/* * linux/arch/arm/mach-cintegrator/platsmp.c * * Copyright (C) 2002 ARM Ltd. * All Rights Reserved * * 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 <linux/init.h> #include <linux/kernel.h> #include <linux/sched.h> #include <linux/errno.h> #include <linux/mm.h> #include <asm/atomic.h> #include <asm/cacheflush.h> #include <asm/delay.h> #include <asm/mmu_context.h> #include <asm/procinfo.h> #include <asm/ptrace.h> #include <asm/smp.h> extern void integrator_secondary_startup(void); /* * control for which core is the next to come out of the secondary * boot "holding pen" */ volatile int __cpuinitdata pen_release = -1; unsigned long __cpuinitdata phys_pen_release = 0; static DEFINE_SPINLOCK(boot_lock); void __cpuinit platform_secondary_init(unsigned int cpu) { /* * the primary core may have used a "cross call" soft interrupt * to get this processor out of WFI in the BootMonitor - make * sure that we are no longer being sent this soft interrupt */ smp_cross_call_done(cpumask_of_cpu(cpu)); /* * 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 */ secondary_scan_irqs(); /* * let the primary processor know we're out of the * pen, then head off into the C entry point */ pen_release = -1; /* * Synchronise with the boot thread. */ spin_lock(&boot_lock); spin_unlock(&boot_lock); } int __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle) { unsigned long timeout; /* * set synchronisation state between this boot processor * and the secondary one */ spin_lock(&boot_lock); /* * The secondary processor is waiting to be released from * the holding pen - release it, then wait for it to flag * that it has been released by resetting pen_release. * * Note that "pen_release" is the hardware CPU ID, whereas * "cpu" is Linux's internal ID. */ pen_release = cpu; flush_cache_all(); /* * XXX * * This is a later addition to the booting protocol: the * bootMonitor now puts secondary cores into WFI, so * poke_milo() no longer gets the cores moving; we need * to send a soft interrupt to wake the secondary core. * Use smp_cross_call() for this, since there's little * point duplicating the code here */ smp_cross_call(cpumask_of_cpu(cpu)); timeout = jiffies + (1 * HZ); while (time_before(jiffies, timeout)) { if (pen_release == -1) break; udelay(10); } /* * now the secondary core is starting up let it run its * calibrations, then wait for it to finish */ spin_unlock(&boot_lock); return pen_release != -1 ? -ENOSYS : 0; } static void __init poke_milo(void) { extern void secondary_startup(void); /* nobody is to be released from the pen yet */ pen_release = -1; phys_pen_release = virt_to_phys(&pen_release); /* * write the address of secondary startup into the system-wide * flags register, then clear the bottom two bits, which is what * BootMonitor is waiting for */ #if 1 #define CINTEGRATOR_HDR_FLAGSS_OFFSET 0x30 __raw_writel(virt_to_phys(integrator_secondary_startup), (IO_ADDRESS(INTEGRATOR_HDR_BASE) + CINTEGRATOR_HDR_FLAGSS_OFFSET)); #define CINTEGRATOR_HDR_FLAGSC_OFFSET 0x34 __raw_writel(3, (IO_ADDRESS(INTEGRATOR_HDR_BASE) + CINTEGRATOR_HDR_FLAGSC_OFFSET)); #endif mb(); } void __init smp_prepare_cpus(unsigned int max_cpus) { unsigned int ncores = get_core_count(); unsigned int cpu = smp_processor_id(); int i; /* sanity check */ if (ncores == 0) { printk(KERN_ERR "Integrator/CP: strange CM count of 0? Default to 1\n"); ncores = 1; } if (ncores > NR_CPUS) { printk(KERN_WARNING "Integrator/CP: no. of cores (%d) greater than configured " "maximum of %d - clipping\n", ncores, NR_CPUS); ncores = NR_CPUS; } /* * start with some more config for the Boot CPU, now that * the world is a bit more alive (which was not the case * when smp_prepare_boot_cpu() was called) */ smp_store_cpu_info(cpu); /* * are we trying to boot more cores than exist? */ if (max_cpus > ncores) max_cpus = ncores; /* * Initialise the possible/present maps. * cpu_possible_map describes the set of CPUs which may be present * cpu_present_map describes the set of CPUs populated */ for (i = 0; i < max_cpus; i++) { cpu_set(i, cpu_possible_map); cpu_set(i, cpu_present_map); } /* * Do we need any more CPUs? If so, then let them know where * to start. Note that, on modern versions of MILO, the "poke" * doesn't actually do anything until each individual core is * sent a soft interrupt to get it out of WFI */ if (max_cpus > 1) poke_milo(); }