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Diffstat (limited to 'arch/arm/mach-wmt/platsmp.c')
| -rwxr-xr-x | arch/arm/mach-wmt/platsmp.c | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/arch/arm/mach-wmt/platsmp.c b/arch/arm/mach-wmt/platsmp.c new file mode 100755 index 00000000..4f781017 --- /dev/null +++ b/arch/arm/mach-wmt/platsmp.c @@ -0,0 +1,202 @@ +/*++ + linux/arch/arm/mach-wmt/platsmp.c + + Copyright (c) 2013 WonderMedia Technologies, Inc. + + 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 as published by the Free Software Foundation, + either version 2 of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, but WITHOUT + ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A + PARTICULAR PURPOSE. See the GNU General Public License for more details. + You should have received a copy of the GNU General Public License along with + this program. If not, see <http://www.gnu.org/licenses/>. + + WonderMedia Technologies, Inc. + 10F, 529, Chung-Cheng Road, Hsin-Tien, Taipei 231, R.O.C. +--*/ +#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 <linux/syscore_ops.h> + +#include <asm/cacheflush.h> +#include <asm/hardware/gic.h> +#include <asm/smp_plat.h> +#include <asm/smp_scu.h> + +#include <mach/hardware.h> + +extern void wmt_secondary_startup(void); + +#define CPU1_BOOT_REG HSP7_ADDR +/* + * control for which core is the next to come out of the secondary + * boot "holding pen" + */ + +volatile int __cpuinitdata pen_release = -1; + +/* + * Write pen_release in a way that is guaranteed to be visible to all + * observers, irrespective of whether they're taking part in coherency + * or not. This is necessary for the hotplug code to work reliably. + */ +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 void __iomem *scu_base_addr(void) +{ + return (void __iomem *)(MPCORE_PRIVATE_MEM); +} + +static DEFINE_SPINLOCK(boot_lock); + +void __cpuinit platform_secondary_init(unsigned int 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 + */ + gic_secondary_init(0); + + /* + * 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 __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); + + /* + * This is really belt and braces; we hold unintended secondary + * CPUs in the holding pen until we're ready for them. However, + * since we haven't sent them a soft interrupt, they shouldn't + * be there. + */ + write_pen_release(cpu_logical_map(cpu)); + + /* + * 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. + */ + + timeout = jiffies + (1 * HZ); + while (time_before(jiffies, timeout)) { + smp_rmb(); + + __raw_writel(virt_to_phys(wmt_secondary_startup), + CPU1_BOOT_REG); + gic_raise_softirq(cpumask_of(cpu), 1); + + 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 > nr_cpu_ids) { + pr_warn("SMP: %u cores greater than maximum (%u), clipping\n", + ncores, nr_cpu_ids); + ncores = nr_cpu_ids; + } + + for (i = 0; i < ncores; i++) + set_cpu_possible(i, true); + + set_smp_cross_call(gic_raise_softirq); +} + +void __init platform_smp_prepare_cpus(unsigned int max_cpus) +{ + *(volatile unsigned int *)MPCORE_PRIVATE_MEM |= BIT5 | BIT6; + 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(virt_to_phys(wmt_secondary_startup), + CPU1_BOOT_REG); +} + +static int wmt_pm_suspend(void) +{ + return 0; +} + +static void wmt_pm_resume(void) +{ +#ifdef CONFIG_SMP + *(volatile unsigned int *)MPCORE_PRIVATE_MEM |= BIT5 | BIT6; + scu_enable(scu_base_addr()); +#endif + return; +} + +static struct syscore_ops wmt_pm_syscore_ops = { + .suspend = wmt_pm_suspend, + .resume = wmt_pm_resume, +}; + +static __init int wmt_pm_syscore_init(void) +{ + register_syscore_ops(&wmt_pm_syscore_ops); + return 0; +} +arch_initcall(wmt_pm_syscore_init); |