[PATCH v2 3/5] powerpc: Use preemption model accessors

From: Valentin Schneider <valentin.schneider@arm.com>
To: linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com,
	linuxppc-dev@lists.ozlabs.org, linux-kbuild@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@kernel.org>,
	Frederic Weisbecker <frederic@kernel.org>,
	Mike Galbraith <efault@gmx.de>, Marco Elver <elver@google.com>,
	Dmitry Vyukov <dvyukov@google.com>,
	Michael Ellerman <mpe@ellerman.id.au>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Paul Mackerras <paulus@samba.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	Masahiro Yamada <masahiroy@kernel.org>,
	Michal Marek <michal.lkml@markovi.net>,
	Nick Desaulniers <ndesaulniers@google.com>
Subject: [PATCH v2 3/5] powerpc: Use preemption model accessors
Date: Wed, 10 Nov 2021 20:24:46 +0000	[thread overview]
Message-ID: <20211110202448.4054153-4-valentin.schneider@arm.com> (raw)
In-Reply-To: <20211110202448.4054153-1-valentin.schneider@arm.com>

Per PREEMPT_DYNAMIC, checking CONFIG_PREEMPT doesn't tell you the actual
preemption model of the live kernel. Use the newly-introduced accessors
instead.

sched_init() -> preempt_dynamic_init() happens way before IRQs are set up,
so this should be fine.

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
---
 arch/powerpc/kernel/interrupt.c | 2 +-
 arch/powerpc/kernel/traps.c     | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/interrupt.c b/arch/powerpc/kernel/interrupt.c
index de10a2697258..c56c10b59be3 100644
--- a/arch/powerpc/kernel/interrupt.c
+++ b/arch/powerpc/kernel/interrupt.c
@@ -552,7 +552,7 @@ notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs)
 		/* Returning to a kernel context with local irqs enabled. */
 		WARN_ON_ONCE(!(regs->msr & MSR_EE));
 again:
-		if (IS_ENABLED(CONFIG_PREEMPT)) {
+		if (is_preempt_full()) {
 			/* Return to preemptible kernel context */
 			if (unlikely(current_thread_info()->flags & _TIF_NEED_RESCHED)) {
 				if (preempt_count() == 0)
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index aac8c0412ff9..1cb31bbdc925 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -265,7 +265,7 @@ static int __die(const char *str, struct pt_regs *regs, long err)
 	printk("%s PAGE_SIZE=%luK%s%s%s%s%s%s %s\n",
 	       IS_ENABLED(CONFIG_CPU_LITTLE_ENDIAN) ? "LE" : "BE",
 	       PAGE_SIZE / 1024, get_mmu_str(),
-	       IS_ENABLED(CONFIG_PREEMPT) ? " PREEMPT" : "",
+	       is_preempt_full() ? " PREEMPT" : "",
 	       IS_ENABLED(CONFIG_SMP) ? " SMP" : "",
 	       IS_ENABLED(CONFIG_SMP) ? (" NR_CPUS=" __stringify(NR_CPUS)) : "",
 	       debug_pagealloc_enabled() ? " DEBUG_PAGEALLOC" : "",
-- 
2.25.1

