diff options
Diffstat (limited to 'arch/arm/mach-s5pv310/platsmp.c')
| -rw-r--r-- | arch/arm/mach-s5pv310/platsmp.c | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/arch/arm/mach-s5pv310/platsmp.c b/arch/arm/mach-s5pv310/platsmp.c new file mode 100644 index 00000000000..fe9469abd00 --- /dev/null +++ b/arch/arm/mach-s5pv310/platsmp.c @@ -0,0 +1,192 @@ +/* linux/arch/arm/mach-s5pv310/platsmp.c + * + * Copyright (c) 2010 Samsung Electronics Co., Ltd. + * http://www.samsung.com/ + * + * Cloned from linux/arch/arm/mach-vexpress/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/errno.h> +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/jiffies.h> +#include <linux/smp.h> +#include <linux/io.h> + +#include <asm/cacheflush.h> +#include <asm/localtimer.h> +#include <asm/smp_scu.h> +#include <asm/unified.h> + +#include <mach/hardware.h> +#include <mach/regs-clock.h> + +extern void s5pv310_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; + +static void __iomem *scu_base_addr(void) +{ + return (void __iomem *)(S5P_VA_SCU); +} + +static DEFINE_SPINLOCK(boot_lock); + +void __cpuinit platform_secondary_init(unsigned int cpu) +{ + trace_hardirqs_off(); + + /* + * 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_cpu_init(0, gic_cpu_base_addr); + + /* + * let the primary processor know we're out of the + * pen, then head off into the C entry point + */ + pen_release = -1; + smp_wmb(); + + /* + * 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; + __cpuc_flush_dcache_area((void *)&pen_release, sizeof(pen_release)); + outer_clean_range(__pa(&pen_release), __pa(&pen_release + 1)); + + /* + * Send the secondary CPU a soft interrupt, thereby causing + * the boot monitor to read the system wide flags register, + * and branch to the address found there. + */ + smp_cross_call(cpumask_of(cpu)); + + timeout = jiffies + (1 * HZ); + while (time_before(jiffies, timeout)) { + smp_rmb(); + 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; +} + +/* + * 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) +{ + void __iomem *scu_base = scu_base_addr(); + unsigned int i, ncores; + + ncores = scu_base ? scu_get_core_count(scu_base) : 1; + + /* sanity check */ + if (ncores == 0) { + printk(KERN_ERR + "S5PV310: strange CM count of 0? Default to 1\n"); + + ncores = 1; + } + + if (ncores > NR_CPUS) { + printk(KERN_WARNING + "S5PV310: no. of cores (%d) greater than configured " + "maximum of %d - clipping\n", + ncores, NR_CPUS); + ncores = NR_CPUS; + } + + for (i = 0; i < ncores; i++) + set_cpu_possible(i, true); +} + +void __init smp_prepare_cpus(unsigned int max_cpus) +{ + unsigned int ncores = num_possible_cpus(); + unsigned int cpu = smp_processor_id(); + int i; + + smp_store_cpu_info(cpu); + + /* are we trying to boot more cores than exist? */ + if (max_cpus > ncores) + max_cpus = ncores; + + /* + * Initialise the present map, which describes the set of CPUs + * actually populated at the present time. + */ + for (i = 0; i < max_cpus; i++) + set_cpu_present(i, true); + + /* + * Initialise the SCU if there are more than one CPU and let + * them know where to start. + */ + if (max_cpus > 1) { + /* + * Enable the local timer or broadcast device for the + * boot CPU, but only if we have more than one CPU. + */ + percpu_timer_setup(); + + scu_enable(scu_base_addr()); + + /* + * Write the address of secondary startup into the + * system-wide flags register. The boot monitor waits + * until it receives a soft interrupt, and then the + * secondary CPU branches to this address. + */ + __raw_writel(BSYM(virt_to_phys(s5pv310_secondary_startup)), S5P_INFORM0); + } +} |