traps: x86: converge trap_init functions

- set_system_gate on i386 is really set_system_trap_gate
 - set_system_gate on x86_64 is really set_system_intr_gate
 - ist=0 means no special stack switch is done:
	- introduce STACKFAULT_STACK, DOUBLEFAULT_STACK, NMI_STACK,
		DEBUG_STACK and MCE_STACK as on x86_64.
	- use the _ist variants with XXX_STACK set to zero
 - remove set_system_gate

Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

traps: x86: correct copy/paste bug: a trap is a GATE_TRAP

Fix copy/paste/forgot-to-edit bug in desc.h.

Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/traps_32.c b/arch/x86/kernel/traps_32.c
index 953172a..2c7ea38 100644
--- a/arch/x86/kernel/traps_32.c
+++ b/arch/x86/kernel/traps_32.c
@@ -847,10 +847,12 @@
 #endif
 
 	set_intr_gate(0, &divide_error);
-	set_intr_gate(1, &debug);
-	set_intr_gate(2, &nmi);
-	set_system_intr_gate(3, &int3); /* int3 can be called from all */
-	set_system_intr_gate(4, &overflow); /* int4 can be called from all */
+	set_intr_gate_ist(1, &debug, DEBUG_STACK);
+	set_intr_gate_ist(2, &nmi, NMI_STACK);
+	/* int3 can be called from all */
+	set_system_intr_gate_ist(3, &int3, DEBUG_STACK);
+	/* int4 can be called from all */
+	set_system_intr_gate(4, &overflow);
 	set_intr_gate(5, &bounds);
 	set_intr_gate(6, &invalid_op);
 	set_intr_gate(7, &device_not_available);
@@ -858,14 +860,14 @@
 	set_intr_gate(9, &coprocessor_segment_overrun);
 	set_intr_gate(10, &invalid_TSS);
 	set_intr_gate(11, &segment_not_present);
-	set_intr_gate(12, &stack_segment);
+	set_intr_gate_ist(12, &stack_segment, STACKFAULT_STACK);
 	set_intr_gate(13, &general_protection);
 	set_intr_gate(14, &page_fault);
 	set_intr_gate(15, &spurious_interrupt_bug);
 	set_intr_gate(16, &coprocessor_error);
 	set_intr_gate(17, &alignment_check);
 #ifdef CONFIG_X86_MCE
-	set_intr_gate(18, &machine_check);
+	set_intr_gate_ist(18, &machine_check, MCE_STACK);
 #endif
 	set_intr_gate(19, &simd_coprocessor_error);
 
@@ -881,7 +883,7 @@
 		printk("done.\n");
 	}
 
-	set_system_gate(SYSCALL_VECTOR, &system_call);
+	set_system_trap_gate(SYSCALL_VECTOR, &system_call);
 
 	/* Reserve all the builtin and the syscall vector: */
 	for (i = 0; i < FIRST_EXTERNAL_VECTOR; i++)