From patchwork Wed Jun 29 09:21:14 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Russell King - ARM Linux X-Patchwork-Id: 927822 Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by demeter2.kernel.org (8.14.4/8.14.4) with ESMTP id p5T9NeTU024821 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Wed, 29 Jun 2011 09:24:01 GMT Received: from canuck.infradead.org ([134.117.69.58]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1Qbqy2-0007bA-GG; Wed, 29 Jun 2011 09:21:55 +0000 Received: from localhost ([127.0.0.1] helo=canuck.infradead.org) by canuck.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1Qbqxu-00010k-3s; Wed, 29 Jun 2011 09:21:46 +0000 Received: from [2002:4e20:1eda::1] (helo=caramon.arm.linux.org.uk) by canuck.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1QbqxU-0000tV-GG for linux-arm-kernel@lists.infradead.org; Wed, 29 Jun 2011 09:21:22 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=arm.linux.org.uk; s=caramon; h=Date:Sender:Message-Id:Content-Type:MIME-Version:Subject:To:From:References:In-Reply-To; bh=WrtfmSBrXWDnZYl/ldVuleata+nJ68F81CVd8syBD2I=; b=UJ96hfb/Rx30jtBSLUOIg5K1VKKyAkjQA3gAQcbHNVLXPBuoE/ZJe/klqZi3vXErRqf+cdZSQwR/U9xnr/iDUp/7/QTM24nqirwCLhzXAeMRuEf3LnN+AoL6eH0b5DMVVLJ86y0q5Jk70IoQIQTgOb90KtOx8caas+iGgXEs2ZA=; Received: from e0022681537dd.dyn.arm.linux.org.uk ([2002:4e20:1eda:1:222:68ff:fe15:37dd] helo=rmk-PC.arm.linux.org.uk) by caramon.arm.linux.org.uk with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.72) (envelope-from ) id 1QbqxQ-00040J-2F for linux-arm-kernel@lists.infradead.org; Wed, 29 Jun 2011 10:21:16 +0100 Received: from rmk by rmk-PC.arm.linux.org.uk with local (Exim 4.76) (envelope-from ) id 1QbqxO-0002F8-Gm for linux-arm-kernel@lists.infradead.org; Wed, 29 Jun 2011 10:21:14 +0100 In-Reply-To: <20110629091853.GK21898@n2100.arm.linux.org.uk> References: <20110629091853.GK21898@n2100.arm.linux.org.uk> From: Russell King - ARM Linux To: linux-arm-kernel@lists.infradead.org Subject: [PATCH 07/23] ARM: entry: no need to increase preempt count for IRQ handlers MIME-Version: 1.0 Content-Disposition: inline Message-Id: Date: Wed, 29 Jun 2011 10:21:14 +0100 X-CRM114-Version: 20090807-BlameThorstenAndJenny ( TRE 0.7.6 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20110629_052121_265179_C1912472 X-CRM114-Status: GOOD ( 11.09 ) X-Spam-Score: 1.2 (+) X-Spam-Report: SpamAssassin version 3.3.1 on canuck.infradead.org summary: Content analysis details: (1.2 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature 1.3 RDNS_NONE Delivered to internal network by a host with no rDNS 0.0 TO_NO_BRKTS_NORDNS To: misformatted and no rDNS X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter2.kernel.org [140.211.167.43]); Wed, 29 Jun 2011 09:24:01 +0000 (UTC) irq_enter() and irq_exit() already take care of the preempt_count handling for interrupts, which increment and decrement the hardirq bits of the preempt count. So we can remove the preempt count handing in our IRQ entry/exit assembly, like x86 did some 9 years ago. Signed-off-by: Russell King --- arch/arm/kernel/entry-armv.S | 27 ++++----------------------- 1 files changed, 4 insertions(+), 23 deletions(-) diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S index 6855f6d..1e5f387 100644 --- a/arch/arm/kernel/entry-armv.S +++ b/arch/arm/kernel/entry-armv.S @@ -220,16 +220,12 @@ __irq_svc: #ifdef CONFIG_TRACE_IRQFLAGS bl trace_hardirqs_off #endif -#ifdef CONFIG_PREEMPT - get_thread_info tsk - ldr r8, [tsk, #TI_PREEMPT] @ get preempt count - add r7, r8, #1 @ increment it - str r7, [tsk, #TI_PREEMPT] -#endif irq_handler + #ifdef CONFIG_PREEMPT - str r8, [tsk, #TI_PREEMPT] @ restore preempt count + get_thread_info tsk + ldr r8, [tsk, #TI_PREEMPT] @ get preempt count ldr r0, [tsk, #TI_FLAGS] @ get flags teq r8, #0 @ if preempt count != 0 movne r0, #0 @ force flags to 0 @@ -432,23 +428,8 @@ __irq_usr: bl trace_hardirqs_off #endif - get_thread_info tsk -#ifdef CONFIG_PREEMPT - ldr r8, [tsk, #TI_PREEMPT] @ get preempt count - add r7, r8, #1 @ increment it - str r7, [tsk, #TI_PREEMPT] -#endif - irq_handler -#ifdef CONFIG_PREEMPT - ldr r0, [tsk, #TI_PREEMPT] - str r8, [tsk, #TI_PREEMPT] - teq r0, r7 - ARM( strne r0, [r0, -r0] ) - THUMB( movne r0, #0 ) - THUMB( strne r0, [r0] ) -#endif - + get_thread_info tsk mov why, #0 b ret_to_user_from_irq UNWIND(.fnend )