From patchwork Sun Sep 27 19:49:21 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Gleixner X-Patchwork-Id: 258387 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B7A93C4727E for ; Sun, 27 Sep 2020 19:59:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8025623A53 for ; Sun, 27 Sep 2020 19:59:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="aHzJrPYU"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="mU8Ag4Ub" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726699AbgI0T7H (ORCPT ); Sun, 27 Sep 2020 15:59:07 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:41008 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727132AbgI0T6F (ORCPT ); Sun, 27 Sep 2020 15:58:05 -0400 Message-Id: <20200927194923.358900104@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1601236669; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: references:references; bh=ksaGPqhXSZGY4WnWtBR0byDM8dQ34v3PX/0X3fUvpQM=; b=aHzJrPYU7FfUq814LOC20bsDMxiPF9kl5hv062qPTqnIj6StKd0bSDSLccSvRmXIASHhqf aZR5++WuDmDCfI0fjwrlc0bANro81Ge/6/SkWNWmZ7CknohO75MPmk9RUBx5Zs8csm8eJT +Vmk+qsZAPDw/MNaszn3bnwgnoPnRmygxJEr9cPQJPSgLgnjJpMVakzJ8DEfBCO7HU43Im Ooc/O8v/j4db+A3q92vkqFI0aR/1S7RwPqw3jHr20cFbFMPPTVPePJFAwB/2G0nzplV+hz gvCImYxktX+py8y+YnjKDpKSVo5Z89DdMSDLczbEle3un0h6LIMG4Nn2GX9S8g== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1601236669; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: references:references; bh=ksaGPqhXSZGY4WnWtBR0byDM8dQ34v3PX/0X3fUvpQM=; b=mU8Ag4UbwIj964lLMObE7JECFn2QEeMPOgKxS1KjDCTPv+aDXN3i+2v1K3ZjxYIiCh4FfZ AJv7/jn/6+S5qpBQ== Date: Sun, 27 Sep 2020 21:49:21 +0200 From: Thomas Gleixner To: LKML Cc: Peter Zijlstra , Linus Torvalds , Paul McKenney , Matthew Wilcox , Sebastian Andrzej Siewior , Ping-Ke Shih , Kalle Valo , "David S. Miller" , Jakub Kicinski , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, Christian Benvenuti , Govindarajulu Varadarajan <_govind@gmx.com>, Dave Miller , Jonathan Corbet , Mauro Carvalho Chehab , linux-doc@vger.kernel.org, Luc Van Oostenryck , Jay Cliburn , Chris Snook , Vishal Kulkarni , Jeff Kirsher , intel-wired-lan@lists.osuosl.org, Shannon Nelson , Pensando Drivers , Andrew Lunn , Heiner Kallweit , Russell King , Thomas Bogendoerfer , Solarflare linux maintainers , Edward Cree , Martin Habets , Jon Mason , Daniel Drake , Ulrich Kunitz , linux-usb@vger.kernel.org, Greg Kroah-Hartman , Arend van Spriel , Franky Lin , Hante Meuleman , Chi-Hsien Lin , Wright Feng , brcm80211-dev-list.pdl@broadcom.com, brcm80211-dev-list@cypress.com, Stanislav Yakovlev , Stanislaw Gruszka , Johannes Berg , Emmanuel Grumbach , Luca Coelho , Intel Linux Wireless , Jouni Malinen , Amitkumar Karwar , Ganapathi Bhat , Xinming Hu , libertas-dev@lists.infradead.org, Pascal Terjan Subject: [patch 35/35] net: rtlwifi: Replace in_interrupt() for context detection References: <20200927194846.045411263@linutronix.de> MIME-Version: 1.0 Content-transfer-encoding: 8-bit Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org From: Sebastian Andrzej Siewior rtl_lps_enter() and rtl_lps_leave() are using in_interrupt() to detect whether it is safe to acquire a mutex or if it is required to defer to a workqueue. The usage of in_interrupt() in drivers is phased out and Linus clearly requested that code which changes behaviour depending on context should either be seperated or the context be conveyed in an argument passed by the caller, which usually knows the context. in_interrupt() also is only partially correct because it fails to chose the correct code path when just preemption or interrupts are disabled. Add an argument 'may_block' to both functions and adjust the callers to pass the context information. The following call chains were analyzed to be safe to block: rtl_watchdog_wq_callback() rlf_lps_leave/enter() rtl_op_suspend() rtl_lps_leave() rtl_op_bss_info_changed() rtl_lps_leave() rtl_op_sw_scan_start() rtl_lps_leave() The following call chains were analyzed to be unsafe to block: _rtl_pci_interrupt() _rtl_pci_rx_interrupt() rtl_lps_leave() _rtl_pci_interrupt() _rtl_pci_rx_interrupt() rtl_is_special_data() rtl_lps_leave() _rtl_pci_interrupt() _rtl_pci_rx_interrupt() rtl_is_special_data() setup_special_tx() rtl_lps_leave() _rtl_pci_interrupt() _rtl_pci_tx_isr rtl_lps_leave() halbtc_leave_lps() rtl_lps_leave() This leaves four callers of rtl_lps_enter/leave() where the analyzis stopped dead in the maze of several nested pointer based callchains and lack of rtlwifi hardware to debug this via tracing: halbtc_leave_lps(), halbtc_enter_lps(), halbtc_normal_lps(), halbtc_pre_normal_lps() These four have been cautionally marked to be unable to block which is the safe option, but the rtwifi wizards should be able to clarify that. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner Cc: Ping-Ke Shih Cc: Kalle Valo Cc: "David S. Miller" Cc: Jakub Kicinski Cc: linux-wireless@vger.kernel.org Cc: netdev@vger.kernel.org --- drivers/net/wireless/realtek/rtlwifi/base.c | 8 +++--- drivers/net/wireless/realtek/rtlwifi/btcoexist/halbtcoutsrc.c | 12 ++++++---- drivers/net/wireless/realtek/rtlwifi/core.c | 6 ++--- drivers/net/wireless/realtek/rtlwifi/pci.c | 4 +-- drivers/net/wireless/realtek/rtlwifi/ps.c | 8 +++--- drivers/net/wireless/realtek/rtlwifi/ps.h | 4 +-- 6 files changed, 23 insertions(+), 19 deletions(-) --- a/drivers/net/wireless/realtek/rtlwifi/base.c +++ b/drivers/net/wireless/realtek/rtlwifi/base.c @@ -1456,7 +1456,7 @@ static void setup_special_tx(struct rtl_ if (rtlpriv->cfg->ops->get_btc_status()) rtlpriv->btcoexist.btc_ops->btc_special_packet_notify( rtlpriv, type); - rtl_lps_leave(hw); + rtl_lps_leave(hw, false); ppsc->last_delaylps_stamp_jiffies = jiffies; } @@ -1546,7 +1546,7 @@ u8 rtl_is_special_data(struct ieee80211_ if (is_tx) { rtlpriv->ra.is_special_data = true; - rtl_lps_leave(hw); + rtl_lps_leave(hw, false); ppsc->last_delaylps_stamp_jiffies = jiffies; setup_special_tx(rtlpriv, ppsc, PACKET_EAPOL); @@ -2147,9 +2147,9 @@ static void rtl_watchdog_wq_callback(str if (rtlpriv->link_info.num_rx_inperiod + rtlpriv->link_info.num_tx_inperiod > 8 || rtlpriv->link_info.num_rx_inperiod > 2) - rtl_lps_leave(hw); + rtl_lps_leave(hw, true); else - rtl_lps_enter(hw); + rtl_lps_enter(hw, true); label_lps_done: ; --- a/drivers/net/wireless/realtek/rtlwifi/btcoexist/halbtcoutsrc.c +++ b/drivers/net/wireless/realtek/rtlwifi/btcoexist/halbtcoutsrc.c @@ -285,7 +285,8 @@ static void halbtc_leave_lps(struct btc_ btcoexist->bt_info.bt_ctrl_lps = true; btcoexist->bt_info.bt_lps_on = false; - rtl_lps_leave(rtlpriv->mac80211.hw); + /* FIXME: Context is unclear. Is it allowed to block? */ + rtl_lps_leave(rtlpriv->mac80211.hw, false); } static void halbtc_enter_lps(struct btc_coexist *btcoexist) @@ -306,7 +307,8 @@ static void halbtc_enter_lps(struct btc_ btcoexist->bt_info.bt_ctrl_lps = true; btcoexist->bt_info.bt_lps_on = true; - rtl_lps_enter(rtlpriv->mac80211.hw); + /* FIXME: Context is unclear. Is it allowed to block? */ + rtl_lps_enter(rtlpriv->mac80211.hw, false); } static void halbtc_normal_lps(struct btc_coexist *btcoexist) @@ -317,7 +319,8 @@ static void halbtc_normal_lps(struct btc if (btcoexist->bt_info.bt_ctrl_lps) { btcoexist->bt_info.bt_lps_on = false; - rtl_lps_leave(rtlpriv->mac80211.hw); + /* FIXME: Context is unclear. Is it allowed to block? */ + rtl_lps_leave(rtlpriv->mac80211.hw, false); btcoexist->bt_info.bt_ctrl_lps = false; } } @@ -328,7 +331,8 @@ static void halbtc_pre_normal_lps(struct if (btcoexist->bt_info.bt_ctrl_lps) { btcoexist->bt_info.bt_lps_on = false; - rtl_lps_leave(rtlpriv->mac80211.hw); + /* FIXME: Context is unclear. Is it allowed to block? */ + rtl_lps_leave(rtlpriv->mac80211.hw, false); } } --- a/drivers/net/wireless/realtek/rtlwifi/core.c +++ b/drivers/net/wireless/realtek/rtlwifi/core.c @@ -544,7 +544,7 @@ static int rtl_op_suspend(struct ieee802 rtlhal->driver_is_goingto_unload = true; rtlhal->enter_pnp_sleep = true; - rtl_lps_leave(hw); + rtl_lps_leave(hw, true); rtl_op_stop(hw); device_set_wakeup_enable(wiphy_dev(hw->wiphy), true); return 0; @@ -1151,7 +1151,7 @@ static void rtl_op_bss_info_changed(stru mstatus = RT_MEDIA_DISCONNECT; if (mac->link_state == MAC80211_LINKED) - rtl_lps_leave(hw); + rtl_lps_leave(hw, true); if (ppsc->p2p_ps_info.p2p_ps_mode > P2P_PS_NONE) rtl_p2p_ps_cmd(hw, P2P_PS_DISABLE); mac->link_state = MAC80211_NOLINK; @@ -1448,7 +1448,7 @@ static void rtl_op_sw_scan_start(struct } if (mac->link_state == MAC80211_LINKED) { - rtl_lps_leave(hw); + rtl_lps_leave(hw, true); mac->link_state = MAC80211_LINKED_SCANNING; } else { rtl_ips_nic_on(hw); --- a/drivers/net/wireless/realtek/rtlwifi/pci.c +++ b/drivers/net/wireless/realtek/rtlwifi/pci.c @@ -622,7 +622,7 @@ static void _rtl_pci_tx_isr(struct ieee8 if (((rtlpriv->link_info.num_rx_inperiod + rtlpriv->link_info.num_tx_inperiod) > 8) || rtlpriv->link_info.num_rx_inperiod > 2) - rtl_lps_leave(hw); + rtl_lps_leave(hw, false); } static int _rtl_pci_init_one_rxdesc(struct ieee80211_hw *hw, @@ -875,7 +875,7 @@ static void _rtl_pci_rx_interrupt(struct if (((rtlpriv->link_info.num_rx_inperiod + rtlpriv->link_info.num_tx_inperiod) > 8) || rtlpriv->link_info.num_rx_inperiod > 2) - rtl_lps_leave(hw); + rtl_lps_leave(hw, false); skb = new_skb; no_new: if (rtlpriv->use_new_trx_flow) { --- a/drivers/net/wireless/realtek/rtlwifi/ps.c +++ b/drivers/net/wireless/realtek/rtlwifi/ps.c @@ -653,22 +653,22 @@ void rtl_lps_change_work_callback(struct } EXPORT_SYMBOL_GPL(rtl_lps_change_work_callback); -void rtl_lps_enter(struct ieee80211_hw *hw) +void rtl_lps_enter(struct ieee80211_hw *hw, bool may_block) { struct rtl_priv *rtlpriv = rtl_priv(hw); - if (!in_interrupt()) + if (may_block) return rtl_lps_enter_core(hw); rtlpriv->enter_ps = true; schedule_work(&rtlpriv->works.lps_change_work); } EXPORT_SYMBOL_GPL(rtl_lps_enter); -void rtl_lps_leave(struct ieee80211_hw *hw) +void rtl_lps_leave(struct ieee80211_hw *hw, bool may_block) { struct rtl_priv *rtlpriv = rtl_priv(hw); - if (!in_interrupt()) + if (may_block) return rtl_lps_leave_core(hw); rtlpriv->enter_ps = false; schedule_work(&rtlpriv->works.lps_change_work); --- a/drivers/net/wireless/realtek/rtlwifi/ps.h +++ b/drivers/net/wireless/realtek/rtlwifi/ps.h @@ -11,8 +11,8 @@ bool rtl_ps_disable_nic(struct ieee80211 void rtl_ips_nic_off(struct ieee80211_hw *hw); void rtl_ips_nic_on(struct ieee80211_hw *hw); void rtl_ips_nic_off_wq_callback(struct work_struct *work); -void rtl_lps_enter(struct ieee80211_hw *hw); -void rtl_lps_leave(struct ieee80211_hw *hw); +void rtl_lps_enter(struct ieee80211_hw *hw, bool may_block); +void rtl_lps_leave(struct ieee80211_hw *hw, bool may_block); void rtl_lps_set_psmode(struct ieee80211_hw *hw, u8 rt_psmode);