drivers/clocksource/arm_arch_timer.c

   1 /*
   2  *  linux/drivers/clocksource/arm_arch_timer.c
   3  *
   4  *  Copyright (C) 2011 ARM Ltd.
   5  *  All Rights Reserved
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11 #include <linux/init.h>
  12 #include <linux/kernel.h>
  13 #include <linux/device.h>
  14 #include <linux/smp.h>
  15 #include <linux/cpu.h>
  16 #include <linux/cpu_pm.h>
  17 #include <linux/clockchips.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/of_irq.h>
  20 #include <linux/of_address.h>
  21 #include <linux/io.h>
  22 #include <linux/slab.h>
  23 #include <linux/sched_clock.h>
  24
  25 #include <asm/arch_timer.h>
  26 #include <asm/virt.h>
  27
  28 #include <clocksource/arm_arch_timer.h>
  29
  30 #define CNTTIDR         0x08
  31 #define CNTTIDR_VIRT(n) (BIT(1) << ((n) * 4))
  32
  33 #define CNTVCT_LO       0x08
  34 #define CNTVCT_HI       0x0c
  35 #define CNTFRQ          0x10
  36 #define CNTP_TVAL       0x28
  37 #define CNTP_CTL        0x2c
  38 #define CNTV_TVAL       0x38
  39 #define CNTV_CTL        0x3c
  40
  41 #define ARCH_CP15_TIMER BIT(0)
  42 #define ARCH_MEM_TIMER  BIT(1)
  43 static unsigned arch_timers_present __initdata;
  44
  45 static void __iomem *arch_counter_base;
  46
  47 struct arch_timer {
  48         void __iomem *base;
  49         struct clock_event_device evt;
  50 };
  51
  52 #define to_arch_timer(e) container_of(e, struct arch_timer, evt)
  53
  54 static u32 arch_timer_rate;
  55
  56 enum ppi_nr {
  57         PHYS_SECURE_PPI,
  58         PHYS_NONSECURE_PPI,
  59         VIRT_PPI,
  60         HYP_PPI,
  61         MAX_TIMER_PPI
  62 };
  63
  64 static int arch_timer_ppi[MAX_TIMER_PPI];
  65
  66 static struct clock_event_device __percpu *arch_timer_evt;
  67
  68 static bool arch_timer_use_virtual = true;
  69 static bool arch_timer_mem_use_virtual;
  70
  71 /*
  72  * Architected system timer support.
  73  */
  74
  75 static __always_inline
  76 void arch_timer_reg_write(int access, enum arch_timer_reg reg, u32 val,
  77                           struct clock_event_device *clk)
  78 {
  79         if (access == ARCH_TIMER_MEM_PHYS_ACCESS) {
  80                 struct arch_timer *timer = to_arch_timer(clk);
  81                 switch (reg) {
  82                 case ARCH_TIMER_REG_CTRL:
  83                         writel_relaxed(val, timer->base + CNTP_CTL);
  84                         break;
  85                 case ARCH_TIMER_REG_TVAL:
  86                         writel_relaxed(val, timer->base + CNTP_TVAL);
  87                         break;
  88                 }
  89         } else if (access == ARCH_TIMER_MEM_VIRT_ACCESS) {
  90                 struct arch_timer *timer = to_arch_timer(clk);
  91                 switch (reg) {
  92                 case ARCH_TIMER_REG_CTRL:
  93                         writel_relaxed(val, timer->base + CNTV_CTL);
  94                         break;
  95                 case ARCH_TIMER_REG_TVAL:
  96                         writel_relaxed(val, timer->base + CNTV_TVAL);
  97                         break;
  98                 }
  99         } else {
 100                 arch_timer_reg_write_cp15(access, reg, val);
 101         }
 102 }
 103
 104 static __always_inline
 105 u32 arch_timer_reg_read(int access, enum arch_timer_reg reg,
 106                         struct clock_event_device *clk)
 107 {
 108         u32 val;
 109
 110         if (access == ARCH_TIMER_MEM_PHYS_ACCESS) {
 111                 struct arch_timer *timer = to_arch_timer(clk);
 112                 switch (reg) {
 113                 case ARCH_TIMER_REG_CTRL:
 114                         val = readl_relaxed(timer->base + CNTP_CTL);
 115                         break;
 116                 case ARCH_TIMER_REG_TVAL:
 117                         val = readl_relaxed(timer->base + CNTP_TVAL);
 118                         break;
 119                 }
 120         } else if (access == ARCH_TIMER_MEM_VIRT_ACCESS) {
 121                 struct arch_timer *timer = to_arch_timer(clk);
 122                 switch (reg) {
 123                 case ARCH_TIMER_REG_CTRL:
 124                         val = readl_relaxed(timer->base + CNTV_CTL);
 125                         break;
 126                 case ARCH_TIMER_REG_TVAL:
 127                         val = readl_relaxed(timer->base + CNTV_TVAL);
 128                         break;
 129                 }
 130         } else {
 131                 val = arch_timer_reg_read_cp15(access, reg);
 132         }
 133
 134         return val;
 135 }
 136
 137 static __always_inline irqreturn_t timer_handler(const int access,
 138                                         struct clock_event_device *evt)
 139 {
 140         unsigned long ctrl;
 141
 142         ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL, evt);
 143         if (ctrl & ARCH_TIMER_CTRL_IT_STAT) {
 144                 ctrl |= ARCH_TIMER_CTRL_IT_MASK;
 145                 arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, evt);
 146                 evt->event_handler(evt);
 147                 return IRQ_HANDLED;
 148         }
 149
 150         return IRQ_NONE;
 151 }
 152
 153 static irqreturn_t arch_timer_handler_virt(int irq, void *dev_id)
 154 {
 155         struct clock_event_device *evt = dev_id;
 156
 157         return timer_handler(ARCH_TIMER_VIRT_ACCESS, evt);
 158 }
 159
 160 static irqreturn_t arch_timer_handler_phys(int irq, void *dev_id)
 161 {
 162         struct clock_event_device *evt = dev_id;
 163
 164         return timer_handler(ARCH_TIMER_PHYS_ACCESS, evt);
 165 }
 166
 167 static irqreturn_t arch_timer_handler_phys_mem(int irq, void *dev_id)
 168 {
 169         struct clock_event_device *evt = dev_id;
 170
 171         return timer_handler(ARCH_TIMER_MEM_PHYS_ACCESS, evt);
 172 }
 173
 174 static irqreturn_t arch_timer_handler_virt_mem(int irq, void *dev_id)
 175 {
 176         struct clock_event_device *evt = dev_id;
 177
 178         return timer_handler(ARCH_TIMER_MEM_VIRT_ACCESS, evt);
 179 }
 180
 181 static __always_inline void timer_set_mode(const int access, int mode,
 182                                   struct clock_event_device *clk)
 183 {
 184         unsigned long ctrl;
 185         switch (mode) {
 186         case CLOCK_EVT_MODE_UNUSED:
 187         case CLOCK_EVT_MODE_SHUTDOWN:
 188                 ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL, clk);
 189                 ctrl &= ~ARCH_TIMER_CTRL_ENABLE;
 190                 arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, clk);
 191                 break;
 192         default:
 193                 break;
 194         }
 195 }
 196
 197 static void arch_timer_set_mode_virt(enum clock_event_mode mode,
 198                                      struct clock_event_device *clk)
 199 {
 200         timer_set_mode(ARCH_TIMER_VIRT_ACCESS, mode, clk);
 201 }
 202
 203 static void arch_timer_set_mode_phys(enum clock_event_mode mode,
 204                                      struct clock_event_device *clk)
 205 {
 206         timer_set_mode(ARCH_TIMER_PHYS_ACCESS, mode, clk);
 207 }
 208
 209 static void arch_timer_set_mode_virt_mem(enum clock_event_mode mode,
 210                                          struct clock_event_device *clk)
 211 {
 212         timer_set_mode(ARCH_TIMER_MEM_VIRT_ACCESS, mode, clk);
 213 }
 214
 215 static void arch_timer_set_mode_phys_mem(enum clock_event_mode mode,
 216                                          struct clock_event_device *clk)
 217 {
 218         timer_set_mode(ARCH_TIMER_MEM_PHYS_ACCESS, mode, clk);
 219 }
 220
 221 static __always_inline void set_next_event(const int access, unsigned long evt,
 222                                            struct clock_event_device *clk)
 223 {
 224         unsigned long ctrl;
 225         ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL, clk);
 226         ctrl |= ARCH_TIMER_CTRL_ENABLE;
 227         ctrl &= ~ARCH_TIMER_CTRL_IT_MASK;
 228         arch_timer_reg_write(access, ARCH_TIMER_REG_TVAL, evt, clk);
 229         arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, clk);
 230 }
 231
 232 static int arch_timer_set_next_event_virt(unsigned long evt,
 233                                           struct clock_event_device *clk)
 234 {
 235         set_next_event(ARCH_TIMER_VIRT_ACCESS, evt, clk);
 236         return 0;
 237 }
 238
 239 static int arch_timer_set_next_event_phys(unsigned long evt,
 240                                           struct clock_event_device *clk)
 241 {
 242         set_next_event(ARCH_TIMER_PHYS_ACCESS, evt, clk);
 243         return 0;
 244 }
 245
 246 static int arch_timer_set_next_event_virt_mem(unsigned long evt,
 247                                               struct clock_event_device *clk)
 248 {
 249         set_next_event(ARCH_TIMER_MEM_VIRT_ACCESS, evt, clk);
 250         return 0;
 251 }
 252
 253 static int arch_timer_set_next_event_phys_mem(unsigned long evt,
 254                                               struct clock_event_device *clk)
 255 {
 256         set_next_event(ARCH_TIMER_MEM_PHYS_ACCESS, evt, clk);
 257         return 0;
 258 }
 259
 260 static void __arch_timer_setup(unsigned type,
 261                                struct clock_event_device *clk)
 262 {
 263         clk->features = CLOCK_EVT_FEAT_ONESHOT;
 264
 265         if (type == ARCH_CP15_TIMER) {
 266                 clk->features |= CLOCK_EVT_FEAT_C3STOP;
 267                 clk->name = "arch_sys_timer";
 268                 clk->rating = 450;
 269                 clk->cpumask = cpumask_of(smp_processor_id());
 270                 if (arch_timer_use_virtual) {
 271                         clk->irq = arch_timer_ppi[VIRT_PPI];
 272                         clk->set_mode = arch_timer_set_mode_virt;
 273                         clk->set_next_event = arch_timer_set_next_event_virt;
 274                 } else {
 275                         clk->irq = arch_timer_ppi[PHYS_SECURE_PPI];
 276                         clk->set_mode = arch_timer_set_mode_phys;
 277                         clk->set_next_event = arch_timer_set_next_event_phys;
 278                 }
 279         } else {
 280                 clk->name = "arch_mem_timer";
 281                 clk->rating = 400;
 282                 clk->cpumask = cpu_all_mask;
 283                 if (arch_timer_mem_use_virtual) {
 284                         clk->set_mode = arch_timer_set_mode_virt_mem;
 285                         clk->set_next_event =
 286                                 arch_timer_set_next_event_virt_mem;
 287                 } else {
 288                         clk->set_mode = arch_timer_set_mode_phys_mem;
 289                         clk->set_next_event =
 290                                 arch_timer_set_next_event_phys_mem;
 291                 }
 292         }
 293
 294         clk->set_mode(CLOCK_EVT_MODE_SHUTDOWN, clk);
 295
 296         clockevents_config_and_register(clk, arch_timer_rate, 0xf, 0x7fffffff);
 297 }
 298
 299 static void arch_timer_evtstrm_enable(int divider)
 300 {
 301         u32 cntkctl = arch_timer_get_cntkctl();
 302
 303         cntkctl &= ~ARCH_TIMER_EVT_TRIGGER_MASK;
 304         /* Set the divider and enable virtual event stream */
 305         cntkctl |= (divider << ARCH_TIMER_EVT_TRIGGER_SHIFT)
 306                         | ARCH_TIMER_VIRT_EVT_EN;
 307         arch_timer_set_cntkctl(cntkctl);
 308         elf_hwcap |= HWCAP_EVTSTRM;
 309 #ifdef CONFIG_COMPAT
 310         compat_elf_hwcap |= COMPAT_HWCAP_EVTSTRM;
 311 #endif
 312 }
 313
 314 static void arch_timer_configure_evtstream(void)
 315 {
 316         int evt_stream_div, pos;
 317
 318         /* Find the closest power of two to the divisor */
 319         evt_stream_div = arch_timer_rate / ARCH_TIMER_EVT_STREAM_FREQ;
 320         pos = fls(evt_stream_div);
 321         if (pos > 1 && !(evt_stream_div & (1 << (pos - 2))))
 322                 pos--;
 323         /* enable event stream */
 324         arch_timer_evtstrm_enable(min(pos, 15));
 325 }
 326
 327 static void arch_counter_set_user_access(void)
 328 {
 329         u32 cntkctl = arch_timer_get_cntkctl();
 330
 331         /* Disable user access to the timers and the physical counter */
 332         /* Also disable virtual event stream */
 333         cntkctl &= ~(ARCH_TIMER_USR_PT_ACCESS_EN
 334                         | ARCH_TIMER_USR_VT_ACCESS_EN
 335                         | ARCH_TIMER_VIRT_EVT_EN
 336                         | ARCH_TIMER_USR_PCT_ACCESS_EN);
 337
 338         /* Enable user access to the virtual counter */
 339         cntkctl |= ARCH_TIMER_USR_VCT_ACCESS_EN;
 340
 341         arch_timer_set_cntkctl(cntkctl);
 342 }
 343
 344 static int arch_timer_setup(struct clock_event_device *clk)
 345 {
 346         __arch_timer_setup(ARCH_CP15_TIMER, clk);
 347
 348         if (arch_timer_use_virtual)
 349                 enable_percpu_irq(arch_timer_ppi[VIRT_PPI], 0);
 350         else {
 351                 enable_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI], 0);
 352                 if (arch_timer_ppi[PHYS_NONSECURE_PPI])
 353                         enable_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI], 0);
 354         }
 355
 356         arch_counter_set_user_access();
 357         if (IS_ENABLED(CONFIG_ARM_ARCH_TIMER_EVTSTREAM))
 358                 arch_timer_configure_evtstream();
 359
 360         return 0;
 361 }
 362
 363 static void
 364 arch_timer_detect_rate(void __iomem *cntbase, struct device_node *np)
 365 {
 366         /* Who has more than one independent system counter? */
 367         if (arch_timer_rate)
 368                 return;
 369
 370         /* Try to determine the frequency from the device tree or CNTFRQ */
 371         if (of_property_read_u32(np, "clock-frequency", &arch_timer_rate)) {
 372                 if (cntbase)
 373                         arch_timer_rate = readl_relaxed(cntbase + CNTFRQ);
 374                 else
 375                         arch_timer_rate = arch_timer_get_cntfrq();
 376         }
 377
 378         /* Check the timer frequency. */
 379         if (arch_timer_rate == 0)
 380                 pr_warn("Architected timer frequency not available\n");
 381 }
 382
 383 static void arch_timer_banner(unsigned type)
 384 {
 385         pr_info("Architected %s%s%s timer(s) running at %lu.%02luMHz (%s%s%s).\n",
 386                      type & ARCH_CP15_TIMER ? "cp15" : "",
 387                      type == (ARCH_CP15_TIMER | ARCH_MEM_TIMER) ?  " and " : "",
 388                      type & ARCH_MEM_TIMER ? "mmio" : "",
 389                      (unsigned long)arch_timer_rate / 1000000,
 390                      (unsigned long)(arch_timer_rate / 10000) % 100,
 391                      type & ARCH_CP15_TIMER ?
 392                         arch_timer_use_virtual ? "virt" : "phys" :
 393                         "",
 394                      type == (ARCH_CP15_TIMER | ARCH_MEM_TIMER) ?  "/" : "",
 395                      type & ARCH_MEM_TIMER ?
 396                         arch_timer_mem_use_virtual ? "virt" : "phys" :
 397                         "");
 398 }
 399
 400 u32 arch_timer_get_rate(void)
 401 {
 402         return arch_timer_rate;
 403 }
 404
 405 static u64 arch_counter_get_cntvct_mem(void)
 406 {
 407         u32 vct_lo, vct_hi, tmp_hi;
 408
 409         do {
 410                 vct_hi = readl_relaxed(arch_counter_base + CNTVCT_HI);
 411                 vct_lo = readl_relaxed(arch_counter_base + CNTVCT_LO);
 412                 tmp_hi = readl_relaxed(arch_counter_base + CNTVCT_HI);
 413         } while (vct_hi != tmp_hi);
 414
 415         return ((u64) vct_hi << 32) | vct_lo;
 416 }
 417
 418 /*
 419  * Default to cp15 based access because arm64 uses this function for
 420  * sched_clock() before DT is probed and the cp15 method is guaranteed
 421  * to exist on arm64. arm doesn't use this before DT is probed so even
 422  * if we don't have the cp15 accessors we won't have a problem.
 423  */
 424 u64 (*arch_timer_read_counter)(void) = arch_counter_get_cntvct;
 425
 426 static cycle_t arch_counter_read(struct clocksource *cs)
 427 {
 428         return arch_timer_read_counter();
 429 }
 430
 431 static cycle_t arch_counter_read_cc(const struct cyclecounter *cc)
 432 {
 433         return arch_timer_read_counter();
 434 }
 435
 436 static struct clocksource clocksource_counter = {
 437         .name   = "arch_sys_counter",
 438         .rating = 400,
 439         .read   = arch_counter_read,
 440         .mask   = CLOCKSOURCE_MASK(56),
 441         .flags  = CLOCK_SOURCE_IS_CONTINUOUS | CLOCK_SOURCE_SUSPEND_NONSTOP,
 442 };
 443
 444 static struct cyclecounter cyclecounter = {
 445         .read   = arch_counter_read_cc,
 446         .mask   = CLOCKSOURCE_MASK(56),
 447 };
 448
 449 static struct timecounter timecounter;
 450
 451 struct timecounter *arch_timer_get_timecounter(void)
 452 {
 453         return &timecounter;
 454 }
 455
 456 static void __init arch_counter_register(unsigned type)
 457 {
 458         u64 start_count;
 459
 460         /* Register the CP15 based counter if we have one */
 461         if (type & ARCH_CP15_TIMER)
 462                 arch_timer_read_counter = arch_counter_get_cntvct;
 463         else
 464                 arch_timer_read_counter = arch_counter_get_cntvct_mem;
 465
 466         start_count = arch_timer_read_counter();
 467         clocksource_register_hz(&clocksource_counter, arch_timer_rate);
 468         cyclecounter.mult = clocksource_counter.mult;
 469         cyclecounter.shift = clocksource_counter.shift;
 470         timecounter_init(&timecounter, &cyclecounter, start_count);
 471
 472         /* 56 bits minimum, so we assume worst case rollover */
 473         sched_clock_register(arch_timer_read_counter, 56, arch_timer_rate);
 474 }
 475
 476 static void arch_timer_stop(struct clock_event_device *clk)
 477 {
 478         pr_debug("arch_timer_teardown disable IRQ%d cpu #%d\n",
 479                  clk->irq, smp_processor_id());
 480
 481         if (arch_timer_use_virtual)
 482                 disable_percpu_irq(arch_timer_ppi[VIRT_PPI]);
 483         else {
 484                 disable_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI]);
 485                 if (arch_timer_ppi[PHYS_NONSECURE_PPI])
 486                         disable_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI]);
 487         }
 488
 489         clk->set_mode(CLOCK_EVT_MODE_UNUSED, clk);
 490 }
 491
 492 static int arch_timer_cpu_notify(struct notifier_block *self,
 493                                            unsigned long action, void *hcpu)
 494 {
 495         /*
 496          * Grab cpu pointer in each case to avoid spurious
 497          * preemptible warnings
 498          */
 499         switch (action & ~CPU_TASKS_FROZEN) {
 500         case CPU_STARTING:
 501                 arch_timer_setup(this_cpu_ptr(arch_timer_evt));
 502                 break;
 503         case CPU_DYING:
 504                 arch_timer_stop(this_cpu_ptr(arch_timer_evt));
 505                 break;
 506         }
 507
 508         return NOTIFY_OK;
 509 }
 510
 511 static struct notifier_block arch_timer_cpu_nb = {
 512         .notifier_call = arch_timer_cpu_notify,
 513 };
 514
 515 #ifdef CONFIG_CPU_PM
 516 static unsigned int saved_cntkctl;
 517 static int arch_timer_cpu_pm_notify(struct notifier_block *self,
 518                                     unsigned long action, void *hcpu)
 519 {
 520         if (action == CPU_PM_ENTER)
 521                 saved_cntkctl = arch_timer_get_cntkctl();
 522         else if (action == CPU_PM_ENTER_FAILED || action == CPU_PM_EXIT)
 523                 arch_timer_set_cntkctl(saved_cntkctl);
 524         return NOTIFY_OK;
 525 }
 526
 527 static struct notifier_block arch_timer_cpu_pm_notifier = {
 528         .notifier_call = arch_timer_cpu_pm_notify,
 529 };
 530
 531 static int __init arch_timer_cpu_pm_init(void)
 532 {
 533         return cpu_pm_register_notifier(&arch_timer_cpu_pm_notifier);
 534 }
 535 #else
 536 static int __init arch_timer_cpu_pm_init(void)
 537 {
 538         return 0;
 539 }
 540 #endif
 541
 542 static int __init arch_timer_register(void)
 543 {
 544         int err;
 545         int ppi;
 546
 547         arch_timer_evt = alloc_percpu(struct clock_event_device);
 548         if (!arch_timer_evt) {
 549                 err = -ENOMEM;
 550                 goto out;
 551         }
 552
 553         if (arch_timer_use_virtual) {
 554                 ppi = arch_timer_ppi[VIRT_PPI];
 555                 err = request_percpu_irq(ppi, arch_timer_handler_virt,
 556                                          "arch_timer", arch_timer_evt);
 557         } else {
 558                 ppi = arch_timer_ppi[PHYS_SECURE_PPI];
 559                 err = request_percpu_irq(ppi, arch_timer_handler_phys,
 560                                          "arch_timer", arch_timer_evt);
 561                 if (!err && arch_timer_ppi[PHYS_NONSECURE_PPI]) {
 562                         ppi = arch_timer_ppi[PHYS_NONSECURE_PPI];
 563                         err = request_percpu_irq(ppi, arch_timer_handler_phys,
 564                                                  "arch_timer", arch_timer_evt);
 565                         if (err)
 566                                 free_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI],
 567                                                 arch_timer_evt);
 568                 }
 569         }
 570
 571         if (err) {
 572                 pr_err("arch_timer: can't register interrupt %d (%d)\n",
 573                        ppi, err);
 574                 goto out_free;
 575         }
 576
 577         err = register_cpu_notifier(&arch_timer_cpu_nb);
 578         if (err)
 579                 goto out_free_irq;
 580
 581         err = arch_timer_cpu_pm_init();
 582         if (err)
 583                 goto out_unreg_notify;
 584
 585         /* Immediately configure the timer on the boot CPU */
 586         arch_timer_setup(this_cpu_ptr(arch_timer_evt));
 587
 588         return 0;
 589
 590 out_unreg_notify:
 591         unregister_cpu_notifier(&arch_timer_cpu_nb);
 592 out_free_irq:
 593         if (arch_timer_use_virtual)
 594                 free_percpu_irq(arch_timer_ppi[VIRT_PPI], arch_timer_evt);
 595         else {
 596                 free_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI],
 597                                 arch_timer_evt);
 598                 if (arch_timer_ppi[PHYS_NONSECURE_PPI])
 599                         free_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI],
 600                                         arch_timer_evt);
 601         }
 602
 603 out_free:
 604         free_percpu(arch_timer_evt);
 605 out:
 606         return err;
 607 }
 608
 609 static int __init arch_timer_mem_register(void __iomem *base, unsigned int irq)
 610 {
 611         int ret;
 612         irq_handler_t func;
 613         struct arch_timer *t;
 614
 615         t = kzalloc(sizeof(*t), GFP_KERNEL);
 616         if (!t)
 617                 return -ENOMEM;
 618
 619         t->base = base;
 620         t->evt.irq = irq;
 621         __arch_timer_setup(ARCH_MEM_TIMER, &t->evt);
 622
 623         if (arch_timer_mem_use_virtual)
 624                 func = arch_timer_handler_virt_mem;
 625         else
 626                 func = arch_timer_handler_phys_mem;
 627
 628         ret = request_irq(irq, func, IRQF_TIMER, "arch_mem_timer", &t->evt);
 629         if (ret) {
 630                 pr_err("arch_timer: Failed to request mem timer irq\n");
 631                 kfree(t);
 632         }
 633
 634         return ret;
 635 }
 636
 637 static const struct of_device_id arch_timer_of_match[] __initconst = {
 638         { .compatible   = "arm,armv7-timer",    },
 639         { .compatible   = "arm,armv8-timer",    },
 640         {},
 641 };
 642
 643 static const struct of_device_id arch_timer_mem_of_match[] __initconst = {
 644         { .compatible   = "arm,armv7-timer-mem", },
 645         {},
 646 };
 647
 648 static void __init arch_timer_common_init(void)
 649 {
 650         unsigned mask = ARCH_CP15_TIMER | ARCH_MEM_TIMER;
 651
 652         /* Wait until both nodes are probed if we have two timers */
 653         if ((arch_timers_present & mask) != mask) {
 654                 if (of_find_matching_node(NULL, arch_timer_mem_of_match) &&
 655                                 !(arch_timers_present & ARCH_MEM_TIMER))
 656                         return;
 657                 if (of_find_matching_node(NULL, arch_timer_of_match) &&
 658                                 !(arch_timers_present & ARCH_CP15_TIMER))
 659                         return;
 660         }
 661
 662         arch_timer_banner(arch_timers_present);
 663         arch_counter_register(arch_timers_present);
 664         arch_timer_arch_init();
 665 }
 666
 667 static void __init arch_timer_init(struct device_node *np)
 668 {
 669         int i;
 670
 671         if (arch_timers_present & ARCH_CP15_TIMER) {
 672                 pr_warn("arch_timer: multiple nodes in dt, skipping\n");
 673                 return;
 674         }
 675
 676         arch_timers_present |= ARCH_CP15_TIMER;
 677         for (i = PHYS_SECURE_PPI; i < MAX_TIMER_PPI; i++)
 678                 arch_timer_ppi[i] = irq_of_parse_and_map(np, i);
 679         arch_timer_detect_rate(NULL, np);
 680
 681         /*
 682          * If HYP mode is available, we know that the physical timer
 683          * has been configured to be accessible from PL1. Use it, so
 684          * that a guest can use the virtual timer instead.
 685          *
 686          * If no interrupt provided for virtual timer, we'll have to
 687          * stick to the physical timer. It'd better be accessible...
 688          */
 689         if (is_hyp_mode_available() || !arch_timer_ppi[VIRT_PPI]) {
 690                 arch_timer_use_virtual = false;
 691
 692                 if (!arch_timer_ppi[PHYS_SECURE_PPI] ||
 693                     !arch_timer_ppi[PHYS_NONSECURE_PPI]) {
 694                         pr_warn("arch_timer: No interrupt available, giving up\n");
 695                         return;
 696                 }
 697         }
 698
 699         arch_timer_register();
 700         arch_timer_common_init();
 701 }
 702 CLOCKSOURCE_OF_DECLARE(armv7_arch_timer, "arm,armv7-timer", arch_timer_init);
 703 CLOCKSOURCE_OF_DECLARE(armv8_arch_timer, "arm,armv8-timer", arch_timer_init);
 704
 705 static void __init arch_timer_mem_init(struct device_node *np)
 706 {
 707         struct device_node *frame, *best_frame = NULL;
 708         void __iomem *cntctlbase, *base;
 709         unsigned int irq;
 710         u32 cnttidr;
 711
 712         arch_timers_present |= ARCH_MEM_TIMER;
 713         cntctlbase = of_iomap(np, 0);
 714         if (!cntctlbase) {
 715                 pr_err("arch_timer: Can't find CNTCTLBase\n");
 716                 return;
 717         }
 718
 719         cnttidr = readl_relaxed(cntctlbase + CNTTIDR);
 720         iounmap(cntctlbase);
 721
 722         /*
 723          * Try to find a virtual capable frame. Otherwise fall back to a
 724          * physical capable frame.
 725          */
 726         for_each_available_child_of_node(np, frame) {
 727                 int n;
 728
 729                 if (of_property_read_u32(frame, "frame-number", &n)) {
 730                         pr_err("arch_timer: Missing frame-number\n");
 731                         of_node_put(best_frame);
 732                         of_node_put(frame);
 733                         return;
 734                 }
 735
 736                 if (cnttidr & CNTTIDR_VIRT(n)) {
 737                         of_node_put(best_frame);
 738                         best_frame = frame;
 739                         arch_timer_mem_use_virtual = true;
 740                         break;
 741                 }
 742                 of_node_put(best_frame);
 743                 best_frame = of_node_get(frame);
 744         }
 745
 746         base = arch_counter_base = of_iomap(best_frame, 0);
 747         if (!base) {
 748                 pr_err("arch_timer: Can't map frame's registers\n");
 749                 of_node_put(best_frame);
 750                 return;
 751         }
 752
 753         if (arch_timer_mem_use_virtual)
 754                 irq = irq_of_parse_and_map(best_frame, 1);
 755         else
 756                 irq = irq_of_parse_and_map(best_frame, 0);
 757         of_node_put(best_frame);
 758         if (!irq) {
 759                 pr_err("arch_timer: Frame missing %s irq",
 760                        arch_timer_mem_use_virtual ? "virt" : "phys");
 761                 return;
 762         }
 763
 764         arch_timer_detect_rate(base, np);
 765         arch_timer_mem_register(base, irq);
 766         arch_timer_common_init();
 767 }
 768 CLOCKSOURCE_OF_DECLARE(armv7_arch_timer_mem, "arm,armv7-timer-mem",
 769                        arch_timer_mem_init);