diff options
Diffstat (limited to 'arch/x86/kernel/i8259_32.c')
-rw-r--r-- | arch/x86/kernel/i8259_32.c | 295 |
1 files changed, 0 insertions, 295 deletions
diff --git a/arch/x86/kernel/i8259_32.c b/arch/x86/kernel/i8259_32.c index fe631967d62..d66914287ee 100644 --- a/arch/x86/kernel/i8259_32.c +++ b/arch/x86/kernel/i8259_32.c @@ -21,302 +21,7 @@ #include <asm/arch_hooks.h> #include <asm/i8259.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. - */ - -static int i8259A_auto_eoi; -DEFINE_SPINLOCK(i8259A_lock); -static void mask_and_ack_8259A(unsigned int); - -static struct irq_chip i8259A_chip = { - .name = "XT-PIC", - .mask = disable_8259A_irq, - .disable = disable_8259A_irq, - .unmask = enable_8259A_irq, - .mask_ack = mask_and_ack_8259A, -}; - -/* - * 8259A PIC functions to handle ISA devices: - */ - -/* - * This contains the irq mask for both 8259A irq controllers, - */ -unsigned int cached_irq_mask = 0xffff; - -/* - * 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_slave_mask, PIC_SLAVE_IMR); - else - outb(cached_master_mask, PIC_MASTER_IMR); - 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_slave_mask, PIC_SLAVE_IMR); - else - outb(cached_master_mask, PIC_MASTER_IMR); - 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(PIC_MASTER_CMD) & mask; - else - ret = inb(PIC_SLAVE_CMD) & (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); - set_irq_chip_and_handler_name(irq, &i8259A_chip, handle_level_irq, - "XT"); - 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,PIC_MASTER_CMD); /* ISR register */ - value = inb(PIC_MASTER_CMD) & irqmask; - outb(0x0A,PIC_MASTER_CMD); /* back to the IRR register */ - return value; - } - outb(0x0B,PIC_SLAVE_CMD); /* ISR register */ - value = inb(PIC_SLAVE_CMD) & (irqmask >> 8); - outb(0x0A,PIC_SLAVE_CMD); /* 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 unnecessarily. - * - * 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(PIC_SLAVE_IMR); /* DUMMY - (do we need this?) */ - outb(cached_slave_mask, PIC_SLAVE_IMR); - outb(0x60+(irq&7),PIC_SLAVE_CMD);/* 'Specific EOI' to slave */ - outb(0x60+PIC_CASCADE_IR,PIC_MASTER_CMD); /* 'Specific EOI' to master-IRQ2 */ - } else { - inb(PIC_MASTER_IMR); /* DUMMY - (do we need this?) */ - outb(cached_master_mask, PIC_MASTER_IMR); - outb(0x60+irq,PIC_MASTER_CMD); /* '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; - } -} - -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(i8259A_auto_eoi); - restore_ELCR(irq_trigger); - return 0; -} - -static int i8259A_suspend(struct sys_device *dev, pm_message_t state) -{ - save_ELCR(irq_trigger); - return 0; -} - -static int i8259A_shutdown(struct sys_device *dev) -{ - /* Put the i8259A into a quiescent state that - * the kernel initialization code can get it - * out of. - */ - outb(0xff, PIC_MASTER_IMR); /* mask all of 8259A-1 */ - outb(0xff, PIC_SLAVE_IMR); /* mask all of 8259A-1 */ - return 0; -} - -static struct sysdev_class i8259_sysdev_class = { - .name = "i8259", - .suspend = i8259A_suspend, - .resume = i8259A_resume, - .shutdown = i8259A_shutdown, -}; - -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); - -void init_8259A(int auto_eoi) -{ - unsigned long flags; - - i8259A_auto_eoi = auto_eoi; - - spin_lock_irqsave(&i8259A_lock, flags); - - outb(0xff, PIC_MASTER_IMR); /* mask all of 8259A-1 */ - outb(0xff, PIC_SLAVE_IMR); /* mask all of 8259A-2 */ - - /* - * outb_pic - this has to work on a wide range of PC hardware. - */ - outb_pic(0x11, PIC_MASTER_CMD); /* ICW1: select 8259A-1 init */ - outb_pic(0x20 + 0, PIC_MASTER_IMR); /* ICW2: 8259A-1 IR0-7 mapped to 0x20-0x27 */ - outb_pic(1U << PIC_CASCADE_IR, PIC_MASTER_IMR); /* 8259A-1 (the master) has a slave on IR2 */ - if (auto_eoi) /* master does Auto EOI */ - outb_pic(MASTER_ICW4_DEFAULT | PIC_ICW4_AEOI, PIC_MASTER_IMR); - else /* master expects normal EOI */ - outb_pic(MASTER_ICW4_DEFAULT, PIC_MASTER_IMR); - - outb_pic(0x11, PIC_SLAVE_CMD); /* ICW1: select 8259A-2 init */ - outb_pic(0x20 + 8, PIC_SLAVE_IMR); /* ICW2: 8259A-2 IR0-7 mapped to 0x28-0x2f */ - outb_pic(PIC_CASCADE_IR, PIC_SLAVE_IMR); /* 8259A-2 is a slave on master's IR2 */ - outb_pic(SLAVE_ICW4_DEFAULT, PIC_SLAVE_IMR); /* (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_chip.mask_ack = disable_8259A_irq; - else - i8259A_chip.mask_ack = mask_and_ack_8259A; - - udelay(100); /* wait for 8259A to initialize */ - - outb(cached_master_mask, PIC_MASTER_IMR); /* restore master IRQ mask */ - outb(cached_slave_mask, PIC_SLAVE_IMR); /* 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 |