x86: remove include of apic.h from hardirq_64.h

[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / arch / blackfin / kernel / ipipe.c

/* -*- linux-c -*-
 * linux/arch/blackfin/kernel/ipipe.c
 *
 * Copyright (C) 2005-2007 Philippe Gerum.
 *
 * 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, Inc., 675 Mass Ave, Cambridge MA 02139,
 * USA; 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 * Architecture-dependent I-pipe support for the Blackfin.
 */

#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/percpu.h>
#include <linux/bitops.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/kthread.h>
#include <asm/unistd.h>
#include <asm/system.h>
#include <asm/atomic.h>
#include <asm/io.h>

static int create_irq_threads;

DEFINE_PER_CPU(struct pt_regs, __ipipe_tick_regs);

static DEFINE_PER_CPU(unsigned long, pending_irqthread_mask);

static DEFINE_PER_CPU(int [IVG13 + 1], pending_irq_count);

asmlinkage void asm_do_IRQ(unsigned int irq, struct pt_regs *regs);

static void __ipipe_no_irqtail(void);

unsigned long __ipipe_irq_tail_hook = (unsigned long)&__ipipe_no_irqtail;
EXPORT_SYMBOL(__ipipe_irq_tail_hook);

unsigned long __ipipe_core_clock;
EXPORT_SYMBOL(__ipipe_core_clock);

unsigned long __ipipe_freq_scale;
EXPORT_SYMBOL(__ipipe_freq_scale);

atomic_t __ipipe_irq_lvdepth[IVG15 + 1];

unsigned long __ipipe_irq_lvmask = __all_masked_irq_flags;
EXPORT_SYMBOL(__ipipe_irq_lvmask);

static void __ipipe_ack_irq(unsigned irq, struct irq_desc *desc)
{
        desc->ipipe_ack(irq, desc);
}

/*
 * __ipipe_enable_pipeline() -- We are running on the boot CPU, hw
 * interrupts are off, and secondary CPUs are still lost in space.
 */
void __ipipe_enable_pipeline(void)
{
        unsigned irq;

        __ipipe_core_clock = get_cclk(); /* Fetch this once. */
        __ipipe_freq_scale = 1000000000UL / __ipipe_core_clock;

        for (irq = 0; irq < NR_IRQS; ++irq)
                ipipe_virtualize_irq(ipipe_root_domain,
                                     irq,
                                     (ipipe_irq_handler_t)&asm_do_IRQ,
                                     NULL,
                                     &__ipipe_ack_irq,
                                     IPIPE_HANDLE_MASK | IPIPE_PASS_MASK);
}

/*
 * __ipipe_handle_irq() -- IPIPE's generic IRQ handler. An optimistic
 * interrupt protection log is maintained here for each domain. Hw
 * interrupts are masked on entry.
 */
void __ipipe_handle_irq(unsigned irq, struct pt_regs *regs)
{
        struct ipipe_domain *this_domain, *next_domain;
        struct list_head *head, *pos;
        int m_ack, s = -1;

        /*
         * Software-triggered IRQs do not need any ack.  The contents
         * of the register frame should only be used when processing
         * the timer interrupt, but not for handling any other
         * interrupt.
         */
        m_ack = (regs == NULL || irq == IRQ_SYSTMR || irq == IRQ_CORETMR);

        this_domain = ipipe_current_domain;

        if (unlikely(test_bit(IPIPE_STICKY_FLAG, &this_domain->irqs[irq].control)))
                head = &this_domain->p_link;
        else {
                head = __ipipe_pipeline.next;
                next_domain = list_entry(head, struct ipipe_domain, p_link);
                if (likely(test_bit(IPIPE_WIRED_FLAG, &next_domain->irqs[irq].control))) {
                        if (!m_ack && next_domain->irqs[irq].acknowledge != NULL)
                                next_domain->irqs[irq].acknowledge(irq, irq_desc + irq);
                        if (test_bit(IPIPE_ROOTLOCK_FLAG, &ipipe_root_domain->flags))
                                s = __test_and_set_bit(IPIPE_STALL_FLAG,
                                                       &ipipe_root_cpudom_var(status));
                        __ipipe_dispatch_wired(next_domain, irq);
                                goto finalize;
                        return;
                }
        }

        /* Ack the interrupt. */

        pos = head;

        while (pos != &__ipipe_pipeline) {
                next_domain = list_entry(pos, struct ipipe_domain, p_link);
                /*
                 * For each domain handling the incoming IRQ, mark it
                 * as pending in its log.
                 */
                if (test_bit(IPIPE_HANDLE_FLAG, &next_domain->irqs[irq].control)) {
                        /*
                         * Domains that handle this IRQ are polled for
                         * acknowledging it by decreasing priority
                         * order. The interrupt must be made pending
                         * _first_ in the domain's status flags before
                         * the PIC is unlocked.
                         */
                        __ipipe_set_irq_pending(next_domain, irq);

                        if (!m_ack && next_domain->irqs[irq].acknowledge != NULL) {
                                next_domain->irqs[irq].acknowledge(irq, irq_desc + irq);
                                m_ack = 1;
                        }
                }

                /*
                 * If the domain does not want the IRQ to be passed
                 * down the interrupt pipe, exit the loop now.
                 */
                if (!test_bit(IPIPE_PASS_FLAG, &next_domain->irqs[irq].control))
                        break;

                pos = next_domain->p_link.next;
        }

        /*
         * Now walk the pipeline, yielding control to the highest
         * priority domain that has pending interrupt(s) or
         * immediately to the current domain if the interrupt has been
         * marked as 'sticky'. This search does not go beyond the
         * current domain in the pipeline. We also enforce the
         * additional root stage lock (blackfin-specific). */

        if (test_bit(IPIPE_ROOTLOCK_FLAG, &ipipe_root_domain->flags))
                s = __test_and_set_bit(IPIPE_STALL_FLAG,
                                       &ipipe_root_cpudom_var(status));
finalize:

        __ipipe_walk_pipeline(head);

        if (!s)
                __clear_bit(IPIPE_STALL_FLAG,
                            &ipipe_root_cpudom_var(status));
}

int __ipipe_check_root(void)
{
        return ipipe_root_domain_p;
}

void __ipipe_enable_irqdesc(struct ipipe_domain *ipd, unsigned irq)
{
        struct irq_desc *desc = irq_desc + irq;
        int prio = desc->ic_prio;

        desc->depth = 0;
        if (ipd != &ipipe_root &&
            atomic_inc_return(&__ipipe_irq_lvdepth[prio]) == 1)
                __set_bit(prio, &__ipipe_irq_lvmask);
}
EXPORT_SYMBOL(__ipipe_enable_irqdesc);

void __ipipe_disable_irqdesc(struct ipipe_domain *ipd, unsigned irq)
{
        struct irq_desc *desc = irq_desc + irq;
        int prio = desc->ic_prio;

        if (ipd != &ipipe_root &&
            atomic_dec_and_test(&__ipipe_irq_lvdepth[prio]))
                __clear_bit(prio, &__ipipe_irq_lvmask);
}
EXPORT_SYMBOL(__ipipe_disable_irqdesc);

void __ipipe_stall_root_raw(void)
{
        /*
         * This code is called by the ins{bwl} routines (see
         * arch/blackfin/lib/ins.S), which are heavily used by the
         * network stack. It masks all interrupts but those handled by
         * non-root domains, so that we keep decent network transfer
         * rates for Linux without inducing pathological jitter for
         * the real-time domain.
         */
        __asm__ __volatile__ ("sti %0;" : : "d"(__ipipe_irq_lvmask));

        __set_bit(IPIPE_STALL_FLAG,
                  &ipipe_root_cpudom_var(status));
}

void __ipipe_unstall_root_raw(void)
{
        __clear_bit(IPIPE_STALL_FLAG,
                    &ipipe_root_cpudom_var(status));

        __asm__ __volatile__ ("sti %0;" : : "d"(bfin_irq_flags));
}

int __ipipe_syscall_root(struct pt_regs *regs)
{
        unsigned long flags;

        /* We need to run the IRQ tail hook whenever we don't
         * propagate a syscall to higher domains, because we know that
         * important operations might be pending there (e.g. Xenomai
         * deferred rescheduling). */

        if (!__ipipe_syscall_watched_p(current, regs->orig_p0)) {
                void (*hook)(void) = (void (*)(void))__ipipe_irq_tail_hook;
                hook();
                return 0;
        }

        /*
         * This routine either returns:
         * 0 -- if the syscall is to be passed to Linux;
         * 1 -- if the syscall should not be passed to Linux, and no
         * tail work should be performed;
         * -1 -- if the syscall should not be passed to Linux but the
         * tail work has to be performed (for handling signals etc).
         */

        if (__ipipe_event_monitored_p(IPIPE_EVENT_SYSCALL) &&
            __ipipe_dispatch_event(IPIPE_EVENT_SYSCALL, regs) > 0) {
                if (ipipe_root_domain_p && !in_atomic()) {
                        /*
                         * Sync pending VIRQs before _TIF_NEED_RESCHED
                         * is tested.
                         */
                        local_irq_save_hw(flags);
                        if ((ipipe_root_cpudom_var(irqpend_himask) & IPIPE_IRQMASK_VIRT) != 0)
                                __ipipe_sync_pipeline(IPIPE_IRQMASK_VIRT);
                        local_irq_restore_hw(flags);
                        return -1;
                }
                return 1;
        }

        return 0;
}

unsigned long ipipe_critical_enter(void (*syncfn) (void))
{
        unsigned long flags;

        local_irq_save_hw(flags);

        return flags;
}

void ipipe_critical_exit(unsigned long flags)
{
        local_irq_restore_hw(flags);
}

static void __ipipe_no_irqtail(void)
{
}

int ipipe_get_sysinfo(struct ipipe_sysinfo *info)
{
        info->ncpus = num_online_cpus();
        info->cpufreq = ipipe_cpu_freq();
        info->archdep.tmirq = IPIPE_TIMER_IRQ;
        info->archdep.tmfreq = info->cpufreq;

        return 0;
}

/*
 * ipipe_trigger_irq() -- Push the interrupt at front of the pipeline
 * just like if it has been actually received from a hw source. Also
 * works for virtual interrupts.
 */
int ipipe_trigger_irq(unsigned irq)
{
        unsigned long flags;

        if (irq >= IPIPE_NR_IRQS ||
            (ipipe_virtual_irq_p(irq)
             && !test_bit(irq - IPIPE_VIRQ_BASE, &__ipipe_virtual_irq_map)))
                return -EINVAL;

        local_irq_save_hw(flags);

        __ipipe_handle_irq(irq, NULL);

        local_irq_restore_hw(flags);

        return 1;
}

/* Move Linux IRQ to threads. */

static int do_irqd(void *__desc)
{
        struct irq_desc *desc = __desc;
        unsigned irq = desc - irq_desc;
        int thrprio = desc->thr_prio;
        int thrmask = 1 << thrprio;
        int cpu = smp_processor_id();
        cpumask_t cpumask;

        sigfillset(&current->blocked);
        current->flags |= PF_NOFREEZE;
        cpumask = cpumask_of_cpu(cpu);
        set_cpus_allowed(current, cpumask);
        ipipe_setscheduler_root(current, SCHED_FIFO, 50 + thrprio);

        while (!kthread_should_stop()) {
                local_irq_disable();
                if (!(desc->status & IRQ_SCHEDULED)) {
                        set_current_state(TASK_INTERRUPTIBLE);
resched:
                        local_irq_enable();
                        schedule();
                        local_irq_disable();
                }
                __set_current_state(TASK_RUNNING);
                /*
                 * If higher priority interrupt servers are ready to
                 * run, reschedule immediately. We need this for the
                 * GPIO demux IRQ handler to unmask the interrupt line
                 * _last_, after all GPIO IRQs have run.
                 */
                if (per_cpu(pending_irqthread_mask, cpu) & ~(thrmask|(thrmask-1)))
                        goto resched;
                if (--per_cpu(pending_irq_count[thrprio], cpu) == 0)
                        per_cpu(pending_irqthread_mask, cpu) &= ~thrmask;
                desc->status &= ~IRQ_SCHEDULED;
                desc->thr_handler(irq, &__raw_get_cpu_var(__ipipe_tick_regs));
                local_irq_enable();
        }
        __set_current_state(TASK_RUNNING);
        return 0;
}

static void kick_irqd(unsigned irq, void *cookie)
{
        struct irq_desc *desc = irq_desc + irq;
        int thrprio = desc->thr_prio;
        int thrmask = 1 << thrprio;
        int cpu = smp_processor_id();

        if (!(desc->status & IRQ_SCHEDULED)) {
                desc->status |= IRQ_SCHEDULED;
                per_cpu(pending_irqthread_mask, cpu) |= thrmask;
                ++per_cpu(pending_irq_count[thrprio], cpu);
                wake_up_process(desc->thread);
        }
}

int ipipe_start_irq_thread(unsigned irq, struct irq_desc *desc)
{
        if (desc->thread || !create_irq_threads)
                return 0;

        desc->thread = kthread_create(do_irqd, desc, "IRQ %d", irq);
        if (desc->thread == NULL) {
                printk(KERN_ERR "irqd: could not create IRQ thread %d!\n", irq);
                return -ENOMEM;
        }

        wake_up_process(desc->thread);

        desc->thr_handler = ipipe_root_domain->irqs[irq].handler;
        ipipe_root_domain->irqs[irq].handler = &kick_irqd;

        return 0;
}

void __init ipipe_init_irq_threads(void)
{
        unsigned irq;
        struct irq_desc *desc;

        create_irq_threads = 1;

        for (irq = 0; irq < NR_IRQS; irq++) {
                desc = irq_desc + irq;
                if (desc->action != NULL ||
                        (desc->status & IRQ_NOREQUEST) != 0)
                        ipipe_start_irq_thread(irq, desc);
        }
}

EXPORT_SYMBOL(show_stack);

#ifdef CONFIG_IPIPE_TRACE_MCOUNT
void notrace _mcount(void);
EXPORT_SYMBOL(_mcount);
#endif /* CONFIG_IPIPE_TRACE_MCOUNT */