Russell King wrote: > > On Fri, Jul 16, 2010 at 05:58:28PM +0900, Kukjin Kim wrote: > > diff --git a/arch/arm/mach-s5pv310/platsmp.c b/arch/arm/mach- > s5pv310/platsmp.c > > new file mode 100644 > > index 0000000..9325ac2 > > --- /dev/null > > +++ b/arch/arm/mach-s5pv310/platsmp.c > > @@ -0,0 +1,212 @@ > > +/* linux/arch/arm/mach-s5pv310/platsmp.c > > + * > > + * Copyright (c) 2010 Samsung Electronics Co., Ltd. > > + * http://www.samsung.com/ > > + * > > + * Cloned from linux/arch/arm/mach-realview/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 <mach/hardware.h> > > +#include <asm/mach-types.h> > > +#include <asm/localtimer.h> > > +#include <asm/unified.h> > > + > > +#include <asm/smp_scu.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 inline unsigned int get_core_count(void) > > +{ > > + void __iomem *scu_base = scu_base_addr(); > > + if (scu_base) > > + return scu_get_core_count(scu_base); > > + return 1; > > +} > > + > > +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; > > + 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)); > > + > > + 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; > > +} > > + > > +static void __init poke_milo(void) > > +{ > > + /* nobody is to be released from the pen yet */ > > + pen_release = -1; > > + > > + /* > > + * Write the address of secondary startup into the system-wide flags > > + * register. The BootMonitor waits for this register to become > > + * non-zero. > > + */ > > + __raw_writel(BSYM(virt_to_phys(s5pv310_secondary_startup)), > S5P_INFORM0); > > + > > + 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 = get_core_count(); > > + > > + for (i = 0; i < ncores; i++) > > + set_cpu_possible(i, true); > > +} > > + > > +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 > > + "Realview: strange CM count of 0? Default to 1\n"); > > + > > + ncores = 1; > > + } > > + > > + if (ncores > NR_CPUS) { > > + printk(KERN_WARNING > > + "Realview: no. of cores (%d) greater than configured " > > + "maximum of %d - clipping\n", > > + ncores, NR_CPUS); > > + ncores = NR_CPUS; > > + } > > + > > + 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. 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) { > > + /* > > + * 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()); > > + poke_milo(); > > + } > > +} > > Please can you model this on the Versatile Express platsmp.c rather than > the Realview platsmp.c ? > Sure, will do it.
> The Realview platsmp.c implementation contains a lot of left-overs from > the initial Integrator-based SMP implementation which we really shouldn't > be carrying endlessly forward. Oh, I didn't know/check about that. Thanks for your information and inputs. Thanks. Best regards, Kgene. -- Kukjin Kim <kgene....@samsung.com>, Senior Engineer, SW Solution Development Team, Samsung Electronics Co., Ltd. -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
