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