diff options
Diffstat (limited to 'arch/powerpc/platforms/chrp/smp.c')
| -rw-r--r-- | arch/powerpc/platforms/chrp/smp.c | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/chrp/smp.c b/arch/powerpc/platforms/chrp/smp.c new file mode 100644 index 00000000000..31ee49c2501 --- /dev/null +++ b/arch/powerpc/platforms/chrp/smp.c @@ -0,0 +1,122 @@ +/* + * Smp support for CHRP machines. + * + * Written by Cort Dougan (cort@cs.nmt.edu) borrowing a great + * deal of code from the sparc and intel versions. + * + * Copyright (C) 1999 Cort Dougan <cort@cs.nmt.edu> + * + */ + +#include <linux/config.h> +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/smp.h> +#include <linux/smp_lock.h> +#include <linux/interrupt.h> +#include <linux/kernel_stat.h> +#include <linux/delay.h> +#include <linux/init.h> +#include <linux/spinlock.h> + +#include <asm/ptrace.h> +#include <asm/atomic.h> +#include <asm/irq.h> +#include <asm/page.h> +#include <asm/pgtable.h> +#include <asm/sections.h> +#include <asm/io.h> +#include <asm/prom.h> +#include <asm/smp.h> +#include <asm/residual.h> +#include <asm/time.h> +#include <asm/open_pic.h> +#include <asm/machdep.h> +#include <asm/smp.h> +#include <asm/mpic.h> + +extern unsigned long smp_chrp_cpu_nr; + +static int __init smp_chrp_probe(void) +{ + struct device_node *cpus = NULL; + unsigned int *reg; + int reglen; + int ncpus = 0; + int cpuid; + unsigned int phys; + + /* Count CPUs in the device-tree */ + cpuid = 1; /* the boot cpu is logical cpu 0 */ + while ((cpus = of_find_node_by_type(cpus, "cpu")) != NULL) { + phys = ncpus; + reg = (unsigned int *) get_property(cpus, "reg", ®len); + if (reg && reglen >= sizeof(unsigned int)) + /* hmmm, not having a reg property would be bad */ + phys = *reg; + if (phys != boot_cpuid_phys) { + set_hard_smp_processor_id(cpuid, phys); + ++cpuid; + } + ++ncpus; + } + + printk(KERN_INFO "CHRP SMP probe found %d cpus\n", ncpus); + + /* Nothing more to do if less than 2 of them */ + if (ncpus <= 1) + return 1; + + mpic_request_ipis(); + + return ncpus; +} + +static void __devinit smp_chrp_kick_cpu(int nr) +{ + *(unsigned long *)KERNELBASE = nr; + asm volatile("dcbf 0,%0"::"r"(KERNELBASE):"memory"); +} + +static void __devinit smp_chrp_setup_cpu(int cpu_nr) +{ + mpic_setup_this_cpu(); +} + +static DEFINE_SPINLOCK(timebase_lock); +static unsigned int timebase_upper = 0, timebase_lower = 0; + +void __devinit smp_chrp_give_timebase(void) +{ + spin_lock(&timebase_lock); + rtas_call(rtas_token("freeze-time-base"), 0, 1, NULL); + timebase_upper = get_tbu(); + timebase_lower = get_tbl(); + spin_unlock(&timebase_lock); + + while (timebase_upper || timebase_lower) + barrier(); + rtas_call(rtas_token("thaw-time-base"), 0, 1, NULL); +} + +void __devinit smp_chrp_take_timebase(void) +{ + while (!(timebase_upper || timebase_lower)) + barrier(); + spin_lock(&timebase_lock); + set_tb(timebase_upper, timebase_lower); + timebase_upper = 0; + timebase_lower = 0; + spin_unlock(&timebase_lock); + printk("CPU %i taken timebase\n", smp_processor_id()); +} + +/* CHRP with openpic */ +struct smp_ops_t chrp_smp_ops = { + .message_pass = smp_mpic_message_pass, + .probe = smp_chrp_probe, + .kick_cpu = smp_chrp_kick_cpu, + .setup_cpu = smp_chrp_setup_cpu, + .give_timebase = smp_chrp_give_timebase, + .take_timebase = smp_chrp_take_timebase, +}; |