From patchwork Fri Jan 11 15:28:58 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Will Deacon X-Patchwork-Id: 1966551 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by patchwork2.kernel.org (Postfix) with ESMTP id 031AEDF2A2 for ; Fri, 11 Jan 2013 15:33:43 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1TtgXh-0000We-4N; Fri, 11 Jan 2013 15:29:13 +0000 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1TtgXc-0000VD-Pp for linux-arm-kernel@lists.infradead.org; Fri, 11 Jan 2013 15:29:10 +0000 Received: from mudshark.cambridge.arm.com (mudshark.cambridge.arm.com [10.1.79.58]) by cam-admin0.cambridge.arm.com (8.12.6/8.12.6) with ESMTP id r0BFT5ki015730; Fri, 11 Jan 2013 15:29:05 GMT Received: by mudshark.cambridge.arm.com (Postfix, from userid 1000) id D91A4C2A9D; Fri, 11 Jan 2013 15:28:59 +0000 (GMT) From: Will Deacon To: linux-arm-kernel@lists.infradead.org Subject: [PATCH 3/3] ARM: hw_breakpoint: Debug powerdown support for self-hosted debug Date: Fri, 11 Jan 2013 15:28:58 +0000 Message-Id: <1357918138-20222-4-git-send-email-will.deacon@arm.com> X-Mailer: git-send-email 1.8.0 In-Reply-To: <1357918138-20222-1-git-send-email-will.deacon@arm.com> References: <1357918138-20222-1-git-send-email-will.deacon@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130111_102909_185978_19C315CA X-CRM114-Status: GOOD ( 16.95 ) X-Spam-Score: -7.6 (-------) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-7.6 points) pts rule name description ---- ---------------------- -------------------------------------------------- -5.0 RCVD_IN_DNSWL_HI RBL: Sender listed at http://www.dnswl.org/, high trust [217.140.96.50 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record -0.7 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: Will Deacon , Dietmar Eggemann X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org From: Dietmar Eggemann This patch introduces debug powerdown support for self-hosted debug for v7 and v7.1 debug architecture for a SinglePower system, i.e. a system without a separate core and debug power domain. On a SinglePower system the OS Lock is lost over a powerdown. If CONFIG_CPU_PM is set the new function pm_init() registers hw_breakpoint with CPU PM for a system supporting OS Save and Restore. Receiving a CPU PM EXIT notifier indicates that a single CPU has exited a low power state. A call to reset_ctrl_regs() is hooked into the CPU PM EXIT notifier chain. This function makes sure that the sticky power-down is clear (only v7 debug), the OS Double Lock is clear (only v7.1 debug) and it clears the OS Lock for v7 debug (for a system supporting OS Save and Restore) and v7.1 debug. Furthermore, it clears any vector-catch events and all breakpoint/watchpoint control/value registers for v7 and v7.1 debug. Signed-off-by: Dietmar Eggemann [will: removed redundant has_ossr check] Signed-off-by: Will Deacon --- arch/arm/kernel/hw_breakpoint.c | 28 +++++++++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-) diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c index 201d440..5eae53e 100644 --- a/arch/arm/kernel/hw_breakpoint.c +++ b/arch/arm/kernel/hw_breakpoint.c @@ -28,6 +28,7 @@ #include #include #include +#include #include #include @@ -1032,6 +1033,30 @@ static struct notifier_block __cpuinitdata dbg_reset_nb = { .notifier_call = dbg_reset_notify, }; +#ifdef CONFIG_CPU_PM +static int dbg_cpu_pm_notify(struct notifier_block *self, unsigned long action, + void *v) +{ + if (action == CPU_PM_EXIT) + reset_ctrl_regs(NULL); + + return NOTIFY_OK; +} + +static struct notifier_block __cpuinitdata dbg_cpu_pm_nb = { + .notifier_call = dbg_cpu_pm_notify, +}; + +static void __init pm_init(void) +{ + cpu_pm_register_notifier(&dbg_cpu_pm_nb); +} +#else +static inline void pm_init(void) +{ +} +#endif + static int __init arch_hw_breakpoint_init(void) { debug_arch = get_debug_arch(); @@ -1081,8 +1106,9 @@ static int __init arch_hw_breakpoint_init(void) hook_ifault_code(FAULT_CODE_DEBUG, hw_breakpoint_pending, SIGTRAP, TRAP_HWBKPT, "breakpoint debug exception"); - /* Register hotplug notifier. */ + /* Register hotplug and PM notifiers. */ register_cpu_notifier(&dbg_reset_nb); + pm_init(); return 0; } arch_initcall(arch_hw_breakpoint_init);