// SPDX-License-Identifier: GPL-2.0
/*
 * Alpha specific irq code.
 */

#include <linux/init.h>
#include <linux/sched.h>
#include <linux/irq.h>
#include <linux/kernel_stat.h>
#include <linux/module.h>

#include <asm/machvec.h>
#include <asm/dma.h>
#include <asm/perf_event.h>
#include <asm/mce.h>

#include "proto.h"
#include "irq_impl.h"

/* Hack minimum IPL during interrupt processing for broken hardware.  */
#ifdef CONFIG_ALPHA_BROKEN_IRQ_MASK
int __min_ipl;
EXPORT_SYMBOL(__min_ipl);
#endif

/*
 * Performance counter hook.  A module can override this to
 * do something useful.
 */
static void
dummy_perf(unsigned long vector, struct pt_regs *regs)
{
        irq_err_count++;
        printk(KERN_CRIT "Performance counter interrupt!\n");
}

void (*perf_irq)(unsigned long, struct pt_regs *) = dummy_perf;
EXPORT_SYMBOL(perf_irq);

/*
 * The main interrupt entry point.
 */

asmlinkage void 
do_entInt(unsigned long type, unsigned long vector,
          unsigned long la_ptr, struct pt_regs *regs)
{
        struct pt_regs *old_regs;

        /*
         * Disable interrupts during IRQ handling.
         * Note that there is no matching local_irq_enable() due to
         * severe problems with RTI at IPL0 and some MILO PALcode
         * (namely LX164).
         */
        local_irq_disable();
        switch (type) {
        case 0:
#ifdef CONFIG_SMP
                handle_ipi(regs);
                return;
#else
                irq_err_count++;
                printk(KERN_CRIT "Interprocessor interrupt? "
                       "You must be kidding!\n");
#endif
                break;
        case 1:
                old_regs = set_irq_regs(regs);
                handle_irq(RTC_IRQ);
                set_irq_regs(old_regs);
                return;
        case 2:
                old_regs = set_irq_regs(regs);
                alpha_mv.machine_check(vector, la_ptr);
                set_irq_regs(old_regs);
                return;
        case 3:
                old_regs = set_irq_regs(regs);
                alpha_mv.device_interrupt(vector);
                set_irq_regs(old_regs);
                return;
        case 4:
                perf_irq(la_ptr, regs);
                return;
        default:
                printk(KERN_CRIT "Hardware intr %ld %lx? Huh?\n",
                       type, vector);
        }
        printk(KERN_CRIT "PC = %016lx PS=%04lx\n", regs->pc, regs->ps);
}

void __init
common_init_isa_dma(void)
{
        outb(0, DMA1_RESET_REG);
        outb(0, DMA2_RESET_REG);
        outb(0, DMA1_CLR_MASK_REG);
        outb(0, DMA2_CLR_MASK_REG);
}

void __init
init_IRQ(void)
{
        /* Just in case the platform init_irq() causes interrupts/mchecks
           (as is the case with RAWHIDE, at least).  */
        wrent(entInt, 0);

        alpha_mv.init_irq();
}

/*
 * machine error checks
 */
#define MCHK_K_TPERR           0x0080
#define MCHK_K_TCPERR          0x0082
#define MCHK_K_HERR            0x0084
#define MCHK_K_ECC_C           0x0086
#define MCHK_K_ECC_NC          0x0088
#define MCHK_K_OS_BUGCHECK     0x008A
#define MCHK_K_PAL_BUGCHECK    0x0090

#ifndef CONFIG_SMP
struct mcheck_info __mcheck_info;
#endif

void
process_mcheck_info(unsigned long vector, unsigned long la_ptr,
                    const char *machine, int expected)
{
        struct el_common *mchk_header;
        const char *reason;

        /*
         * See if the machine check is due to a badaddr() and if so,
         * ignore it.
         */

#ifdef CONFIG_VERBOSE_MCHECK
        if (alpha_verbose_mcheck > 1) {
                printk(KERN_CRIT "%s machine check %s\n", machine,
                       expected ? "expected." : "NOT expected!!!");
        }
#endif

        if (expected) {
                int cpu = smp_processor_id();
                mcheck_expected(cpu) = 0;
                mcheck_taken(cpu) = 1;
                return;
        }

        mchk_header = (struct el_common *)la_ptr;

        printk(KERN_CRIT "%s machine check: vector=0x%lx pc=0x%lx code=0x%x\n",
               machine, vector, get_irq_regs()->pc, mchk_header->code);

        switch (mchk_header->code) {
        /* Machine check reasons.  Defined according to PALcode sources.  */
        case 0x80: reason = "tag parity error"; break;
        case 0x82: reason = "tag control parity error"; break;
        case 0x84: reason = "generic hard error"; break;
        case 0x86: reason = "correctable ECC error"; break;
        case 0x88: reason = "uncorrectable ECC error"; break;
        case 0x8A: reason = "OS-specific PAL bugcheck"; break;
        case 0x90: reason = "callsys in kernel mode"; break;
        case 0x96: reason = "i-cache read retryable error"; break;
        case 0x98: reason = "processor detected hard error"; break;
        
        /* System specific (these are for Alcor, at least): */
        case 0x202: reason = "system detected hard error"; break;
        case 0x203: reason = "system detected uncorrectable ECC error"; break;
        case 0x204: reason = "SIO SERR occurred on PCI bus"; break;
        case 0x205: reason = "parity error detected by core logic"; break;
        case 0x206: reason = "SIO IOCHK occurred on ISA bus"; break;
        case 0x207: reason = "non-existent memory error"; break;
        case 0x208: reason = "MCHK_K_DCSR"; break;
        case 0x209: reason = "PCI SERR detected"; break;
        case 0x20b: reason = "PCI data parity error detected"; break;
        case 0x20d: reason = "PCI address parity error detected"; break;
        case 0x20f: reason = "PCI master abort error"; break;
        case 0x211: reason = "PCI target abort error"; break;
        case 0x213: reason = "scatter/gather PTE invalid error"; break;
        case 0x215: reason = "flash ROM write error"; break;
        case 0x217: reason = "IOA timeout detected"; break;
        case 0x219: reason = "IOCHK#, EISA add-in board parity or other catastrophic error"; break;
        case 0x21b: reason = "EISA fail-safe timer timeout"; break;
        case 0x21d: reason = "EISA bus time-out"; break;
        case 0x21f: reason = "EISA software generated NMI"; break;
        case 0x221: reason = "unexpected ev5 IRQ[3] interrupt"; break;
        default: reason = "unknown"; break;
        }

        printk(KERN_CRIT "machine check type: %s%s\n",
               reason, mchk_header->retry ? " (retryable)" : "");

        dik_show_regs(get_irq_regs(), NULL);

#ifdef CONFIG_VERBOSE_MCHECK
        if (alpha_verbose_mcheck > 1) {
                /* Dump the logout area to give all info.  */
                unsigned long *ptr = (unsigned long *)la_ptr;
                long i;
                for (i = 0; i < mchk_header->size / sizeof(long); i += 2) {
                        printk(KERN_CRIT "   +%8lx %016lx %016lx\n",
                               i*sizeof(long), ptr[i], ptr[i+1]);
                }
        }
#endif /* CONFIG_VERBOSE_MCHECK */
}

/*
 * The special RTC interrupt type.  The interrupt itself was
 * processed by PALcode, and comes in via entInt vector 1.
 */
void __init
init_rtc_irq(irq_handler_t handler)
{
        irq_set_chip_and_handler_name(RTC_IRQ, &dummy_irq_chip,
                                      handle_percpu_irq, "RTC");
        if (!handler)
                handler = rtc_timer_interrupt;
        if (request_irq(RTC_IRQ, handler, 0, "timer", NULL))
                pr_err("Failed to register timer interrupt\n");
}