Revert "arm64: preempt: Fix big-endian when checking preempt count in assembly"

This reverts commit 64694b276d74c653051637caa4bfa5e8c27b30ad which is
commit 7faa313f upstream.

Turns out one of the pre-requsite patches wasn't in 4.19.y, so this
patch didn't make sense.  So let's revert it.
Reported-by: NSteven Rostedt <rostedt@goodmis.org>
Reported-by: NWill Deacon <will@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Sasha Levin <sashal@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Conflicts:
  arch/arm64/kernel/entry.S
[yyl: adjust context]
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

arch/arm64/include/asm/assembler.h

@@ -675,9 +675,11 @@ USER(\label, ic	ivau, \tmp2)			// invalidate I line PoU
 	.macro		if_will_cond_yield_neon
 #ifdef CONFIG_PREEMPT
 	get_thread_info	x0
-	ldr		x0, [x0, #TSK_TI_PREEMPT]
-	sub		x0, x0, #PREEMPT_DISABLE_OFFSET
-	cbz		x0, .Lyield_\@
+	ldr		w1, [x0, #TSK_TI_PREEMPT]
+	ldr		x0, [x0, #TSK_TI_FLAGS]
+	cmp		w1, #PREEMPT_DISABLE_OFFSET
+	csel		x0, x0, xzr, eq
+	tbnz		x0, #TIF_NEED_RESCHED, .Lyield_\@	// needs rescheduling?
 	/* fall through to endif_yield_neon */
 	.subsection	1
 .Lyield_\@ :

arch/arm64/kernel/entry.S

@@ -681,16 +681,18 @@ el1_irq:
 	irq_handler
 
 #ifdef CONFIG_PREEMPT
-	ldr	x24, [tsk, #TSK_TI_PREEMPT]	// get preempt count
+	ldr	w24, [tsk, #TSK_TI_PREEMPT]	// get preempt count
 alternative_if ARM64_HAS_IRQ_PRIO_MASKING
 	/*
 	 * DA_F were cleared at start of handling. If anything is set in DAIF,
 	 * we come back from an NMI, so skip preemption
 	 */
 	mrs	x0, daif
-	orr	x24, x24, x0
+	orr	w24, w24, w0
 alternative_else_nop_endif
-	cbnz	x24, 1f				// preempt count != 0 || NMI return path
+	cbnz	w24, 1f				// preempt count != 0 || NMI return path
+	ldr	x0, [tsk, #TSK_TI_FLAGS]	// get flags
+	tbz	x0, #TIF_NEED_RESCHED, 1f	// needs rescheduling?
 	bl	el1_preempt
 1:
 #endif