)) {
  99                 printk(KERN_ERR
 100                        "leon_get_irqmask: false irq number: %d\n", irq);
 101                 mask = 0;
 102         } else {
 103                 mask = LEON_HARD_INT(irq);
 104         }
 105         return mask;
 106 }
 107
 108 #ifdef CONFIG_SMP
 109 static int irq_choose_cpu(const struct cpumask *affinity)
 110 {
 111         cpumask_t mask;
 112
 113         cpumask_and(&mask, cpu_online_mask, affinity);
 114         if (cpumask_equal(&mask, cpu_online_mask) || cpumask_empty(&mask))
 115                 return boot_cpu_id;
 116         else
 117                 return cpumask_first(&mask);
 118 }
 119 #else
 120 #define irq_choose_cpu(affinity) boot_cpu_id
 121 #endif
 122
 123 static int leon_set_affinity(struct irq_data *data, const struct cpumask *dest,
 124                              bool force)
 125 {
 126         unsigned long mask, oldmask, flags;
 127         int oldcpu, newcpu;
 128
 129         mask = (unsigned long)data->chip_data;
 130         oldcpu = irq_choose_cpu(irq_data_get_affinity_mask(data));
 131         newcpu = irq_choose_cpu(dest);
 132
 133         if (oldcpu == newcpu)
 134                 goto out;
 135
 136         /* unmask on old CPU first before enabling on the selected CPU */
 137         spin_lock_irqsave(&leon_irq_lock, flags);
 138         oldmask = LEON3_BYPASS_LOAD_PA(LEON_IMASK(oldcpu));
 139         LEON3_BYPASS_STORE_PA(LEON_IMASK(oldcpu), (oldmask & ~mask));
 140         oldmask = LEON3_BYPASS_LOAD_PA(LEON_IMASK(newcpu));
 141         LEON3_BYPASS_STORE_PA(LEON_IMASK(newcpu), (oldmask | mask));
 142         spin_unlock_irqrestore(&leon_irq_lock, flags);
 143 out:
 144         return IRQ_SET_MASK_OK;
 145 }
 146
 147 static void leon_unmask_irq(struct irq_data *data)
 148 {
 149         unsigned long mask, oldmask, flags;
 150         int cpu;
 151
 152         mask = (unsigned long)data->chip_data;
 153         cpu = irq_choose_cpu(irq_data_get_affinity_mask(data));
 154         spin_lock_irqsave(&leon_irq_lock, flags);
 155         oldmask = LEON3_BYPASS_LOAD_PA(LEON_IMASK(cpu));
 156         LEON3_BYPASS_STORE_PA(LEON_IMASK(cpu), (oldmask | mask));
 157         spin_unlock_irqrestore(&leon_irq_lock, flags);
 158 }
 159
 160 static void leon_mask_irq(struct irq_data *data)
 161 {
 162         unsigned long mask, oldmask, flags;
 163         int cpu;
 164
 165         mask = (unsigned long)data->chip_data;
 166         cpu = irq_choose_cpu(irq_data_get_affinity_mask(data));
 167         spin_lock_irqsave(&leon_irq_lock, flags);
 168         oldmask = LEON3_BYPASS_LOAD_PA(LEON_IMASK(cpu));
 169         LEON3_BYPASS_STORE_PA(LEON_IMASK(cpu), (oldmask & ~mask));
 170         spin_unlock_irqrestore(&leon_irq_lock, flags);
 171 }
 172
 173 static unsigned int leon_startup_irq(struct irq_data *data)
 174 {
 175         irq_link(data->irq);
 176         leon_unmask_irq(data);
 177         return 0;
 178 }
 179
 180 static void leon_shutdown_irq(struct irq_data *data)
 181 {
 182         leon_mask_irq(data);
 183         irq_unlink(data->irq);
 184 }
 185
 186 /* Used by external level sensitive IRQ handlers on the LEON: ACK IRQ ctrl */
 187 static void leon_eoi_irq(struct irq_data *data)
 188 {
 189         unsigned long mask = (unsigned long)data->chip_data;
 190
 191         if (mask & LEON_DO_ACK_HW)
 192                 LEON3_BYPASS_STORE_PA(LEON_IACK, mask & ~LEON_DO_ACK_HW);
 193 }
 194
 195 static struct irq_chip leon_irq = {
 196         .name                   = "leon",
 197         .irq_startup            = leon_startup_irq,
 198         .irq_shutdown           = leon_shutdown_irq,
 199         .irq_mask               = leon_mask_irq,
 200         .irq_unmask             = leon_unmask_irq,
 201         .irq_eoi                = leon_eoi_irq,
 202         .irq_set_affinity       = leon_set_affinity,
 203 };
 204
 205 /*
 206  * Build a LEON IRQ for the edge triggered LEON IRQ controller:
 207  *  Edge (normal) IRQ           - handle_simple_irq, ack=DON'T-CARE, never ack
 208  *  Level IRQ (PCI|Level-GPIO)  - handle_fasteoi_irq, ack=1, ack after ISR
 209  *  Per-CPU Edge                - handle_percpu_irq, ack=0
 210  */
 211 unsigned int leon_build_device_irq(unsigned int real_irq,
 212                                     irq_flow_handler_t flow_handler,
 213                                     const char *name, int do_ack)
 214 {
 215         unsigned int irq;
 216         unsigned long mask;
 217         struct irq_desc *desc;
 218
 219         irq = 0;
 220         mask = leon_get_irqmask(real_irq);
 221         if (mask == 0)
 222                 goto out;
 223
 224         irq = irq_alloc(real_irq, real_irq);
 225         if (irq == 0)
 226                 goto out;
 227
 228         if (do_ack)
 229                 mask |= LEON_DO_ACK_HW;
 230
 231         desc = irq_to_desc(irq);
 232         if (!desc || !desc->handle_irq || desc->handle_irq == handle_bad_irq) {
 233                 irq_set_chip_and_handler_name(irq, &leon_irq,
 234                                               flow_handler, name);
 235                 irq_set_chip_data(irq, (void *)mask);
 236         }
 237
 238 out:
 239         return irq;
 240 }
 241
 242 static unsigned int _leon_build_device_irq(struct platform_device *op,
 243                                            unsigned int real_irq)
 244 {
 245         return leon_build_device_irq(real_irq, handle_simple_irq, "edge", 0);
 246 }
 247
 248 void leon_update_virq_handling(unsigned int virq,
 249                               irq_flow_handler_t flow_handler,
 250                               const char *name, int do_ack)
 251 {
 252         unsigned long mask = (unsigned long)irq_get_chip_data(virq);
 253
 254         mask &= ~LEON_DO_ACK_HW;
 255         if (do_ack)
 256                 mask |= LEON_DO_ACK_HW;
 257
 258         irq_set_chip_and_handler_name(virq, &leon_irq,
 259                                       flow_handler, name);
 260         irq_set_chip_data(virq, (void *)mask);
 261 }
 262
 263 static u32 leon_cycles_offset(void)
 264 {
 265         u32 rld, val, ctrl, off;
 266
 267         rld = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].rld);
 268         val = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].val);
 269         ctrl = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl);
 270         if (LEON3_GPTIMER_CTRL_ISPENDING(ctrl)) {
 271                 val = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].val);
 272                 off = 2 * rld - val;
 273         } else {
 274                 off = rld - val;
 275         }
 276
 277         return off;
 278 }
 279
 280 #ifdef CONFIG_SMP
 281
 282 /* smp clockevent irq */
 283 static irqreturn_t leon_percpu_timer_ce_interrupt(int irq, void *unused)
 284 {
 285         struct clock_event_device *ce;
 286         int cpu = smp_processor_id();
 287
 288         leon_clear_profile_irq(cpu);
 289
 290         if (cpu == boot_cpu_id)
 291                 timer_interrupt(irq, NULL);
 292
 293         ce = &per_cpu(sparc32_clockevent, cpu);
 294
 295         irq_enter();
 296         if (ce->event_handler)
 297                 ce->event_handler(ce);
 298         irq_exit();
 299
 300         return IRQ_HANDLED;
 301 }
 302
 303 #endif /* CONFIG_SMP */
 304
 305 void __init leon_init_timers(void)
 306 {
 307         int irq, eirq;
 308         struct device_node *rootnp, *np, *nnp;
 309         struct property *pp;
 310         int len;
 311         int icsel;
 312         int ampopts;
 313         int err;
 314         u32 config;
 315         u32 ctrl;
 316
 317         sparc_config.get_cycles_offset = leon_cycles_offset;
 318         sparc_config.cs_period = 1000000 / HZ;
 319         sparc_config.features |= FEAT_L10_CLOCKSOURCE;
 320
 321 #ifndef CONFIG_SMP
 322         sparc_config.features |= FEAT_L10_CLOCKEVENT;
 323 #endif
 324
 325         leondebug_irq_disable = 0;
 326         leon_debug_irqout = 0;
 327         master_l10_counter = (u32 __iomem *)&dummy_master_l10_counter;
 328         dummy_master_l10_counter = 0;
 329
 330         rootnp = of_find_node_by_path("/ambapp0");
 331         if (!rootnp)
 332                 goto bad;
 333
 334         /* Find System ID: GRLIB build ID and optional CHIP ID */
 335         pp = of_find_property(rootnp, "systemid", &len);
 336         if (pp)
 337                 amba_system_id = *(unsigned long *)pp->value;
 338
 339         /* Find IRQMP IRQ Controller Registers base adr otherwise bail out */
 340         np = of_find_node_by_name(rootnp, "GAISLER_IRQMP");
 341         if (!np) {
 342                 np = of_find_node_by_name(rootnp, "01_00d");
 343                 if (!np)
 344                         goto bad;
 345         }
 346         pp = of_find_property(np, "reg", &len);
 347         if (!pp)
 348                 goto bad;
 349         leon3_irqctrl_regs = *(struct leon3_irqctrl_regs_map **)pp->value;
 350
 351         /* Find GPTIMER Timer Registers base address otherwise bail out. */
 352         nnp = rootnp;
 353
 354 retry:
 355         np = of_find_node_by_name(nnp, "GAISLER_GPTIMER");
 356         if (!np) {
 357                 np = of_find_node_by_name(nnp, "01_011");
 358                 if (!np)
 359                         goto bad;
 360         }
 361
 362         ampopts = 0;
 363         pp = of_find_property(np, "ampopts", &len);
 364         if (pp) {
 365                 ampopts = *(int *)pp->value;
 366                 if (ampopts == 0) {
 367                         /* Skip this instance, resource already
 368                          * allocated by other OS */
 369                         nnp = np;
 370                         goto retry;
 371                 }
 372         }
 373
 374         /* Select Timer-Instance on Timer Core. Default is zero */
 375         leon3_gptimer_idx = ampopts & 0x7;
 376
 377         pp = of_find_property(np, "reg", &len);
 378         if (pp)
 379                 leon3_gptimer_regs = *(struct leon3_gptimer_regs_map **)
 380                                         pp->value;
 381         pp = of_find_property(np, "interrupts", &len);
 382         if (pp)
 383                 leon3_gptimer_irq = *(unsigned int *)pp->value;
 384
 385         if (!(leon3_gptimer_regs && leon3_irqctrl_regs && leon3_gptimer_irq))
 386                 goto bad;
 387
 388         ctrl = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl);
 389         LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl,
 390                               ctrl | LEON3_GPTIMER_CTRL_PENDING);
 391         ctrl = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl);
 392
 393         if ((ctrl & LEON3_GPTIMER_CTRL_PENDING) != 0)
 394                 leon3_gptimer_ackmask = ~LEON3_GPTIMER_CTRL_PENDING;
 395         else
 396                 leon3_gptimer_ackmask = ~0;
 397
 398         LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].val, 0);
 399         LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].rld,
 400                                 (((1000000 / HZ) - 1)));
 401         LEON3_BYPASS_STORE_PA(
 402                         &leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl, 0);
 403
 404         /*
 405          * The IRQ controller may (if implemented) consist of multiple
 406          * IRQ controllers, each mapped on a 4Kb boundary.
 407          * Each CPU may be routed to different IRQCTRLs, however
 408          * we assume that all CPUs (in SMP system) is routed to the
 409          * same IRQ Controller, and for non-SMP only one IRQCTRL is
 410          * accessed anyway.
 411          * In AMP systems, Linux must run on CPU0 for the time being.
 412          */
 413         icsel = LEON3_BYPASS_LOAD_PA(&leon3_irqctrl_regs->icsel[boot_cpu_id/8]);
 414         icsel = (icsel >> ((7 - (boot_cpu_id&0x7)) * 4)) & 0xf;
 415         leon3_irqctrl_regs += icsel;
 416
 417         /* Mask all IRQs on boot-cpu IRQ controller */
 418         LEON3_BYPASS_STORE_PA(&leon3_irqctrl_regs->mask[boot_cpu_id], 0);
 419
 420         /* Probe extended IRQ controller */
 421         eirq = (LEON3_BYPASS_LOAD_PA(&leon3_irqctrl_regs->mpstatus)
 422                 >> 16) & 0xf;
 423         if (eirq != 0)
 424                 leon_eirq_setup(eirq);
 425
 426 #ifdef CONFIG_SMP
 427         {
 428                 unsigned long flags;
 429
 430                 /*
 431                  * In SMP, sun4m adds a IPI handler to IRQ trap handler that
 432                  * LEON never must take, sun4d and LEON overwrites the branch
 433                  * with a NOP.
 434                  */
 435                 local_irq_save(flags);
 436                 patchme_maybe_smp_msg[0] = 0x01000000; /* NOP out the branch */
 437                 local_ops->cache_all();
 438                 local_irq_restore(flags);
 439         }
 440 #endif
 441
 442         config = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->config);
 443         if (config & (1 << LEON3_GPTIMER_SEPIRQ))
 444                 leon3_gptimer_irq += leon3_gptimer_idx;
 445         else if ((config & LEON3_GPTIMER_TIMERS) > 1)
 446                 pr_warn("GPTIMER uses shared irqs, using other timers of the same core will fail.\n");
 447
 448 #ifdef CONFIG_SMP
 449         /* Install per-cpu IRQ handler for broadcasted ticker */
 450         irq = leon_build_device_irq(leon3_gptimer_irq, handle_percpu_irq,
 451                                     "per-cpu", 0);
 452         err = request_irq(irq, leon_percpu_timer_ce_interrupt,
 453                           IRQF_PERCPU | IRQF_TIMER, "timer", NULL);
 454 #else
 455         irq = _leon_build_device_irq(NULL, leon3_gptimer_irq);
 456         err = request_irq(irq, timer_interrupt, IRQF_TIMER, "timer", NULL);
 457 #endif
 458         if (err) {
 459                 pr_err("Unable to attach timer IRQ%d\n", irq);
 460                 prom_halt();
 461         }
 462         LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl,
 463                               LEON3_GPTIMER_EN |
 464                               LEON3_GPTIMER_RL |
 465                               LEON3_GPTIMER_LD |
 466                               LEON3_GPTIMER_IRQEN);
 467         return;
 468 bad:
 469         printk(KERN_ERR "No Timer/irqctrl found\n");
 470         BUG();
 471         return;
 472 }
 473
 474 static void leon_clear_clock_irq(void)
 475 {
 476         u32 ctrl;
 477
 478         ctrl = LEON3_BYPASS_LOAD_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl);
 479         LEON3_BYPASS_STORE_PA(&leon3_gptimer_regs->e[leon3_gptimer_idx].ctrl,
 480                               ctrl & leon3_gptimer_ackmask);
 481 }
 482
 483 static void leon_load_profile_irq(int cpu, unsigned int limit)
 484 {
 485 }
 486
 487 #ifdef CONFIG_SMP
 488 void leon_clear_profile_irq(int cpu)
 489 {
 490 }
 491
 492 void leon_enable_irq_cpu(unsigned int irq_nr, unsigned int cpu)
 493 {
 494         unsigned long mask, flags, *addr;
 495         mask = leon_get_irqmask(irq_nr);
 496         spin_lock_irqsave(&leon_irq_lock, flags);
 497         addr = (unsigned long *)LEON_IMASK(cpu);
 498         LEON3_BYPASS_STORE_PA(addr, (LEON3_BYPASS_LOAD_PA(addr) | mask));
 499         spin_unlock_irqrestore(&leon_irq_lock, flags);
 500 }
 501
 502 #endif
 503
 504 void __init leon_init_IRQ(void)
 505 {
 506         sparc_config.init_timers      = leon_init_timers;
 507         sparc_config.build_device_irq = _leon_build_device_irq;
 508         sparc_config.clock_rate       = 1000000;
 509         sparc_config.clear_clock_irq  = leon_clear_clock_irq;
 510         sparc_config.load_profile_irq = leon_load_profile_irq;
 511 }