diff options
Diffstat (limited to 'arch/arm/mach-sti/platsmp.c')
-rw-r--r-- | arch/arm/mach-sti/platsmp.c | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/arch/arm/mach-sti/platsmp.c b/arch/arm/mach-sti/platsmp.c new file mode 100644 index 00000000000..dce50d983a8 --- /dev/null +++ b/arch/arm/mach-sti/platsmp.c @@ -0,0 +1,117 @@ +/* + * arch/arm/mach-sti/platsmp.c + * + * Copyright (C) 2013 STMicroelectronics (R&D) Limited. + * http://www.st.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/smp.h> +#include <linux/io.h> +#include <linux/of.h> +#include <linux/of_address.h> + +#include <asm/cacheflush.h> +#include <asm/smp_plat.h> +#include <asm/smp_scu.h> + +#include "smp.h" + +static void write_pen_release(int val) +{ + pen_release = val; + smp_wmb(); + __cpuc_flush_dcache_area((void *)&pen_release, sizeof(pen_release)); + outer_clean_range(__pa(&pen_release), __pa(&pen_release + 1)); +} + +static DEFINE_SPINLOCK(boot_lock); + +void sti_secondary_init(unsigned int cpu) +{ + trace_hardirqs_off(); + + /* + * let the primary processor know we're out of the + * pen, then head off into the C entry point + */ + write_pen_release(-1); + + /* + * Synchronise with the boot thread. + */ + spin_lock(&boot_lock); + spin_unlock(&boot_lock); +} + +int sti_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. + */ + write_pen_release(cpu_logical_map(cpu)); + + /* + * Send the secondary CPU a soft interrupt, thereby causing + * it to jump to the secondary entrypoint. + */ + arch_send_wakeup_ipi_mask(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; +} + +void __init sti_smp_prepare_cpus(unsigned int max_cpus) +{ + void __iomem *scu_base = NULL; + struct device_node *np = of_find_compatible_node( + NULL, NULL, "arm,cortex-a9-scu"); + if (np) { + scu_base = of_iomap(np, 0); + scu_enable(scu_base); + of_node_put(np); + } +} + +struct smp_operations __initdata sti_smp_ops = { + .smp_prepare_cpus = sti_smp_prepare_cpus, + .smp_secondary_init = sti_secondary_init, + .smp_boot_secondary = sti_boot_secondary, +}; |