From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EFB48C433EF for ; Fri, 29 Apr 2022 14:36:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1377520AbiD2Ojq (ORCPT ); Fri, 29 Apr 2022 10:39:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56690 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1377679AbiD2Oj0 (ORCPT ); Fri, 29 Apr 2022 10:39:26 -0400 Received: from fanzine2.igalia.com (fanzine.igalia.com [178.60.130.6]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3AEBC27B33; Fri, 29 Apr 2022 07:36:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Content-Transfer-Encoding:Content-Type:In-Reply-To:From: References:Cc:To:Subject:MIME-Version:Date:Message-ID:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=ZdZBPtTkXvskvklO0DqGHW3vJ6Arb57ZyicMdsmwPPs=; b=Id0YxwZLmWV943xSSctc382COx slYd+Mbgd8mluBGRTtubiqJcFH7Jw+KCfrIBUuJ6IBjkEi3jycQJ/GZIWCNzfYdJZGxOzIKlAq9i5 NGU7dMo+j6aXXuC9zPnllvKUmp4j7d1NBQPsBNjzH1goO9ZNvF9j+05V5SxGqrz8IpFC/ke6Hqou9 ZUhvlX5vvgSwWpU57PqA3cf0RcC09NkmKHiXH92FbdJDx27V/PJs6cBfrjjyUhrMtQCOhvF+z0Tsu zF1ocWG4HwYZ0G6pmdbbbK4PGRnRNWBCGP+4DKIndhzsOY9kfvz7NjpBrTKt1RM1gSIvJ0Gc9QwYA dmc3mStA==; Received: from [179.113.53.197] (helo=[192.168.1.60]) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_128_GCM:128) (Exim) id 1nkRiK-0009WD-3O; Fri, 29 Apr 2022 16:35:20 +0200 Message-ID: <4a7d9670-92f8-3e12-a619-aaa64adca093@igalia.com> Date: Fri, 29 Apr 2022 11:34:51 -0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.8.0 Subject: Re: [PATCH 12/30] parisc: Replace regular spinlock with spin_trylock on panic path Content-Language: en-US To: Helge Deller , akpm@linux-foundation.org, bhe@redhat.com, pmladek@suse.com, kexec@lists.infradead.org Cc: linux-kernel@vger.kernel.org, bcm-kernel-feedback-list@broadcom.com, linuxppc-dev@lists.ozlabs.org, linux-alpha@vger.kernel.org, linux-edac@vger.kernel.org, linux-hyperv@vger.kernel.org, linux-leds@vger.kernel.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linux-pm@vger.kernel.org, linux-remoteproc@vger.kernel.org, linux-s390@vger.kernel.org, linux-tegra@vger.kernel.org, linux-um@lists.infradead.org, linux-xtensa@linux-xtensa.org, netdev@vger.kernel.org, openipmi-developer@lists.sourceforge.net, rcu@vger.kernel.org, sparclinux@vger.kernel.org, xen-devel@lists.xenproject.org, x86@kernel.org, kernel-dev@igalia.com, kernel@gpiccoli.net, halves@canonical.com, fabiomirmar@gmail.com, alejandro.j.jimenez@oracle.com, andriy.shevchenko@linux.intel.com, arnd@arndb.de, bp@alien8.de, corbet@lwn.net, d.hatayama@jp.fujitsu.com, dave.hansen@linux.intel.com, dyoung@redhat.com, feng.tang@intel.com, gregkh@linuxfoundation.org, mikelley@microsoft.com, hidehiro.kawai.ez@hitachi.com, jgross@suse.com, john.ogness@linutronix.de, keescook@chromium.org, luto@kernel.org, mhiramat@kernel.org, mingo@redhat.com, paulmck@kernel.org, peterz@infradead.org, rostedt@goodmis.org, senozhatsky@chromium.org, stern@rowland.harvard.edu, tglx@linutronix.de, vgoyal@redhat.com, vkuznets@redhat.com, will@kernel.org, "James E.J. Bottomley" References: <20220427224924.592546-1-gpiccoli@igalia.com> <20220427224924.592546-13-gpiccoli@igalia.com> <6a7c924a-54a9-c5ea-8a9d-3ea92987b436@gmx.de> From: "Guilherme G. Piccoli" In-Reply-To: <6a7c924a-54a9-c5ea-8a9d-3ea92987b436@gmx.de> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-remoteproc@vger.kernel.org On 28/04/2022 13:55, Helge Deller wrote: > [...] > You may add: > Acked-by: Helge Deller # parisc > > Helge Thanks Helge, added! Cheers, Guilherme > > >> --- >> arch/parisc/include/asm/pdc.h | 1 + >> arch/parisc/kernel/firmware.c | 27 +++++++++++++++++++++++---- >> drivers/parisc/power.c | 17 ++++++++++------- >> 3 files changed, 34 insertions(+), 11 deletions(-) >> >> diff --git a/arch/parisc/include/asm/pdc.h b/arch/parisc/include/asm/pdc.h >> index b643092d4b98..7a106008e258 100644 >> --- a/arch/parisc/include/asm/pdc.h >> +++ b/arch/parisc/include/asm/pdc.h >> @@ -83,6 +83,7 @@ int pdc_do_firm_test_reset(unsigned long ftc_bitmap); >> int pdc_do_reset(void); >> int pdc_soft_power_info(unsigned long *power_reg); >> int pdc_soft_power_button(int sw_control); >> +int pdc_soft_power_button_panic(int sw_control); >> void pdc_io_reset(void); >> void pdc_io_reset_devices(void); >> int pdc_iodc_getc(void); >> diff --git a/arch/parisc/kernel/firmware.c b/arch/parisc/kernel/firmware.c >> index 6a7e315bcc2e..0e2f70b592f4 100644 >> --- a/arch/parisc/kernel/firmware.c >> +++ b/arch/parisc/kernel/firmware.c >> @@ -1232,15 +1232,18 @@ int __init pdc_soft_power_info(unsigned long *power_reg) >> } >> >> /* >> - * pdc_soft_power_button - Control the soft power button behaviour >> - * @sw_control: 0 for hardware control, 1 for software control >> + * pdc_soft_power_button{_panic} - Control the soft power button behaviour >> + * @sw_control: 0 for hardware control, 1 for software control >> * >> * >> * This PDC function places the soft power button under software or >> * hardware control. >> - * Under software control the OS may control to when to allow to shut >> - * down the system. Under hardware control pressing the power button >> + * Under software control the OS may control to when to allow to shut >> + * down the system. Under hardware control pressing the power button >> * powers off the system immediately. >> + * >> + * The _panic version relies in spin_trylock to prevent deadlock >> + * on panic path. >> */ >> int pdc_soft_power_button(int sw_control) >> { >> @@ -1254,6 +1257,22 @@ int pdc_soft_power_button(int sw_control) >> return retval; >> } >> >> +int pdc_soft_power_button_panic(int sw_control) >> +{ >> + int retval; >> + unsigned long flags; >> + >> + if (!spin_trylock_irqsave(&pdc_lock, flags)) { >> + pr_emerg("Couldn't enable soft power button\n"); >> + return -EBUSY; /* ignored by the panic notifier */ >> + } >> + >> + retval = mem_pdc_call(PDC_SOFT_POWER, PDC_SOFT_POWER_ENABLE, __pa(pdc_result), sw_control); >> + spin_unlock_irqrestore(&pdc_lock, flags); >> + >> + return retval; >> +} >> + >> /* >> * pdc_io_reset - Hack to avoid overlapping range registers of Bridges devices. >> * Primarily a problem on T600 (which parisc-linux doesn't support) but >> diff --git a/drivers/parisc/power.c b/drivers/parisc/power.c >> index 456776bd8ee6..8512884de2cf 100644 >> --- a/drivers/parisc/power.c >> +++ b/drivers/parisc/power.c >> @@ -37,7 +37,6 @@ >> #include >> #include >> #include >> -#include >> #include >> #include >> #include >> @@ -175,16 +174,21 @@ static void powerfail_interrupt(int code, void *x) >> >> >> >> -/* parisc_panic_event() is called by the panic handler. >> - * As soon as a panic occurs, our tasklets above will not be >> - * executed any longer. This function then re-enables the >> - * soft-power switch and allows the user to switch off the system >> +/* >> + * parisc_panic_event() is called by the panic handler. >> + * >> + * As soon as a panic occurs, our tasklets above will not >> + * be executed any longer. This function then re-enables >> + * the soft-power switch and allows the user to switch off >> + * the system. We rely in pdc_soft_power_button_panic() >> + * since this version spin_trylocks (instead of regular >> + * spinlock), preventing deadlocks on panic path. >> */ >> static int parisc_panic_event(struct notifier_block *this, >> unsigned long event, void *ptr) >> { >> /* re-enable the soft-power switch */ >> - pdc_soft_power_button(0); >> + pdc_soft_power_button_panic(0); >> return NOTIFY_DONE; >> } >> >> @@ -193,7 +197,6 @@ static struct notifier_block parisc_panic_block = { >> .priority = INT_MAX, >> }; >> >> - >> static int __init power_init(void) >> { >> unsigned long ret; > From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 6067BC433F5 for ; Fri, 29 Apr 2022 14:36:54 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4KqZnJ4hjPz3brb for ; Sat, 30 Apr 2022 00:36:52 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=igalia.com header.i=@igalia.com header.a=rsa-sha256 header.s=20170329 header.b=Id0YxwZL; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=igalia.com (client-ip=178.60.130.6; helo=fanzine2.igalia.com; envelope-from=gpiccoli@igalia.com; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=igalia.com header.i=@igalia.com header.a=rsa-sha256 header.s=20170329 header.b=Id0YxwZL; dkim-atps=neutral Received: from fanzine2.igalia.com (fanzine.igalia.com [178.60.130.6]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4KqZmc25Mfz2ybB for ; Sat, 30 Apr 2022 00:36:11 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Content-Transfer-Encoding:Content-Type:In-Reply-To:From: References:Cc:To:Subject:MIME-Version:Date:Message-ID:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=ZdZBPtTkXvskvklO0DqGHW3vJ6Arb57ZyicMdsmwPPs=; b=Id0YxwZLmWV943xSSctc382COx slYd+Mbgd8mluBGRTtubiqJcFH7Jw+KCfrIBUuJ6IBjkEi3jycQJ/GZIWCNzfYdJZGxOzIKlAq9i5 NGU7dMo+j6aXXuC9zPnllvKUmp4j7d1NBQPsBNjzH1goO9ZNvF9j+05V5SxGqrz8IpFC/ke6Hqou9 ZUhvlX5vvgSwWpU57PqA3cf0RcC09NkmKHiXH92FbdJDx27V/PJs6cBfrjjyUhrMtQCOhvF+z0Tsu zF1ocWG4HwYZ0G6pmdbbbK4PGRnRNWBCGP+4DKIndhzsOY9kfvz7NjpBrTKt1RM1gSIvJ0Gc9QwYA dmc3mStA==; Received: from [179.113.53.197] (helo=[192.168.1.60]) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_128_GCM:128) (Exim) id 1nkRiK-0009WD-3O; Fri, 29 Apr 2022 16:35:20 +0200 Message-ID: <4a7d9670-92f8-3e12-a619-aaa64adca093@igalia.com> Date: Fri, 29 Apr 2022 11:34:51 -0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.8.0 Subject: Re: [PATCH 12/30] parisc: Replace regular spinlock with spin_trylock on panic path Content-Language: en-US To: Helge Deller , akpm@linux-foundation.org, bhe@redhat.com, pmladek@suse.com, kexec@lists.infradead.org References: <20220427224924.592546-1-gpiccoli@igalia.com> <20220427224924.592546-13-gpiccoli@igalia.com> <6a7c924a-54a9-c5ea-8a9d-3ea92987b436@gmx.de> From: "Guilherme G. Piccoli" In-Reply-To: <6a7c924a-54a9-c5ea-8a9d-3ea92987b436@gmx.de> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-hyperv@vger.kernel.org, halves@canonical.com, gregkh@linuxfoundation.org, peterz@infradead.org, alejandro.j.jimenez@oracle.com, linux-remoteproc@vger.kernel.org, feng.tang@intel.com, linux-mips@vger.kernel.org, "James E.J. Bottomley" , hidehiro.kawai.ez@hitachi.com, sparclinux@vger.kernel.org, will@kernel.org, tglx@linutronix.de, linux-leds@vger.kernel.org, linux-s390@vger.kernel.org, mikelley@microsoft.com, john.ogness@linutronix.de, corbet@lwn.net, paulmck@kernel.org, fabiomirmar@gmail.com, x86@kernel.org, mingo@redhat.com, bcm-kernel-feedback-list@broadcom.com, xen-devel@lists.xenproject.org, dyoung@redhat.com, vgoyal@redhat.com, linux-xtensa@linux-xtensa.org, dave.hansen@linux.intel.com, keescook@chromium.org, arnd@arndb.de, linux-pm@vger.kernel.org, linux-um@lists.infradead.org, rostedt@goodmis.org, rcu@vger.kernel.org, bp@alien8.de, luto@kernel.org, linux-tegra@vger.kernel.org, openipmi-developer@lists.sourceforge.net, andriy.shevchenko@linux.intel.com, linux-edac@vger.kernel.org, jgross@suse.com, linux-parisc@vger.kernel.org, netdev@vger.kernel.org, kernel@gpiccoli.net, linux-kernel@vger.kernel.org, stern@rowland.harvard.edu, senozhatsky@chromium.org, d.hatayama@jp.fujitsu.com, mhiramat@kernel.org, kernel-dev@igalia.com, linux-alpha@vger.kernel.org, vkuznets@redhat.com, linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On 28/04/2022 13:55, Helge Deller wrote: > [...] > You may add: > Acked-by: Helge Deller # parisc > > Helge Thanks Helge, added! Cheers, Guilherme > > >> --- >> arch/parisc/include/asm/pdc.h | 1 + >> arch/parisc/kernel/firmware.c | 27 +++++++++++++++++++++++---- >> drivers/parisc/power.c | 17 ++++++++++------- >> 3 files changed, 34 insertions(+), 11 deletions(-) >> >> diff --git a/arch/parisc/include/asm/pdc.h b/arch/parisc/include/asm/pdc.h >> index b643092d4b98..7a106008e258 100644 >> --- a/arch/parisc/include/asm/pdc.h >> +++ b/arch/parisc/include/asm/pdc.h >> @@ -83,6 +83,7 @@ int pdc_do_firm_test_reset(unsigned long ftc_bitmap); >> int pdc_do_reset(void); >> int pdc_soft_power_info(unsigned long *power_reg); >> int pdc_soft_power_button(int sw_control); >> +int pdc_soft_power_button_panic(int sw_control); >> void pdc_io_reset(void); >> void pdc_io_reset_devices(void); >> int pdc_iodc_getc(void); >> diff --git a/arch/parisc/kernel/firmware.c b/arch/parisc/kernel/firmware.c >> index 6a7e315bcc2e..0e2f70b592f4 100644 >> --- a/arch/parisc/kernel/firmware.c >> +++ b/arch/parisc/kernel/firmware.c >> @@ -1232,15 +1232,18 @@ int __init pdc_soft_power_info(unsigned long *power_reg) >> } >> >> /* >> - * pdc_soft_power_button - Control the soft power button behaviour >> - * @sw_control: 0 for hardware control, 1 for software control >> + * pdc_soft_power_button{_panic} - Control the soft power button behaviour >> + * @sw_control: 0 for hardware control, 1 for software control >> * >> * >> * This PDC function places the soft power button under software or >> * hardware control. >> - * Under software control the OS may control to when to allow to shut >> - * down the system. Under hardware control pressing the power button >> + * Under software control the OS may control to when to allow to shut >> + * down the system. Under hardware control pressing the power button >> * powers off the system immediately. >> + * >> + * The _panic version relies in spin_trylock to prevent deadlock >> + * on panic path. >> */ >> int pdc_soft_power_button(int sw_control) >> { >> @@ -1254,6 +1257,22 @@ int pdc_soft_power_button(int sw_control) >> return retval; >> } >> >> +int pdc_soft_power_button_panic(int sw_control) >> +{ >> + int retval; >> + unsigned long flags; >> + >> + if (!spin_trylock_irqsave(&pdc_lock, flags)) { >> + pr_emerg("Couldn't enable soft power button\n"); >> + return -EBUSY; /* ignored by the panic notifier */ >> + } >> + >> + retval = mem_pdc_call(PDC_SOFT_POWER, PDC_SOFT_POWER_ENABLE, __pa(pdc_result), sw_control); >> + spin_unlock_irqrestore(&pdc_lock, flags); >> + >> + return retval; >> +} >> + >> /* >> * pdc_io_reset - Hack to avoid overlapping range registers of Bridges devices. >> * Primarily a problem on T600 (which parisc-linux doesn't support) but >> diff --git a/drivers/parisc/power.c b/drivers/parisc/power.c >> index 456776bd8ee6..8512884de2cf 100644 >> --- a/drivers/parisc/power.c >> +++ b/drivers/parisc/power.c >> @@ -37,7 +37,6 @@ >> #include >> #include >> #include >> -#include >> #include >> #include >> #include >> @@ -175,16 +174,21 @@ static void powerfail_interrupt(int code, void *x) >> >> >> >> -/* parisc_panic_event() is called by the panic handler. >> - * As soon as a panic occurs, our tasklets above will not be >> - * executed any longer. This function then re-enables the >> - * soft-power switch and allows the user to switch off the system >> +/* >> + * parisc_panic_event() is called by the panic handler. >> + * >> + * As soon as a panic occurs, our tasklets above will not >> + * be executed any longer. This function then re-enables >> + * the soft-power switch and allows the user to switch off >> + * the system. We rely in pdc_soft_power_button_panic() >> + * since this version spin_trylocks (instead of regular >> + * spinlock), preventing deadlocks on panic path. >> */ >> static int parisc_panic_event(struct notifier_block *this, >> unsigned long event, void *ptr) >> { >> /* re-enable the soft-power switch */ >> - pdc_soft_power_button(0); >> + pdc_soft_power_button_panic(0); >> return NOTIFY_DONE; >> } >> >> @@ -193,7 +197,6 @@ static struct notifier_block parisc_panic_block = { >> .priority = INT_MAX, >> }; >> >> - >> static int __init power_init(void) >> { >> unsigned long ret; > From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guilherme G. Piccoli Date: Fri, 29 Apr 2022 11:34:51 -0300 Subject: [PATCH 12/30] parisc: Replace regular spinlock with spin_trylock on panic path In-Reply-To: <6a7c924a-54a9-c5ea-8a9d-3ea92987b436@gmx.de> References: <20220427224924.592546-1-gpiccoli@igalia.com> <20220427224924.592546-13-gpiccoli@igalia.com> <6a7c924a-54a9-c5ea-8a9d-3ea92987b436@gmx.de> Message-ID: <4a7d9670-92f8-3e12-a619-aaa64adca093@igalia.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: kexec@lists.infradead.org On 28/04/2022 13:55, Helge Deller wrote: > [...] > You may add: > Acked-by: Helge Deller # parisc > > Helge Thanks Helge, added! Cheers, Guilherme > > >> --- >> arch/parisc/include/asm/pdc.h | 1 + >> arch/parisc/kernel/firmware.c | 27 +++++++++++++++++++++++---- >> drivers/parisc/power.c | 17 ++++++++++------- >> 3 files changed, 34 insertions(+), 11 deletions(-) >> >> diff --git a/arch/parisc/include/asm/pdc.h b/arch/parisc/include/asm/pdc.h >> index b643092d4b98..7a106008e258 100644 >> --- a/arch/parisc/include/asm/pdc.h >> +++ b/arch/parisc/include/asm/pdc.h >> @@ -83,6 +83,7 @@ int pdc_do_firm_test_reset(unsigned long ftc_bitmap); >> int pdc_do_reset(void); >> int pdc_soft_power_info(unsigned long *power_reg); >> int pdc_soft_power_button(int sw_control); >> +int pdc_soft_power_button_panic(int sw_control); >> void pdc_io_reset(void); >> void pdc_io_reset_devices(void); >> int pdc_iodc_getc(void); >> diff --git a/arch/parisc/kernel/firmware.c b/arch/parisc/kernel/firmware.c >> index 6a7e315bcc2e..0e2f70b592f4 100644 >> --- a/arch/parisc/kernel/firmware.c >> +++ b/arch/parisc/kernel/firmware.c >> @@ -1232,15 +1232,18 @@ int __init pdc_soft_power_info(unsigned long *power_reg) >> } >> >> /* >> - * pdc_soft_power_button - Control the soft power button behaviour >> - * @sw_control: 0 for hardware control, 1 for software control >> + * pdc_soft_power_button{_panic} - Control the soft power button behaviour >> + * @sw_control: 0 for hardware control, 1 for software control >> * >> * >> * This PDC function places the soft power button under software or >> * hardware control. >> - * Under software control the OS may control to when to allow to shut >> - * down the system. Under hardware control pressing the power button >> + * Under software control the OS may control to when to allow to shut >> + * down the system. Under hardware control pressing the power button >> * powers off the system immediately. >> + * >> + * The _panic version relies in spin_trylock to prevent deadlock >> + * on panic path. >> */ >> int pdc_soft_power_button(int sw_control) >> { >> @@ -1254,6 +1257,22 @@ int pdc_soft_power_button(int sw_control) >> return retval; >> } >> >> +int pdc_soft_power_button_panic(int sw_control) >> +{ >> + int retval; >> + unsigned long flags; >> + >> + if (!spin_trylock_irqsave(&pdc_lock, flags)) { >> + pr_emerg("Couldn't enable soft power button\n"); >> + return -EBUSY; /* ignored by the panic notifier */ >> + } >> + >> + retval = mem_pdc_call(PDC_SOFT_POWER, PDC_SOFT_POWER_ENABLE, __pa(pdc_result), sw_control); >> + spin_unlock_irqrestore(&pdc_lock, flags); >> + >> + return retval; >> +} >> + >> /* >> * pdc_io_reset - Hack to avoid overlapping range registers of Bridges devices. >> * Primarily a problem on T600 (which parisc-linux doesn't support) but >> diff --git a/drivers/parisc/power.c b/drivers/parisc/power.c >> index 456776bd8ee6..8512884de2cf 100644 >> --- a/drivers/parisc/power.c >> +++ b/drivers/parisc/power.c >> @@ -37,7 +37,6 @@ >> #include >> #include >> #include >> -#include >> #include >> #include >> #include >> @@ -175,16 +174,21 @@ static void powerfail_interrupt(int code, void *x) >> >> >> >> -/* parisc_panic_event() is called by the panic handler. >> - * As soon as a panic occurs, our tasklets above will not be >> - * executed any longer. This function then re-enables the >> - * soft-power switch and allows the user to switch off the system >> +/* >> + * parisc_panic_event() is called by the panic handler. >> + * >> + * As soon as a panic occurs, our tasklets above will not >> + * be executed any longer. This function then re-enables >> + * the soft-power switch and allows the user to switch off >> + * the system. We rely in pdc_soft_power_button_panic() >> + * since this version spin_trylocks (instead of regular >> + * spinlock), preventing deadlocks on panic path. >> */ >> static int parisc_panic_event(struct notifier_block *this, >> unsigned long event, void *ptr) >> { >> /* re-enable the soft-power switch */ >> - pdc_soft_power_button(0); >> + pdc_soft_power_button_panic(0); >> return NOTIFY_DONE; >> } >> >> @@ -193,7 +197,6 @@ static struct notifier_block parisc_panic_block = { >> .priority = INT_MAX, >> }; >> >> - >> static int __init power_init(void) >> { >> unsigned long ret; > From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <4a7d9670-92f8-3e12-a619-aaa64adca093@igalia.com> Date: Fri, 29 Apr 2022 11:34:51 -0300 MIME-Version: 1.0 Subject: Re: [PATCH 12/30] parisc: Replace regular spinlock with spin_trylock on panic path Content-Language: en-US References: <20220427224924.592546-1-gpiccoli@igalia.com> <20220427224924.592546-13-gpiccoli@igalia.com> <6a7c924a-54a9-c5ea-8a9d-3ea92987b436@gmx.de> From: "Guilherme G. Piccoli" In-Reply-To: <6a7c924a-54a9-c5ea-8a9d-3ea92987b436@gmx.de> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-um" Errors-To: linux-um-bounces+geert=linux-m68k.org@lists.infradead.org To: Helge Deller , akpm@linux-foundation.org, bhe@redhat.com, pmladek@suse.com, kexec@lists.infradead.org Cc: linux-kernel@vger.kernel.org, bcm-kernel-feedback-list@broadcom.com, linuxppc-dev@lists.ozlabs.org, linux-alpha@vger.kernel.org, linux-edac@vger.kernel.org, linux-hyperv@vger.kernel.org, linux-leds@vger.kernel.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linux-pm@vger.kernel.org, linux-remoteproc@vger.kernel.org, linux-s390@vger.kernel.org, linux-tegra@vger.kernel.org, linux-um@lists.infradead.org, linux-xtensa@linux-xtensa.org, netdev@vger.kernel.org, openipmi-developer@lists.sourceforge.net, rcu@vger.kernel.org, sparclinux@vger.kernel.org, xen-devel@lists.xenproject.org, x86@kernel.org, kernel-dev@igalia.com, kernel@gpiccoli.net, halves@canonical.com, fabiomirmar@gmail.com, alejandro.j.jimenez@oracle.com, andriy.shevchenko@linux.intel.com, arnd@arndb.de, bp@alien8.de, corbet@lwn.net, d.hatayama@jp.fujitsu.com, dave.hansen@linux.intel.com, dyoung@redhat.com, feng.tang@intel.com, gregkh@linuxfoundation.org, mikelley@microsoft.com, hidehiro.kawai.ez@hitachi.com, jgross@suse.com, john.ogness@linutronix.de, keescook@chromium.org, luto@kernel.org, mhiramat@kernel.org, mingo@redhat.com, paulmck@kernel.org, peterz@infradead.org, rostedt@goodmis.org, senozhatsky@chromium.org, stern@rowland.harvard.edu, tglx@linutronix.de, vgoyal@redhat.com, vkuznets@redhat.com, will@kernel.org, "James E.J. Bottomley" On 28/04/2022 13:55, Helge Deller wrote: > [...] > You may add: > Acked-by: Helge Deller # parisc > > Helge Thanks Helge, added! Cheers, Guilherme > > >> --- >> arch/parisc/include/asm/pdc.h | 1 + >> arch/parisc/kernel/firmware.c | 27 +++++++++++++++++++++++---- >> drivers/parisc/power.c | 17 ++++++++++------- >> 3 files changed, 34 insertions(+), 11 deletions(-) >> >> diff --git a/arch/parisc/include/asm/pdc.h b/arch/parisc/include/asm/pdc.h >> index b643092d4b98..7a106008e258 100644 >> --- a/arch/parisc/include/asm/pdc.h >> +++ b/arch/parisc/include/asm/pdc.h >> @@ -83,6 +83,7 @@ int pdc_do_firm_test_reset(unsigned long ftc_bitmap); >> int pdc_do_reset(void); >> int pdc_soft_power_info(unsigned long *power_reg); >> int pdc_soft_power_button(int sw_control); >> +int pdc_soft_power_button_panic(int sw_control); >> void pdc_io_reset(void); >> void pdc_io_reset_devices(void); >> int pdc_iodc_getc(void); >> diff --git a/arch/parisc/kernel/firmware.c b/arch/parisc/kernel/firmware.c >> index 6a7e315bcc2e..0e2f70b592f4 100644 >> --- a/arch/parisc/kernel/firmware.c >> +++ b/arch/parisc/kernel/firmware.c >> @@ -1232,15 +1232,18 @@ int __init pdc_soft_power_info(unsigned long *power_reg) >> } >> >> /* >> - * pdc_soft_power_button - Control the soft power button behaviour >> - * @sw_control: 0 for hardware control, 1 for software control >> + * pdc_soft_power_button{_panic} - Control the soft power button behaviour >> + * @sw_control: 0 for hardware control, 1 for software control >> * >> * >> * This PDC function places the soft power button under software or >> * hardware control. >> - * Under software control the OS may control to when to allow to shut >> - * down the system. Under hardware control pressing the power button >> + * Under software control the OS may control to when to allow to shut >> + * down the system. Under hardware control pressing the power button >> * powers off the system immediately. >> + * >> + * The _panic version relies in spin_trylock to prevent deadlock >> + * on panic path. >> */ >> int pdc_soft_power_button(int sw_control) >> { >> @@ -1254,6 +1257,22 @@ int pdc_soft_power_button(int sw_control) >> return retval; >> } >> >> +int pdc_soft_power_button_panic(int sw_control) >> +{ >> + int retval; >> + unsigned long flags; >> + >> + if (!spin_trylock_irqsave(&pdc_lock, flags)) { >> + pr_emerg("Couldn't enable soft power button\n"); >> + return -EBUSY; /* ignored by the panic notifier */ >> + } >> + >> + retval = mem_pdc_call(PDC_SOFT_POWER, PDC_SOFT_POWER_ENABLE, __pa(pdc_result), sw_control); >> + spin_unlock_irqrestore(&pdc_lock, flags); >> + >> + return retval; >> +} >> + >> /* >> * pdc_io_reset - Hack to avoid overlapping range registers of Bridges devices. >> * Primarily a problem on T600 (which parisc-linux doesn't support) but >> diff --git a/drivers/parisc/power.c b/drivers/parisc/power.c >> index 456776bd8ee6..8512884de2cf 100644 >> --- a/drivers/parisc/power.c >> +++ b/drivers/parisc/power.c >> @@ -37,7 +37,6 @@ >> #include >> #include >> #include >> -#include >> #include >> #include >> #include >> @@ -175,16 +174,21 @@ static void powerfail_interrupt(int code, void *x) >> >> >> >> -/* parisc_panic_event() is called by the panic handler. >> - * As soon as a panic occurs, our tasklets above will not be >> - * executed any longer. This function then re-enables the >> - * soft-power switch and allows the user to switch off the system >> +/* >> + * parisc_panic_event() is called by the panic handler. >> + * >> + * As soon as a panic occurs, our tasklets above will not >> + * be executed any longer. This function then re-enables >> + * the soft-power switch and allows the user to switch off >> + * the system. We rely in pdc_soft_power_button_panic() >> + * since this version spin_trylocks (instead of regular >> + * spinlock), preventing deadlocks on panic path. >> */ >> static int parisc_panic_event(struct notifier_block *this, >> unsigned long event, void *ptr) >> { >> /* re-enable the soft-power switch */ >> - pdc_soft_power_button(0); >> + pdc_soft_power_button_panic(0); >> return NOTIFY_DONE; >> } >> >> @@ -193,7 +197,6 @@ static struct notifier_block parisc_panic_block = { >> .priority = INT_MAX, >> }; >> >> - >> static int __init power_init(void) >> { >> unsigned long ret; > _______________________________________________ linux-um mailing list linux-um@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-um From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Guilherme G. Piccoli" Subject: Re: [PATCH 12/30] parisc: Replace regular spinlock with spin_trylock on panic path Date: Fri, 29 Apr 2022 11:34:51 -0300 Message-ID: <4a7d9670-92f8-3e12-a619-aaa64adca093@igalia.com> References: <20220427224924.592546-1-gpiccoli@igalia.com> <20220427224924.592546-13-gpiccoli@igalia.com> <6a7c924a-54a9-c5ea-8a9d-3ea92987b436@gmx.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:From:References:Cc:To: Subject:MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=v44ZSdg7YMnBctrhBB6ScTdxL422Tf9ejrh22etJgAs=; b=rP+X3GRRA1hQ5x O2L1xdmheT+IpS9rf++ikpZHx6Iefcxk7N/buVQI9riCHbffynedYl+OXStVArIp2Uk0Y3OnKm9XP sclfxWgt7M+9EO3xID1kro/s9eCOuYi4p8Ywwa47qw+w5GBNU+0yE2eAwNVf6/Jwd9etiwvqilew1 EilXt803jZcnX35Gn3tCUYj4usNCfgOoilL3uYiTjZupeIvfulEpIboYDFUFnzfFx2dV+XkCAcRrP f8wCB+rnIIuRmnf52huXYPVP6M2y2AnFAAdVEOdtCbVPNDM8wSWSvkhwXcWRi6cZeFDOyrgaCPIga Inv8MjdGvQqHrdrWcQOA==; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Content-Transfer-Encoding:Content-Type:In-Reply-To:From: References:Cc:To:Subject:MIME-Version:Date:Message-ID:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=ZdZBPtTkXvskvklO0DqGHW3vJ6Arb57ZyicMdsmwPPs=; b=Id0YxwZLmWV943xSSctc382COx slYd+Mbgd8mluBGRTtubiqJcFH7Jw+KCfrIBUuJ6IBjkEi3jycQJ/GZIWCNzfYdJZGxOzIKlAq9i5 NGU7dMo+j6aXXuC9zPnllvKUmp4j7d1NBQPsBNjzH1goO9ZNvF9j+05V5SxGqrz8IpFC/ke6Hqou9 ZUhvlX5vvgSwWpU57PqA3cf0RcC09NkmKHiXH92FbdJDx27V/PJs6cBfrjjyUhrMtQCOhvF+z0Tsu zF1ocWG4HwYZ0G6pmdbbbK4PGRnRNWBCGP+4DKIndhzsOY9kfvz7NjpBrTKt1RM1gSIvJ0Gc9QwYA dmc3mStA==; Content-Language: en-US In-Reply-To: <6a7c924a-54a9-c5ea-8a9d-3ea92987b436@gmx.de> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-um" Errors-To: linux-um-bounces+glud-user-mode-linux-devel=m.gmane-mx.org@lists.infradead.org To: Helge Deller , akpm@linux-foundation.org, bhe@redhat.com, pmladek@suse.com, kexec@lists.infradead.org Cc: linux-kernel@vger.kernel.org, bcm-kernel-feedback-list@broadcom.com, linuxppc-dev@lists.ozlabs.org, linux-alpha@vger.kernel.org, linux-edac@vger.kernel.org, linux-hyperv@vger.kernel.org, linux-leds@vger.kernel.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linux-pm@vger.kernel.org, linux-remoteproc@vger.kernel.org, linux-s390@vger.kernel.org, linux-tegra@vger.kernel.org, linux-um@lists.infradead.org, linux-xtensa@linux-xtensa.org, netdev@vger.kernel.org, openipmi-developer@lists.sourceforge.net, rcu@vger.kernel.org, sparclinux@vger.kernel.org, xen-devel@lists.xenproject.org, x86@kernel.org, kernel-dev@igalia.com, kernel@gpiccoli.net, halves@canonical.com, fabiomirmar@gmail.com, alejandro.j.jimenez@oracle.com, andriy.shevchenko@linux.intel.com, arnd@arndb.de, bp@alien8.de, corbet@lwn.net, d.hatayama@jp.fujitsu.com, dave.hansen@linux.intel.com, dyoung@redh On 28/04/2022 13:55, Helge Deller wrote: > [...] > You may add: > Acked-by: Helge Deller # parisc > > Helge Thanks Helge, added! Cheers, Guilherme > > >> --- >> arch/parisc/include/asm/pdc.h | 1 + >> arch/parisc/kernel/firmware.c | 27 +++++++++++++++++++++++---- >> drivers/parisc/power.c | 17 ++++++++++------- >> 3 files changed, 34 insertions(+), 11 deletions(-) >> >> diff --git a/arch/parisc/include/asm/pdc.h b/arch/parisc/include/asm/pdc.h >> index b643092d4b98..7a106008e258 100644 >> --- a/arch/parisc/include/asm/pdc.h >> +++ b/arch/parisc/include/asm/pdc.h >> @@ -83,6 +83,7 @@ int pdc_do_firm_test_reset(unsigned long ftc_bitmap); >> int pdc_do_reset(void); >> int pdc_soft_power_info(unsigned long *power_reg); >> int pdc_soft_power_button(int sw_control); >> +int pdc_soft_power_button_panic(int sw_control); >> void pdc_io_reset(void); >> void pdc_io_reset_devices(void); >> int pdc_iodc_getc(void); >> diff --git a/arch/parisc/kernel/firmware.c b/arch/parisc/kernel/firmware.c >> index 6a7e315bcc2e..0e2f70b592f4 100644 >> --- a/arch/parisc/kernel/firmware.c >> +++ b/arch/parisc/kernel/firmware.c >> @@ -1232,15 +1232,18 @@ int __init pdc_soft_power_info(unsigned long *power_reg) >> } >> >> /* >> - * pdc_soft_power_button - Control the soft power button behaviour >> - * @sw_control: 0 for hardware control, 1 for software control >> + * pdc_soft_power_button{_panic} - Control the soft power button behaviour >> + * @sw_control: 0 for hardware control, 1 for software control >> * >> * >> * This PDC function places the soft power button under software or >> * hardware control. >> - * Under software control the OS may control to when to allow to shut >> - * down the system. Under hardware control pressing the power button >> + * Under software control the OS may control to when to allow to shut >> + * down the system. Under hardware control pressing the power button >> * powers off the system immediately. >> + * >> + * The _panic version relies in spin_trylock to prevent deadlock >> + * on panic path. >> */ >> int pdc_soft_power_button(int sw_control) >> { >> @@ -1254,6 +1257,22 @@ int pdc_soft_power_button(int sw_control) >> return retval; >> } >> >> +int pdc_soft_power_button_panic(int sw_control) >> +{ >> + int retval; >> + unsigned long flags; >> + >> + if (!spin_trylock_irqsave(&pdc_lock, flags)) { >> + pr_emerg("Couldn't enable soft power button\n"); >> + return -EBUSY; /* ignored by the panic notifier */ >> + } >> + >> + retval = mem_pdc_call(PDC_SOFT_POWER, PDC_SOFT_POWER_ENABLE, __pa(pdc_result), sw_control); >> + spin_unlock_irqrestore(&pdc_lock, flags); >> + >> + return retval; >> +} >> + >> /* >> * pdc_io_reset - Hack to avoid overlapping range registers of Bridges devices. >> * Primarily a problem on T600 (which parisc-linux doesn't support) but >> diff --git a/drivers/parisc/power.c b/drivers/parisc/power.c >> index 456776bd8ee6..8512884de2cf 100644 >> --- a/drivers/parisc/power.c >> +++ b/drivers/parisc/power.c >> @@ -37,7 +37,6 @@ >> #include >> #include >> #include >> -#include >> #include >> #include >> #include >> @@ -175,16 +174,21 @@ static void powerfail_interrupt(int code, void *x) >> >> >> >> -/* parisc_panic_event() is called by the panic handler. >> - * As soon as a panic occurs, our tasklets above will not be >> - * executed any longer. This function then re-enables the >> - * soft-power switch and allows the user to switch off the system >> +/* >> + * parisc_panic_event() is called by the panic handler. >> + * >> + * As soon as a panic occurs, our tasklets above will not >> + * be executed any longer. This function then re-enables >> + * the soft-power switch and allows the user to switch off >> + * the system. We rely in pdc_soft_power_button_panic() >> + * since this version spin_trylocks (instead of regular >> + * spinlock), preventing deadlocks on panic path. >> */ >> static int parisc_panic_event(struct notifier_block *this, >> unsigned long event, void *ptr) >> { >> /* re-enable the soft-power switch */ >> - pdc_soft_power_button(0); >> + pdc_soft_power_button_panic(0); >> return NOTIFY_DONE; >> } >> >> @@ -193,7 +197,6 @@ static struct notifier_block parisc_panic_block = { >> .priority = INT_MAX, >> }; >> >> - >> static int __init power_init(void) >> { >> unsigned long ret; >