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From:   Santosh Sivaraj <santosh@fossix.org>
To:     linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
        Linux Kernel <linux-kernel@vger.kernel.org>
Cc:     "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>,
        Mahesh Salgaonkar <mahesh@linux.ibm.com>,
        Reza Arbab <arbab@linux.ibm.com>,
        Balbir Singh <bsingharora@gmail.com>,
        Chandan Rajendra <chandan@linux.vnet.ibm.com>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Nicholas Piggin <npiggin@gmail.com>,
        christophe leroy <christophe.leroy@c-s.fr>,
        Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>,
        stable@vger.kernel.org
Subject: [PATCH v9 1/7] powerpc/mce: Schedule work from irq_work
Date:   Mon, 12 Aug 2019 14:52:30 +0530
Message-Id: <20190812092236.16648-2-santosh@fossix.org>
In-Reply-To: <20190812092236.16648-1-santosh@fossix.org>
References: <20190812092236.16648-1-santosh@fossix.org>
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Sender: linux-kernel-owner@vger.kernel.org
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schedule_work() cannot be called from MCE exception context as MCE can
interrupt even in interrupt disabled context.

fixes: 733e4a4c ("powerpc/mce: hookup memory_failure for UE errors")
Suggested-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Santosh Sivaraj <santosh@fossix.org>
Cc: stable@vger.kernel.org # v4.15+
---
 arch/powerpc/kernel/mce.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/mce.c b/arch/powerpc/kernel/mce.c
index b18df633eae9..cff31d4a501f 100644
--- a/arch/powerpc/kernel/mce.c
+++ b/arch/powerpc/kernel/mce.c
@@ -33,6 +33,7 @@ static DEFINE_PER_CPU(struct machine_check_event[MAX_MC_EVT],
 					mce_ue_event_queue);
 
 static void machine_check_process_queued_event(struct irq_work *work);
+static void machine_check_ue_irq_work(struct irq_work *work);
 void machine_check_ue_event(struct machine_check_event *evt);
 static void machine_process_ue_event(struct work_struct *work);
 
@@ -40,6 +41,10 @@ static struct irq_work mce_event_process_work = {
         .func = machine_check_process_queued_event,
 };
 
+static struct irq_work mce_ue_event_irq_work = {
+	.func = machine_check_ue_irq_work,
+};
+
 DECLARE_WORK(mce_ue_event_work, machine_process_ue_event);
 
 static void mce_set_error_info(struct machine_check_event *mce,
@@ -199,6 +204,10 @@ void release_mce_event(void)
 	get_mce_event(NULL, true);
 }
 
+static void machine_check_ue_irq_work(struct irq_work *work)
+{
+	schedule_work(&mce_ue_event_work);
+}
 
 /*
  * Queue up the MCE event which then can be handled later.
@@ -216,7 +225,7 @@ void machine_check_ue_event(struct machine_check_event *evt)
 	memcpy(this_cpu_ptr(&mce_ue_event_queue[index]), evt, sizeof(*evt));
 
 	/* Queue work to process this event later. */
-	schedule_work(&mce_ue_event_work);
+	irq_work_queue(&mce_ue_event_irq_work);
 }
 
 /*
-- 
2.21.0