diff options
Diffstat (limited to 'kernel/arch/blackfin/mach-common/smp.c')
| -rw-r--r-- | kernel/arch/blackfin/mach-common/smp.c | 431 |
1 files changed, 431 insertions, 0 deletions
diff --git a/kernel/arch/blackfin/mach-common/smp.c b/kernel/arch/blackfin/mach-common/smp.c new file mode 100644 index 000000000..1c7259597 --- /dev/null +++ b/kernel/arch/blackfin/mach-common/smp.c @@ -0,0 +1,431 @@ +/* + * IPI management based on arch/arm/kernel/smp.c (Copyright 2002 ARM Limited) + * + * Copyright 2007-2009 Analog Devices Inc. + * Philippe Gerum <rpm@xenomai.org> + * + * Licensed under the GPL-2. + */ + +#include <linux/module.h> +#include <linux/delay.h> +#include <linux/init.h> +#include <linux/spinlock.h> +#include <linux/sched.h> +#include <linux/interrupt.h> +#include <linux/cache.h> +#include <linux/clockchips.h> +#include <linux/profile.h> +#include <linux/errno.h> +#include <linux/mm.h> +#include <linux/cpu.h> +#include <linux/smp.h> +#include <linux/cpumask.h> +#include <linux/seq_file.h> +#include <linux/irq.h> +#include <linux/slab.h> +#include <linux/atomic.h> +#include <asm/cacheflush.h> +#include <asm/irq_handler.h> +#include <asm/mmu_context.h> +#include <asm/pgtable.h> +#include <asm/pgalloc.h> +#include <asm/processor.h> +#include <asm/ptrace.h> +#include <asm/cpu.h> +#include <asm/time.h> +#include <linux/err.h> + +/* + * Anomaly notes: + * 05000120 - we always define corelock as 32-bit integer in L2 + */ +struct corelock_slot corelock __attribute__ ((__section__(".l2.bss"))); + +#ifdef CONFIG_ICACHE_FLUSH_L1 +unsigned long blackfin_iflush_l1_entry[NR_CPUS]; +#endif + +struct blackfin_initial_pda initial_pda_coreb; + +enum ipi_message_type { + BFIN_IPI_NONE, + BFIN_IPI_TIMER, + BFIN_IPI_RESCHEDULE, + BFIN_IPI_CALL_FUNC, + BFIN_IPI_CPU_STOP, +}; + +struct blackfin_flush_data { + unsigned long start; + unsigned long end; +}; + +void *secondary_stack; + +static struct blackfin_flush_data smp_flush_data; + +static DEFINE_SPINLOCK(stop_lock); + +/* A magic number - stress test shows this is safe for common cases */ +#define BFIN_IPI_MSGQ_LEN 5 + +/* Simple FIFO buffer, overflow leads to panic */ +struct ipi_data { + atomic_t count; + atomic_t bits; +}; + +static DEFINE_PER_CPU(struct ipi_data, bfin_ipi); + +static void ipi_cpu_stop(unsigned int cpu) +{ + spin_lock(&stop_lock); + printk(KERN_CRIT "CPU%u: stopping\n", cpu); + dump_stack(); + spin_unlock(&stop_lock); + + set_cpu_online(cpu, false); + + local_irq_disable(); + + while (1) + SSYNC(); +} + +static void ipi_flush_icache(void *info) +{ + struct blackfin_flush_data *fdata = info; + + /* Invalidate the memory holding the bounds of the flushed region. */ + blackfin_dcache_invalidate_range((unsigned long)fdata, + (unsigned long)fdata + sizeof(*fdata)); + + /* Make sure all write buffers in the data side of the core + * are flushed before trying to invalidate the icache. This + * needs to be after the data flush and before the icache + * flush so that the SSYNC does the right thing in preventing + * the instruction prefetcher from hitting things in cached + * memory at the wrong time -- it runs much further ahead than + * the pipeline. + */ + SSYNC(); + + /* ipi_flaush_icache is invoked by generic flush_icache_range, + * so call blackfin arch icache flush directly here. + */ + blackfin_icache_flush_range(fdata->start, fdata->end); +} + +/* Use IRQ_SUPPLE_0 to request reschedule. + * When returning from interrupt to user space, + * there is chance to reschedule */ +static irqreturn_t ipi_handler_int0(int irq, void *dev_instance) +{ + unsigned int cpu = smp_processor_id(); + + platform_clear_ipi(cpu, IRQ_SUPPLE_0); + return IRQ_HANDLED; +} + +DECLARE_PER_CPU(struct clock_event_device, coretmr_events); +void ipi_timer(void) +{ + int cpu = smp_processor_id(); + struct clock_event_device *evt = &per_cpu(coretmr_events, cpu); + evt->event_handler(evt); +} + +static irqreturn_t ipi_handler_int1(int irq, void *dev_instance) +{ + struct ipi_data *bfin_ipi_data; + unsigned int cpu = smp_processor_id(); + unsigned long pending; + unsigned long msg; + + platform_clear_ipi(cpu, IRQ_SUPPLE_1); + + smp_rmb(); + bfin_ipi_data = this_cpu_ptr(&bfin_ipi); + while ((pending = atomic_xchg(&bfin_ipi_data->bits, 0)) != 0) { + msg = 0; + do { + msg = find_next_bit(&pending, BITS_PER_LONG, msg + 1); + switch (msg) { + case BFIN_IPI_TIMER: + ipi_timer(); + break; + case BFIN_IPI_RESCHEDULE: + scheduler_ipi(); + break; + case BFIN_IPI_CALL_FUNC: + generic_smp_call_function_interrupt(); + break; + case BFIN_IPI_CPU_STOP: + ipi_cpu_stop(cpu); + break; + default: + goto out; + } + atomic_dec(&bfin_ipi_data->count); + } while (msg < BITS_PER_LONG); + + } +out: + return IRQ_HANDLED; +} + +static void bfin_ipi_init(void) +{ + unsigned int cpu; + struct ipi_data *bfin_ipi_data; + for_each_possible_cpu(cpu) { + bfin_ipi_data = &per_cpu(bfin_ipi, cpu); + atomic_set(&bfin_ipi_data->bits, 0); + atomic_set(&bfin_ipi_data->count, 0); + } +} + +void send_ipi(const struct cpumask *cpumask, enum ipi_message_type msg) +{ + unsigned int cpu; + struct ipi_data *bfin_ipi_data; + unsigned long flags; + + local_irq_save(flags); + for_each_cpu(cpu, cpumask) { + bfin_ipi_data = &per_cpu(bfin_ipi, cpu); + atomic_set_mask((1 << msg), &bfin_ipi_data->bits); + atomic_inc(&bfin_ipi_data->count); + } + local_irq_restore(flags); + smp_wmb(); + for_each_cpu(cpu, cpumask) + platform_send_ipi_cpu(cpu, IRQ_SUPPLE_1); +} + +void arch_send_call_function_single_ipi(int cpu) +{ + send_ipi(cpumask_of(cpu), BFIN_IPI_CALL_FUNC); +} + +void arch_send_call_function_ipi_mask(const struct cpumask *mask) +{ + send_ipi(mask, BFIN_IPI_CALL_FUNC); +} + +void smp_send_reschedule(int cpu) +{ + send_ipi(cpumask_of(cpu), BFIN_IPI_RESCHEDULE); + + return; +} + +void smp_send_msg(const struct cpumask *mask, unsigned long type) +{ + send_ipi(mask, type); +} + +void smp_timer_broadcast(const struct cpumask *mask) +{ + smp_send_msg(mask, BFIN_IPI_TIMER); +} + +void smp_send_stop(void) +{ + cpumask_t callmap; + + preempt_disable(); + cpumask_copy(&callmap, cpu_online_mask); + cpumask_clear_cpu(smp_processor_id(), &callmap); + if (!cpumask_empty(&callmap)) + send_ipi(&callmap, BFIN_IPI_CPU_STOP); + + preempt_enable(); + + return; +} + +int __cpu_up(unsigned int cpu, struct task_struct *idle) +{ + int ret; + + secondary_stack = task_stack_page(idle) + THREAD_SIZE; + + ret = platform_boot_secondary(cpu, idle); + + secondary_stack = NULL; + + return ret; +} + +static void setup_secondary(unsigned int cpu) +{ + unsigned long ilat; + + bfin_write_IMASK(0); + CSYNC(); + ilat = bfin_read_ILAT(); + CSYNC(); + bfin_write_ILAT(ilat); + CSYNC(); + + /* Enable interrupt levels IVG7-15. IARs have been already + * programmed by the boot CPU. */ + bfin_irq_flags |= IMASK_IVG15 | + IMASK_IVG14 | IMASK_IVG13 | IMASK_IVG12 | IMASK_IVG11 | + IMASK_IVG10 | IMASK_IVG9 | IMASK_IVG8 | IMASK_IVG7 | IMASK_IVGHW; +} + +void secondary_start_kernel(void) +{ + unsigned int cpu = smp_processor_id(); + struct mm_struct *mm = &init_mm; + + if (_bfin_swrst & SWRST_DBL_FAULT_B) { + printk(KERN_EMERG "CoreB Recovering from DOUBLE FAULT event\n"); +#ifdef CONFIG_DEBUG_DOUBLEFAULT + printk(KERN_EMERG " While handling exception (EXCAUSE = %#x) at %pF\n", + initial_pda_coreb.seqstat_doublefault & SEQSTAT_EXCAUSE, + initial_pda_coreb.retx_doublefault); + printk(KERN_NOTICE " DCPLB_FAULT_ADDR: %pF\n", + initial_pda_coreb.dcplb_doublefault_addr); + printk(KERN_NOTICE " ICPLB_FAULT_ADDR: %pF\n", + initial_pda_coreb.icplb_doublefault_addr); +#endif + printk(KERN_NOTICE " The instruction at %pF caused a double exception\n", + initial_pda_coreb.retx); + } + + /* + * We want the D-cache to be enabled early, in case the atomic + * support code emulates cache coherence (see + * __ARCH_SYNC_CORE_DCACHE). + */ + init_exception_vectors(); + + local_irq_disable(); + + /* Attach the new idle task to the global mm. */ + atomic_inc(&mm->mm_users); + atomic_inc(&mm->mm_count); + current->active_mm = mm; + + preempt_disable(); + + setup_secondary(cpu); + + platform_secondary_init(cpu); + /* setup local core timer */ + bfin_local_timer_setup(); + + local_irq_enable(); + + bfin_setup_caches(cpu); + + notify_cpu_starting(cpu); + /* + * Calibrate loops per jiffy value. + * IRQs need to be enabled here - D-cache can be invalidated + * in timer irq handler, so core B can read correct jiffies. + */ + calibrate_delay(); + + /* We are done with local CPU inits, unblock the boot CPU. */ + set_cpu_online(cpu, true); + cpu_startup_entry(CPUHP_ONLINE); +} + +void __init smp_prepare_boot_cpu(void) +{ +} + +void __init smp_prepare_cpus(unsigned int max_cpus) +{ + platform_prepare_cpus(max_cpus); + bfin_ipi_init(); + platform_request_ipi(IRQ_SUPPLE_0, ipi_handler_int0); + platform_request_ipi(IRQ_SUPPLE_1, ipi_handler_int1); +} + +void __init smp_cpus_done(unsigned int max_cpus) +{ + unsigned long bogosum = 0; + unsigned int cpu; + + for_each_online_cpu(cpu) + bogosum += loops_per_jiffy; + + printk(KERN_INFO "SMP: Total of %d processors activated " + "(%lu.%02lu BogoMIPS).\n", + num_online_cpus(), + bogosum / (500000/HZ), + (bogosum / (5000/HZ)) % 100); +} + +void smp_icache_flush_range_others(unsigned long start, unsigned long end) +{ + smp_flush_data.start = start; + smp_flush_data.end = end; + + preempt_disable(); + if (smp_call_function(&ipi_flush_icache, &smp_flush_data, 1)) + printk(KERN_WARNING "SMP: failed to run I-cache flush request on other CPUs\n"); + preempt_enable(); +} +EXPORT_SYMBOL_GPL(smp_icache_flush_range_others); + +#ifdef __ARCH_SYNC_CORE_ICACHE +unsigned long icache_invld_count[NR_CPUS]; +void resync_core_icache(void) +{ + unsigned int cpu = get_cpu(); + blackfin_invalidate_entire_icache(); + icache_invld_count[cpu]++; + put_cpu(); +} +EXPORT_SYMBOL(resync_core_icache); +#endif + +#ifdef __ARCH_SYNC_CORE_DCACHE +unsigned long dcache_invld_count[NR_CPUS]; +unsigned long barrier_mask __attribute__ ((__section__(".l2.bss"))); + +void resync_core_dcache(void) +{ + unsigned int cpu = get_cpu(); + blackfin_invalidate_entire_dcache(); + dcache_invld_count[cpu]++; + put_cpu(); +} +EXPORT_SYMBOL(resync_core_dcache); +#endif + +#ifdef CONFIG_HOTPLUG_CPU +int __cpu_disable(void) +{ + unsigned int cpu = smp_processor_id(); + + if (cpu == 0) + return -EPERM; + + set_cpu_online(cpu, false); + return 0; +} + +int __cpu_die(unsigned int cpu) +{ + return cpu_wait_death(cpu, 5); +} + +void cpu_die(void) +{ + (void)cpu_report_death(); + + atomic_dec(&init_mm.mm_users); + atomic_dec(&init_mm.mm_count); + + local_irq_disable(); + platform_cpu_die(); +} +#endif |