diff options
Diffstat (limited to 'arch/x86/kernel/i8259.c')
| -rw-r--r-- | arch/x86/kernel/i8259.c | 107 |
1 files changed, 83 insertions, 24 deletions
diff --git a/arch/x86/kernel/i8259.c b/arch/x86/kernel/i8259.c index 9a5c460404dc..f67063df6723 100644 --- a/arch/x86/kernel/i8259.c +++ b/arch/x86/kernel/i8259.c @@ -1,9 +1,11 @@ +// SPDX-License-Identifier: GPL-2.0 #include <linux/linkage.h> #include <linux/errno.h> #include <linux/signal.h> #include <linux/sched.h> #include <linux/ioport.h> #include <linux/interrupt.h> +#include <linux/irq.h> #include <linux/timex.h> #include <linux/random.h> #include <linux/init.h> @@ -13,14 +15,15 @@ #include <linux/acpi.h> #include <linux/io.h> #include <linux/delay.h> +#include <linux/pgtable.h> #include <linux/atomic.h> #include <asm/timer.h> #include <asm/hw_irq.h> -#include <asm/pgtable.h> #include <asm/desc.h> #include <asm/apic.h> #include <asm/i8259.h> +#include <asm/io_apic.h> /* * This is the 'legacy' 8259A Programmable Interrupt Controller, @@ -30,6 +33,7 @@ */ static void init_8259A(int auto_eoi); +static bool pcat_compat __ro_after_init; static int i8259A_auto_eoi; DEFINE_RAW_SPINLOCK(i8259A_lock); @@ -111,9 +115,10 @@ static void make_8259A_irq(unsigned int irq) { disable_irq_nosync(irq); io_apic_irqs &= ~(1<<irq); - irq_set_chip_and_handler_name(irq, &i8259A_chip, handle_level_irq, - i8259A_chip.name); + irq_set_chip_and_handler(irq, &i8259A_chip, handle_level_irq); + irq_set_status_flags(irq, IRQ_LEVEL); enable_irq(irq); + lapic_assign_legacy_vector(irq, true); } /* @@ -205,7 +210,7 @@ spurious_8259A_irq: * lets ACK and report it. [once per IRQ] */ if (!(spurious_irq_mask & irqmask)) { - printk(KERN_DEBUG + printk_deferred(KERN_DEBUG "spurious 8259A interrupt: IRQ%d.\n", irq); spurious_irq_mask |= irqmask; } @@ -228,35 +233,33 @@ struct irq_chip i8259A_chip = { }; static char irq_trigger[2]; -/** - * ELCR registers (0x4d0, 0x4d1) control edge/level of IRQ - */ +/* ELCR registers (0x4d0, 0x4d1) control edge/level of IRQ */ static void restore_ELCR(char *trigger) { - outb(trigger[0], 0x4d0); - outb(trigger[1], 0x4d1); + outb(trigger[0], PIC_ELCR1); + outb(trigger[1], PIC_ELCR2); } 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; + trigger[0] = inb(PIC_ELCR1) & 0xF8; + trigger[1] = inb(PIC_ELCR2) & 0xDE; } -static void i8259A_resume(void) +static void i8259A_resume(void *data) { init_8259A(i8259A_auto_eoi); restore_ELCR(irq_trigger); } -static int i8259A_suspend(void) +static int i8259A_suspend(void *data) { save_ELCR(irq_trigger); return 0; } -static void i8259A_shutdown(void) +static void i8259A_shutdown(void *data) { /* Put the i8259A into a quiescent state that * the kernel initialization code can get it @@ -266,12 +269,16 @@ static void i8259A_shutdown(void) outb(0xff, PIC_SLAVE_IMR); /* mask all of 8259A-2 */ } -static struct syscore_ops i8259_syscore_ops = { +static const struct syscore_ops i8259_syscore_ops = { .suspend = i8259A_suspend, .resume = i8259A_resume, .shutdown = i8259A_shutdown, }; +static struct syscore i8259_syscore = { + .ops = &i8259_syscore_ops, +}; + static void mask_8259A(void) { unsigned long flags; @@ -296,6 +303,49 @@ static void unmask_8259A(void) raw_spin_unlock_irqrestore(&i8259A_lock, flags); } +static int probe_8259A(void) +{ + unsigned char new_val, probe_val = ~(1 << PIC_CASCADE_IR); + unsigned long flags; + + /* + * If MADT has the PCAT_COMPAT flag set, then do not bother probing + * for the PIC. Some BIOSes leave the PIC uninitialized and probing + * fails. + * + * Right now this causes problems as quite some code depends on + * nr_legacy_irqs() > 0 or has_legacy_pic() == true. This is silly + * when the system has an IO/APIC because then PIC is not required + * at all, except for really old machines where the timer interrupt + * must be routed through the PIC. So just pretend that the PIC is + * there and let legacy_pic->init() initialize it for nothing. + * + * Alternatively this could just try to initialize the PIC and + * repeat the probe, but for cases where there is no PIC that's + * just pointless. + */ + if (pcat_compat) + return nr_legacy_irqs(); + + /* + * Check to see if we have a PIC. Mask all except the cascade and + * read back the value we just wrote. If we don't have a PIC, we + * will read 0xff as opposed to the value we wrote. + */ + raw_spin_lock_irqsave(&i8259A_lock, flags); + + outb(0xff, PIC_SLAVE_IMR); /* mask all of 8259A-2 */ + outb(probe_val, PIC_MASTER_IMR); + new_val = inb(PIC_MASTER_IMR); + if (new_val != probe_val) { + printk(KERN_INFO "Using NULL legacy PIC\n"); + legacy_pic = &null_legacy_pic; + } + + raw_spin_unlock_irqrestore(&i8259A_lock, flags); + return nr_legacy_irqs(); +} + static void init_8259A(int auto_eoi) { unsigned long flags; @@ -305,16 +355,14 @@ static void init_8259A(int auto_eoi) raw_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 */ - /* ICW2: 8259A-1 IR0-7 mapped to 0x30-0x37 on x86-64, - to 0x20-0x27 on i386 */ - outb_pic(IRQ0_VECTOR, PIC_MASTER_IMR); + /* ICW2: 8259A-1 IR0-7 mapped to ISA_IRQ_VECTOR(0) */ + outb_pic(ISA_IRQ_VECTOR(0), PIC_MASTER_IMR); /* 8259A-1 (the master) has a slave on IR2 */ outb_pic(1U << PIC_CASCADE_IR, PIC_MASTER_IMR); @@ -326,8 +374,8 @@ static void init_8259A(int auto_eoi) outb_pic(0x11, PIC_SLAVE_CMD); /* ICW1: select 8259A-2 init */ - /* ICW2: 8259A-2 IR0-7 mapped to IRQ8_VECTOR */ - outb_pic(IRQ8_VECTOR, PIC_SLAVE_IMR); + /* ICW2: 8259A-2 IR0-7 mapped to ISA_IRQ_VECTOR(8) */ + outb_pic(ISA_IRQ_VECTOR(8), PIC_SLAVE_IMR); /* 8259A-2 is a slave on master's IR2 */ outb_pic(PIC_CASCADE_IR, PIC_SLAVE_IMR); /* (slave's support for AEOI in flat mode is to be investigated) */ @@ -363,6 +411,10 @@ static int legacy_pic_irq_pending_noop(unsigned int irq) { return 0; } +static int legacy_pic_probe(void) +{ + return 0; +} struct legacy_pic null_legacy_pic = { .nr_legacy_irqs = 0, @@ -372,11 +424,12 @@ struct legacy_pic null_legacy_pic = { .mask_all = legacy_pic_noop, .restore_mask = legacy_pic_noop, .init = legacy_pic_int_noop, + .probe = legacy_pic_probe, .irq_pending = legacy_pic_irq_pending_noop, .make_irq = legacy_pic_uint_noop, }; -struct legacy_pic default_legacy_pic = { +static struct legacy_pic default_legacy_pic = { .nr_legacy_irqs = NR_IRQS_LEGACY, .chip = &i8259A_chip, .mask = mask_8259A_irq, @@ -384,18 +437,24 @@ struct legacy_pic default_legacy_pic = { .mask_all = mask_8259A, .restore_mask = unmask_8259A, .init = init_8259A, + .probe = probe_8259A, .irq_pending = i8259A_irq_pending, .make_irq = make_8259A_irq, }; struct legacy_pic *legacy_pic = &default_legacy_pic; +EXPORT_SYMBOL(legacy_pic); static int __init i8259A_init_ops(void) { if (legacy_pic == &default_legacy_pic) - register_syscore_ops(&i8259_syscore_ops); + register_syscore(&i8259_syscore); return 0; } - device_initcall(i8259A_init_ops); + +void __init legacy_pic_pcat_compat(void) +{ + pcat_compat = true; +} |