diff options
Diffstat (limited to 'arch/arm/mach-ux500/platsmp.c')
| -rw-r--r-- | arch/arm/mach-ux500/platsmp.c | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/arch/arm/mach-ux500/platsmp.c b/arch/arm/mach-ux500/platsmp.c new file mode 100644 index 00000000000..8dfe7ca245d --- /dev/null +++ b/arch/arm/mach-ux500/platsmp.c @@ -0,0 +1,177 @@ +/* + * Copyright (C) 2002 ARM Ltd. + * Copyright (C) 2008 STMicroelctronics. + * Copyright (C) 2009 ST-Ericsson. + * Author: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com> + * + * This file is based on arm realview platform + * + * 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/smp.h> +#include <linux/io.h> + +#include <asm/cacheflush.h> +#include <asm/localtimer.h> +#include <asm/smp_scu.h> +#include <mach/hardware.h> + +/* + * control for which core is the next to come out of the secondary + * boot "holding pen" + */ +volatile int __cpuinitdata pen_release = -1; + +static unsigned int __init get_core_count(void) +{ + return scu_get_core_count(__io_address(U8500_SCU_BASE)); +} + +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, __io_address(U8500_GIC_CPU_BASE)); + + /* + * 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. + */ + pen_release = cpu; + flush_cache_all(); + + timeout = jiffies + (1 * HZ); + while (time_before(jiffies, timeout)) { + if (pen_release == -1) + break; + } + + /* + * 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 wakeup_secondary(void) +{ + /* nobody is to be released from the pen yet */ + pen_release = -1; + + /* + * write the address of secondary startup into the backup ram register + * at offset 0x1FF4, then write the magic number 0xA1FEED01 to the + * backup ram register at offset 0x1FF0, which is what boot rom code + * is waiting for. This would wake up the secondary core from WFE + */ +#define U8500_CPU1_JUMPADDR_OFFSET 0x1FF4 + __raw_writel(virt_to_phys(u8500_secondary_startup), + (void __iomem *)IO_ADDRESS(U8500_BACKUPRAM0_BASE) + + U8500_CPU1_JUMPADDR_OFFSET); + +#define U8500_CPU1_WAKEMAGIC_OFFSET 0x1FF0 + __raw_writel(0xA1FEED01, + (void __iomem *)IO_ADDRESS(U8500_BACKUPRAM0_BASE) + + U8500_CPU1_WAKEMAGIC_OFFSET); + + /* make sure write buffer is drained */ + 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 + "U8500: strange CM count of 0? Default to 1\n"); + ncores = 1; + } + + if (ncores > num_possible_cpus()) { + printk(KERN_WARNING + "U8500: no. of cores (%d) greater than configured " + "maximum of %d - clipping\n", + ncores, num_possible_cpus()); + ncores = num_possible_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); + + 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(__io_address(U8500_SCU_BASE)); + wakeup_secondary(); + } +} |