#include <linux/config.h> #include <linux/ptrace.h> #include <linux/errno.h> #include <linux/signal.h> #include <linux/sched.h> #include <linux/ioport.h> #include <linux/interrupt.h> #include <linux/timex.h> #include <linux/slab.h> #include <linux/random.h> #include <linux/smp_lock.h> #include <linux/init.h> #include <linux/kernel_stat.h> #include <linux/device.h> #include <asm/atomic.h> #include <asm/system.h> #include <asm/io.h> #include <asm/irq.h> #include <asm/bitops.h> #include <asm/pgtable.h> #include <asm/delay.h> #include <asm/desc.h> #include <asm/apic.h> #include <linux/irq.h> /* * This is the 'legacy' 8259A Programmable Interrupt Controller, * present in the majority of PC/AT boxes. * plus some generic x86 specific things if generic specifics makes * any sense at all. * this file should become arch/i386/kernel/irq.c when the old irq.c * moves to arch independent land */ spinlock_t i8259A_lock = SPIN_LOCK_UNLOCKED; static void end_8259A_irq (unsigned int irq) { if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS))) enable_8259A_irq(irq); } #define shutdown_8259A_irq disable_8259A_irq void mask_and_ack_8259A(unsigned int); static unsigned int startup_8259A_irq(unsigned int irq) { enable_8259A_irq(irq); return 0; /* never anything pending */ } static struct hw_interrupt_type i8259A_irq_type = { "XT-PIC", startup_8259A_irq, shutdown_8259A_irq, enable_8259A_irq, disable_8259A_irq, mask_and_ack_8259A, end_8259A_irq, NULL }; /* * 8259A PIC functions to handle ISA devices: */ /* * This contains the irq mask for both 8259A irq controllers, */ static unsigned int cached_irq_mask = 0xffff; #define __byte(x,y) (((unsigned char *)&(y))[x]) #define cached_21 (__byte(0,cached_irq_mask)) #define cached_A1 (__byte(1,cached_irq_mask)) /* * Not all IRQs can be routed through the IO-APIC, eg. on certain (older) * boards the timer interrupt is not really connected to any IO-APIC pin, * it's fed to the master 8259A's IR0 line only. * * Any '1' bit in this mask means the IRQ is routed through the IO-APIC. * this 'mixed mode' IRQ handling costs nothing because it's only used * at IRQ setup time. */ unsigned long io_apic_irqs; void disable_8259A_irq(unsigned int irq) { unsigned int mask = 1 << irq; unsigned long flags; spin_lock_irqsave(&i8259A_lock, flags); cached_irq_mask |= mask; if (irq & 8) outb(cached_A1,0xA1); else outb(cached_21,0x21); spin_unlock_irqrestore(&i8259A_lock, flags); } void enable_8259A_irq(unsigned int irq) { unsigned int mask = ~(1 << irq); unsigned long flags; spin_lock_irqsave(&i8259A_lock, flags); cached_irq_mask &= mask; if (irq & 8) outb(cached_A1,0xA1); else outb(cached_21,0x21); spin_unlock_irqrestore(&i8259A_lock, flags); } int i8259A_irq_pending(unsigned int irq) { unsigned int mask = 1<<irq; unsigned long flags; int ret; spin_lock_irqsave(&i8259A_lock, flags); if (irq < 8) ret = inb(0x20) & mask; else ret = inb(0xA0) & (mask >> 8); spin_unlock_irqrestore(&i8259A_lock, flags); return ret; } void make_8259A_irq(unsigned int irq) { disable_irq_nosync(irq); io_apic_irqs &= ~(1<<irq); irq_desc[irq].handler = &i8259A_irq_type; enable_irq(irq); } /* * This function assumes to be called rarely. Switching between * 8259A registers is slow. * This has to be protected by the irq controller spinlock * before being called. */ static inline int i8259A_irq_real(unsigned int irq) { int value; int irqmask = 1<<irq; if (irq < 8) { outb(0x0B,0x20); /* ISR register */ value = inb(0x20) & irqmask; outb(0x0A,0x20); /* back to the IRR register */ return value; } outb(0x0B,0xA0); /* ISR register */ value = inb(0xA0) & (irqmask >> 8); outb(0x0A,0xA0); /* back to the IRR register */ return value; } /* * Careful! The 8259A is a fragile beast, it pretty * much _has_ to be done exactly like this (mask it * first, _then_ send the EOI, and the order of EOI * to the two 8259s is important! */ void mask_and_ack_8259A(unsigned int irq) { unsigned int irqmask = 1 << irq; unsigned long flags; spin_lock_irqsave(&i8259A_lock, flags); /* * Lightweight spurious IRQ detection. We do not want * to overdo spurious IRQ handling - it's usually a sign * of hardware problems, so we only do the checks we can * do without slowing down good hardware unnecesserily. * * Note that IRQ7 and IRQ15 (the two spurious IRQs * usually resulting from the 8259A-1|2 PICs) occur * even if the IRQ is masked in the 8259A. Thus we * can check spurious 8259A IRQs without doing the * quite slow i8259A_irq_real() call for every IRQ. * This does not cover 100% of spurious interrupts, * but should be enough to warn the user that there * is something bad going on ... */ if (cached_irq_mask & irqmask) goto spurious_8259A_irq; cached_irq_mask |= irqmask; handle_real_irq: if (irq & 8) { inb(0xA1); /* DUMMY - (do we need this?) */ outb(cached_A1,0xA1); outb(0x60+(irq&7),0xA0);/* 'Specific EOI' to slave */ outb(0x62,0x20); /* 'Specific EOI' to master-IRQ2 */ } else { inb(0x21); /* DUMMY - (do we need this?) */ outb(cached_21,0x21); outb(0x60+irq,0x20); /* 'Specific EOI' to master */ } spin_unlock_irqrestore(&i8259A_lock, flags); return; spurious_8259A_irq: /* * this is the slow path - should happen rarely. */ if (i8259A_irq_real(irq)) /* * oops, the IRQ _is_ in service according to the * 8259A - not spurious, go handle it. */ goto handle_real_irq; { static int spurious_irq_mask; /* * At this point we can be sure the IRQ is spurious, * lets ACK and report it. [once per IRQ] */ if (!(spurious_irq_mask & irqmask)) { printk("spurious 8259A interrupt: IRQ%d.\n", irq); spurious_irq_mask |= irqmask; } atomic_inc(&irq_err_count); /* * Theoretically we do not have to handle this IRQ, * but in Linux this does not cause problems and is * simpler for us. */ goto handle_real_irq; } } static struct device device_i8259A = { name: "i8259A", bus_id: "0020", }; static void __init init_8259A_devicefs(void) { register_sys_device(&device_i8259A); } __initcall(init_8259A_devicefs); void init_8259A(int auto_eoi) { unsigned long flags; spin_lock_irqsave(&i8259A_lock, flags); outb(0xff, 0x21); /* mask all of 8259A-1 */ outb(0xff, 0xA1); /* mask all of 8259A-2 */ /* * outb_p - this has to work on a wide range of PC hardware. */ outb_p(0x11, 0x20); /* ICW1: select 8259A-1 init */ outb_p(0x20 + 0, 0x21); /* ICW2: 8259A-1 IR0-7 mapped to 0x20-0x27 */ outb_p(0x04, 0x21); /* 8259A-1 (the master) has a slave on IR2 */ if (auto_eoi) outb_p(0x03, 0x21); /* master does Auto EOI */ else outb_p(0x01, 0x21); /* master expects normal EOI */ outb_p(0x11, 0xA0); /* ICW1: select 8259A-2 init */ outb_p(0x20 + 8, 0xA1); /* ICW2: 8259A-2 IR0-7 mapped to 0x28-0x2f */ outb_p(0x02, 0xA1); /* 8259A-2 is a slave on master's IR2 */ outb_p(0x01, 0xA1); /* (slave's support for AEOI in flat mode is to be investigated) */ if (auto_eoi) /* * in AEOI mode we just have to mask the interrupt * when acking. */ i8259A_irq_type.ack = disable_8259A_irq; else i8259A_irq_type.ack = mask_and_ack_8259A; udelay(100); /* wait for 8259A to initialize */ outb(cached_21, 0x21); /* restore master IRQ mask */ outb(cached_A1, 0xA1); /* restore slave IRQ mask */ spin_unlock_irqrestore(&i8259A_lock, flags); } /* * Note that on a 486, we don't want to do a SIGFPE on an irq13 * as the irq is unreliable, and exception 16 works correctly * (ie as explained in the intel literature). On a 386, you * can't use exception 16 due to bad IBM design, so we have to * rely on the less exact irq13. * * Careful.. Not only is IRQ13 unreliable, but it is also * leads to races. IBM designers who came up with it should * be shot. */ static void math_error_irq(int cpl, void *dev_id, struct pt_regs *regs) { extern void math_error(void *); outb(0,0xF0); if (ignore_irq13 || !boot_cpu_data.hard_math) return; math_error((void *)regs->eip); } /* * New motherboards sometimes make IRQ 13 be a PCI interrupt, * so allow interrupt sharing. */ static struct irqaction irq13 = { math_error_irq, 0, 0, "fpu", NULL, NULL }; /* * IRQ2 is cascade interrupt to second interrupt controller */ #ifndef CONFIG_VISWS static struct irqaction irq2 = { no_action, 0, 0, "cascade", NULL, NULL}; #endif void __init init_ISA_irqs (void) { int i; #ifdef CONFIG_X86_LOCAL_APIC init_bsp_APIC(); #endif init_8259A(0); for (i = 0; i < NR_IRQS; i++) { irq_desc[i].status = IRQ_DISABLED; irq_desc[i].action = 0; irq_desc[i].depth = 1; if (i < 16) { /* * 16 old-style INTA-cycle interrupts: */ irq_desc[i].handler = &i8259A_irq_type; } else { /* * 'high' PCI IRQs filled in on demand */ irq_desc[i].handler = &no_irq_type; } } } void __init init_IRQ(void) { int i; #ifndef CONFIG_X86_VISWS_APIC init_ISA_irqs(); #else init_VISWS_APIC_irqs(); #endif /* * Cover the whole vector space, no vector can escape * us. (some of these will be overridden and become * 'special' SMP interrupts) */ for (i = 0; i < NR_IRQS; i++) { int vector = FIRST_EXTERNAL_VECTOR + i; if (vector != SYSCALL_VECTOR) set_intr_gate(vector, interrupt[i]); } #ifdef CONFIG_SMP /* * IRQ0 must be given a fixed assignment and initialized, * because it's used before the IO-APIC is set up. */ set_intr_gate(FIRST_DEVICE_VECTOR, interrupt[0]); /* * The reschedule interrupt is a CPU-to-CPU reschedule-helper * IPI, driven by wakeup. */ set_intr_gate(RESCHEDULE_VECTOR, reschedule_interrupt); /* IPI for invalidation */ set_intr_gate(INVALIDATE_TLB_VECTOR, invalidate_interrupt); /* IPI for generic function call */ set_intr_gate(CALL_FUNCTION_VECTOR, call_function_interrupt); #endif #ifdef CONFIG_X86_LOCAL_APIC /* self generated IPI for local APIC timer */ set_intr_gate(LOCAL_TIMER_VECTOR, apic_timer_interrupt); /* IPI vectors for APIC spurious and error interrupts */ set_intr_gate(SPURIOUS_APIC_VECTOR, spurious_interrupt); set_intr_gate(ERROR_APIC_VECTOR, error_interrupt); /* thermal monitor LVT interrupt */ #ifdef CONFIG_X86_MCE_P4THERMAL set_intr_gate(THERMAL_APIC_VECTOR, smp_thermal_interrupt); #endif #endif /* * Set the clock to HZ Hz, we already have a valid * vector now: */ outb_p(0x34,0x43); /* binary, mode 2, LSB/MSB, ch 0 */ outb_p(LATCH & 0xff , 0x40); /* LSB */ outb(LATCH >> 8 , 0x40); /* MSB */ #ifndef CONFIG_VISWS setup_irq(2, &irq2); #endif /* * External FPU? Set up irq13 if so, for * original braindamaged IBM FERR coupling. */ if (boot_cpu_data.hard_math && !cpu_has_fpu) setup_irq(13, &irq13); }