/*
 * Local APIC related interfaces to support IOAPIC, MSI, HT_IRQ etc.
 *
 * Copyright (C) 1997, 1998, 1999, 2000, 2009 Ingo Molnar, Hajnalka Szabo
 *      Moved from arch/x86/kernel/apic/io_apic.c.
 *
 * 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/interrupt.h>
#include <linux/init.h>
#include <linux/compiler.h>
#include <linux/irqdomain.h>
#include <linux/slab.h>
#include <asm/hw_irq.h>
#include <asm/apic.h>
#include <asm/i8259.h>
#include <asm/desc.h>
#include <asm/irq_remapping.h>

static DEFINE_RAW_SPINLOCK(vector_lock);

void lock_vector_lock(void)
{
        /* Used to the online set of cpus does not change
         * during assign_irq_vector.
         */
        raw_spin_lock(&vector_lock);
}

void unlock_vector_lock(void)
{
        raw_spin_unlock(&vector_lock);
}

struct irq_cfg *irq_cfg(unsigned int irq)
{
        return irq_get_chip_data(irq);
}

struct irq_cfg *irqd_cfg(struct irq_data *irq_data)
{
        return irq_data->chip_data;
}

static struct irq_cfg *alloc_irq_cfg(unsigned int irq, int node)
{
        struct irq_cfg *cfg;

        cfg = kzalloc_node(sizeof(*cfg), GFP_KERNEL, node);
        if (!cfg)
                return NULL;
        if (!zalloc_cpumask_var_node(&cfg->domain, GFP_KERNEL, node))
                goto out_cfg;
        if (!zalloc_cpumask_var_node(&cfg->old_domain, GFP_KERNEL, node))
                goto out_domain;
#ifdef  CONFIG_X86_IO_APIC
        INIT_LIST_HEAD(&cfg->irq_2_pin);
#endif
        return cfg;
out_domain:
        free_cpumask_var(cfg->domain);
out_cfg:
        kfree(cfg);
        return NULL;
}

struct irq_cfg *alloc_irq_and_cfg_at(unsigned int at, int node)
{
        int res = irq_alloc_desc_at(at, node);
        struct irq_cfg *cfg;

        if (res < 0) {
                if (res != -EEXIST)
                        return NULL;
                cfg = irq_cfg(at);
                if (cfg)
                        return cfg;
        }

        cfg = alloc_irq_cfg(at, node);
        if (cfg)
                irq_set_chip_data(at, cfg);
        else
                irq_free_desc(at);
        return cfg;
}

static void free_irq_cfg(unsigned int at, struct irq_cfg *cfg)
{
        if (!cfg)
                return;
        irq_set_chip_data(at, NULL);
        free_cpumask_var(cfg->domain);
        free_cpumask_var(cfg->old_domain);
        kfree(cfg);
}

static int
__assign_irq_vector(int irq, struct irq_cfg *cfg, const struct cpumask *mask)
{
        /*
         * NOTE! The local APIC isn't very good at handling
         * multiple interrupts at the same interrupt level.
         * As the interrupt level is determined by taking the
         * vector number and shifting that right by 4, we
         * want to spread these out a bit so that they don't
         * all fall in the same interrupt level.
         *
         * Also, we've got to be careful not to trash gate
         * 0x80, because int 0x80 is hm, kind of importantish. ;)
         */
        static int current_vector = FIRST_EXTERNAL_VECTOR + VECTOR_OFFSET_START;
        static int current_offset = VECTOR_OFFSET_START % 16;
        int cpu, err;
        cpumask_var_t tmp_mask;

        if (cfg->move_in_progress)
                return -EBUSY;

        if (!alloc_cpumask_var(&tmp_mask, GFP_ATOMIC))
                return -ENOMEM;

        /* Only try and allocate irqs on cpus that are present */
        err = -ENOSPC;
        cpumask_clear(cfg->old_domain);
        cpu = cpumask_first_and(mask, cpu_online_mask);
        while (cpu < nr_cpu_ids) {
                int new_cpu, vector, offset;

                apic->vector_allocation_domain(cpu, tmp_mask, mask);

                if (cpumask_subset(tmp_mask, cfg->domain)) {
                        err = 0;
                        if (cpumask_equal(tmp_mask, cfg->domain))
                                break;
                        /*
                         * New cpumask using the vector is a proper subset of
                         * the current in use mask. So cleanup the vector
                         * allocation for the members that are not used anymore.
                         */
                        cpumask_andnot(cfg->old_domain, cfg->domain, tmp_mask);
                        cfg->move_in_progress =
                           cpumask_intersects(cfg->old_domain, cpu_online_mask);
                        cpumask_and(cfg->domain, cfg->domain, tmp_mask);
                        break;
                }

                vector = current_vector;
                offset = current_offset;
next:
                vector += 16;
                if (vector >= first_system_vector) {
                        offset = (offset + 1) % 16;
                        vector = FIRST_EXTERNAL_VECTOR + offset;
                }

                if (unlikely(current_vector == vector)) {
                        cpumask_or(cfg->old_domain, cfg->old_domain, tmp_mask);
                        cpumask_andnot(tmp_mask, mask, cfg->old_domain);
                        cpu = cpumask_first_and(tmp_mask, cpu_online_mask);
                        continue;
                }

                if (test_bit(vector, used_vectors))
                        goto next;

                for_each_cpu_and(new_cpu, tmp_mask, cpu_online_mask) {
                        if (per_cpu(vector_irq, new_cpu)[vector] >
                            VECTOR_UNDEFINED)
                                goto next;
                }
                /* Found one! */
                current_vector = vector;
                current_offset = offset;
                if (cfg->vector) {
                        cpumask_copy(cfg->old_domain, cfg->domain);
                        cfg->move_in_progress =
                           cpumask_intersects(cfg->old_domain, cpu_online_mask);
                }
                for_each_cpu_and(new_cpu, tmp_mask, cpu_online_mask)
                        per_cpu(vector_irq, new_cpu)[vector] = irq;
                cfg->vector = vector;
                cpumask_copy(cfg->domain, tmp_mask);
                err = 0;
                break;
        }
        free_cpumask_var(tmp_mask);

        return err;
}

int assign_irq_vector(int irq, struct irq_cfg *cfg, const struct cpumask *mask)
{
        int err;
        unsigned long flags;

        raw_spin_lock_irqsave(&vector_lock, flags);
        err = __assign_irq_vector(irq, cfg, mask);
        raw_spin_unlock_irqrestore(&vector_lock, flags);
        return err;
}

void clear_irq_vector(int irq, struct irq_cfg *cfg)
{
        int cpu, vector;
        unsigned long flags;

        raw_spin_lock_irqsave(&vector_lock, flags);
        BUG_ON(!cfg->vector);

        vector = cfg->vector;
        for_each_cpu_and(cpu, cfg->domain, cpu_online_mask)
                per_cpu(vector_irq, cpu)[vector] = VECTOR_UNDEFINED;

        cfg->vector = 0;
        cpumask_clear(cfg->domain);

        if (likely(!cfg->move_in_progress)) {
                raw_spin_unlock_irqrestore(&vector_lock, flags);
                return;
        }

        for_each_cpu_and(cpu, cfg->old_domain, cpu_online_mask) {
                for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS;
                     vector++) {
                        if (per_cpu(vector_irq, cpu)[vector] != irq)
                                continue;
                        per_cpu(vector_irq, cpu)[vector] = VECTOR_UNDEFINED;
                        break;
                }
        }
        cfg->move_in_progress = 0;
        raw_spin_unlock_irqrestore(&vector_lock, flags);
}

int __init arch_probe_nr_irqs(void)
{
        int nr;

        if (nr_irqs > (NR_VECTORS * nr_cpu_ids))
                nr_irqs = NR_VECTORS * nr_cpu_ids;

        nr = (gsi_top + nr_legacy_irqs()) + 8 * nr_cpu_ids;
#if defined(CONFIG_PCI_MSI) || defined(CONFIG_HT_IRQ)
        /*
         * for MSI and HT dyn irq
         */
        if (gsi_top <= NR_IRQS_LEGACY)
                nr +=  8 * nr_cpu_ids;
        else
                nr += gsi_top * 16;
#endif
        if (nr < nr_irqs)
                nr_irqs = nr;

        return nr_legacy_irqs();
}

int __init arch_early_irq_init(void)
{
        return arch_early_ioapic_init();
}

static void __setup_vector_irq(int cpu)
{
        /* Initialize vector_irq on a new cpu */
        int irq, vector;
        struct irq_cfg *cfg;

        /*
         * vector_lock will make sure that we don't run into irq vector
         * assignments that might be happening on another cpu in parallel,
         * while we setup our initial vector to irq mappings.
         */
        raw_spin_lock(&vector_lock);
        /* Mark the inuse vectors */
        for_each_active_irq(irq) {
                cfg = irq_cfg(irq);
                if (!cfg)
                        continue;

                if (!cpumask_test_cpu(cpu, cfg->domain))
                        continue;
                vector = cfg->vector;
                per_cpu(vector_irq, cpu)[vector] = irq;
        }
        /* Mark the free vectors */
        for (vector = 0; vector < NR_VECTORS; ++vector) {
                irq = per_cpu(vector_irq, cpu)[vector];
                if (irq <= VECTOR_UNDEFINED)
                        continue;

                cfg = irq_cfg(irq);
                if (!cpumask_test_cpu(cpu, cfg->domain))
                        per_cpu(vector_irq, cpu)[vector] = VECTOR_UNDEFINED;
        }
        raw_spin_unlock(&vector_lock);
}

/*
 * Setup the vector to irq mappings.
 */
void setup_vector_irq(int cpu)
{
        int irq;

        /*
         * On most of the platforms, legacy PIC delivers the interrupts on the
         * boot cpu. But there are certain platforms where PIC interrupts are
         * delivered to multiple cpu's. If the legacy IRQ is handled by the
         * legacy PIC, for the new cpu that is coming online, setup the static
         * legacy vector to irq mapping:
         */
        for (irq = 0; irq < nr_legacy_irqs(); irq++)
                per_cpu(vector_irq, cpu)[IRQ0_VECTOR + irq] = irq;

        __setup_vector_irq(cpu);
}

int apic_retrigger_irq(struct irq_data *data)
{
        struct irq_cfg *cfg = irqd_cfg(data);
        unsigned long flags;
        int cpu;

        raw_spin_lock_irqsave(&vector_lock, flags);
        cpu = cpumask_first_and(cfg->domain, cpu_online_mask);
        apic->send_IPI_mask(cpumask_of(cpu), cfg->vector);
        raw_spin_unlock_irqrestore(&vector_lock, flags);

        return 1;
}

void apic_ack_edge(struct irq_data *data)
{
        irq_complete_move(irqd_cfg(data));
        irq_move_irq(data);
        ack_APIC_irq();
}

/*
 * Either sets data->affinity to a valid value, and returns
 * ->cpu_mask_to_apicid of that in dest_id, or returns -1 and
 * leaves data->affinity untouched.
 */
int apic_set_affinity(struct irq_data *data, const struct cpumask *mask,
                      unsigned int *dest_id)
{
        struct irq_cfg *cfg = irqd_cfg(data);
        unsigned int irq = data->irq;
        int err;

        if (!config_enabled(CONFIG_SMP))
                return -EPERM;

        if (!cpumask_intersects(mask, cpu_online_mask))
                return -EINVAL;

        err = assign_irq_vector(irq, cfg, mask);
        if (err)
                return err;

        err = apic->cpu_mask_to_apicid_and(mask, cfg->domain, dest_id);
        if (err) {
                if (assign_irq_vector(irq, cfg, data->affinity))
                        pr_err("Failed to recover vector for irq %d\n", irq);
                return err;
        }

        cpumask_copy(data->affinity, mask);

        return 0;
}

#ifdef CONFIG_SMP
void send_cleanup_vector(struct irq_cfg *cfg)
{
        cpumask_var_t cleanup_mask;

        if (unlikely(!alloc_cpumask_var(&cleanup_mask, GFP_ATOMIC))) {
                unsigned int i;

                for_each_cpu_and(i, cfg->old_domain, cpu_online_mask)
                        apic->send_IPI_mask(cpumask_of(i),
                                            IRQ_MOVE_CLEANUP_VECTOR);
        } else {
                cpumask_and(cleanup_mask, cfg->old_domain, cpu_online_mask);
                apic->send_IPI_mask(cleanup_mask, IRQ_MOVE_CLEANUP_VECTOR);
                free_cpumask_var(cleanup_mask);
        }
        cfg->move_in_progress = 0;
}

asmlinkage __visible void smp_irq_move_cleanup_interrupt(void)
{
        unsigned vector, me;

        ack_APIC_irq();
        irq_enter();
        exit_idle();

        me = smp_processor_id();
        for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; vector++) {
                int irq;
                unsigned int irr;
                struct irq_desc *desc;
                struct irq_cfg *cfg;

                irq = __this_cpu_read(vector_irq[vector]);

                if (irq <= VECTOR_UNDEFINED)
                        continue;

                desc = irq_to_desc(irq);
                if (!desc)
                        continue;

                cfg = irq_cfg(irq);
                if (!cfg)
                        continue;

                raw_spin_lock(&desc->lock);

                /*
                 * Check if the irq migration is in progress. If so, we
                 * haven't received the cleanup request yet for this irq.
                 */
                if (cfg->move_in_progress)
                        goto unlock;

                if (vector == cfg->vector && cpumask_test_cpu(me, cfg->domain))
                        goto unlock;

                irr = apic_read(APIC_IRR + (vector / 32 * 0x10));
                /*
                 * Check if the vector that needs to be cleanedup is
                 * registered at the cpu's IRR. If so, then this is not
                 * the best time to clean it up. Lets clean it up in the
                 * next attempt by sending another IRQ_MOVE_CLEANUP_VECTOR
                 * to myself.
                 */
                if (irr  & (1 << (vector % 32))) {
                        apic->send_IPI_self(IRQ_MOVE_CLEANUP_VECTOR);
                        goto unlock;
                }
                __this_cpu_write(vector_irq[vector], VECTOR_UNDEFINED);
unlock:
                raw_spin_unlock(&desc->lock);
        }

        irq_exit();
}

static void __irq_complete_move(struct irq_cfg *cfg, unsigned vector)
{
        unsigned me;

        if (likely(!cfg->move_in_progress))
                return;

        me = smp_processor_id();

        if (vector == cfg->vector && cpumask_test_cpu(me, cfg->domain))
                send_cleanup_vector(cfg);
}

void irq_complete_move(struct irq_cfg *cfg)
{
        __irq_complete_move(cfg, ~get_irq_regs()->orig_ax);
}

void irq_force_complete_move(int irq)
{
        struct irq_cfg *cfg = irq_cfg(irq);

        if (!cfg)
                return;

        __irq_complete_move(cfg, cfg->vector);
}
#endif

/*
 * Dynamic irq allocate and deallocation. Should be replaced by irq domains!
 */
int arch_setup_hwirq(unsigned int irq, int node)
{
        struct irq_cfg *cfg;
        unsigned long flags;
        int ret;

        cfg = alloc_irq_cfg(irq, node);
        if (!cfg)
                return -ENOMEM;

        raw_spin_lock_irqsave(&vector_lock, flags);
        ret = __assign_irq_vector(irq, cfg, apic->target_cpus());
        raw_spin_unlock_irqrestore(&vector_lock, flags);

        if (!ret)
                irq_set_chip_data(irq, cfg);
        else
                free_irq_cfg(irq, cfg);
        return ret;
}

void arch_teardown_hwirq(unsigned int irq)
{
        struct irq_cfg *cfg = irq_cfg(irq);

        free_remapped_irq(irq);
        clear_irq_vector(irq, cfg);
        free_irq_cfg(irq, cfg);
}

static void __init print_APIC_field(int base)
{
        int i;

        printk(KERN_DEBUG);

        for (i = 0; i < 8; i++)
                pr_cont("%08x", apic_read(base + i*0x10));

        pr_cont("\n");
}

static void __init print_local_APIC(void *dummy)
{
        unsigned int i, v, ver, maxlvt;
        u64 icr;

        pr_debug("printing local APIC contents on CPU#%d/%d:\n",
                 smp_processor_id(), hard_smp_processor_id());
        v = apic_read(APIC_ID);
        pr_info("... APIC ID:      %08x (%01x)\n", v, read_apic_id());
        v = apic_read(APIC_LVR);
        pr_info("... APIC VERSION: %08x\n", v);
        ver = GET_APIC_VERSION(v);
        maxlvt = lapic_get_maxlvt();

        v = apic_read(APIC_TASKPRI);
        pr_debug("... APIC TASKPRI: %08x (%02x)\n", v, v & APIC_TPRI_MASK);

        /* !82489DX */
        if (APIC_INTEGRATED(ver)) {
                if (!APIC_XAPIC(ver)) {
                        v = apic_read(APIC_ARBPRI);
                        pr_debug("... APIC ARBPRI: %08x (%02x)\n",
                                 v, v & APIC_ARBPRI_MASK);
                }
                v = apic_read(APIC_PROCPRI);
                pr_debug("... APIC PROCPRI: %08x\n", v);
        }

        /*
         * Remote read supported only in the 82489DX and local APIC for
         * Pentium processors.
         */
        if (!APIC_INTEGRATED(ver) || maxlvt == 3) {
                v = apic_read(APIC_RRR);
                pr_debug("... APIC RRR: %08x\n", v);
        }

        v = apic_read(APIC_LDR);
        pr_debug("... APIC LDR: %08x\n", v);
        if (!x2apic_enabled()) {
                v = apic_read(APIC_DFR);
                pr_debug("... APIC DFR: %08x\n", v);
        }
        v = apic_read(APIC_SPIV);
        pr_debug("... APIC SPIV: %08x\n", v);

        pr_debug("... APIC ISR field:\n");
        print_APIC_field(APIC_ISR);
        pr_debug("... APIC TMR field:\n");
        print_APIC_field(APIC_TMR);
        pr_debug("... APIC IRR field:\n");
        print_APIC_field(APIC_IRR);

        /* !82489DX */
        if (APIC_INTEGRATED(ver)) {
                /* Due to the Pentium erratum 3AP. */
                if (maxlvt > 3)
                        apic_write(APIC_ESR, 0);

                v = apic_read(APIC_ESR);
                pr_debug("... APIC ESR: %08x\n", v);
        }

        icr = apic_icr_read();
        pr_debug("... APIC ICR: %08x\n", (u32)icr);
        pr_debug("... APIC ICR2: %08x\n", (u32)(icr >> 32));

        v = apic_read(APIC_LVTT);
        pr_debug("... APIC LVTT: %08x\n", v);

        if (maxlvt > 3) {
                /* PC is LVT#4. */
                v = apic_read(APIC_LVTPC);
                pr_debug("... APIC LVTPC: %08x\n", v);
        }
        v = apic_read(APIC_LVT0);
        pr_debug("... APIC LVT0: %08x\n", v);
        v = apic_read(APIC_LVT1);
        pr_debug("... APIC LVT1: %08x\n", v);

        if (maxlvt > 2) {
                /* ERR is LVT#3. */
                v = apic_read(APIC_LVTERR);
                pr_debug("... APIC LVTERR: %08x\n", v);
        }

        v = apic_read(APIC_TMICT);
        pr_debug("... APIC TMICT: %08x\n", v);
        v = apic_read(APIC_TMCCT);
        pr_debug("... APIC TMCCT: %08x\n", v);
        v = apic_read(APIC_TDCR);
        pr_debug("... APIC TDCR: %08x\n", v);

        if (boot_cpu_has(X86_FEATURE_EXTAPIC)) {
                v = apic_read(APIC_EFEAT);
                maxlvt = (v >> 16) & 0xff;
                pr_debug("... APIC EFEAT: %08x\n", v);
                v = apic_read(APIC_ECTRL);
                pr_debug("... APIC ECTRL: %08x\n", v);
                for (i = 0; i < maxlvt; i++) {
                        v = apic_read(APIC_EILVTn(i));
                        pr_debug("... APIC EILVT%d: %08x\n", i, v);
                }
        }
        pr_cont("\n");
}

static void __init print_local_APICs(int maxcpu)
{
        int cpu;

        if (!maxcpu)
                return;

        preempt_disable();
        for_each_online_cpu(cpu) {
                if (cpu >= maxcpu)
                        break;
                smp_call_function_single(cpu, print_local_APIC, NULL, 1);
        }
        preempt_enable();
}

static void __init print_PIC(void)
{
        unsigned int v;
        unsigned long flags;

        if (!nr_legacy_irqs())
                return;

        pr_debug("\nprinting PIC contents\n");

        raw_spin_lock_irqsave(&i8259A_lock, flags);

        v = inb(0xa1) << 8 | inb(0x21);
        pr_debug("... PIC  IMR: %04x\n", v);

        v = inb(0xa0) << 8 | inb(0x20);
        pr_debug("... PIC  IRR: %04x\n", v);

        outb(0x0b, 0xa0);
        outb(0x0b, 0x20);
        v = inb(0xa0) << 8 | inb(0x20);
        outb(0x0a, 0xa0);
        outb(0x0a, 0x20);

        raw_spin_unlock_irqrestore(&i8259A_lock, flags);

        pr_debug("... PIC  ISR: %04x\n", v);

        v = inb(0x4d1) << 8 | inb(0x4d0);
        pr_debug("... PIC ELCR: %04x\n", v);
}

static int show_lapic __initdata = 1;
static __init int setup_show_lapic(char *arg)
{
        int num = -1;

        if (strcmp(arg, "all") == 0) {
                show_lapic = CONFIG_NR_CPUS;
        } else {
                get_option(&arg, &num);
                if (num >= 0)
                        show_lapic = num;
        }

        return 1;
}
__setup("show_lapic=", setup_show_lapic);

static int __init print_ICs(void)
{
        if (apic_verbosity == APIC_QUIET)
                return 0;

        print_PIC();

        /* don't print out if apic is not there */
        if (!cpu_has_apic && !apic_from_smp_config())
                return 0;

        print_local_APICs(show_lapic);
        print_IO_APICs();

        return 0;
}

late_initcall(print_ICs);