int-handler.s

一个2.4.21版本的嵌入式linux内核

/*
 * int-handler.S
 *
 * Based on the cobalt handler.
 */
#include <asm/asm.h>
#include <asm/mipsregs.h>
#include <asm/addrspace.h>
#include <asm/regdef.h>
#include <asm/stackframe.h>

/*
 * galileo_handle_int -
 *      We check for the timer first, then check PCI ints A and D.
 *      Then check for serial IRQ and fall through.
 */
		.align	5
		.set	reorder
		.set	noat
		NESTED(galileo_handle_int, PT_SIZE, sp)
		SAVE_ALL
		CLI
		.set	at
		mfc0	t0,CP0_CAUSE
		mfc0	t2,CP0_STATUS

		and	t0,t2

		andi	t1,t0,STATUSF_IP4 /* int2 hardware line (timer) */
		bnez	t1,ll_galileo_irq
		andi	t1,t0,STATUSF_IP2 /* int0 hardware line */
		bnez	t1,ll_pci_intA
		andi	t1,t0,STATUSF_IP5 /* int3 hardware line */
		bnez	t1,ll_pci_intD
		andi	t1,t0,STATUSF_IP6 /* int4 hardware line */
		bnez	t1,ll_serial_irq
		andi	t1,t0,STATUSF_IP7 /* compare int */
		bnez	t1,ll_compare_irq
		nop

    /* wrong alarm or masked ... */
		j	spurious_interrupt
		nop
		END(galileo_handle_int)


		.align	5
		.set	reorder
ll_galileo_irq:
		li	a0,4
		move	a1,sp
		jal	do_IRQ
		nop
		j	ret_from_irq
		nop

		.align	5
		.set	reorder
ll_compare_irq:
		li 	a0,7
		move	a1,sp
		jal	do_IRQ
		nop
		j	ret_from_irq
		nop

		.align	5
		.set	reorder
ll_pci_intA:
		move	a0,sp
		jal	pci_intA
		nop
		j	ret_from_irq
		nop

#if 0
		.align	5
		.set	reorder
ll_pci_intB:
		move 	a0,sp
		jal	pci_intB
		nop
		j	ret_from_irq
		nop

		.align	5
		.set	reorder
ll_pci_intC:
		move 	a0,sp
		jal	pci_intC
		nop
		j	ret_from_irq
		nop
#endif

		.align	5
		.set	reorder
ll_pci_intD:
		move 	a0,sp
		jal	pci_intD
		nop
		j	ret_from_irq
		nop

		.align	5
		.set	reorder
ll_serial_irq:
		li	a0,6
		move	a1,sp
		jal	do_IRQ
		nop
		j	ret_from_irq
		nop