// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright 2006-2007, Michael Ellerman, IBM Corporation.
 */

#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/of_irq.h>
#include <linux/bitmap.h>
#include <linux/msi.h>
#include <asm/mpic.h>
#include <asm/hw_irq.h>
#include <asm/ppc-pci.h>
#include <asm/msi_bitmap.h>

#include <sysdev/mpic.h>

void mpic_msi_reserve_hwirq(struct mpic *mpic, irq_hw_number_t hwirq)
{
        /* The mpic calls this even when there is no allocator setup */
        if (!mpic->msi_bitmap.bitmap)
                return;

        msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, hwirq);
}

#ifdef CONFIG_MPIC_U3_HT_IRQS
static int __init mpic_msi_reserve_u3_hwirqs(struct mpic *mpic)
{
        irq_hw_number_t hwirq;
        const struct irq_domain_ops *ops = mpic->irqhost->ops;
        struct device_node *np;
        int flags, index, i;
        struct of_phandle_args oirq;

        pr_debug("mpic: found U3, guessing msi allocator setup\n");

        /* Reserve source numbers we know are reserved in the HW.
         *
         * This is a bit of a mix of U3 and U4 reserves but that's going
         * to work fine, we have plenty enough numbers left so let's just
         * mark anything we don't like reserved.
         */
        for (i = 0;   i < 8;   i++)
                msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, i);

        for (i = 42;  i < 46;  i++)
                msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, i);

        for (i = 100; i < 105; i++)
                msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, i);

        for (i = 124; i < mpic->num_sources; i++)
                msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, i);


        np = NULL;
        while ((np = of_find_all_nodes(np))) {
                pr_debug("mpic: mapping hwirqs for %pOF\n", np);

                index = 0;
                while (of_irq_parse_one(np, index++, &oirq) == 0) {
                        ops->xlate(mpic->irqhost, NULL, oirq.args,
                                                oirq.args_count, &hwirq, &flags);
                        msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, hwirq);
                }
        }

        return 0;
}
#else
static int __init mpic_msi_reserve_u3_hwirqs(struct mpic *mpic)
{
        return -1;
}
#endif

int __init mpic_msi_init_allocator(struct mpic *mpic)
{
        int rc;

        rc = msi_bitmap_alloc(&mpic->msi_bitmap, mpic->num_sources,
                              irq_domain_get_of_node(mpic->irqhost));
        if (rc)
                return rc;

        rc = msi_bitmap_reserve_dt_hwirqs(&mpic->msi_bitmap);
        if (rc > 0) {
                if (mpic->flags & MPIC_U3_HT_IRQS)
                        rc = mpic_msi_reserve_u3_hwirqs(mpic);

                if (rc) {
                        msi_bitmap_free(&mpic->msi_bitmap);
                        return rc;
                }
        }

        return 0;
}