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
  26 #include "omap-secure.h"
  27 #include "omap-wakeupgen.h"
  28 #include <asm/cputype.h>
  29
  30 #include "soc.h"
  31 #include "iomap.h"
  32 #include "common.h"
  33 #include "clockdomain.h"
  34 #include "pm.h"
  35
  36 #define CPU_MASK                0xff0ffff0
  37 #define CPU_CORTEX_A9           0x410FC090
  38 #define CPU_CORTEX_A15          0x410FC0F0
  39
  40 #define OMAP5_CORE_COUNT        0x2
  41
  42 u16 pm44xx_errata;
  43
  44 /* SCU base address */
  45 static void __iomem *scu_base;
  46
  47 static DEFINE_SPINLOCK(boot_lock);
  48
  49 void __iomem *omap4_get_scu_base(void)
  50 {
  51         return scu_base;
  52 }
  53
  54 static void omap4_secondary_init(unsigned int cpu)
  55 {
  56         /*
  57          * Configure ACTRL and enable NS SMP bit access on CPU1 on HS device.
  58          * OMAP44XX EMU/HS devices - CPU0 SMP bit access is enabled in PPA
  59          * init and for CPU1, a secure PPA API provided. CPU0 must be ON
  60          * while executing NS_SMP API on CPU1 and PPA version must be 1.4.0+.
  61          * OMAP443X GP devices- SMP bit isn't accessible.
  62          * OMAP446X GP devices - SMP bit access is enabled on both CPUs.
  63          */
  64         if (cpu_is_omap443x() && (omap_type() != OMAP2_DEVICE_TYPE_GP))
  65                 omap_secure_dispatcher(OMAP4_PPA_CPU_ACTRL_SMP_INDEX,
  66                                                         4, 0, 0, 0, 0, 0);
  67
  68         /*
  69          * Synchronise with the boot thread.
  70          */
  71         spin_lock(&boot_lock);
  72         spin_unlock(&boot_lock);
  73 }
  74
  75 static int omap4_boot_secondary(unsigned int cpu, struct task_struct *idle)
  76 {
  77         static struct clockdomain *cpu1_clkdm;
  78         static bool booted;
  79         static struct powerdomain *cpu1_pwrdm;
  80         void __iomem *base = omap_get_wakeupgen_base();
  81
  82         /*
  83          * Set synchronisation state between this boot processor
  84          * and the secondary one
  85          */
  86         spin_lock(&boot_lock);
  87
  88         /*
  89          * Update the AuxCoreBoot0 with boot state for secondary core.
  90          * omap4_secondary_startup() routine will hold the secondary core till
  91          * the AuxCoreBoot1 register is updated with cpu state
  92          * A barrier is added to ensure that write buffer is drained
  93          */
  94         if (omap_secure_apis_support())
  95                 omap_modify_auxcoreboot0(0x200, 0xfffffdff);
  96         else
  97                 __raw_writel(0x20, base + OMAP_AUX_CORE_BOOT_0);
  98
  99         if (!cpu1_clkdm && !cpu1_pwrdm) {
 100                 cpu1_clkdm = clkdm_lookup("mpu1_clkdm");
 101                 cpu1_pwrdm = pwrdm_lookup("cpu1_pwrdm");
 102         }
 103
 104         /*
 105          * The SGI(Software Generated Interrupts) are not wakeup capable
 106          * from low power states. This is known limitation on OMAP4 and
 107          * needs to be worked around by using software forced clockdomain
 108          * wake-up. To wakeup CPU1, CPU0 forces the CPU1 clockdomain to
 109          * software force wakeup. The clockdomain is then put back to
 110          * hardware supervised mode.
 111          * More details can be found in OMAP4430 TRM - Version J
 112          * Section :
 113          *      4.3.4.2 Power States of CPU0 and CPU1
 114          */
 115         if (booted && cpu1_pwrdm && cpu1_clkdm) {
 116                 /*
 117                  * GIC distributor control register has changed between
 118                  * CortexA9 r1pX and r2pX. The Control Register secure
 119                  * banked version is now composed of 2 bits:
 120                  * bit 0 == Secure Enable
 121                  * bit 1 == Non-Secure Enable
 122                  * The Non-Secure banked register has not changed
 123                  * Because the ROM Code is based on the r1pX GIC, the CPU1
 124                  * GIC restoration will cause a problem to CPU0 Non-Secure SW.
 125                  * The workaround must be:
 126                  * 1) Before doing the CPU1 wakeup, CPU0 must disable
 127                  * the GIC distributor
 128                  * 2) CPU1 must re-enable the GIC distributor on
 129                  * it's wakeup path.
 130                  */
 131                 if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD)) {
 132                         local_irq_disable();
 133                         gic_dist_disable();
 134                 }
 135
 136                 /*
 137                  * Ensure that CPU power state is set to ON to avoid CPU
 138                  * powerdomain transition on wfi
 139                  */
 140                 clkdm_wakeup(cpu1_clkdm);
 141                 omap_set_pwrdm_state(cpu1_pwrdm, PWRDM_POWER_ON);
 142                 clkdm_allow_idle(cpu1_clkdm);
 143
 144                 if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD)) {
 145                         while (gic_dist_disabled()) {
 146                                 udelay(1);
 147                                 cpu_relax();
 148                         }
 149                         gic_timer_retrigger();
 150                         local_irq_enable();
 151                 }
 152         } else {
 153                 dsb_sev();
 154                 booted = true;
 155         }
 156
 157         arch_send_wakeup_ipi_mask(cpumask_of(cpu));
 158
 159         /*
 160          * Now the secondary core is starting up let it run its
 161          * calibrations, then wait for it to finish
 162          */
 163         spin_unlock(&boot_lock);
 164
 165         return 0;
 166 }
 167
 168 /*
 169  * Initialise the CPU possible map early - this describes the CPUs
 170  * which may be present or become present in the system.
 171  */
 172 static void __init omap4_smp_init_cpus(void)
 173 {
 174         unsigned int i = 0, ncores = 1, cpu_id;
 175
 176         /* Use ARM cpuid check here, as SoC detection will not work so early */
 177         cpu_id = read_cpuid_id() & CPU_MASK;
 178         if (cpu_id == CPU_CORTEX_A9) {
 179                 /*
 180                  * Currently we can't call ioremap here because
 181                  * SoC detection won't work until after init_early.
 182                  */
 183                 scu_base =  OMAP2_L4_IO_ADDRESS(scu_a9_get_base());
 184                 BUG_ON(!scu_base);
 185                 ncores = scu_get_core_count(scu_base);
 186         } else if (cpu_id == CPU_CORTEX_A15) {
 187                 ncores = OMAP5_CORE_COUNT;
 188         }
 189
 190         /* sanity check */
 191         if (ncores > nr_cpu_ids) {
 192                 pr_warn("SMP: %u cores greater than maximum (%u), clipping\n",
 193                         ncores, nr_cpu_ids);
 194                 ncores = nr_cpu_ids;
 195         }
 196
 197         for (i = 0; i < ncores; i++)
 198                 set_cpu_possible(i, true);
 199 }
 200
 201 static void __init omap4_smp_prepare_cpus(unsigned int max_cpus)
 202 {
 203         void *startup_addr = omap4_secondary_startup;
 204         void __iomem *base = omap_get_wakeupgen_base();
 205
 206         /*
 207          * Initialise the SCU and wake up the secondary core using
 208          * wakeup_secondary().
 209          */
 210         if (scu_base)
 211                 scu_enable(scu_base);
 212
 213         if (cpu_is_omap446x()) {
 214                 startup_addr = omap4460_secondary_startup;
 215                 pm44xx_errata |= PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD;
 216         }
 217
 218         /*
 219          * Write the address of secondary startup routine into the
 220          * AuxCoreBoot1 where ROM code will jump and start executing
 221          * on secondary core once out of WFE
 222          * A barrier is added to ensure that write buffer is drained
 223          */
 224         if (omap_secure_apis_support())
 225                 omap_auxcoreboot_addr(virt_to_phys(startup_addr));
 226         else
 227                 __raw_writel(virt_to_phys(omap5_secondary_startup),
 228                                                 base + OMAP_AUX_CORE_BOOT_1);
 229
 230 }
 231
 232 struct smp_operations omap4_smp_ops __initdata = {
 233         .smp_init_cpus          = omap4_smp_init_cpus,
 234         .smp_prepare_cpus       = omap4_smp_prepare_cpus,
 235         .smp_secondary_init     = omap4_secondary_init,
 236         .smp_boot_secondary     = omap4_boot_secondary,
 237 #ifdef CONFIG_HOTPLUG_CPU
 238         .cpu_die                = omap4_cpu_die,
 239 #endif
 240 };