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/smp_scu.h>
  25 #include <asm/virt.h>
  26
  27 #include "omap-secure.h"
  28 #include "omap-wakeupgen.h"
  29 #include <asm/cputype.h>
  30
  31 #include "soc.h"
  32 #include "iomap.h"
  33 #include "common.h"
  34 #include "clockdomain.h"
  35 #include "pm.h"
  36
  37 #define CPU_MASK                0xff0ffff0
  38 #define CPU_CORTEX_A9           0x410FC090
  39 #define CPU_CORTEX_A15          0x410FC0F0
  40
  41 #define OMAP5_CORE_COUNT        0x2
  42
  43 /* SCU base address */
  44 static void __iomem *scu_base;
  45
  46 static DEFINE_SPINLOCK(boot_lock);
  47
  48 void __iomem *omap4_get_scu_base(void)
  49 {
  50         return scu_base;
  51 }
  52
  53 static void omap4_secondary_init(unsigned int cpu)
  54 {
  55         /*
  56          * Configure ACTRL and enable NS SMP bit access on CPU1 on HS device.
  57          * OMAP44XX EMU/HS devices - CPU0 SMP bit access is enabled in PPA
  58          * init and for CPU1, a secure PPA API provided. CPU0 must be ON
  59          * while executing NS_SMP API on CPU1 and PPA version must be 1.4.0+.
  60          * OMAP443X GP devices- SMP bit isn't accessible.
  61          * OMAP446X GP devices - SMP bit access is enabled on both CPUs.
  62          */
  63         if (cpu_is_omap443x() && (omap_type() != OMAP2_DEVICE_TYPE_GP))
  64                 omap_secure_dispatcher(OMAP4_PPA_CPU_ACTRL_SMP_INDEX,
  65                                                         4, 0, 0, 0, 0, 0);
  66
  67         /*
  68          * Configure the CNTFRQ register for the secondary cpu's which
  69          * indicates the frequency of the cpu local timers.
  70          */
  71         if (soc_is_omap54xx() || soc_is_dra7xx())
  72                 set_cntfreq();
  73
  74         /*
  75          * Synchronise with the boot thread.
  76          */
  77         spin_lock(&boot_lock);
  78         spin_unlock(&boot_lock);
  79 }
  80
  81 static int omap4_boot_secondary(unsigned int cpu, struct task_struct *idle)
  82 {
  83         static struct clockdomain *cpu1_clkdm;
  84         static bool booted;
  85         static struct powerdomain *cpu1_pwrdm;
  86         void __iomem *base = omap_get_wakeupgen_base();
  87
  88         /*
  89          * Set synchronisation state between this boot processor
  90          * and the secondary one
  91          */
  92         spin_lock(&boot_lock);
  93
  94         /*
  95          * Update the AuxCoreBoot0 with boot state for secondary core.
  96          * omap4_secondary_startup() routine will hold the secondary core till
  97          * the AuxCoreBoot1 register is updated with cpu state
  98          * A barrier is added to ensure that write buffer is drained
  99          */
 100         if (omap_secure_apis_support())
 101                 omap_modify_auxcoreboot0(0x200, 0xfffffdff);
 102         else
 103                 writel_relaxed(0x20, base + OMAP_AUX_CORE_BOOT_0);
 104
 105         if (!cpu1_clkdm && !cpu1_pwrdm) {
 106                 cpu1_clkdm = clkdm_lookup("mpu1_clkdm");
 107                 cpu1_pwrdm = pwrdm_lookup("cpu1_pwrdm");
 108         }
 109
 110         /*
 111          * The SGI(Software Generated Interrupts) are not wakeup capable
 112          * from low power states. This is known limitation on OMAP4 and
 113          * needs to be worked around by using software forced clockdomain
 114          * wake-up. To wakeup CPU1, CPU0 forces the CPU1 clockdomain to
 115          * software force wakeup. The clockdomain is then put back to
 116          * hardware supervised mode.
 117          * More details can be found in OMAP4430 TRM - Version J
 118          * Section :
 119          *      4.3.4.2 Power States of CPU0 and CPU1
 120          */
 121         if (booted && cpu1_pwrdm && cpu1_clkdm) {
 122                 /*
 123                  * GIC distributor control register has changed between
 124                  * CortexA9 r1pX and r2pX. The Control Register secure
 125                  * banked version is now composed of 2 bits:
 126                  * bit 0 == Secure Enable
 127                  * bit 1 == Non-Secure Enable
 128                  * The Non-Secure banked register has not changed
 129                  * Because the ROM Code is based on the r1pX GIC, the CPU1
 130                  * GIC restoration will cause a problem to CPU0 Non-Secure SW.
 131                  * The workaround must be:
 132                  * 1) Before doing the CPU1 wakeup, CPU0 must disable
 133                  * the GIC distributor
 134                  * 2) CPU1 must re-enable the GIC distributor on
 135                  * it's wakeup path.
 136                  */
 137                 if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD)) {
 138                         local_irq_disable();
 139                         gic_dist_disable();
 140                 }
 141
 142                 /*
 143                  * Ensure that CPU power state is set to ON to avoid CPU
 144                  * powerdomain transition on wfi
 145                  */
 146                 clkdm_wakeup_nolock(cpu1_clkdm);
 147                 pwrdm_set_next_pwrst(cpu1_pwrdm, PWRDM_POWER_ON);
 148                 clkdm_allow_idle_nolock(cpu1_clkdm);
 149
 150                 if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD)) {
 151                         while (gic_dist_disabled()) {
 152                                 udelay(1);
 153                                 cpu_relax();
 154                         }
 155                         gic_timer_retrigger();
 156                         local_irq_enable();
 157                 }
 158         } else {
 159                 dsb_sev();
 160                 booted = true;
 161         }
 162
 163         arch_send_wakeup_ipi_mask(cpumask_of(cpu));
 164
 165         /*
 166          * Now the secondary core is starting up let it run its
 167          * calibrations, then wait for it to finish
 168          */
 169         spin_unlock(&boot_lock);
 170
 171         return 0;
 172 }
 173
 174 /*
 175  * Initialise the CPU possible map early - this describes the CPUs
 176  * which may be present or become present in the system.
 177  */
 178 static void __init omap4_smp_init_cpus(void)
 179 {
 180         unsigned int i = 0, ncores = 1, cpu_id;
 181
 182         /* Use ARM cpuid check here, as SoC detection will not work so early */
 183         cpu_id = read_cpuid_id() & CPU_MASK;
 184         if (cpu_id == CPU_CORTEX_A9) {
 185                 /*
 186                  * Currently we can't call ioremap here because
 187                  * SoC detection won't work until after init_early.
 188                  */
 189                 scu_base =  OMAP2_L4_IO_ADDRESS(scu_a9_get_base());
 190                 BUG_ON(!scu_base);
 191                 ncores = scu_get_core_count(scu_base);
 192         } else if (cpu_id == CPU_CORTEX_A15) {
 193                 ncores = OMAP5_CORE_COUNT;
 194         }
 195
 196         /* sanity check */
 197         if (ncores > nr_cpu_ids) {
 198                 pr_warn("SMP: %u cores greater than maximum (%u), clipping\n",
 199                         ncores, nr_cpu_ids);
 200                 ncores = nr_cpu_ids;
 201         }
 202
 203         for (i = 0; i < ncores; i++)
 204                 set_cpu_possible(i, true);
 205 }
 206
 207 static void __init omap4_smp_prepare_cpus(unsigned int max_cpus)
 208 {
 209         void *startup_addr = omap4_secondary_startup;
 210         void __iomem *base = omap_get_wakeupgen_base();
 211
 212         /*
 213          * Initialise the SCU and wake up the secondary core using
 214          * wakeup_secondary().
 215          */
 216         if (scu_base)
 217                 scu_enable(scu_base);
 218
 219         if (cpu_is_omap446x())
 220                 startup_addr = omap4460_secondary_startup;
 221
 222         /*
 223          * Write the address of secondary startup routine into the
 224          * AuxCoreBoot1 where ROM code will jump and start executing
 225          * on secondary core once out of WFE
 226          * A barrier is added to ensure that write buffer is drained
 227          */
 228         if (omap_secure_apis_support())
 229                 omap_auxcoreboot_addr(virt_to_phys(startup_addr));
 230         else
 231                 /*
 232                  * If the boot CPU is in HYP mode then start secondary
 233                  * CPU in HYP mode as well.
 234                  */
 235                 if ((__boot_cpu_mode & MODE_MASK) == HYP_MODE)
 236                         writel_relaxed(virt_to_phys(omap5_secondary_hyp_startup),
 237                                        base + OMAP_AUX_CORE_BOOT_1);
 238                 else
 239                         writel_relaxed(virt_to_phys(omap5_secondary_startup),
 240                                        base + OMAP_AUX_CORE_BOOT_1);
 241
 242 }
 243
 244 const struct smp_operations omap4_smp_ops __initconst = {
 245         .smp_init_cpus          = omap4_smp_init_cpus,
 246         .smp_prepare_cpus       = omap4_smp_prepare_cpus,
 247         .smp_secondary_init     = omap4_secondary_init,
 248         .smp_boot_secondary     = omap4_boot_secondary,
 249 #ifdef CONFIG_HOTPLUG_CPU
 250         .cpu_die                = omap4_cpu_die,
 251 #endif
 252 };