/* * OMAP4 SMP source file. It contains platform specific fucntions * needed for the linux smp kernel. * * Copyright (C) 2009 Texas Instruments, Inc. * * Author: * Santosh Shilimkar * * Platform file needed for the OMAP4 SMP. This file is based on arm * realview smp platform. * * Copyright (c) 2002 ARM Limited. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include #include #include #include #include #include #include #include #include #include "iomap.h" #include "common.h" #include "clockdomain.h" /* SCU base address */ static void __iomem *scu_base; static DEFINE_RAW_SPINLOCK(boot_lock); void __iomem *omap4_get_scu_base(void) { return scu_base; } void __cpuinit platform_secondary_init(unsigned int cpu) { /* * Configure ACTRL and enable NS SMP bit access on CPU1 on HS device. * OMAP44XX EMU/HS devices - CPU0 SMP bit access is enabled in PPA * init and for CPU1, a secure PPA API provided. CPU0 must be ON * while executing NS_SMP API on CPU1 and PPA version must be 1.4.0+. * OMAP443X GP devices- SMP bit isn't accessible. * OMAP446X GP devices - SMP bit access is enabled on both CPUs. */ if (cpu_is_omap443x() && (omap_type() != OMAP2_DEVICE_TYPE_GP)) omap_secure_dispatcher(OMAP4_PPA_CPU_ACTRL_SMP_INDEX, 4, 0, 0, 0, 0, 0); /* * If any interrupts are already enabled for the primary * core (e.g. timer irq), then they will not have been enabled * for us: do so */ gic_secondary_init(0); /* * Synchronise with the boot thread. */ raw_spin_lock(&boot_lock); raw_spin_unlock(&boot_lock); } int __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle) { static struct clockdomain *cpu1_clkdm; static bool booted; /* * Set synchronisation state between this boot processor * and the secondary one */ raw_spin_lock(&boot_lock); /* * Update the AuxCoreBoot0 with boot state for secondary core. * omap_secondary_startup() routine will hold the secondary core till * the AuxCoreBoot1 register is updated with cpu state * A barrier is added to ensure that write buffer is drained */ omap_modify_auxcoreboot0(0x200, 0xfffffdff); flush_cache_all(); smp_wmb(); if (!cpu1_clkdm) cpu1_clkdm = clkdm_lookup("mpu1_clkdm"); /* * The SGI(Software Generated Interrupts) are not wakeup capable * from low power states. This is known limitation on OMAP4 and * needs to be worked around by using software forced clockdomain * wake-up. To wakeup CPU1, CPU0 forces the CPU1 clockdomain to * software force wakeup. The clockdomain is then put back to * hardware supervised mode. * More details can be found in OMAP4430 TRM - Version J * Section : * 4.3.4.2 Power States of CPU0 and CPU1 */ if (booted) { clkdm_wakeup(cpu1_clkdm); clkdm_allow_idle(cpu1_clkdm); } else { dsb_sev(); booted = true; } gic_raise_softirq(cpumask_of(cpu), 1); /* * Now the secondary core is starting up let it run its * calibrations, then wait for it to finish */ raw_spin_unlock(&boot_lock); return 0; } static void __init wakeup_secondary(void) { /* * Write the address of secondary startup routine into the * AuxCoreBoot1 where ROM code will jump and start executing * on secondary core once out of WFE * A barrier is added to ensure that write buffer is drained */ omap_auxcoreboot_addr(virt_to_phys(omap_secondary_startup)); smp_wmb(); /* * Send a 'sev' to wake the secondary core from WFE. * Drain the outstanding writes to memory */ dsb_sev(); mb(); } /* * Initialise the CPU possible map early - this describes the CPUs * which may be present or become present in the system. */ void __init smp_init_cpus(void) { unsigned int i, ncores; /* * Currently we can't call ioremap here because * SoC detection won't work until after init_early. */ scu_base = OMAP2_L4_IO_ADDRESS(OMAP44XX_SCU_BASE); BUG_ON(!scu_base); ncores = scu_get_core_count(scu_base); /* sanity check */ if (ncores > nr_cpu_ids) { pr_warn("SMP: %u cores greater than maximum (%u), clipping\n", ncores, nr_cpu_ids); ncores = nr_cpu_ids; } for (i = 0; i < ncores; i++) set_cpu_possible(i, true); set_smp_cross_call(gic_raise_softirq); } void __init platform_smp_prepare_cpus(unsigned int max_cpus) { /* * Initialise the SCU and wake up the secondary core using * wakeup_secondary(). */ scu_enable(scu_base); wakeup_secondary(); }