// SPDX-License-Identifier: GPL-2.0
/*
 * sun4m irq support
 *
 *  djhr: Hacked out of irq.c into a CPU dependent version.
 *
 *  Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
 *  Copyright (C) 1995 Miguel de Icaza (miguel@nuclecu.unam.mx)
 *  Copyright (C) 1995 Pete A. Zaitcev (zaitcev@yahoo.com)
 *  Copyright (C) 1996 Dave Redman (djhr@tadpole.co.uk)
 */

#include <linux/slab.h>
#include <linux/sched/debug.h>
#include <linux/pgtable.h>

#include <asm/timer.h>
#include <asm/traps.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <asm/cacheflush.h>

#include "irq.h"
#include "kernel.h"

/* Sample sun4m IRQ layout:
 *
 * 0x22 - Power
 * 0x24 - ESP SCSI
 * 0x26 - Lance ethernet
 * 0x2b - Floppy
 * 0x2c - Zilog uart
 * 0x32 - SBUS level 0
 * 0x33 - Parallel port, SBUS level 1
 * 0x35 - SBUS level 2
 * 0x37 - SBUS level 3
 * 0x39 - Audio, Graphics card, SBUS level 4
 * 0x3b - SBUS level 5
 * 0x3d - SBUS level 6
 *
 * Each interrupt source has a mask bit in the interrupt registers.
 * When the mask bit is set, this blocks interrupt deliver.  So you
 * clear the bit to enable the interrupt.
 *
 * Interrupts numbered less than 0x10 are software triggered interrupts
 * and unused by Linux.
 *
 * Interrupt level assignment on sun4m:
 *
 *      level           source
 * ------------------------------------------------------------
 *        1             softint-1
 *        2             softint-2, VME/SBUS level 1
 *        3             softint-3, VME/SBUS level 2
 *        4             softint-4, onboard SCSI
 *        5             softint-5, VME/SBUS level 3
 *        6             softint-6, onboard ETHERNET
 *        7             softint-7, VME/SBUS level 4
 *        8             softint-8, onboard VIDEO
 *        9             softint-9, VME/SBUS level 5, Module Interrupt
 *       10             softint-10, system counter/timer
 *       11             softint-11, VME/SBUS level 6, Floppy
 *       12             softint-12, Keyboard/Mouse, Serial
 *       13             softint-13, VME/SBUS level 7, ISDN Audio
 *       14             softint-14, per-processor counter/timer
 *       15             softint-15, Asynchronous Errors (broadcast)
 *
 * Each interrupt source is masked distinctly in the sun4m interrupt
 * registers.  The PIL level alone is therefore ambiguous, since multiple
 * interrupt sources map to a single PIL.
 *
 * This ambiguity is resolved in the 'intr' property for device nodes
 * in the OF device tree.  Each 'intr' property entry is composed of
 * two 32-bit words.  The first word is the IRQ priority value, which
 * is what we're intersted in.  The second word is the IRQ vector, which
 * is unused.
 *
 * The low 4 bits of the IRQ priority indicate the PIL, and the upper
 * 4 bits indicate onboard vs. SBUS leveled vs. VME leveled.  0x20
 * means onboard, 0x30 means SBUS leveled, and 0x40 means VME leveled.
 *
 * For example, an 'intr' IRQ priority value of 0x24 is onboard SCSI
 * whereas a value of 0x33 is SBUS level 2.  Here are some sample
 * 'intr' property IRQ priority values from ss4, ss5, ss10, ss20, and
 * Tadpole S3 GX systems.
 *
 * esp:         0x24    onboard ESP SCSI
 * le:          0x26    onboard Lance ETHERNET
 * p9100:       0x32    SBUS level 1 P9100 video
 * bpp:         0x33    SBUS level 2 BPP parallel port device
 * DBRI:        0x39    SBUS level 5 DBRI ISDN audio
 * SUNW,leo:    0x39    SBUS level 5 LEO video
 * pcmcia:      0x3b    SBUS level 6 PCMCIA controller
 * uctrl:       0x3b    SBUS level 6 UCTRL device
 * modem:       0x3d    SBUS level 7 MODEM
 * zs:          0x2c    onboard keyboard/mouse/serial
 * floppy:      0x2b    onboard Floppy
 * power:       0x22    onboard power device (XXX unknown mask bit XXX)
 */


/* Code in entry.S needs to get at these register mappings.  */
struct sun4m_irq_percpu __iomem *sun4m_irq_percpu[SUN4M_NCPUS];
struct sun4m_irq_global __iomem *sun4m_irq_global;

struct sun4m_handler_data {
        bool    percpu;
        long    mask;
};

/* Dave Redman (djhr@tadpole.co.uk)
 * The sun4m interrupt registers.
 */
#define SUN4M_INT_ENABLE        0x80000000
#define SUN4M_INT_E14           0x00000080
#define SUN4M_INT_E10           0x00080000

#define SUN4M_INT_MASKALL       0x80000000        /* mask all interrupts */
#define SUN4M_INT_MODULE_ERR    0x40000000        /* module error */
#define SUN4M_INT_M2S_WRITE_ERR 0x20000000        /* write buffer error */
#define SUN4M_INT_ECC_ERR       0x10000000        /* ecc memory error */
#define SUN4M_INT_VME_ERR       0x08000000        /* vme async error */
#define SUN4M_INT_FLOPPY        0x00400000        /* floppy disk */
#define SUN4M_INT_MODULE        0x00200000        /* module interrupt */
#define SUN4M_INT_VIDEO         0x00100000        /* onboard video */
#define SUN4M_INT_REALTIME      0x00080000        /* system timer */
#define SUN4M_INT_SCSI          0x00040000        /* onboard scsi */
#define SUN4M_INT_AUDIO         0x00020000        /* audio/isdn */
#define SUN4M_INT_ETHERNET      0x00010000        /* onboard ethernet */
#define SUN4M_INT_SERIAL        0x00008000        /* serial ports */
#define SUN4M_INT_KBDMS         0x00004000        /* keyboard/mouse */
#define SUN4M_INT_SBUSBITS      0x00003F80        /* sbus int bits */
#define SUN4M_INT_VMEBITS       0x0000007F        /* vme int bits */

#define SUN4M_INT_ERROR         (SUN4M_INT_MODULE_ERR |    \
                                 SUN4M_INT_M2S_WRITE_ERR | \
                                 SUN4M_INT_ECC_ERR |       \
                                 SUN4M_INT_VME_ERR)

#define SUN4M_INT_SBUS(x)       (1 << (x+7))
#define SUN4M_INT_VME(x)        (1 << (x))

/* Interrupt levels used by OBP */
#define OBP_INT_LEVEL_SOFT      0x10
#define OBP_INT_LEVEL_ONBOARD   0x20
#define OBP_INT_LEVEL_SBUS      0x30
#define OBP_INT_LEVEL_VME       0x40

#define SUN4M_TIMER_IRQ         (OBP_INT_LEVEL_ONBOARD | 10)
#define SUN4M_PROFILE_IRQ       (OBP_INT_LEVEL_ONBOARD | 14)

static unsigned long sun4m_imask[0x50] = {
        /* 0x00 - SMP */
        0,  SUN4M_SOFT_INT(1),
        SUN4M_SOFT_INT(2),  SUN4M_SOFT_INT(3),
        SUN4M_SOFT_INT(4),  SUN4M_SOFT_INT(5),
        SUN4M_SOFT_INT(6),  SUN4M_SOFT_INT(7),
        SUN4M_SOFT_INT(8),  SUN4M_SOFT_INT(9),
        SUN4M_SOFT_INT(10), SUN4M_SOFT_INT(11),
        SUN4M_SOFT_INT(12), SUN4M_SOFT_INT(13),
        SUN4M_SOFT_INT(14), SUN4M_SOFT_INT(15),
        /* 0x10 - soft */
        0,  SUN4M_SOFT_INT(1),
        SUN4M_SOFT_INT(2),  SUN4M_SOFT_INT(3),
        SUN4M_SOFT_INT(4),  SUN4M_SOFT_INT(5),
        SUN4M_SOFT_INT(6),  SUN4M_SOFT_INT(7),
        SUN4M_SOFT_INT(8),  SUN4M_SOFT_INT(9),
        SUN4M_SOFT_INT(10), SUN4M_SOFT_INT(11),
        SUN4M_SOFT_INT(12), SUN4M_SOFT_INT(13),
        SUN4M_SOFT_INT(14), SUN4M_SOFT_INT(15),
        /* 0x20 - onboard */
        0, 0, 0, 0,
        SUN4M_INT_SCSI,  0, SUN4M_INT_ETHERNET, 0,
        SUN4M_INT_VIDEO, SUN4M_INT_MODULE,
        SUN4M_INT_REALTIME, SUN4M_INT_FLOPPY,
        (SUN4M_INT_SERIAL | SUN4M_INT_KBDMS),
        SUN4M_INT_AUDIO, SUN4M_INT_E14, SUN4M_INT_MODULE_ERR,
        /* 0x30 - sbus */
        0, 0, SUN4M_INT_SBUS(0), SUN4M_INT_SBUS(1),
        0, SUN4M_INT_SBUS(2), 0, SUN4M_INT_SBUS(3),
        0, SUN4M_INT_SBUS(4), 0, SUN4M_INT_SBUS(5),
        0, SUN4M_INT_SBUS(6), 0, 0,
        /* 0x40 - vme */
        0, 0, SUN4M_INT_VME(0), SUN4M_INT_VME(1),
        0, SUN4M_INT_VME(2), 0, SUN4M_INT_VME(3),
        0, SUN4M_INT_VME(4), 0, SUN4M_INT_VME(5),
        0, SUN4M_INT_VME(6), 0, 0
};

static void sun4m_mask_irq(struct irq_data *data)
{
        struct sun4m_handler_data *handler_data;
        int cpu = smp_processor_id();

        handler_data = irq_data_get_irq_handler_data(data);
        if (handler_data->mask) {
                unsigned long flags;

                local_irq_save(flags);
                if (handler_data->percpu) {
                        sbus_writel(handler_data->mask, &sun4m_irq_percpu[cpu]->set);
                } else {
                        sbus_writel(handler_data->mask, &sun4m_irq_global->mask_set);
                }
                local_irq_restore(flags);
        }
}

static void sun4m_unmask_irq(struct irq_data *data)
{
        struct sun4m_handler_data *handler_data;
        int cpu = smp_processor_id();

        handler_data = irq_data_get_irq_handler_data(data);
        if (handler_data->mask) {
                unsigned long flags;

                local_irq_save(flags);
                if (handler_data->percpu) {
                        sbus_writel(handler_data->mask, &sun4m_irq_percpu[cpu]->clear);
                } else {
                        sbus_writel(handler_data->mask, &sun4m_irq_global->mask_clear);
                }
                local_irq_restore(flags);
        }
}

static unsigned int sun4m_startup_irq(struct irq_data *data)
{
        irq_link(data->irq);
        sun4m_unmask_irq(data);
        return 0;
}

static void sun4m_shutdown_irq(struct irq_data *data)
{
        sun4m_mask_irq(data);
        irq_unlink(data->irq);
}

static struct irq_chip sun4m_irq = {
        .name           = "sun4m",
        .irq_startup    = sun4m_startup_irq,
        .irq_shutdown   = sun4m_shutdown_irq,
        .irq_mask       = sun4m_mask_irq,
        .irq_unmask     = sun4m_unmask_irq,
};


static unsigned int sun4m_build_device_irq(struct platform_device *op,
                                           unsigned int real_irq)
{
        struct sun4m_handler_data *handler_data;
        unsigned int irq;
        unsigned int pil;

        if (real_irq >= OBP_INT_LEVEL_VME) {
                prom_printf("Bogus sun4m IRQ %u\n", real_irq);
                prom_halt();
        }
        pil = (real_irq & 0xf);
        irq = irq_alloc(real_irq, pil);

        if (irq == 0)
                goto out;

        handler_data = irq_get_handler_data(irq);
        if (unlikely(handler_data))
                goto out;

        handler_data = kzalloc_obj(struct sun4m_handler_data, GFP_ATOMIC);
        if (unlikely(!handler_data)) {
                prom_printf("IRQ: kzalloc(sun4m_handler_data) failed.\n");
                prom_halt();
        }

        handler_data->mask = sun4m_imask[real_irq];
        handler_data->percpu = real_irq < OBP_INT_LEVEL_ONBOARD;
        irq_set_chip_and_handler_name(irq, &sun4m_irq,
                                      handle_level_irq, "level");
        irq_set_handler_data(irq, handler_data);

out:
        return irq;
}

struct sun4m_timer_percpu {
        u32             l14_limit;
        u32             l14_count;
        u32             l14_limit_noclear;
        u32             user_timer_start_stop;
};

static struct sun4m_timer_percpu __iomem *timers_percpu[SUN4M_NCPUS];

struct sun4m_timer_global {
        u32             l10_limit;
        u32             l10_count;
        u32             l10_limit_noclear;
        u32             reserved;
        u32             timer_config;
};

static struct sun4m_timer_global __iomem *timers_global;

static void sun4m_clear_clock_irq(void)
{
        sbus_readl(&timers_global->l10_limit);
}

void sun4m_nmi(struct pt_regs *regs)
{
        unsigned long afsr, afar, si;

        printk(KERN_ERR "Aieee: sun4m NMI received!\n");
        /* XXX HyperSparc hack XXX */
        __asm__ __volatile__("mov 0x500, %%g1\n\t"
                             "lda [%%g1] 0x4, %0\n\t"
                             "mov 0x600, %%g1\n\t"
                             "lda [%%g1] 0x4, %1\n\t" :
                             "=r" (afsr), "=r" (afar));
        printk(KERN_ERR "afsr=%08lx afar=%08lx\n", afsr, afar);
        si = sbus_readl(&sun4m_irq_global->pending);
        printk(KERN_ERR "si=%08lx\n", si);
        if (si & SUN4M_INT_MODULE_ERR)
                printk(KERN_ERR "Module async error\n");
        if (si & SUN4M_INT_M2S_WRITE_ERR)
                printk(KERN_ERR "MBus/SBus async error\n");
        if (si & SUN4M_INT_ECC_ERR)
                printk(KERN_ERR "ECC memory error\n");
        if (si & SUN4M_INT_VME_ERR)
                printk(KERN_ERR "VME async error\n");
        printk(KERN_ERR "you lose buddy boy...\n");
        show_regs(regs);
        prom_halt();
}

void sun4m_unmask_profile_irq(void)
{
        unsigned long flags;

        local_irq_save(flags);
        sbus_writel(sun4m_imask[SUN4M_PROFILE_IRQ], &sun4m_irq_global->mask_clear);
        local_irq_restore(flags);
}

void sun4m_clear_profile_irq(int cpu)
{
        sbus_readl(&timers_percpu[cpu]->l14_limit);
}

static void sun4m_load_profile_irq(int cpu, unsigned int limit)
{
        unsigned int value = limit ? timer_value(limit) : 0;
        sbus_writel(value, &timers_percpu[cpu]->l14_limit);
}

static void __init sun4m_init_timers(void)
{
        struct device_node *dp = of_find_node_by_name(NULL, "counter");
        int i, err, len, num_cpu_timers;
        unsigned int irq;
        const u32 *addr;

        if (!dp) {
                printk(KERN_ERR "sun4m_init_timers: No 'counter' node.\n");
                return;
        }

        addr = of_get_property(dp, "address", &len);
        of_node_put(dp);
        if (!addr) {
                printk(KERN_ERR "sun4m_init_timers: No 'address' prop.\n");
                return;
        }

        num_cpu_timers = (len / sizeof(u32)) - 1;
        for (i = 0; i < num_cpu_timers; i++) {
                timers_percpu[i] = (void __iomem *)
                        (unsigned long) addr[i];
        }
        timers_global = (void __iomem *)
                (unsigned long) addr[num_cpu_timers];

        /* Every per-cpu timer works in timer mode */
        sbus_writel(0x00000000, &timers_global->timer_config);

#ifdef CONFIG_SMP
        sparc_config.cs_period = SBUS_CLOCK_RATE * 2;  /* 2 seconds */
        sparc_config.features |= FEAT_L14_ONESHOT;
#else
        sparc_config.cs_period = SBUS_CLOCK_RATE / HZ; /* 1/HZ sec  */
        sparc_config.features |= FEAT_L10_CLOCKEVENT;
#endif
        sparc_config.features |= FEAT_L10_CLOCKSOURCE;
        sbus_writel(timer_value(sparc_config.cs_period),
                    &timers_global->l10_limit);

        master_l10_counter = &timers_global->l10_count;

        irq = sun4m_build_device_irq(NULL, SUN4M_TIMER_IRQ);

        err = request_irq(irq, timer_interrupt, IRQF_TIMER, "timer", NULL);
        if (err) {
                printk(KERN_ERR "sun4m_init_timers: Register IRQ error %d.\n",
                        err);
                return;
        }

        for (i = 0; i < num_cpu_timers; i++)
                sbus_writel(0, &timers_percpu[i]->l14_limit);
        if (num_cpu_timers == 4)
                sbus_writel(SUN4M_INT_E14, &sun4m_irq_global->mask_set);

#ifdef CONFIG_SMP
        {
                unsigned long flags;
                struct tt_entry *trap_table = &sparc_ttable[SP_TRAP_IRQ1 + (14 - 1)];

                /* For SMP we use the level 14 ticker, however the bootup code
                 * has copied the firmware's level 14 vector into the boot cpu's
                 * trap table, we must fix this now or we get squashed.
                 */
                local_irq_save(flags);
                trap_table->inst_one = lvl14_save[0];
                trap_table->inst_two = lvl14_save[1];
                trap_table->inst_three = lvl14_save[2];
                trap_table->inst_four = lvl14_save[3];
                local_ops->cache_all();
                local_irq_restore(flags);
        }
#endif
}

void __init sun4m_init_IRQ(void)
{
        struct device_node *dp = of_find_node_by_name(NULL, "interrupt");
        int len, i, mid, num_cpu_iregs;
        const u32 *addr;

        if (!dp) {
                printk(KERN_ERR "sun4m_init_IRQ: No 'interrupt' node.\n");
                return;
        }

        addr = of_get_property(dp, "address", &len);
        of_node_put(dp);
        if (!addr) {
                printk(KERN_ERR "sun4m_init_IRQ: No 'address' prop.\n");
                return;
        }

        num_cpu_iregs = (len / sizeof(u32)) - 1;
        for (i = 0; i < num_cpu_iregs; i++) {
                sun4m_irq_percpu[i] = (void __iomem *)
                        (unsigned long) addr[i];
        }
        sun4m_irq_global = (void __iomem *)
                (unsigned long) addr[num_cpu_iregs];

        local_irq_disable();

        sbus_writel(~SUN4M_INT_MASKALL, &sun4m_irq_global->mask_set);
        for (i = 0; !cpu_find_by_instance(i, NULL, &mid); i++)
                sbus_writel(~0x17fff, &sun4m_irq_percpu[mid]->clear);

        if (num_cpu_iregs == 4)
                sbus_writel(0, &sun4m_irq_global->interrupt_target);

        sparc_config.init_timers      = sun4m_init_timers;
        sparc_config.build_device_irq = sun4m_build_device_irq;
        sparc_config.clock_rate       = SBUS_CLOCK_RATE;
        sparc_config.clear_clock_irq  = sun4m_clear_clock_irq;
        sparc_config.load_profile_irq = sun4m_load_profile_irq;


        /* Cannot enable interrupts until OBP ticker is disabled. */
}