text: // 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");
  }
  