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/include/asm-x86/desc.h b/include/asm-x86/desc.h
index ebc3078..f06adac 100644
--- a/include/asm-x86/desc.h
+++ b/include/asm-x86/desc.h
@@ -351,22 +351,18 @@
 	_set_gate(n, GATE_INTERRUPT, addr, 0x3, 0, __KERNEL_CS);
 }
 
+static inline void set_system_trap_gate(unsigned int n, void *addr)
+{
+	BUG_ON((unsigned)n > 0xFF);
+	_set_gate(n, GATE_TRAP, addr, 0x3, 0, __KERNEL_CS);
+}
+
 static inline void set_trap_gate(unsigned int n, void *addr)
 {
 	BUG_ON((unsigned)n > 0xFF);
 	_set_gate(n, GATE_TRAP, addr, 0, 0, __KERNEL_CS);
 }
 
-static inline void set_system_gate(unsigned int n, void *addr)
-{
-	BUG_ON((unsigned)n > 0xFF);
-#ifdef CONFIG_X86_32
-	_set_gate(n, GATE_TRAP, addr, 0x3, 0, __KERNEL_CS);
-#else
-	_set_gate(n, GATE_INTERRUPT, addr, 0x3, 0, __KERNEL_CS);
-#endif
-}
-
 static inline void set_task_gate(unsigned int n, unsigned int gdt_entry)
 {
 	BUG_ON((unsigned)n > 0xFF);
@@ -379,7 +375,7 @@
 	_set_gate(n, GATE_INTERRUPT, addr, 0, ist, __KERNEL_CS);
 }
 
-static inline void set_system_gate_ist(int n, void *addr, unsigned ist)
+static inline void set_system_intr_gate_ist(int n, void *addr, unsigned ist)
 {
 	BUG_ON((unsigned)n > 0xFF);
 	_set_gate(n, GATE_INTERRUPT, addr, 0x3, ist, __KERNEL_CS);