linux-kernel - [PATCH v6 4/8] PCI/quirks: Abstract LBMS seen check into own function

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20240516093222.1684-5-ilpo.jarvinen@linux.intel.com>
Date: Thu, 16 May 2024 12:32:18 +0300
From: Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>
To: linux-pci@...r.kernel.org,
	Bjorn Helgaas <bhelgaas@...gle.com>,
	Lorenzo Pieralisi <lorenzo.pieralisi@....com>,
	Rob Herring <robh@...nel.org>,
	Krzysztof Wilczyński <kw@...ux.com>,
	"Maciej W . Rozycki" <macro@...am.me.uk>,
	Jonathan Cameron <Jonathan.Cameron@...wei.com>,
	Lukas Wunner <lukas@...ner.de>,
	Alexandru Gagniuc <mr.nuke.me@...il.com>,
	Krishna chaitanya chundru <quic_krichai@...cinc.com>,
	Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>,
	"Rafael J. Wysocki" <rafael@...nel.org>,
	linux-pm@...r.kernel.org,
	linux-kernel@...r.kernel.org
Cc: Daniel Lezcano <daniel.lezcano@...aro.org>,
	Amit Kucheria <amitk@...nel.org>,
	Zhang Rui <rui.zhang@...el.com>,
	Christophe JAILLET <christophe.jaillet@...adoo.fr>,
	Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>
Subject: [PATCH v6 4/8] PCI/quirks: Abstract LBMS seen check into own function

The speed quirk in pcie_failed_link_retrain() uses the presence of LBMS
bit as one of the triggering conditions effectively monopolizing the
use of that bit. An upcoming change will introduce a PCIe bandwidth
controller which sets up an interrupt to track LBMS. As LBMS will be
cleared by the interrupt handler, the speed quirk will no longer be
able to observe LBMS directly.

As a preparatory step for the change, extract the LBMS seen check into
own function out of pcie_failed_link_retrain().

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>
---
 drivers/pci/quirks.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 2ae06c7b1917..9be942623573 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -33,6 +33,11 @@
 #include <linux/switchtec.h>
 #include "pci.h"
 
+static bool pcie_lbms_seen(struct pci_dev *dev, u16 lnksta)
+{
+	return lnksta & PCI_EXP_LNKSTA_LBMS;
+}
+
 /*
  * Retrain the link of a downstream PCIe port by hand if necessary.
  *
@@ -92,8 +97,7 @@ int pcie_failed_link_retrain(struct pci_dev *dev)
 
 	pcie_capability_read_word(dev, PCI_EXP_LNKCTL2, &lnkctl2);
 	pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &lnksta);
-	if ((lnksta & (PCI_EXP_LNKSTA_LBMS | PCI_EXP_LNKSTA_DLLLA)) ==
-	    PCI_EXP_LNKSTA_LBMS) {
+	if (!(lnksta & PCI_EXP_LNKSTA_DLLLA) && pcie_lbms_seen(dev, lnksta)) {
 		pci_info(dev, "broken device, retraining non-functional downstream link at 2.5GT/s\n");
 
 		lnkctl2 &= ~PCI_EXP_LNKCTL2_TLS;
-- 
2.39.2