arch/arm/mach-omap2/omap-smp.c

   1 /*
   2  * OMAP4 SMP source file. It contains platform specific functions
   3  * needed for the linux smp kernel.
   4  *
   5  * Copyright (C) 2009 Texas Instruments, Inc.
   6  *
   7  * Author:
   8  *      Santosh Shilimkar <santosh.shilimkar@ti.com>
   9  *
  10  * Platform file needed for the OMAP4 SMP. This file is based on arm
  11  * realview smp platform.
  12  * * Copyright (c) 2002 ARM Limited.
  13  *
  14  * This program is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License version 2 as
  16  * published by the Free Software Foundation.
  17  */
  18 #include <linux/init.h>
  19 #include <linux/device.h>
  20 #include <linux/smp.h>
  21 #include <linux/io.h>
  22 #include <linux/irqchip/arm-gic.h>
  23
  24 #include <asm/sections.h>
  25 #include <asm/smp_scu.h>
  26 #include <asm/virt.h>
  27
  28 #include "omap-secure.h"
  29 #include "omap-wakeupgen.h"
  30 #include <asm/cputype.h>
  31
  32 #include "soc.h"
  33 #include "iomap.h"
  34 #include "common.h"
  35 #include "clockdomain.h"
  36 #include "pm.h"
  37
  38 #define CPU_MASK                0xff0ffff0
  39 #define CPU_CORTEX_A9           0x410FC090
  40 #define CPU_CORTEX_A15          0x410FC0F0
  41
  42 #define OMAP5_CORE_COUNT        0x2
  43
  44 #define AUX_CORE_BOOT0_GP_RELEASE       0x020
  45 #define AUX_CORE_BOOT0_HS_RELEASE       0x200
  46
  47 struct omap_smp_config {
  48         unsigned long cpu1_rstctrl_pa;
  49         void __iomem *cpu1_rstctrl_va;
  50         void __iomem *scu_base;
  51         void __iomem *wakeupgen_base;
  52         void *startup_addr;
  53 };
  54
  55 static struct omap_smp_config cfg;
  56
  57 static const struct omap_smp_config omap443x_cfg __initconst = {
  58         .cpu1_rstctrl_pa = 0x4824380c,
  59         .startup_addr = omap4_secondary_startup,
  60 };
  61
  62 static const struct omap_smp_config omap446x_cfg __initconst = {
  63         .cpu1_rstctrl_pa = 0x4824380c,
  64         .startup_addr = omap4460_secondary_startup,
  65 };
  66
  67 static const struct omap_smp_config omap5_cfg __initconst = {
  68         .cpu1_rstctrl_pa = 0x48243810,
  69         .startup_addr = omap5_secondary_startup,
  70 };
  71
  72 static DEFINE_SPINLOCK(boot_lock);
  73
  74 void __iomem *omap4_get_scu_base(void)
  75 {
  76         return cfg.scu_base;
  77 }
  78
  79 #ifdef CONFIG_OMAP5_ERRATA_801819
  80 void omap5_erratum_workaround_801819(void)
  81 {
  82         u32 acr, revidr;
  83         u32 acr_mask;
  84
  85         /* REVIDR[3] indicates erratum fix available on silicon */
  86         asm volatile ("mrc p15, 0, %0, c0, c0, 6" : "=r" (revidr));
  87         if (revidr & (0x1 << 3))
  88                 return;
  89
  90         asm volatile ("mrc p15, 0, %0, c1, c0, 1" : "=r" (acr));
  91         /*
  92          * BIT(27) - Disables streaming. All write-allocate lines allocate in
  93          * the L1 or L2 cache.
  94          * BIT(25) - Disables streaming. All write-allocate lines allocate in
  95          * the L1 cache.
  96          */
  97         acr_mask = (0x3 << 25) | (0x3 << 27);
  98         /* do we already have it done.. if yes, skip expensive smc */
  99         if ((acr & acr_mask) == acr_mask)
 100                 return;
 101
 102         acr |= acr_mask;
 103         omap_smc1(OMAP5_DRA7_MON_SET_ACR_INDEX, acr);
 104
 105         pr_debug("%s: ARM erratum workaround 801819 applied on CPU%d\n",
 106                  __func__, smp_processor_id());
 107 }
 108 #else
 109 static inline void omap5_erratum_workaround_801819(void) { }
 110 #endif
 111
 112 static void omap4_secondary_init(unsigned int cpu)
 113 {
 114         /*
 115          * Configure ACTRL and enable NS SMP bit access on CPU1 on HS device.
 116          * OMAP44XX EMU/HS devices - CPU0 SMP bit access is enabled in PPA
 117          * init and for CPU1, a secure PPA API provided. CPU0 must be ON
 118          * while executing NS_SMP API on CPU1 and PPA version must be 1.4.0+.
 119          * OMAP443X GP devices- SMP bit isn't accessible.
 120          * OMAP446X GP devices - SMP bit access is enabled on both CPUs.
 121          */
 122         if (soc_is_omap443x() && (omap_type() != OMAP2_DEVICE_TYPE_GP))
 123                 omap_secure_dispatcher(OMAP4_PPA_CPU_ACTRL_SMP_INDEX,
 124                                                         4, 0, 0, 0, 0, 0);
 125
 126         if (soc_is_omap54xx() || soc_is_dra7xx()) {
 127                 /*
 128                  * Configure the CNTFRQ register for the secondary cpu's which
 129                  * indicates the frequency of the cpu local timers.
 130                  */
 131                 set_cntfreq();
 132                 /* Configure ACR to disable streaming WA for 801819 */
 133                 omap5_erratum_workaround_801819();
 134         }
 135
 136         /*
 137          * Synchronise with the boot thread.
 138          */
 139         spin_lock(&boot_lock);
 140         spin_unlock(&boot_lock);
 141 }
 142
 143 static int omap4_boot_secondary(unsigned int cpu, struct task_struct *idle)
 144 {
 145         static struct clockdomain *cpu1_clkdm;
 146         static bool booted;
 147         static struct powerdomain *cpu1_pwrdm;
 148
 149         /*
 150          * Set synchronisation state between this boot processor
 151          * and the secondary one
 152          */
 153         spin_lock(&boot_lock);
 154
 155         /*
 156          * Update the AuxCoreBoot0 with boot state for secondary core.
 157          * omap4_secondary_startup() routine will hold the secondary core till
 158          * the AuxCoreBoot1 register is updated with cpu state
 159          * A barrier is added to ensure that write buffer is drained
 160          */
 161         if (omap_secure_apis_support())
 162                 omap_modify_auxcoreboot0(AUX_CORE_BOOT0_HS_RELEASE,
 163                                          0xfffffdff);
 164         else
 165                 writel_relaxed(AUX_CORE_BOOT0_GP_RELEASE,
 166                                cfg.wakeupgen_base + OMAP_AUX_CORE_BOOT_0);
 167
 168         if (!cpu1_clkdm && !cpu1_pwrdm) {
 169                 cpu1_clkdm = clkdm_lookup("mpu1_clkdm");
 170                 cpu1_pwrdm = pwrdm_lookup("cpu1_pwrdm");
 171         }
 172
 173         /*
 174          * The SGI(Software Generated Interrupts) are not wakeup capable
 175          * from low power states. This is known limitation on OMAP4 and
 176          * needs to be worked around by using software forced clockdomain
 177          * wake-up. To wakeup CPU1, CPU0 forces the CPU1 clockdomain to
 178          * software force wakeup. The clockdomain is then put back to
 179          * hardware supervised mode.
 180          * More details can be found in OMAP4430 TRM - Version J
 181          * Section :
 182          *      4.3.4.2 Power States of CPU0 and CPU1
 183          */
 184         if (booted && cpu1_pwrdm && cpu1_clkdm) {
 185                 /*
 186                  * GIC distributor control register has changed between
 187                  * CortexA9 r1pX and r2pX. The Control Register secure
 188                  * banked version is now composed of 2 bits:
 189                  * bit 0 == Secure Enable
 190                  * bit 1 == Non-Secure Enable
 191                  * The Non-Secure banked register has not changed
 192                  * Because the ROM Code is based on the r1pX GIC, the CPU1
 193                  * GIC restoration will cause a problem to CPU0 Non-Secure SW.
 194                  * The workaround must be:
 195                  * 1) Before doing the CPU1 wakeup, CPU0 must disable
 196                  * the GIC distributor
 197                  * 2) CPU1 must re-enable the GIC distributor on
 198                  * it's wakeup path.
 199                  */
 200                 if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD)) {
 201                         local_irq_disable();
 202                         gic_dist_disable();
 203                 }
 204
 205                 /*
 206                  * Ensure that CPU power state is set to ON to avoid CPU
 207                  * powerdomain transition on wfi
 208                  */
 209                 clkdm_deny_idle_nolock(cpu1_clkdm);
 210                 pwrdm_set_next_pwrst(cpu1_pwrdm, PWRDM_POWER_ON);
 211                 clkdm_allow_idle_nolock(cpu1_clkdm);
 212
 213                 if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD)) {
 214                         while (gic_dist_disabled()) {
 215                                 udelay(1);
 216                                 cpu_relax();
 217                         }
 218                         gic_timer_retrigger();
 219                         local_irq_enable();
 220                 }
 221         } else {
 222                 dsb_sev();
 223                 booted = true;
 224         }
 225
 226         arch_send_wakeup_ipi_mask(cpumask_of(cpu));
 227
 228         /*
 229          * Now the secondary core is starting up let it run its
 230          * calibrations, then wait for it to finish
 231          */
 232         spin_unlock(&boot_lock);
 233
 234         return 0;
 235 }
 236
 237 /*
 238  * Initialise the CPU possible map early - this describes the CPUs
 239  * which may be present or become present in the system.
 240  */
 241 static void __init omap4_smp_init_cpus(void)
 242 {
 243         unsigned int i = 0, ncores = 1, cpu_id;
 244
 245         /* Use ARM cpuid check here, as SoC detection will not work so early */
 246         cpu_id = read_cpuid_id() & CPU_MASK;
 247         if (cpu_id == CPU_CORTEX_A9) {
 248                 /*
 249                  * Currently we can't call ioremap here because
 250                  * SoC detection won't work until after init_early.
 251                  */
 252                 cfg.scu_base =  OMAP2_L4_IO_ADDRESS(scu_a9_get_base());
 253                 BUG_ON(!cfg.scu_base);
 254                 ncores = scu_get_core_count(cfg.scu_base);
 255         } else if (cpu_id == CPU_CORTEX_A15) {
 256                 ncores = OMAP5_CORE_COUNT;
 257         }
 258
 259         /* sanity check */
 260         if (ncores > nr_cpu_ids) {
 261                 pr_warn("SMP: %u cores greater than maximum (%u), clipping\n",
 262                         ncores, nr_cpu_ids);
 263                 ncores = nr_cpu_ids;
 264         }
 265
 266         for (i = 0; i < ncores; i++)
 267                 set_cpu_possible(i, true);
 268 }
 269
 270 /*
 271  * For now, just make sure the start-up address is not within the booting
 272  * kernel space as that means we just overwrote whatever secondary_startup()
 273  * code there was.
 274  */
 275 static bool __init omap4_smp_cpu1_startup_valid(unsigned long addr)
 276 {
 277         if ((addr >= __pa(PAGE_OFFSET)) && (addr <= __pa(__bss_start)))
 278                 return false;
 279
 280         return true;
 281 }
 282
 283 /*
 284  * We may need to reset CPU1 before configuring, otherwise kexec boot can end
 285  * up trying to use old kernel startup address or suspend-resume will
 286  * occasionally fail to bring up CPU1 on 4430 if CPU1 fails to enter deeper
 287  * idle states.
 288  */
 289 static void __init omap4_smp_maybe_reset_cpu1(struct omap_smp_config *c)
 290 {
 291         unsigned long cpu1_startup_pa, cpu1_ns_pa_addr;
 292         bool needs_reset = false;
 293         u32 released;
 294
 295         if (omap_secure_apis_support())
 296                 released = omap_read_auxcoreboot0() & AUX_CORE_BOOT0_HS_RELEASE;
 297         else
 298                 released = readl_relaxed(cfg.wakeupgen_base +
 299                                          OMAP_AUX_CORE_BOOT_0) &
 300                                                 AUX_CORE_BOOT0_GP_RELEASE;
 301         if (released) {
 302                 pr_warn("smp: CPU1 not parked?\n");
 303
 304                 return;
 305         }
 306
 307         cpu1_startup_pa = readl_relaxed(cfg.wakeupgen_base +
 308                                         OMAP_AUX_CORE_BOOT_1);
 309         cpu1_ns_pa_addr = omap4_get_cpu1_ns_pa_addr();
 310
 311         /* Did the configured secondary_startup() get overwritten? */
 312         if (!omap4_smp_cpu1_startup_valid(cpu1_startup_pa))
 313                 needs_reset = true;
 314
 315         /*
 316          * If omap4 or 5 has NS_PA_ADDR configured, CPU1 may be in a
 317          * deeper idle state in WFI and will wake to an invalid address.
 318          */
 319         if ((soc_is_omap44xx() || soc_is_omap54xx()) &&
 320             !omap4_smp_cpu1_startup_valid(cpu1_ns_pa_addr))
 321                 needs_reset = true;
 322
 323         if (!needs_reset || !c->cpu1_rstctrl_va)
 324                 return;
 325
 326         pr_info("smp: CPU1 parked within kernel, needs reset (0x%lx 0x%lx)\n",
 327                 cpu1_startup_pa, cpu1_ns_pa_addr);
 328
 329         writel_relaxed(1, c->cpu1_rstctrl_va);
 330         readl_relaxed(c->cpu1_rstctrl_va);
 331         writel_relaxed(0, c->cpu1_rstctrl_va);
 332 }
 333
 334 static void __init omap4_smp_prepare_cpus(unsigned int max_cpus)
 335 {
 336         const struct omap_smp_config *c = NULL;
 337
 338         if (soc_is_omap443x())
 339                 c = &omap443x_cfg;
 340         else if (soc_is_omap446x())
 341                 c = &omap446x_cfg;
 342         else if (soc_is_dra74x() || soc_is_omap54xx())
 343                 c = &omap5_cfg;
 344
 345         if (!c) {
 346                 pr_err("%s Unknown SMP SoC?\n", __func__);
 347                 return;
 348         }
 349
 350         /* Must preserve cfg.scu_base set earlier */
 351         cfg.cpu1_rstctrl_pa = c->cpu1_rstctrl_pa;
 352         cfg.startup_addr = c->startup_addr;
 353         cfg.wakeupgen_base = omap_get_wakeupgen_base();
 354
 355         if (soc_is_dra74x() || soc_is_omap54xx()) {
 356                 if ((__boot_cpu_mode & MODE_MASK) == HYP_MODE)
 357                         cfg.startup_addr = omap5_secondary_hyp_startup;
 358                 omap5_erratum_workaround_801819();
 359         }
 360
 361         cfg.cpu1_rstctrl_va = ioremap(cfg.cpu1_rstctrl_pa, 4);
 362         if (!cfg.cpu1_rstctrl_va)
 363                 return;
 364
 365         /*
 366          * Initialise the SCU and wake up the secondary core using
 367          * wakeup_secondary().
 368          */
 369         if (cfg.scu_base)
 370                 scu_enable(cfg.scu_base);
 371
 372         omap4_smp_maybe_reset_cpu1(&cfg);
 373
 374         /*
 375          * Write the address of secondary startup routine into the
 376          * AuxCoreBoot1 where ROM code will jump and start executing
 377          * on secondary core once out of WFE
 378          * A barrier is added to ensure that write buffer is drained
 379          */
 380         if (omap_secure_apis_support())
 381                 omap_auxcoreboot_addr(__pa_symbol(cfg.startup_addr));
 382         else
 383                 writel_relaxed(__pa_symbol(cfg.startup_addr),
 384                                cfg.wakeupgen_base + OMAP_AUX_CORE_BOOT_1);
 385 }
 386
 387 const struct smp_operations omap4_smp_ops __initconst = {
 388         .smp_init_cpus          = omap4_smp_init_cpus,
 389         .smp_prepare_cpus       = omap4_smp_prepare_cpus,
 390         .smp_secondary_init     = omap4_secondary_init,
 391         .smp_boot_secondary     = omap4_boot_secondary,
 392 #ifdef CONFIG_HOTPLUG_CPU
 393         .cpu_die                = omap4_cpu_die,
 394         .cpu_kill               = omap4_cpu_kill,
 395 #endif
 396 };