From patchwork Mon Mar 11 16:38:29 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Anderson X-Patchwork-Id: 1910515 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=Bv7q5Bim; dkim-atps=neutral Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org (client-ip=2404:9400:2:0:216:3eff:fee1:b9f1; helo=lists.ozlabs.org; envelope-from=linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org; receiver=patchwork.ozlabs.org) Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2404:9400:2:0:216:3eff:fee1:b9f1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (secp384r1)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4TtjDh6smyz1yWn for ; Tue, 12 Mar 2024 03:40:04 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=Bv7q5Bim; dkim-atps=neutral Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4TtjDh5pnbz3d44 for ; Tue, 12 Mar 2024 03:40:04 +1100 (AEDT) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=Bv7q5Bim; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=linux.dev (client-ip=2001:41d0:203:375::ad; helo=out-173.mta1.migadu.com; envelope-from=sean.anderson@linux.dev; receiver=lists.ozlabs.org) Received: from out-173.mta1.migadu.com (out-173.mta1.migadu.com [IPv6:2001:41d0:203:375::ad]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4TtjCY6Vnhz3cCc for ; Tue, 12 Mar 2024 03:39:05 +1100 (AEDT) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1710175117; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=O7tlgS7MkdA1L6vxpIiDfXudireah7BPJ6Dyc7UeOKw=; b=Bv7q5BimvkpO9anPRBMYoOspFxVDOVVeean5r4hhR5qcI67SSwkdmHXBWSfRuoUrVAtONA jSJFmD4UCmRU1PkDPNdkWxAQlym/zE9CqmNL+Ruq8UggVTFYTeaRVKnZTPSC+xlvEbCxXH uCgVk+o8tWjxaDXctw24umeB9lIYu5g= From: Sean Anderson To: "David S . Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , netdev@vger.kernel.org Subject: [PATCH net v5 1/2] soc: fsl: qbman: Always disable interrupts when taking cgr_lock Date: Mon, 11 Mar 2024 12:38:29 -0400 Message-Id: <20240311163830.12952-1-sean.anderson@linux.dev> MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT 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: Sean Anderson , Madalin Bucur , Vladimir Oltean , Roy Pledge , linux-kernel@vger.kernel.org, Li Yang , Scott Wood , Claudiu Manoil , Camelia Groza , stable@vger.kernel.org, Steffen Trumtrar , linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org Errors-To: linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" smp_call_function_single disables IRQs when executing the callback. To prevent deadlocks, we must disable IRQs when taking cgr_lock elsewhere. This is already done by qman_update_cgr and qman_delete_cgr; fix the other lockers. Fixes: 96f413f47677 ("soc/fsl/qbman: fix issue in qman_delete_cgr_safe()") CC: stable@vger.kernel.org Signed-off-by: Sean Anderson Reviewed-by: Camelia Groza Tested-by: Vladimir Oltean --- Resent from a non-mangling email. (no changes since v3) Changes in v3: - Change blamed commit to something more appropriate Changes in v2: - Fix one additional call to spin_unlock drivers/soc/fsl/qbman/qman.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/soc/fsl/qbman/qman.c b/drivers/soc/fsl/qbman/qman.c index 739e4eee6b75..1bf1f1ea67f0 100644 --- a/drivers/soc/fsl/qbman/qman.c +++ b/drivers/soc/fsl/qbman/qman.c @@ -1456,11 +1456,11 @@ static void qm_congestion_task(struct work_struct *work) union qm_mc_result *mcr; struct qman_cgr *cgr; - spin_lock(&p->cgr_lock); + spin_lock_irq(&p->cgr_lock); qm_mc_start(&p->p); qm_mc_commit(&p->p, QM_MCC_VERB_QUERYCONGESTION); if (!qm_mc_result_timeout(&p->p, &mcr)) { - spin_unlock(&p->cgr_lock); + spin_unlock_irq(&p->cgr_lock); dev_crit(p->config->dev, "QUERYCONGESTION timeout\n"); qman_p_irqsource_add(p, QM_PIRQ_CSCI); return; @@ -1476,7 +1476,7 @@ static void qm_congestion_task(struct work_struct *work) list_for_each_entry(cgr, &p->cgr_cbs, node) if (cgr->cb && qman_cgrs_get(&c, cgr->cgrid)) cgr->cb(p, cgr, qman_cgrs_get(&rr, cgr->cgrid)); - spin_unlock(&p->cgr_lock); + spin_unlock_irq(&p->cgr_lock); qman_p_irqsource_add(p, QM_PIRQ_CSCI); } @@ -2440,7 +2440,7 @@ int qman_create_cgr(struct qman_cgr *cgr, u32 flags, preempt_enable(); cgr->chan = p->config->channel; - spin_lock(&p->cgr_lock); + spin_lock_irq(&p->cgr_lock); if (opts) { struct qm_mcc_initcgr local_opts = *opts; @@ -2477,7 +2477,7 @@ int qman_create_cgr(struct qman_cgr *cgr, u32 flags, qman_cgrs_get(&p->cgrs[1], cgr->cgrid)) cgr->cb(p, cgr, 1); out: - spin_unlock(&p->cgr_lock); + spin_unlock_irq(&p->cgr_lock); put_affine_portal(); return ret; } From patchwork Mon Mar 11 16:38:30 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Anderson X-Patchwork-Id: 1910514 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=qpRAOM6b; dkim-atps=neutral Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org (client-ip=2404:9400:2:0:216:3eff:fee1:b9f1; helo=lists.ozlabs.org; envelope-from=linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org; receiver=patchwork.ozlabs.org) Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2404:9400:2:0:216:3eff:fee1:b9f1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (secp384r1) server-digest SHA384) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4TtjCw6prtz1yWm for ; Tue, 12 Mar 2024 03:39:24 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=qpRAOM6b; dkim-atps=neutral Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4TtjCv6nnnz3cWB for ; Tue, 12 Mar 2024 03:39:23 +1100 (AEDT) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=qpRAOM6b; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=linux.dev (client-ip=95.215.58.173; helo=out-173.mta1.migadu.com; envelope-from=sean.anderson@linux.dev; receiver=lists.ozlabs.org) Received: from out-173.mta1.migadu.com (out-173.mta1.migadu.com [95.215.58.173]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4TtjCX3m1Wz3c9r for ; Tue, 12 Mar 2024 03:39:01 +1100 (AEDT) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1710175120; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=CysZkS7WCe+8wsvCDFOXdWUmYLLJcMTKk+L8QiL4FiE=; b=qpRAOM6bPLgH8lhUR+OsZuQzuhAuG/Ta6lrS5+lMOJSpSOVCmEYtJ95gEsB/xwPdQ7r9bi 7h70wYlB7gHmoFqYikGTmQBdKo4Et2xPqbeM+KFQH4JYKUq6cN1NrlQl7M94oxxtLyNSqx ARWrSi7IwUUl9Lu2EsvkPRV4e7BktK0= From: Sean Anderson To: "David S . Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , netdev@vger.kernel.org Subject: [PATCH net v5 2/2] soc: fsl: qbman: Use raw spinlock for cgr_lock Date: Mon, 11 Mar 2024 12:38:30 -0400 Message-Id: <20240311163830.12952-2-sean.anderson@linux.dev> In-Reply-To: <20240311163830.12952-1-sean.anderson@linux.dev> References: <20240311163830.12952-1-sean.anderson@linux.dev> MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT 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: Sean Anderson , Madalin Bucur , Vladimir Oltean , Roy Pledge , linux-kernel@vger.kernel.org, Li Yang , Scott Wood , Claudiu Manoil , Camelia Groza , stable@vger.kernel.org, Steffen Trumtrar , linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org Errors-To: linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" smp_call_function always runs its callback in hard IRQ context, even on PREEMPT_RT, where spinlocks can sleep. So we need to use a raw spinlock for cgr_lock to ensure we aren't waiting on a sleeping task. Although this bug has existed for a while, it was not apparent until commit ef2a8d5478b9 ("net: dpaa: Adjust queue depth on rate change") which invokes smp_call_function_single via qman_update_cgr_safe every time a link goes up or down. Fixes: 96f413f47677 ("soc/fsl/qbman: fix issue in qman_delete_cgr_safe()") CC: stable@vger.kernel.org Reported-by: Vladimir Oltean Closes: https://lore.kernel.org/all/20230323153935.nofnjucqjqnz34ej@skbuf/ Reported-by: Steffen Trumtrar Closes: https://lore.kernel.org/linux-arm-kernel/87wmsyvclu.fsf@pengutronix.de/ Signed-off-by: Sean Anderson Reviewed-by: Camelia Groza Tested-by: Vladimir Oltean --- Changes in v5: - Clarify commit message Changes in v4: - Add a note about how raw spinlocks aren't quite right Changes in v3: - Change blamed commit to something more appropriate drivers/soc/fsl/qbman/qman.c | 25 ++++++++++++++----------- 1 file changed, 14 insertions(+), 11 deletions(-) diff --git a/drivers/soc/fsl/qbman/qman.c b/drivers/soc/fsl/qbman/qman.c index 1bf1f1ea67f0..7e9074519ad2 100644 --- a/drivers/soc/fsl/qbman/qman.c +++ b/drivers/soc/fsl/qbman/qman.c @@ -991,7 +991,7 @@ struct qman_portal { /* linked-list of CSCN handlers. */ struct list_head cgr_cbs; /* list lock */ - spinlock_t cgr_lock; + raw_spinlock_t cgr_lock; struct work_struct congestion_work; struct work_struct mr_work; char irqname[MAX_IRQNAME]; @@ -1281,7 +1281,7 @@ static int qman_create_portal(struct qman_portal *portal, /* if the given mask is NULL, assume all CGRs can be seen */ qman_cgrs_fill(&portal->cgrs[0]); INIT_LIST_HEAD(&portal->cgr_cbs); - spin_lock_init(&portal->cgr_lock); + raw_spin_lock_init(&portal->cgr_lock); INIT_WORK(&portal->congestion_work, qm_congestion_task); INIT_WORK(&portal->mr_work, qm_mr_process_task); portal->bits = 0; @@ -1456,11 +1456,14 @@ static void qm_congestion_task(struct work_struct *work) union qm_mc_result *mcr; struct qman_cgr *cgr; - spin_lock_irq(&p->cgr_lock); + /* + * FIXME: QM_MCR_TIMEOUT is 10ms, which is too long for a raw spinlock! + */ + raw_spin_lock_irq(&p->cgr_lock); qm_mc_start(&p->p); qm_mc_commit(&p->p, QM_MCC_VERB_QUERYCONGESTION); if (!qm_mc_result_timeout(&p->p, &mcr)) { - spin_unlock_irq(&p->cgr_lock); + raw_spin_unlock_irq(&p->cgr_lock); dev_crit(p->config->dev, "QUERYCONGESTION timeout\n"); qman_p_irqsource_add(p, QM_PIRQ_CSCI); return; @@ -1476,7 +1479,7 @@ static void qm_congestion_task(struct work_struct *work) list_for_each_entry(cgr, &p->cgr_cbs, node) if (cgr->cb && qman_cgrs_get(&c, cgr->cgrid)) cgr->cb(p, cgr, qman_cgrs_get(&rr, cgr->cgrid)); - spin_unlock_irq(&p->cgr_lock); + raw_spin_unlock_irq(&p->cgr_lock); qman_p_irqsource_add(p, QM_PIRQ_CSCI); } @@ -2440,7 +2443,7 @@ int qman_create_cgr(struct qman_cgr *cgr, u32 flags, preempt_enable(); cgr->chan = p->config->channel; - spin_lock_irq(&p->cgr_lock); + raw_spin_lock_irq(&p->cgr_lock); if (opts) { struct qm_mcc_initcgr local_opts = *opts; @@ -2477,7 +2480,7 @@ int qman_create_cgr(struct qman_cgr *cgr, u32 flags, qman_cgrs_get(&p->cgrs[1], cgr->cgrid)) cgr->cb(p, cgr, 1); out: - spin_unlock_irq(&p->cgr_lock); + raw_spin_unlock_irq(&p->cgr_lock); put_affine_portal(); return ret; } @@ -2512,7 +2515,7 @@ int qman_delete_cgr(struct qman_cgr *cgr) return -EINVAL; memset(&local_opts, 0, sizeof(struct qm_mcc_initcgr)); - spin_lock_irqsave(&p->cgr_lock, irqflags); + raw_spin_lock_irqsave(&p->cgr_lock, irqflags); list_del(&cgr->node); /* * If there are no other CGR objects for this CGRID in the list, @@ -2537,7 +2540,7 @@ int qman_delete_cgr(struct qman_cgr *cgr) /* add back to the list */ list_add(&cgr->node, &p->cgr_cbs); release_lock: - spin_unlock_irqrestore(&p->cgr_lock, irqflags); + raw_spin_unlock_irqrestore(&p->cgr_lock, irqflags); put_affine_portal(); return ret; } @@ -2577,9 +2580,9 @@ static int qman_update_cgr(struct qman_cgr *cgr, struct qm_mcc_initcgr *opts) if (!p) return -EINVAL; - spin_lock_irqsave(&p->cgr_lock, irqflags); + raw_spin_lock_irqsave(&p->cgr_lock, irqflags); ret = qm_modify_cgr(cgr, 0, opts); - spin_unlock_irqrestore(&p->cgr_lock, irqflags); + raw_spin_unlock_irqrestore(&p->cgr_lock, irqflags); put_affine_portal(); return ret; }