added 2.6.29.6 aldebaran kernel

[nao-ulib.git] / kernel / 2.6.29.6-aldebaran-rt / arch / mips / cavium-octeon / octeon-irq.c

/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2004-2008 Cavium Networks
 */
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/hardirq.h>

#include <asm/octeon/octeon.h>

DEFINE_RWLOCK(octeon_irq_ciu0_rwlock);
DEFINE_RWLOCK(octeon_irq_ciu1_rwlock);
DEFINE_SPINLOCK(octeon_irq_msi_lock);

static void octeon_irq_core_ack(unsigned int irq)
{
        unsigned int bit = irq - OCTEON_IRQ_SW0;
        /*
         * We don't need to disable IRQs to make these atomic since
         * they are already disabled earlier in the low level
         * interrupt code.
         */
        clear_c0_status(0x100 << bit);
        /* The two user interrupts must be cleared manually. */
        if (bit < 2)
                clear_c0_cause(0x100 << bit);
}

static void octeon_irq_core_eoi(unsigned int irq)
{
        irq_desc_t *desc = irq_desc + irq;
        unsigned int bit = irq - OCTEON_IRQ_SW0;
        /*
         * If an IRQ is being processed while we are disabling it the
         * handler will attempt to unmask the interrupt after it has
         * been disabled.
         */
        if (desc->status & IRQ_DISABLED)
                return;

        /* There is a race here.  We should fix it.  */

        /*
         * We don't need to disable IRQs to make these atomic since
         * they are already disabled earlier in the low level
         * interrupt code.
         */
        set_c0_status(0x100 << bit);
}

static void octeon_irq_core_enable(unsigned int irq)
{
        unsigned long flags;
        unsigned int bit = irq - OCTEON_IRQ_SW0;

        /*
         * We need to disable interrupts to make sure our updates are
         * atomic.
         */
        local_irq_save(flags);
        set_c0_status(0x100 << bit);
        local_irq_restore(flags);
}

static void octeon_irq_core_disable_local(unsigned int irq)
{
        unsigned long flags;
        unsigned int bit = irq - OCTEON_IRQ_SW0;
        /*
         * We need to disable interrupts to make sure our updates are
         * atomic.
         */
        local_irq_save(flags);
        clear_c0_status(0x100 << bit);
        local_irq_restore(flags);
}

static void octeon_irq_core_disable(unsigned int irq)
{
#ifdef CONFIG_SMP
        on_each_cpu((void (*)(void *)) octeon_irq_core_disable_local,
                    (void *) (long) irq, 1);
#else
        octeon_irq_core_disable_local(irq);
#endif
}

static struct irq_chip octeon_irq_chip_core = {
        .name = "Core",
        .enable = octeon_irq_core_enable,
        .disable = octeon_irq_core_disable,
        .ack = octeon_irq_core_ack,
        .eoi = octeon_irq_core_eoi,
};


static void octeon_irq_ciu0_ack(unsigned int irq)
{
        /*
         * In order to avoid any locking accessing the CIU, we
         * acknowledge CIU interrupts by disabling all of them.  This
         * way we can use a per core register and avoid any out of
         * core locking requirements.  This has the side affect that
         * CIU interrupts can't be processed recursively.
         *
         * We don't need to disable IRQs to make these atomic since
         * they are already disabled earlier in the low level
         * interrupt code.
         */
        clear_c0_status(0x100 << 2);
}

static void octeon_irq_ciu0_eoi(unsigned int irq)
{
        /*
         * Enable all CIU interrupts again.  We don't need to disable
         * IRQs to make these atomic since they are already disabled
         * earlier in the low level interrupt code.
         */
        set_c0_status(0x100 << 2);
}

static void octeon_irq_ciu0_enable(unsigned int irq)
{
        int coreid = cvmx_get_core_num();
        unsigned long flags;
        uint64_t en0;
        int bit = irq - OCTEON_IRQ_WORKQ0;      /* Bit 0-63 of EN0 */

        /*
         * A read lock is used here to make sure only one core is ever
         * updating the CIU enable bits at a time. During an enable
         * the cores don't interfere with each other. During a disable
         * the write lock stops any enables that might cause a
         * problem.
         */
        read_lock_irqsave(&octeon_irq_ciu0_rwlock, flags);
        en0 = cvmx_read_csr(CVMX_CIU_INTX_EN0(coreid * 2));
        en0 |= 1ull << bit;
        cvmx_write_csr(CVMX_CIU_INTX_EN0(coreid * 2), en0);
        cvmx_read_csr(CVMX_CIU_INTX_EN0(coreid * 2));
        read_unlock_irqrestore(&octeon_irq_ciu0_rwlock, flags);
}

static void octeon_irq_ciu0_disable(unsigned int irq)
{
        int bit = irq - OCTEON_IRQ_WORKQ0;      /* Bit 0-63 of EN0 */
        unsigned long flags;
        uint64_t en0;
#ifdef CONFIG_SMP
        int cpu;
        write_lock_irqsave(&octeon_irq_ciu0_rwlock, flags);
        for_each_online_cpu(cpu) {
                int coreid = cpu_logical_map(cpu);
                en0 = cvmx_read_csr(CVMX_CIU_INTX_EN0(coreid * 2));
                en0 &= ~(1ull << bit);
                cvmx_write_csr(CVMX_CIU_INTX_EN0(coreid * 2), en0);
        }
        /*
         * We need to do a read after the last update to make sure all
         * of them are done.
         */
        cvmx_read_csr(CVMX_CIU_INTX_EN0(cvmx_get_core_num() * 2));
        write_unlock_irqrestore(&octeon_irq_ciu0_rwlock, flags);
#else
        int coreid = cvmx_get_core_num();
        local_irq_save(flags);
        en0 = cvmx_read_csr(CVMX_CIU_INTX_EN0(coreid * 2));
        en0 &= ~(1ull << bit);
        cvmx_write_csr(CVMX_CIU_INTX_EN0(coreid * 2), en0);
        cvmx_read_csr(CVMX_CIU_INTX_EN0(coreid * 2));
        local_irq_restore(flags);
#endif
}

#ifdef CONFIG_SMP
static void octeon_irq_ciu0_set_affinity(unsigned int irq, const struct cpumask *dest)
{
        int cpu;
        int bit = irq - OCTEON_IRQ_WORKQ0;      /* Bit 0-63 of EN0 */

        write_lock(&octeon_irq_ciu0_rwlock);
        for_each_online_cpu(cpu) {
                int coreid = cpu_logical_map(cpu);
                uint64_t en0 =
                        cvmx_read_csr(CVMX_CIU_INTX_EN0(coreid * 2));
                if (cpumask_test_cpu(cpu, dest))
                        en0 |= 1ull << bit;
                else
                        en0 &= ~(1ull << bit);
                cvmx_write_csr(CVMX_CIU_INTX_EN0(coreid * 2), en0);
        }
        /*
         * We need to do a read after the last update to make sure all
         * of them are done.
         */
        cvmx_read_csr(CVMX_CIU_INTX_EN0(cvmx_get_core_num() * 2));
        write_unlock(&octeon_irq_ciu0_rwlock);
}
#endif

static struct irq_chip octeon_irq_chip_ciu0 = {
        .name = "CIU0",
        .enable = octeon_irq_ciu0_enable,
        .disable = octeon_irq_ciu0_disable,
        .ack = octeon_irq_ciu0_ack,
        .eoi = octeon_irq_ciu0_eoi,
#ifdef CONFIG_SMP
        .set_affinity = octeon_irq_ciu0_set_affinity,
#endif
};


static void octeon_irq_ciu1_ack(unsigned int irq)
{
        /*
         * In order to avoid any locking accessing the CIU, we
         * acknowledge CIU interrupts by disabling all of them.  This
         * way we can use a per core register and avoid any out of
         * core locking requirements.  This has the side affect that
         * CIU interrupts can't be processed recursively.  We don't
         * need to disable IRQs to make these atomic since they are
         * already disabled earlier in the low level interrupt code.
         */
        clear_c0_status(0x100 << 3);
}

static void octeon_irq_ciu1_eoi(unsigned int irq)
{
        /*
         * Enable all CIU interrupts again.  We don't need to disable
         * IRQs to make these atomic since they are already disabled
         * earlier in the low level interrupt code.
         */
        set_c0_status(0x100 << 3);
}

static void octeon_irq_ciu1_enable(unsigned int irq)
{
        int coreid = cvmx_get_core_num();
        unsigned long flags;
        uint64_t en1;
        int bit = irq - OCTEON_IRQ_WDOG0;       /* Bit 0-63 of EN1 */

        /*
         * A read lock is used here to make sure only one core is ever
         * updating the CIU enable bits at a time.  During an enable
         * the cores don't interfere with each other.  During a disable
         * the write lock stops any enables that might cause a
         * problem.
         */
        read_lock_irqsave(&octeon_irq_ciu1_rwlock, flags);
        en1 = cvmx_read_csr(CVMX_CIU_INTX_EN1(coreid * 2 + 1));
        en1 |= 1ull << bit;
        cvmx_write_csr(CVMX_CIU_INTX_EN1(coreid * 2 + 1), en1);
        cvmx_read_csr(CVMX_CIU_INTX_EN1(coreid * 2 + 1));
        read_unlock_irqrestore(&octeon_irq_ciu1_rwlock, flags);
}

static void octeon_irq_ciu1_disable(unsigned int irq)
{
        int bit = irq - OCTEON_IRQ_WDOG0;       /* Bit 0-63 of EN1 */
        unsigned long flags;
        uint64_t en1;
#ifdef CONFIG_SMP
        int cpu;
        write_lock_irqsave(&octeon_irq_ciu1_rwlock, flags);
        for_each_online_cpu(cpu) {
                int coreid = cpu_logical_map(cpu);
                en1 = cvmx_read_csr(CVMX_CIU_INTX_EN1(coreid * 2 + 1));
                en1 &= ~(1ull << bit);
                cvmx_write_csr(CVMX_CIU_INTX_EN1(coreid * 2 + 1), en1);
        }
        /*
         * We need to do a read after the last update to make sure all
         * of them are done.
         */
        cvmx_read_csr(CVMX_CIU_INTX_EN1(cvmx_get_core_num() * 2 + 1));
        write_unlock_irqrestore(&octeon_irq_ciu1_rwlock, flags);
#else
        int coreid = cvmx_get_core_num();
        local_irq_save(flags);
        en1 = cvmx_read_csr(CVMX_CIU_INTX_EN1(coreid * 2 + 1));
        en1 &= ~(1ull << bit);
        cvmx_write_csr(CVMX_CIU_INTX_EN1(coreid * 2 + 1), en1);
        cvmx_read_csr(CVMX_CIU_INTX_EN1(coreid * 2 + 1));
        local_irq_restore(flags);
#endif
}

#ifdef CONFIG_SMP
static void octeon_irq_ciu1_set_affinity(unsigned int irq, const struct cpumask *dest)
{
        int cpu;
        int bit = irq - OCTEON_IRQ_WDOG0;       /* Bit 0-63 of EN1 */

        write_lock(&octeon_irq_ciu1_rwlock);
        for_each_online_cpu(cpu) {
                int coreid = cpu_logical_map(cpu);
                uint64_t en1 =
                        cvmx_read_csr(CVMX_CIU_INTX_EN1
                                (coreid * 2 + 1));
                if (cpumask_test_cpu(cpu, dest))
                        en1 |= 1ull << bit;
                else
                        en1 &= ~(1ull << bit);
                cvmx_write_csr(CVMX_CIU_INTX_EN1(coreid * 2 + 1), en1);
        }
        /*
         * We need to do a read after the last update to make sure all
         * of them are done.
         */
        cvmx_read_csr(CVMX_CIU_INTX_EN1(cvmx_get_core_num() * 2 + 1));
        write_unlock(&octeon_irq_ciu1_rwlock);
}
#endif

static struct irq_chip octeon_irq_chip_ciu1 = {
        .name = "CIU1",
        .enable = octeon_irq_ciu1_enable,
        .disable = octeon_irq_ciu1_disable,
        .ack = octeon_irq_ciu1_ack,
        .eoi = octeon_irq_ciu1_eoi,
#ifdef CONFIG_SMP
        .set_affinity = octeon_irq_ciu1_set_affinity,
#endif
};

#ifdef CONFIG_PCI_MSI

static void octeon_irq_msi_ack(unsigned int irq)
{
        if (!octeon_has_feature(OCTEON_FEATURE_PCIE)) {
                /* These chips have PCI */
                cvmx_write_csr(CVMX_NPI_NPI_MSI_RCV,
                               1ull << (irq - OCTEON_IRQ_MSI_BIT0));
        } else {
                /*
                 * These chips have PCIe. Thankfully the ACK doesn't
                 * need any locking.
                 */
                cvmx_write_csr(CVMX_PEXP_NPEI_MSI_RCV0,
                               1ull << (irq - OCTEON_IRQ_MSI_BIT0));
        }
}

static void octeon_irq_msi_eoi(unsigned int irq)
{
        /* Nothing needed */
}

static void octeon_irq_msi_enable(unsigned int irq)
{
        if (!octeon_has_feature(OCTEON_FEATURE_PCIE)) {
                /*
                 * Octeon PCI doesn't have the ability to mask/unmask
                 * MSI interrupts individually.  Instead of
                 * masking/unmasking them in groups of 16, we simple
                 * assume MSI devices are well behaved.  MSI
                 * interrupts are always enable and the ACK is assumed
                 * to be enough.
                 */
        } else {
                /* These chips have PCIe.  Note that we only support
                 * the first 64 MSI interrupts.  Unfortunately all the
                 * MSI enables are in the same register.  We use
                 * MSI0's lock to control access to them all.
                 */
                uint64_t en;
                unsigned long flags;
                spin_lock_irqsave(&octeon_irq_msi_lock, flags);
                en = cvmx_read_csr(CVMX_PEXP_NPEI_MSI_ENB0);
                en |= 1ull << (irq - OCTEON_IRQ_MSI_BIT0);
                cvmx_write_csr(CVMX_PEXP_NPEI_MSI_ENB0, en);
                cvmx_read_csr(CVMX_PEXP_NPEI_MSI_ENB0);
                spin_unlock_irqrestore(&octeon_irq_msi_lock, flags);
        }
}

static void octeon_irq_msi_disable(unsigned int irq)
{
        if (!octeon_has_feature(OCTEON_FEATURE_PCIE)) {
                /* See comment in enable */
        } else {
                /*
                 * These chips have PCIe.  Note that we only support
                 * the first 64 MSI interrupts.  Unfortunately all the
                 * MSI enables are in the same register.  We use
                 * MSI0's lock to control access to them all.
                 */
                uint64_t en;
                unsigned long flags;
                spin_lock_irqsave(&octeon_irq_msi_lock, flags);
                en = cvmx_read_csr(CVMX_PEXP_NPEI_MSI_ENB0);
                en &= ~(1ull << (irq - OCTEON_IRQ_MSI_BIT0));
                cvmx_write_csr(CVMX_PEXP_NPEI_MSI_ENB0, en);
                cvmx_read_csr(CVMX_PEXP_NPEI_MSI_ENB0);
                spin_unlock_irqrestore(&octeon_irq_msi_lock, flags);
        }
}

static struct irq_chip octeon_irq_chip_msi = {
        .name = "MSI",
        .enable = octeon_irq_msi_enable,
        .disable = octeon_irq_msi_disable,
        .ack = octeon_irq_msi_ack,
        .eoi = octeon_irq_msi_eoi,
};
#endif

void __init arch_init_irq(void)
{
        int irq;

#ifdef CONFIG_SMP
        /* Set the default affinity to the boot cpu. */
        cpumask_clear(irq_default_affinity);
        cpumask_set_cpu(smp_processor_id(), irq_default_affinity);
#endif

        if (NR_IRQS < OCTEON_IRQ_LAST)
                pr_err("octeon_irq_init: NR_IRQS is set too low\n");

        /* 0 - 15 reserved for i8259 master and slave controller. */

        /* 17 - 23 Mips internal */
        for (irq = OCTEON_IRQ_SW0; irq <= OCTEON_IRQ_TIMER; irq++) {
                set_irq_chip_and_handler(irq, &octeon_irq_chip_core,
                                         handle_percpu_irq);
        }

        /* 24 - 87 CIU_INT_SUM0 */
        for (irq = OCTEON_IRQ_WORKQ0; irq <= OCTEON_IRQ_BOOTDMA; irq++) {
                set_irq_chip_and_handler(irq, &octeon_irq_chip_ciu0,
                                         handle_percpu_irq);
        }

        /* 88 - 151 CIU_INT_SUM1 */
        for (irq = OCTEON_IRQ_WDOG0; irq <= OCTEON_IRQ_RESERVED151; irq++) {
                set_irq_chip_and_handler(irq, &octeon_irq_chip_ciu1,
                                         handle_percpu_irq);
        }

#ifdef CONFIG_PCI_MSI
        /* 152 - 215 PCI/PCIe MSI interrupts */
        for (irq = OCTEON_IRQ_MSI_BIT0; irq <= OCTEON_IRQ_MSI_BIT63; irq++) {
                set_irq_chip_and_handler(irq, &octeon_irq_chip_msi,
                                         handle_percpu_irq);
        }
#endif
        set_c0_status(0x300 << 2);
}

asmlinkage void plat_irq_dispatch(void)
{
        const unsigned long core_id = cvmx_get_core_num();
        const uint64_t ciu_sum0_address = CVMX_CIU_INTX_SUM0(core_id * 2);
        const uint64_t ciu_en0_address = CVMX_CIU_INTX_EN0(core_id * 2);
        const uint64_t ciu_sum1_address = CVMX_CIU_INT_SUM1;
        const uint64_t ciu_en1_address = CVMX_CIU_INTX_EN1(core_id * 2 + 1);
        unsigned long cop0_cause;
        unsigned long cop0_status;
        uint64_t ciu_en;
        uint64_t ciu_sum;

        while (1) {
                cop0_cause = read_c0_cause();
                cop0_status = read_c0_status();
                cop0_cause &= cop0_status;
                cop0_cause &= ST0_IM;

                if (unlikely(cop0_cause & STATUSF_IP2)) {
                        ciu_sum = cvmx_read_csr(ciu_sum0_address);
                        ciu_en = cvmx_read_csr(ciu_en0_address);
                        ciu_sum &= ciu_en;
                        if (likely(ciu_sum))
                                do_IRQ(fls64(ciu_sum) + OCTEON_IRQ_WORKQ0 - 1);
                        else
                                spurious_interrupt();
                } else if (unlikely(cop0_cause & STATUSF_IP3)) {
                        ciu_sum = cvmx_read_csr(ciu_sum1_address);
                        ciu_en = cvmx_read_csr(ciu_en1_address);
                        ciu_sum &= ciu_en;
                        if (likely(ciu_sum))
                                do_IRQ(fls64(ciu_sum) + OCTEON_IRQ_WDOG0 - 1);
                        else
                                spurious_interrupt();
                } else if (likely(cop0_cause)) {
                        do_IRQ(fls(cop0_cause) - 9 + MIPS_CPU_IRQ_BASE);
                } else {
                        break;
                }
        }
}