+
+/* special case for IRQ 7 and IRQ 15, to catch spurious interrupts */
+ .set PIC1_CMD, 0x20
+ .set PIC2_CMD, 0xa0
+ .set OCW2_EOI, 0x20
+ .set OCW3_ISR, 0x0b
+
+ .extern intr_entry_irq7
+ .global irq7_entry_check_spurious
+irq7_entry_check_spurious:
+ push %eax
+ mov $OCW3_ISR, %al
+ out %al, $PIC1_CMD
+ in $PIC1_CMD, %al
+ and $0x80, %al
+ pop %eax
+ jnz intr_entry_irq7
+ iret
+
+ .extern intr_entry_irq15
+ .global irq15_entry_check_spurious
+irq15_entry_check_spurious:
+ push %eax
+ mov $OCW3_ISR, %al
+ out %al, $PIC2_CMD
+ in $PIC2_CMD, %al
+ and $0x80, %al
+ jnz 0f
+ # it was spurious, send EOI to master PIC and iret
+ mov $OCW2_EOI, %al
+ out %al, $PIC1_CMD
+ pop %eax
+ iret
+0: pop %eax
+ jmp intr_entry_irq15
+