linux-kernel - [PATCH RT] powerpc: Fixup compile and lazy-preempt

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Date:   Tue, 3 Dec 2019 18:37:43 +0100
From:   Sebastian Andrzej Siewior <bigeasy@...utronix.de>
To:     LKML <linux-kernel@...r.kernel.org>
Cc:     Steven Rostedt <rostedt@...dmis.org>,
        linux-rt-users <linux-rt-users@...r.kernel.org>,
        Thomas Gleixner <tglx@...utronix.de>
Subject: [PATCH RT] powerpc: Fixup compile and lazy-preempt

Since the softirq rework 32bit POWER does not compile because
get_current() is not provided - just the `current' macro.
Use the `current' instead.

Since the v5.2-RT series, the lazy-preempt code is broken. It loads the
lazy-counter and flags from the R9 but R2 should be used.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@...utronix.de>
---
 arch/powerpc/kernel/entry_32.S | 4 ++--
 include/linux/preempt.h        | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index d37b373104502..004944258387b 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -893,10 +893,10 @@ user_exc_return:		/* r10 contains MSR_KERNEL here */
 	bne	restore_kuap
 	andi.	r8,r8,_TIF_NEED_RESCHED
 	bne+	1f
-	lwz	r0,TI_PREEMPT_LAZY(r9)
+	lwz	r0,TI_PREEMPT_LAZY(r2)
 	cmpwi	0,r0,0          /* if non-zero, just restore regs and return */
 	bne	restore_kuap
-	lwz	r0,TI_FLAGS(r9)
+	lwz	r0,TI_FLAGS(r2)
 	andi.	r0,r0,_TIF_NEED_RESCHED_LAZY
 	beq+	restore_kuap
 1:
diff --git a/include/linux/preempt.h b/include/linux/preempt.h
index d559e3a0379c2..7653dd58b4b21 100644
--- a/include/linux/preempt.h
+++ b/include/linux/preempt.h
@@ -100,9 +100,9 @@
 				   (NMI_MASK | HARDIRQ_MASK | SOFTIRQ_OFFSET)))
 #ifdef CONFIG_PREEMPT_RT_FULL
 
-#define softirq_count()		((long)get_current()->softirq_count)
+#define softirq_count()		(current->softirq_count)
 #define in_softirq()		(softirq_count())
-#define in_serving_softirq()	(get_current()->softirq_count & SOFTIRQ_OFFSET)
+#define in_serving_softirq()	(current->softirq_count & SOFTIRQ_OFFSET)
 
 #else
 
-- 
2.24.0