From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9AE11261389; Thu, 3 Apr 2025 19:20:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743708026; cv=none; b=F1IECPST8KkDwM+FASiZ9a4lhwDcNeQsLm8vn6I54/t9yXhr5ubmFb3Ur75D4FRCttMru4yqK7JJJ1d8EwcMaggwjviT5WT3g1UWj1arERtKxGoJSynajqConW8xucHM6oMaoOpsQCV+fc7GbCNVdUUisx/M6nWEZK2FSar9FXs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743708026; c=relaxed/simple; bh=+tBY6UKWekhQJduG+EZZK0/ueq1BweiGDOAn9x+7Voc=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=jOBZKjooave54BVL6vJb0/ngHe4yExx92tKpHCGDHUZAT8QI1YQrseFAJ20i8UbSfvhAFUQF43YYaiCxa4ZAd/HC1320X8ATffzYtD7abcuwhdA+X09HZ5J4iLA/VgcJX2DafLMTT9uegLlt0+BGwryYRN24cMXXugm1qjEDppE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=rKGFXrX5; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="rKGFXrX5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 91A06C4CEE3; Thu, 3 Apr 2025 19:20:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1743708026; bh=+tBY6UKWekhQJduG+EZZK0/ueq1BweiGDOAn9x+7Voc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rKGFXrX5IScWLvIhJdMq2MyM6SZlZu+a64frc1CPQtfTD8epdfG9P0qTkxgqE5p9i xJ5eUrN02SWjwzvoy1um2g8OnyxaKnsSzlfDWvqB/JnMQsK4cb4dAVxlLKoFdlhMMR hp6/w1rSUpajDxyu04BgJfHD2/HDctLxm7hicLEl1cCvw5zR9PMakjFKg5Ul1S8xkH W9huzk+3xtZoifrMufrm7MKK5jPdCf4CB2MWtFOf5vJgv3095wNjP+07l8WvFYfsZ4 qmGt8dxIS374wV8LpEkeVwYmAi1iHkjUiZwb/tLy07jWVNacUtxuTSP5pxrRntaKWm 6w4RvXK7ycq+A== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Ryo Takakura , "Luis Claudio R . Goncalves" , Sebastian Andrzej Siewior , =?UTF-8?q?Krzysztof=20Wilczy=C5=84ski?= , Bjorn Helgaas , Sasha Levin , nirmal.patel@linux.intel.com, lpieralisi@kernel.org, kw@linux.com, clrkwllms@kernel.org, rostedt@goodmis.org, linux-pci@vger.kernel.org, linux-rt-devel@lists.linux.dev Subject: [PATCH AUTOSEL 5.15 10/12] PCI: vmd: Make vmd_dev::cfg_lock a raw_spinlock_t type Date: Thu, 3 Apr 2025 15:19:59 -0400 Message-Id: <20250403192001.2682149-10-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250403192001.2682149-1-sashal@kernel.org> References: <20250403192001.2682149-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-rt-devel@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 5.15.179 Content-Transfer-Encoding: 8bit From: Ryo Takakura [ Upstream commit 18056a48669a040bef491e63b25896561ee14d90 ] The access to the PCI config space via pci_ops::read and pci_ops::write is a low-level hardware access. The functions can be accessed with disabled interrupts even on PREEMPT_RT. The pci_lock is a raw_spinlock_t for this purpose. A spinlock_t becomes a sleeping lock on PREEMPT_RT, so it cannot be acquired with disabled interrupts. The vmd_dev::cfg_lock is accessed in the same context as the pci_lock. Make vmd_dev::cfg_lock a raw_spinlock_t type so it can be used with interrupts disabled. This was reported as: BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48 Call Trace: rt_spin_lock+0x4e/0x130 vmd_pci_read+0x8d/0x100 [vmd] pci_user_read_config_byte+0x6f/0xe0 pci_read_config+0xfe/0x290 sysfs_kf_bin_read+0x68/0x90 Signed-off-by: Ryo Takakura Tested-by: Luis Claudio R. Goncalves Acked-by: Luis Claudio R. Goncalves [bigeasy: reword commit message] Signed-off-by: Sebastian Andrzej Siewior Tested-off-by: Luis Claudio R. Goncalves Link: https://lore.kernel.org/r/20250218080830.ufw3IgyX@linutronix.de [kwilczynski: commit log] Signed-off-by: Krzysztof Wilczyński [bhelgaas: add back report info from https://lore.kernel.org/lkml/20241218115951.83062-1-ryotkkr98@gmail.com/] Signed-off-by: Bjorn Helgaas Signed-off-by: Sasha Levin --- drivers/pci/controller/vmd.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c index 10a078ef4799d..1195c570599c0 100644 --- a/drivers/pci/controller/vmd.c +++ b/drivers/pci/controller/vmd.c @@ -108,7 +108,7 @@ struct vmd_irq_list { struct vmd_dev { struct pci_dev *dev; - spinlock_t cfg_lock; + raw_spinlock_t cfg_lock; void __iomem *cfgbar; int msix_count; @@ -386,7 +386,7 @@ static int vmd_pci_read(struct pci_bus *bus, unsigned int devfn, int reg, if (!addr) return -EFAULT; - spin_lock_irqsave(&vmd->cfg_lock, flags); + raw_spin_lock_irqsave(&vmd->cfg_lock, flags); switch (len) { case 1: *value = readb(addr); @@ -401,7 +401,7 @@ static int vmd_pci_read(struct pci_bus *bus, unsigned int devfn, int reg, ret = -EINVAL; break; } - spin_unlock_irqrestore(&vmd->cfg_lock, flags); + raw_spin_unlock_irqrestore(&vmd->cfg_lock, flags); return ret; } @@ -421,7 +421,7 @@ static int vmd_pci_write(struct pci_bus *bus, unsigned int devfn, int reg, if (!addr) return -EFAULT; - spin_lock_irqsave(&vmd->cfg_lock, flags); + raw_spin_lock_irqsave(&vmd->cfg_lock, flags); switch (len) { case 1: writeb(value, addr); @@ -439,7 +439,7 @@ static int vmd_pci_write(struct pci_bus *bus, unsigned int devfn, int reg, ret = -EINVAL; break; } - spin_unlock_irqrestore(&vmd->cfg_lock, flags); + raw_spin_unlock_irqrestore(&vmd->cfg_lock, flags); return ret; } @@ -850,7 +850,7 @@ static int vmd_probe(struct pci_dev *dev, const struct pci_device_id *id) if (features & VMD_FEAT_OFFSET_FIRST_VECTOR) vmd->first_vec = 1; - spin_lock_init(&vmd->cfg_lock); + raw_spin_lock_init(&vmd->cfg_lock); pci_set_drvdata(dev, vmd); err = vmd_enable_domain(vmd, features); if (err) -- 2.39.5