From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1755074AbbBTRIr (ORCPT <rfc822;w@1wt.eu>);
	Fri, 20 Feb 2015 12:08:47 -0500
Received: from e8.ny.us.ibm.com ([32.97.182.138]:35510 "EHLO e8.ny.us.ibm.com"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S1754955AbbBTRIp (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
	Fri, 20 Feb 2015 12:08:45 -0500
Message-ID: <54E76A16.306@us.ibm.com>
Date: Fri, 20 Feb 2015 11:08:38 -0600
From: Paul Clarke <pc@us.ibm.com>
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0
MIME-Version: 1.0
To: "linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>
CC: Michael Ellerman <mpe@ellerman.id.au>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        linux-kernel@vger.kernel.org,
        "@linux.vnet.ibm.com,Frederic Weisbecker <fweisbec@gmail.com>"@d01av03.pok.ibm.com
Subject: [PATCH v2] powerpc: re-enable dynticks
References: <54DE52BC.3020303@us.ibm.com> <1424045319.3018.2.camel@ellerman.id.au>
In-Reply-To: <1424045319.3018.2.camel@ellerman.id.au>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 7bit
X-TM-AS-MML: disable
X-Content-Scanned: Fidelis XPS MAILER
x-cbid: 15022017-0029-0000-0000-0000020E42E1
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

implement arch_irq_work_has_interrupt() for powerpc

Commit 9b01f5bf3 introduced a dependency on "IRQ work self-IPIs" for 
full dynamic ticks to be enabled, by expecting architectures to 
implement a suitable arch_irq_work_has_interrupt() routine.

Several arches have implemented this routine, including x86 (3010279f) 
and arm (09f6edd4), but powerpc was omitted.

This patch implements this routine for powerpc.

The symptom, at boot (on powerpc arch systems) with "nohz_full=<CPU 
list>" is displayed:
     NO_HZ: Can't run full dynticks because arch doesn't support irq 
work self-IPIs

after this patch:
     NO_HZ: Full dynticks CPUs: <CPU list>.

Tested against 3.19.

v2: changed "return 1" to "return true", per Michael Ellerman

CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Paul A. Clarke <pc@us.ibm.com>

diff --git a/arch/powerpc/include/asm/irq_work.h 
b/arch/powerpc/include/asm/irq_work.h
new file mode 100644
index 0000000..99cc0aa
--- /dev/null
+++ b/arch/powerpc/include/asm/irq_work.h
@@ -0,0 +1,11 @@
+#ifndef _ASM_IRQ_WORK_H
+#define _ASM_IRQ_WORK_H
+
+#include <asm/processor.h>
+
+static inline bool arch_irq_work_has_interrupt(void)
+{
+	return true;
+}
+
+#endif /* _ASM_IRQ_WORK_H */