diff options
Diffstat (limited to 'arch/x86_64/kernel/i8259.c')
| -rw-r--r-- | arch/x86_64/kernel/i8259.c | 579 |
1 files changed, 579 insertions, 0 deletions
diff --git a/arch/x86_64/kernel/i8259.c b/arch/x86_64/kernel/i8259.c new file mode 100644 index 00000000000..d5270124601 --- /dev/null +++ b/arch/x86_64/kernel/i8259.c @@ -0,0 +1,579 @@ +#include <linux/linkage.h> +#include <linux/config.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/sysdev.h> +#include <linux/bitops.h> + +#include <asm/acpi.h> +#include <asm/atomic.h> +#include <asm/system.h> +#include <asm/io.h> +#include <asm/irq.h> +#include <asm/hw_irq.h> +#include <asm/pgtable.h> +#include <asm/delay.h> +#include <asm/desc.h> +#include <asm/apic.h> + +#include <linux/irq.h> + +/* + * Common place to define all x86 IRQ vectors + * + * This builds up the IRQ handler stubs using some ugly macros in irq.h + * + * These macros create the low-level assembly IRQ routines that save + * register context and call do_IRQ(). do_IRQ() then does all the + * operations that are needed to keep the AT (or SMP IOAPIC) + * interrupt-controller happy. + */ + +#define BI(x,y) \ + BUILD_IRQ(x##y) + +#define BUILD_16_IRQS(x) \ + BI(x,0) BI(x,1) BI(x,2) BI(x,3) \ + BI(x,4) BI(x,5) BI(x,6) BI(x,7) \ + BI(x,8) BI(x,9) BI(x,a) BI(x,b) \ + BI(x,c) BI(x,d) BI(x,e) BI(x,f) + +#define BUILD_14_IRQS(x) \ + BI(x,0) BI(x,1) BI(x,2) BI(x,3) \ + BI(x,4) BI(x,5) BI(x,6) BI(x,7) \ + BI(x,8) BI(x,9) BI(x,a) BI(x,b) \ + BI(x,c) BI(x,d) + +/* + * ISA PIC or low IO-APIC triggered (INTA-cycle or APIC) interrupts: + * (these are usually mapped to vectors 0x20-0x2f) + */ +BUILD_16_IRQS(0x0) + +#ifdef CONFIG_X86_LOCAL_APIC +/* + * The IO-APIC gives us many more interrupt sources. Most of these + * are unused but an SMP system is supposed to have enough memory ... + * sometimes (mostly wrt. hw bugs) we get corrupted vectors all + * across the spectrum, so we really want to be prepared to get all + * of these. Plus, more powerful systems might have more than 64 + * IO-APIC registers. + * + * (these are usually mapped into the 0x30-0xff vector range) + */ + BUILD_16_IRQS(0x1) BUILD_16_IRQS(0x2) BUILD_16_IRQS(0x3) +BUILD_16_IRQS(0x4) BUILD_16_IRQS(0x5) BUILD_16_IRQS(0x6) BUILD_16_IRQS(0x7) +BUILD_16_IRQS(0x8) BUILD_16_IRQS(0x9) BUILD_16_IRQS(0xa) BUILD_16_IRQS(0xb) +BUILD_16_IRQS(0xc) BUILD_16_IRQS(0xd) + +#ifdef CONFIG_PCI_MSI + BUILD_14_IRQS(0xe) +#endif + +#endif + +#undef BUILD_16_IRQS +#undef BUILD_14_IRQS +#undef BI + + +#define IRQ(x,y) \ + IRQ##x##y##_interrupt + +#define IRQLIST_16(x) \ + IRQ(x,0), IRQ(x,1), IRQ(x,2), IRQ(x,3), \ + IRQ(x,4), IRQ(x,5), IRQ(x,6), IRQ(x,7), \ + IRQ(x,8), IRQ(x,9), IRQ(x,a), IRQ(x,b), \ + IRQ(x,c), IRQ(x,d), IRQ(x,e), IRQ(x,f) + +#define IRQLIST_14(x) \ + IRQ(x,0), IRQ(x,1), IRQ(x,2), IRQ(x,3), \ + IRQ(x,4), IRQ(x,5), IRQ(x,6), IRQ(x,7), \ + IRQ(x,8), IRQ(x,9), IRQ(x,a), IRQ(x,b), \ + IRQ(x,c), IRQ(x,d) + +void (*interrupt[NR_IRQS])(void) = { + IRQLIST_16(0x0), + +#ifdef CONFIG_X86_IO_APIC + IRQLIST_16(0x1), IRQLIST_16(0x2), IRQLIST_16(0x3), + IRQLIST_16(0x4), IRQLIST_16(0x5), IRQLIST_16(0x6), IRQLIST_16(0x7), + IRQLIST_16(0x8), IRQLIST_16(0x9), IRQLIST_16(0xa), IRQLIST_16(0xb), + IRQLIST_16(0xc), IRQLIST_16(0xd) + +#ifdef CONFIG_PCI_MSI + , IRQLIST_14(0xe) +#endif + +#endif +}; + +#undef IRQ +#undef IRQLIST_16 +#undef IRQLIST_14 + +/* + * 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 + */ + +DEFINE_SPINLOCK(i8259A_lock); + +static void end_8259A_irq (unsigned int irq) +{ + if (irq > 256) { + char var; + printk("return %p stack %p ti %p\n", __builtin_return_address(0), &var, current->thread_info); + + BUG(); + } + + if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)) && + irq_desc[irq].action) + enable_8259A_irq(irq); +} + +#define shutdown_8259A_irq disable_8259A_irq + +static 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! + */ +static 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(KERN_DEBUG "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; + } +} + +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); +} + +static char irq_trigger[2]; +/** + * ELCR registers (0x4d0, 0x4d1) control edge/level of IRQ + */ +static void restore_ELCR(char *trigger) +{ + outb(trigger[0], 0x4d0); + outb(trigger[1], 0x4d1); +} + +static void save_ELCR(char *trigger) +{ + /* IRQ 0,1,2,8,13 are marked as reserved */ + trigger[0] = inb(0x4d0) & 0xF8; + trigger[1] = inb(0x4d1) & 0xDE; +} + +static int i8259A_resume(struct sys_device *dev) +{ + init_8259A(0); + restore_ELCR(irq_trigger); + return 0; +} + +static int i8259A_suspend(struct sys_device *dev, u32 state) +{ + save_ELCR(irq_trigger); + return 0; +} + +static struct sysdev_class i8259_sysdev_class = { + set_kset_name("i8259"), + .suspend = i8259A_suspend, + .resume = i8259A_resume, +}; + +static struct sys_device device_i8259A = { + .id = 0, + .cls = &i8259_sysdev_class, +}; + +static int __init i8259A_init_sysfs(void) +{ + int error = sysdev_class_register(&i8259_sysdev_class); + if (!error) + error = sysdev_register(&device_i8259A); + return error; +} + +device_initcall(i8259A_init_sysfs); + +/* + * IRQ2 is cascade interrupt to second interrupt controller + */ + +static struct irqaction irq2 = { no_action, 0, CPU_MASK_NONE, "cascade", NULL, NULL}; + +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 = NULL; + 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 apic_timer_interrupt(void); +void spurious_interrupt(void); +void error_interrupt(void); +void reschedule_interrupt(void); +void call_function_interrupt(void); +void invalidate_interrupt(void); +void thermal_interrupt(void); +void i8254_timer_resume(void); + +static void setup_timer(void) +{ + outb_p(0x34,0x43); /* binary, mode 2, LSB/MSB, ch 0 */ + udelay(10); + outb_p(LATCH & 0xff , 0x40); /* LSB */ + udelay(10); + outb(LATCH >> 8 , 0x40); /* MSB */ +} + +static int timer_resume(struct sys_device *dev) +{ + setup_timer(); + return 0; +} + +void i8254_timer_resume(void) +{ + setup_timer(); +} + +static struct sysdev_class timer_sysclass = { + set_kset_name("timer"), + .resume = timer_resume, +}; + +static struct sys_device device_timer = { + .id = 0, + .cls = &timer_sysclass, +}; + +static int __init init_timer_sysfs(void) +{ + int error = sysdev_class_register(&timer_sysclass); + if (!error) + error = sysdev_register(&device_timer); + return error; +} + +device_initcall(init_timer_sysfs); + +void __init init_IRQ(void) +{ + int i; + + init_ISA_irqs(); + /* + * 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_VECTORS - FIRST_EXTERNAL_VECTOR); i++) { + int vector = FIRST_EXTERNAL_VECTOR + i; + if (i >= NR_IRQS) + break; + if (vector != IA32_SYSCALL_VECTOR && vector != KDB_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 + set_intr_gate(THERMAL_APIC_VECTOR, thermal_interrupt); + +#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); +#endif + + /* + * Set the clock to HZ Hz, we already have a valid + * vector now: + */ + setup_timer(); + + if (!acpi_ioapic) + setup_irq(2, &irq2); +} |