From patchwork Mon Jan 23 21:09:47 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans de Goede X-Patchwork-Id: 9533461 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 10F1260434 for ; Mon, 23 Jan 2017 21:10:14 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 031ED27CFC for ; Mon, 23 Jan 2017 21:10:14 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id EBEF5283FD; Mon, 23 Jan 2017 21:10:13 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 9DB3227CFC for ; Mon, 23 Jan 2017 21:10:13 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 93C3D6E627; Mon, 23 Jan 2017 21:10:11 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by gabe.freedesktop.org (Postfix) with ESMTPS id 7E22A6E624; Mon, 23 Jan 2017 21:10:09 +0000 (UTC) Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 0D4B27FE81; Mon, 23 Jan 2017 21:10:10 +0000 (UTC) Received: from shalem.localdomain.com (ovpn-116-98.ams2.redhat.com [10.36.116.98]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id v0NLA0eW025633; Mon, 23 Jan 2017 16:10:07 -0500 From: Hans de Goede To: Daniel Vetter , Jani Nikula , =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= , Jarkko Nikula , Wolfram Sang , Len Brown , Andy Shevchenko , Thomas Gleixner , "H . Peter Anvin" Subject: [PATCH v2 02/13] x86/platform/intel/iosf_mbi: Add a PMIC bus access notifier Date: Mon, 23 Jan 2017 22:09:47 +0100 Message-Id: <20170123210958.18410-3-hdegoede@redhat.com> In-Reply-To: <20170123210958.18410-1-hdegoede@redhat.com> References: <20170123210958.18410-1-hdegoede@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Mon, 23 Jan 2017 21:10:10 +0000 (UTC) Cc: "russianneuromancer @ ya . ru" , intel-gfx , dri-devel@lists.freedesktop.org, Hans de Goede , linux-i2c@vger.kernel.org, Mika Westerberg X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP Some drivers may need to acquire P-Unit managed resources from interrupt context, where they cannot call iosf_mbi_punit_acquire(). This commit adds a notifier chain which allows a driver to get notified (in a process context) before other drivers start accessing the PMIC bus, so that the driver can acquire any resources, which it may need during the window the other driver is accessing the PMIC, before hand. BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=155241 Signed-off-by: Hans de Goede Tested-by: tagorereddy Reviewed-by: Andy Shevchenko --- Changes in v2: -Spelling: P-Unit, PMIC -Adjust for iosf_mbi_punit_lock/_unlock to _acquire/_release rename --- arch/x86/include/asm/iosf_mbi.h | 54 ++++++++++++++++++++++++++++++++++++++ arch/x86/platform/intel/iosf_mbi.c | 36 +++++++++++++++++++++++++ 2 files changed, 90 insertions(+) diff --git a/arch/x86/include/asm/iosf_mbi.h b/arch/x86/include/asm/iosf_mbi.h index f6119d0..59e8f8b 100644 --- a/arch/x86/include/asm/iosf_mbi.h +++ b/arch/x86/include/asm/iosf_mbi.h @@ -47,6 +47,10 @@ #define QRK_MBI_UNIT_MM 0x05 #define QRK_MBI_UNIT_SOC 0x31 +/* Action values for the pmic_bus_access_notifier functions */ +#define MBI_PMIC_BUS_ACCESS_BEGIN 1 +#define MBI_PMIC_BUS_ACCESS_END 2 + #if IS_ENABLED(CONFIG_IOSF_MBI) bool iosf_mbi_available(void); @@ -115,6 +119,38 @@ void iosf_mbi_punit_acquire(void); */ void iosf_mbi_punit_release(void); +/** + * iosf_mbi_register_pmic_bus_access_notifier - Register PMIC bus notifier + * + * This function can be used by drivers which may need to acquire P-Unit + * managed resources from interrupt context, where iosf_mbi_punit_acquire() + * can not be used. + * + * This function allows a driver to register a notifier to get notified (in a + * process context) before other drivers start accessing the PMIC bus. + * + * This allows the driver to acquire any resources, which it may need during + * the window the other driver is accessing the PMIC, before hand. + * + * @nb: notifier_block to register + */ +int iosf_mbi_register_pmic_bus_access_notifier(struct notifier_block *nb); + +/** + * iosf_mbi_register_pmic_bus_access_notifier - Unregister PMIC bus notifier + * + * @nb: notifier_block to unregister + */ +int iosf_mbi_unregister_pmic_bus_access_notifier(struct notifier_block *nb); + +/** + * iosf_mbi_call_pmic_bus_access_notifier_chain - Call PMIC bus notifier chain + * + * @val: action to pass into listener's notifier_call function + * @v: data pointer to pass into listener's notifier_call function + */ +int iosf_mbi_call_pmic_bus_access_notifier_chain(unsigned long val, void *v); + #else /* CONFIG_IOSF_MBI is not enabled */ static inline bool iosf_mbi_available(void) @@ -146,6 +182,24 @@ int iosf_mbi_modify(u8 port, u8 opcode, u32 offset, u32 mdr, u32 mask) static inline void iosf_mbi_punit_acquire(void) {} static inline void iosf_mbi_punit_release(void) {} +static inline +int iosf_mbi_register_pmic_bus_access_notifier(struct notifier_block *nb) +{ + return 0; +} + +static inline +int iosf_mbi_unregister_pmic_bus_access_notifier(struct notifier_block *nb) +{ + return 0; +} + +static inline +int iosf_mbi_call_pmic_bus_access_notifier_chain(unsigned long val, void *v) +{ + return 0; +} + #endif /* CONFIG_IOSF_MBI */ #endif /* IOSF_MBI_SYMS_H */ diff --git a/arch/x86/platform/intel/iosf_mbi.c b/arch/x86/platform/intel/iosf_mbi.c index ed24fa9f..a952ac1 100644 --- a/arch/x86/platform/intel/iosf_mbi.c +++ b/arch/x86/platform/intel/iosf_mbi.c @@ -35,6 +35,7 @@ static struct pci_dev *mbi_pdev; static DEFINE_SPINLOCK(iosf_mbi_lock); static DEFINE_MUTEX(iosf_mbi_punit_mutex); +static BLOCKING_NOTIFIER_HEAD(iosf_mbi_pmic_bus_access_notifier); static inline u32 iosf_mbi_form_mcr(u8 op, u8 port, u8 offset) { @@ -203,6 +204,41 @@ void iosf_mbi_punit_release(void) } EXPORT_SYMBOL(iosf_mbi_punit_release); +int iosf_mbi_register_pmic_bus_access_notifier(struct notifier_block *nb) +{ + int ret; + + /* Wait for the bus to go inactive before registering */ + mutex_lock(&iosf_mbi_punit_mutex); + ret = blocking_notifier_chain_register( + &iosf_mbi_pmic_bus_access_notifier, nb); + mutex_unlock(&iosf_mbi_punit_mutex); + + return ret; +} +EXPORT_SYMBOL(iosf_mbi_register_pmic_bus_access_notifier); + +int iosf_mbi_unregister_pmic_bus_access_notifier(struct notifier_block *nb) +{ + int ret; + + /* Wait for the bus to go inactive before unregistering */ + mutex_lock(&iosf_mbi_punit_mutex); + ret = blocking_notifier_chain_unregister( + &iosf_mbi_pmic_bus_access_notifier, nb); + mutex_unlock(&iosf_mbi_punit_mutex); + + return ret; +} +EXPORT_SYMBOL(iosf_mbi_unregister_pmic_bus_access_notifier); + +int iosf_mbi_call_pmic_bus_access_notifier_chain(unsigned long val, void *v) +{ + return blocking_notifier_call_chain( + &iosf_mbi_pmic_bus_access_notifier, val, v); +} +EXPORT_SYMBOL(iosf_mbi_call_pmic_bus_access_notifier_chain); + #ifdef CONFIG_IOSF_MBI_DEBUG static u32 dbg_mdr; static u32 dbg_mcr;