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: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <5296779.Sb9uPGUboI@kreacher>
Date:   Thu, 09 Jun 2022 16:16:03 +0200
From:   "Rafael J. Wysocki" <rjw@...ysocki.net>
To:     Linux ACPI <linux-acpi@...r.kernel.org>
Cc:     LKML <linux-kernel@...r.kernel.org>,
        Linux PM <linux-pm@...r.kernel.org>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Mika Westerberg <mika.westerberg@...ux.intel.com>,
        Hans de Goede <hdegoede@...hat.com>,
        Sakari Ailus <sakari.ailus@...ux.intel.com>,
        Vinod Koul <vkoul@...nel.org>,
        Bard Liao <yung-chuan.liao@...ux.intel.com>,
        Pierre-Louis Bossart <pierre-louis.bossart@...ux.intel.com>,
        Sanyog Kale <sanyog.r.kale@...el.com>,
        alsa-devel@...a-project.org
Subject: [PATCH v1 14/16] soundwire: Use acpi_dev_for_each_child()

From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>

Instead of walking the list of children of an ACPI device directly,
use acpi_dev_for_each_child() to carry out an action for all of
the given ACPI device's children.

This will help to eliminate the children list head from struct
acpi_device as it is redundant and it is used in questionable ways
in some places (in particular, locking is needed for walking the
list pointed to it safely, but it is often missing).

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
---
 drivers/soundwire/slave.c |  115 ++++++++++++++++++++++++++--------------------
 1 file changed, 67 insertions(+), 48 deletions(-)

Index: linux-pm/drivers/soundwire/slave.c
===================================================================
--- linux-pm.orig/drivers/soundwire/slave.c
+++ linux-pm/drivers/soundwire/slave.c
@@ -127,6 +127,71 @@ static bool find_slave(struct sdw_bus *b
 	return true;
 }
 
+struct sdw_acpi_child_walk_data {
+	struct sdw_bus *bus;
+	struct acpi_device *adev;
+	struct sdw_slave_id id;
+	bool ignore_unique_id;
+};
+
+static int sdw_acpi_check_duplicate(struct acpi_device *adev, void *data)
+{
+	struct sdw_acpi_child_walk_data *cwd = data;
+	struct sdw_bus *bus = cwd->bus;
+	struct sdw_slave_id id;
+
+	if (adev == cwd->adev)
+		return 0;
+
+	if (!find_slave(bus, adev, &id))
+		return 0;
+
+	if (cwd->id.sdw_version != id.sdw_version || cwd->id.mfg_id != id.mfg_id ||
+	    cwd->id.part_id != id.part_id || cwd->id.class_id != id.class_id)
+		return 0;
+
+	if (cwd->id.unique_id != id.unique_id) {
+		dev_dbg(bus->dev,
+			"Valid unique IDs 0x%x 0x%x for Slave mfg_id 0x%04x, part_id 0x%04x\n",
+			cwd->id.unique_id, id.unique_id, cwd->id.mfg_id,
+			cwd->id.part_id);
+		cwd->ignore_unique_id = false;
+		return 0;
+	}
+
+	dev_err(bus->dev,
+		"Invalid unique IDs 0x%x 0x%x for Slave mfg_id 0x%04x, part_id 0x%04x\n",
+		cwd->id.unique_id, id.unique_id, cwd->id.mfg_id, cwd->id.part_id);
+	return -ENODEV;
+}
+
+static int sdw_acpi_find_one(struct acpi_device *adev, void *data)
+{
+	struct sdw_bus *bus = data;
+	struct sdw_acpi_child_walk_data cwd = {
+		.bus = bus,
+		.adev = adev,
+		.ignore_unique_id = true,
+	};
+	int ret;
+
+	if (!find_slave(bus, adev, &cwd.id))
+		return 0;
+
+	/* Brute-force O(N^2) search for duplicates. */
+	ret = acpi_dev_for_each_child(ACPI_COMPANION(bus->dev),
+				      sdw_acpi_check_duplicate, &cwd);
+	if (ret)
+		return ret;
+
+	if (cwd.ignore_unique_id)
+		cwd.id.unique_id = SDW_IGNORED_UNIQUE_ID;
+
+	/* Ignore errors and continue. */
+	sdw_slave_add(bus, &cwd.id, acpi_fwnode_handle(adev));
+	return 0;
+}
+
 /*
  * sdw_acpi_find_slaves() - Find Slave devices in Master ACPI node
  * @bus: SDW bus instance
@@ -135,8 +200,7 @@ static bool find_slave(struct sdw_bus *b
  */
 int sdw_acpi_find_slaves(struct sdw_bus *bus)
 {
-	struct acpi_device *adev, *parent;
-	struct acpi_device *adev2, *parent2;
+	struct acpi_device *parent;
 
 	parent = ACPI_COMPANION(bus->dev);
 	if (!parent) {
@@ -144,52 +208,7 @@ int sdw_acpi_find_slaves(struct sdw_bus
 		return -ENODEV;
 	}
 
-	list_for_each_entry(adev, &parent->children, node) {
-		struct sdw_slave_id id;
-		struct sdw_slave_id id2;
-		bool ignore_unique_id = true;
-
-		if (!find_slave(bus, adev, &id))
-			continue;
-
-		/* brute-force O(N^2) search for duplicates */
-		parent2 = parent;
-		list_for_each_entry(adev2, &parent2->children, node) {
-
-			if (adev == adev2)
-				continue;
-
-			if (!find_slave(bus, adev2, &id2))
-				continue;
-
-			if (id.sdw_version != id2.sdw_version ||
-			    id.mfg_id != id2.mfg_id ||
-			    id.part_id != id2.part_id ||
-			    id.class_id != id2.class_id)
-				continue;
-
-			if (id.unique_id != id2.unique_id) {
-				dev_dbg(bus->dev,
-					"Valid unique IDs 0x%x 0x%x for Slave mfg_id 0x%04x, part_id 0x%04x\n",
-					id.unique_id, id2.unique_id, id.mfg_id, id.part_id);
-				ignore_unique_id = false;
-			} else {
-				dev_err(bus->dev,
-					"Invalid unique IDs 0x%x 0x%x for Slave mfg_id 0x%04x, part_id 0x%04x\n",
-					id.unique_id, id2.unique_id, id.mfg_id, id.part_id);
-				return -ENODEV;
-			}
-		}
-
-		if (ignore_unique_id)
-			id.unique_id = SDW_IGNORED_UNIQUE_ID;
-
-		/*
-		 * don't error check for sdw_slave_add as we want to continue
-		 * adding Slaves
-		 */
-		sdw_slave_add(bus, &id, acpi_fwnode_handle(adev));
-	}
+	acpi_dev_for_each_child(parent, sdw_acpi_find_one, bus);
 
 	return 0;
 }



Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ