linux/arch/x86/kernel/irqinit_32.c

198 lines
4.6 KiB
C
Raw Normal View History

#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/random.h>
#include <linux/init.h>
#include <linux/kernel_stat.h>
#include <linux/sysdev.h>
#include <linux/bitops.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <asm/atomic.h>
#include <asm/system.h>
#include <asm/timer.h>
#include <asm/pgtable.h>
#include <asm/desc.h>
#include <asm/apic.h>
#include <asm/arch_hooks.h>
#include <asm/i8259.h>
#include <asm/traps.h>
/*
* 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.
*/
IRQ: Maintain regs pointer globally rather than passing to IRQ handlers Maintain a per-CPU global "struct pt_regs *" variable which can be used instead of passing regs around manually through all ~1800 interrupt handlers in the Linux kernel. The regs pointer is used in few places, but it potentially costs both stack space and code to pass it around. On the FRV arch, removing the regs parameter from all the genirq function results in a 20% speed up of the IRQ exit path (ie: from leaving timer_interrupt() to leaving do_IRQ()). Where appropriate, an arch may override the generic storage facility and do something different with the variable. On FRV, for instance, the address is maintained in GR28 at all times inside the kernel as part of general exception handling. Having looked over the code, it appears that the parameter may be handed down through up to twenty or so layers of functions. Consider a USB character device attached to a USB hub, attached to a USB controller that posts its interrupts through a cascaded auxiliary interrupt controller. A character device driver may want to pass regs to the sysrq handler through the input layer which adds another few layers of parameter passing. I've build this code with allyesconfig for x86_64 and i386. I've runtested the main part of the code on FRV and i386, though I can't test most of the drivers. I've also done partial conversion for powerpc and MIPS - these at least compile with minimal configurations. This will affect all archs. Mostly the changes should be relatively easy. Take do_IRQ(), store the regs pointer at the beginning, saving the old one: struct pt_regs *old_regs = set_irq_regs(regs); And put the old one back at the end: set_irq_regs(old_regs); Don't pass regs through to generic_handle_irq() or __do_IRQ(). In timer_interrupt(), this sort of change will be necessary: - update_process_times(user_mode(regs)); - profile_tick(CPU_PROFILING, regs); + update_process_times(user_mode(get_irq_regs())); + profile_tick(CPU_PROFILING); I'd like to move update_process_times()'s use of get_irq_regs() into itself, except that i386, alone of the archs, uses something other than user_mode(). Some notes on the interrupt handling in the drivers: (*) input_dev() is now gone entirely. The regs pointer is no longer stored in the input_dev struct. (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does something different depending on whether it's been supplied with a regs pointer or not. (*) Various IRQ handler function pointers have been moved to type irq_handler_t. Signed-Off-By: David Howells <dhowells@redhat.com> (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 13:55:46 +00:00
static irqreturn_t math_error_irq(int cpl, void *dev_id)
{
outb(0, 0xF0);
if (ignore_fpu_irq || !boot_cpu_data.hard_math)
return IRQ_NONE;
math_error((void __user *)get_irq_regs()->ip);
return IRQ_HANDLED;
}
/*
* New motherboards sometimes make IRQ 13 be a PCI interrupt,
* so allow interrupt sharing.
*/
static struct irqaction fpu_irq = {
.handler = math_error_irq,
.mask = CPU_MASK_NONE,
.name = "fpu",
};
void __init init_ISA_irqs(void)
{
int i;
#ifdef CONFIG_X86_LOCAL_APIC
init_bsp_APIC();
#endif
init_8259A(0);
/*
* 16 old-style INTA-cycle interrupts:
*/
for (i = 0; i < NR_IRQS_LEGACY; i++) {
struct irq_desc *desc = irq_to_desc(i);
desc->status = IRQ_DISABLED;
desc->action = NULL;
desc->depth = 1;
set_irq_chip_and_handler_name(i, &i8259A_chip,
handle_level_irq, "XT");
}
}
/*
* IRQ2 is cascade interrupt to second interrupt controller
*/
static struct irqaction irq2 = {
.handler = no_action,
.mask = CPU_MASK_NONE,
.name = "cascade",
};
DEFINE_PER_CPU(vector_irq_t, vector_irq) = {
[0 ... IRQ0_VECTOR - 1] = -1,
[IRQ0_VECTOR] = 0,
[IRQ1_VECTOR] = 1,
[IRQ2_VECTOR] = 2,
[IRQ3_VECTOR] = 3,
[IRQ4_VECTOR] = 4,
[IRQ5_VECTOR] = 5,
[IRQ6_VECTOR] = 6,
[IRQ7_VECTOR] = 7,
[IRQ8_VECTOR] = 8,
[IRQ9_VECTOR] = 9,
[IRQ10_VECTOR] = 10,
[IRQ11_VECTOR] = 11,
[IRQ12_VECTOR] = 12,
[IRQ13_VECTOR] = 13,
[IRQ14_VECTOR] = 14,
[IRQ15_VECTOR] = 15,
[IRQ15_VECTOR + 1 ... NR_VECTORS - 1] = -1
};
int vector_used_by_percpu_irq(unsigned int vector)
{
int cpu;
for_each_online_cpu(cpu) {
if (per_cpu(vector_irq, cpu)[vector] != -1)
return 1;
}
return 0;
}
/* Overridden in paravirt.c */
void init_IRQ(void) __attribute__((weak, alias("native_init_IRQ")));
void __init native_init_IRQ(void)
{
int i;
/* all the set up before the call gates are initialised */
pre_intr_init_hook();
/*
* Cover the whole vector space, no vector can escape
* us. (some of these will be overridden and become
* 'special' SMP interrupts)
*/
for (i = FIRST_EXTERNAL_VECTOR; i < NR_VECTORS; i++) {
/* SYSCALL_VECTOR was reserved in trap_init. */
if (i != SYSCALL_VECTOR)
set_intr_gate(i, interrupt[i-FIRST_EXTERNAL_VECTOR]);
}
#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_SMP)
/*
* The reschedule interrupt is a CPU-to-CPU reschedule-helper
* IPI, driven by wakeup.
*/
alloc_intr_gate(RESCHEDULE_VECTOR, reschedule_interrupt);
/* IPI for invalidation */
alloc_intr_gate(INVALIDATE_TLB_VECTOR, invalidate_interrupt);
/* IPI for generic function call */
alloc_intr_gate(CALL_FUNCTION_VECTOR, call_function_interrupt);
/* IPI for single call function */
alloc_intr_gate(CALL_FUNCTION_SINGLE_VECTOR,
call_function_single_interrupt);
/* Low priority IPI to cleanup after moving an irq */
set_intr_gate(IRQ_MOVE_CLEANUP_VECTOR, irq_move_cleanup_interrupt);
set_bit(IRQ_MOVE_CLEANUP_VECTOR, used_vectors);
#endif
#ifdef CONFIG_X86_LOCAL_APIC
/* self generated IPI for local APIC timer */
alloc_intr_gate(LOCAL_TIMER_VECTOR, apic_timer_interrupt);
/* IPI vectors for APIC spurious and error interrupts */
alloc_intr_gate(SPURIOUS_APIC_VECTOR, spurious_interrupt);
alloc_intr_gate(ERROR_APIC_VECTOR, error_interrupt);
#endif
#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86_MCE_P4THERMAL)
/* thermal monitor LVT interrupt */
alloc_intr_gate(THERMAL_APIC_VECTOR, thermal_interrupt);
#endif
if (!acpi_ioapic)
setup_irq(2, &irq2);
/* setup after call gates are initialised (usually add in
* the architecture specific gates)
*/
intr_init_hook();
/*
* External FPU? Set up irq13 if so, for
* original braindamaged IBM FERR coupling.
*/
if (boot_cpu_data.hard_math && !cpu_has_fpu)
setup_irq(FPU_IRQ, &fpu_irq);
irq_ctx_init(smp_processor_id());
}