From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.10]) (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 710D713E040; Tue, 28 May 2024 23:25:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.10 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716938744; cv=none; b=HrnPPCJ2QbbO/na8C2z2VHWque6oOgn5wrMzkB6LDvH/0VDd+NfPBjuwG4zttowKeFeJv43RoZA4bO8EJPSmniaCN9BCmMvtzw4pC8gNRqXi1CKBRkxXd34fO75T3DJebx67thld7e5RAyeQn/SNYfmzXQUfEn6a8bW2KztdwoM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716938744; c=relaxed/simple; bh=+OjdnvVxrosNviqcLYcJtOSgzE9VkrFf5aqnXPJI/30=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=BC4Q7icpWrxitB0rHi9Je30N2pMMxCfV7gHILyM5XAHAhdL93cj1Z/dgqpB5fPU1FCJdpYXtqrUSfDpz4u8BeeXBD+2IGv/s/qeliQRGDYxER4TUFg9gjemEIPnAunWdqsOFuDNpEDjajQnvV5l/67bdQ33l7MQQNuZGlR0RJXg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=kUBRpwuy; arc=none smtp.client-ip=198.175.65.10 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="kUBRpwuy" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1716938743; x=1748474743; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=+OjdnvVxrosNviqcLYcJtOSgzE9VkrFf5aqnXPJI/30=; b=kUBRpwuyh/tlJqhJ9kGyieE69Xud4i1bRlLOaJawPqBS711pkVgI4OWA bUdPKOgoiaTJewiUBmD6G2CC4ppg45biz9mG9qmFf4Fb5LWgw976Hdn88 3JAJUlghfNT0dWsQDXGr9SpfiYeFCOpUkSCc91ZVWOezL4GHfKLIC3VJC VPq+r2yDqHWQsnJcar59C0htSA9+hEu67RejwciSS+M1YJ4RG0qVETBR+ NoRjYMkLk9Mm6k49zf3HiJ/xubXjs1uu1Qcg/ZGl3My93Y677+q2UKJds OHQfcuP2bmvnbsTzzDMjKXFNbXqUL4Soz1NHMlUKt0u25uNY/3TXu3eK0 A==; X-CSE-ConnectionGUID: acshq1DQT0egMsyvKkEniw== X-CSE-MsgGUID: gwYXOzhHTsS36JOYZW0aQQ== X-IronPort-AV: E=McAfee;i="6600,9927,11085"; a="30817050" X-IronPort-AV: E=Sophos;i="6.08,196,1712646000"; d="scan'208";a="30817050" Received: from fmviesa001.fm.intel.com ([10.60.135.141]) by orvoesa102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 May 2024 16:25:42 -0700 X-CSE-ConnectionGUID: rQWkZPYKQTyPGuNuP3oswQ== X-CSE-MsgGUID: OH1idUQPRlqvagrys08OUg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.08,196,1712646000"; d="scan'208";a="66422043" Received: from djiang5-mobl3.amr.corp.intel.com (HELO [10.125.111.9]) ([10.125.111.9]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 May 2024 16:25:41 -0700 Message-ID: <69703e18-5a11-41c9-b8af-25007b4f6c2d@intel.com> Date: Tue, 28 May 2024 16:25:40 -0700 Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] PCI: Make PCI cfg_access_lock lockdep key a singleton To: Dan Williams , bhelgaas@google.com Cc: Jani Saarinen , linux-cxl@vger.kernel.org, linux-pci@vger.kernel.org References: <171693842964.1298616.14265420982007939967.stgit@dwillia2-xfh.jf.intel.com> Content-Language: en-US From: Dave Jiang In-Reply-To: <171693842964.1298616.14265420982007939967.stgit@dwillia2-xfh.jf.intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 5/28/24 4:22 PM, Dan Williams wrote: > The new lockdep annotation for cfg_access_lock naively registered a new > key per device. This is overkill and leads to warnings on hash > collisions at dynamic registration time: > > WARNING: CPU: 0 PID: 1 at kernel/locking/lockdep.c:1226 lockdep_register_key+0xb0/0x240 > RIP: 0010:lockdep_register_key+0xb0/0x240 > [..] > Call Trace: > > ? __warn+0x8c/0x190 > ? lockdep_register_key+0xb0/0x240 > ? report_bug+0x1f8/0x200 > ? handle_bug+0x3c/0x70 > ? exc_invalid_op+0x18/0x70 > ? asm_exc_invalid_op+0x1a/0x20 > ? lockdep_register_key+0xb0/0x240 > pci_device_add+0x14b/0x560 > ? pci_setup_device+0x42e/0x6a0 > pci_scan_single_device+0xa7/0xd0 > p2sb_scan_and_cache_devfn+0xc/0x90 > p2sb_fs_init+0x15f/0x170 > > Switch to a shared static key for all instances. > > Fixes: 7e89efc6e9e4 ("PCI: Lock upstream bridge for pci_reset_function()") > Reported-by: Jani Saarinen > Closes: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_14834/bat-apl-1/boot0.txt > Cc: Dave Jiang > Cc: Bjorn Helgaas > Signed-off-by: Dan Williams Reviewed-by: Dave Jiang > --- > Hi Bjorn, > > One more fallout from the cfg_access_lock lockdep annotation. This one > still wants a Tested-by from Jani before merging, but wanted to make you > aware of it in case similar reports make their way to you in the > meantime. > > drivers/pci/probe.c | 7 ++++--- > include/linux/pci.h | 1 - > 2 files changed, 4 insertions(+), 4 deletions(-) > > diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c > index 8e696e547565..15168881ec94 100644 > --- a/drivers/pci/probe.c > +++ b/drivers/pci/probe.c > @@ -2533,6 +2533,8 @@ static void pci_set_msi_domain(struct pci_dev *dev) > dev_set_msi_domain(&dev->dev, d); > } > > +static struct lock_class_key cfg_access_key; > + > void pci_device_add(struct pci_dev *dev, struct pci_bus *bus) > { > int ret; > @@ -2546,9 +2548,8 @@ void pci_device_add(struct pci_dev *dev, struct pci_bus *bus) > dev->dev.dma_mask = &dev->dma_mask; > dev->dev.dma_parms = &dev->dma_parms; > dev->dev.coherent_dma_mask = 0xffffffffull; > - lockdep_register_key(&dev->cfg_access_key); > - lockdep_init_map(&dev->cfg_access_lock, dev_name(&dev->dev), > - &dev->cfg_access_key, 0); > + lockdep_init_map(&dev->cfg_access_lock, "&dev->cfg_access_lock", > + &cfg_access_key, 0); > > dma_set_max_seg_size(&dev->dev, 65536); > dma_set_seg_boundary(&dev->dev, 0xffffffff); > diff --git a/include/linux/pci.h b/include/linux/pci.h > index fb004fd4e889..5bece7fd11f8 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -413,7 +413,6 @@ struct pci_dev { > struct resource driver_exclusive_resource; /* driver exclusive resource ranges */ > > bool match_driver; /* Skip attaching driver */ > - struct lock_class_key cfg_access_key; > struct lockdep_map cfg_access_lock; > > unsigned int transparent:1; /* Subtractive decode bridge */ >