sched/rt, ARM: Use CONFIG_PREEMPTION

CONFIG_PREEMPTION is selected by CONFIG_PREEMPT and by CONFIG_PREEMPT_RT.
Both PREEMPT and PREEMPT_RT require the same functionality which today
depends on CONFIG_PREEMPT.

Switch the entry code, cache over to use CONFIG_PREEMPTION and add output
in show_stack() for PREEMPT_RT.

[bigeasy: +traps.c]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20191015191821.11479-2-bigeasy@linutronix.deSigned-off-by: Ingo Molnar <mingo@kernel.org>

arch/arm/include/asm/switch_to.h

@@ -10,7 +10,7 @@
  * to ensure that the maintenance completes in case we migrate to another
  * CPU.
  */
-#if defined(CONFIG_PREEMPT) && defined(CONFIG_SMP) && defined(CONFIG_CPU_V7)
+#if defined(CONFIG_PREEMPTION) && defined(CONFIG_SMP) && defined(CONFIG_CPU_V7)
 #define __complete_pending_tlbi()	dsb(ish)
 #else
 #define __complete_pending_tlbi()

arch/arm/kernel/entry-armv.S

@@ -211,7 +211,7 @@ __irq_svc:
 	svc_entry
 	irq_handler
 
-#ifdef CONFIG_PREEMPT
+#ifdef CONFIG_PREEMPTION
 	ldr	r8, [tsk, #TI_PREEMPT]		@ get preempt count
 	ldr	r0, [tsk, #TI_FLAGS]		@ get flags
 	teq	r8, #0				@ if preempt count != 0
@@ -226,7 +226,7 @@ ENDPROC(__irq_svc)
 
 	.ltorg
 
-#ifdef CONFIG_PREEMPT
+#ifdef CONFIG_PREEMPTION
 svc_preempt:
 	mov	r8, lr
 1:	bl	preempt_schedule_irq		@ irq en/disable is done inside

arch/arm/kernel/traps.c

@@ -248,6 +248,8 @@ void show_stack(struct task_struct *tsk, unsigned long *sp)
 
 #ifdef CONFIG_PREEMPT
 #define S_PREEMPT " PREEMPT"
+#elif defined(CONFIG_PREEMPT_RT)
+#define S_PREEMPT " PREEMPT_RT"
 #else
 #define S_PREEMPT ""
 #endif

arch/arm/mm/cache-v7.S

@@ -135,13 +135,13 @@ flush_levels:
 	and	r1, r1, #7			@ mask of the bits for current cache only
 	cmp	r1, #2				@ see what cache we have at this level
 	blt	skip				@ skip if no cache, or just i-cache
-#ifdef CONFIG_PREEMPT
+#ifdef CONFIG_PREEMPTION
 	save_and_disable_irqs_notrace r9	@ make cssr&csidr read atomic
 #endif
 	mcr	p15, 2, r10, c0, c0, 0		@ select current cache level in cssr
 	isb					@ isb to sych the new cssr&csidr
 	mrc	p15, 1, r1, c0, c0, 0		@ read the new csidr
-#ifdef CONFIG_PREEMPT
+#ifdef CONFIG_PREEMPTION
 	restore_irqs_notrace r9
 #endif
 	and	r2, r1, #7			@ extract the length of the cache lines

arch/arm/mm/cache-v7m.S

@@ -183,13 +183,13 @@ flush_levels:
 	and	r1, r1, #7			@ mask of the bits for current cache only
 	cmp	r1, #2				@ see what cache we have at this level
 	blt	skip				@ skip if no cache, or just i-cache
-#ifdef CONFIG_PREEMPT
+#ifdef CONFIG_PREEMPTION
 	save_and_disable_irqs_notrace r9	@ make cssr&csidr read atomic
 #endif
 	write_csselr r10, r1			@ set current cache level
 	isb					@ isb to sych the new cssr&csidr
 	read_ccsidr r1				@ read the new csidr
-#ifdef CONFIG_PREEMPT
+#ifdef CONFIG_PREEMPTION
 	restore_irqs_notrace r9
 #endif
 	and	r2, r1, #7			@ extract the length of the cache lines