[PATCH v13 01/10] driver core: fw_devlink: Introduce fw_devlink_set_device()

[PATCH v13 01/10] driver core: fw_devlink: Introduce fw_devlink_set_device()

[Herve Codina]

Setting fwnode->dev is specific to fw_devlink.

In order to avoid having a direct 'fwnode->dev = dev;' in several
place in the kernel, introduce fw_devlink_set_device() helper to perform
this operation.

Having this helper allows to hide the fwnode devlink related stuff
behind the helper.

Cc: stable@vger.kernel.org
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Reviewed-by: Richard Cheng <icheng@nvidia.com>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
---
Cc stable because used by other patches with Fixes + Cc stable
---
 include/linux/fwnode.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/include/linux/fwnode.h b/include/linux/fwnode.h
index a9dcaf7e7076..3ce49575cf82 100644
--- a/include/linux/fwnode.h
+++ b/include/linux/fwnode.h
@@ -260,4 +260,10 @@ void fw_devlink_purge_absent_suppliers(struct fwnode_handle *fwnode);
 void fw_devlink_refresh_fwnode(struct fwnode_handle *fwnode);
 bool fw_devlink_is_strict(void);
 
+static inline void fw_devlink_set_device(struct fwnode_handle *fwnode,
+					 struct device *dev)
+{
+	fwnode->dev = dev;
+}
+
 #endif
-- 
2.55.0

[PATCH v13 02/10] drivers: core: Use fw_devlink_set_device()

[Herve Codina]

The code set directly fwnode->dev field.

Use the dedicated fw_devlink_set_device() helper to perform this
operation.

Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Richard Cheng <icheng@nvidia.com>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
---
 drivers/base/core.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 4c0c373998a1..3268e9350c86 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -3754,7 +3754,7 @@ int device_add(struct device *dev)
 	 * device and the driver sync_state callback is called for this device.
 	 */
 	if (dev->fwnode && !dev->fwnode->dev) {
-		dev->fwnode->dev = dev;
+		fw_devlink_set_device(dev->fwnode, dev);
 		fw_devlink_link_device(dev);
 	}
 
@@ -3929,7 +3929,7 @@ void device_del(struct device *dev)
 	device_unlock(dev);
 
 	if (dev->fwnode && dev->fwnode->dev == dev)
-		dev->fwnode->dev = NULL;
+		fw_devlink_set_device(dev->fwnode, NULL);
 
 	/* Notify clients of device removal.  This call must come
 	 * before dpm_sysfs_remove().
-- 
2.55.0

[PATCH v13 03/10] pinctrl: cs42l43: Use fw_devlink_set_device()

[Herve Codina]

The code set directly fwnode->dev field.

Use the dedicated fw_devlink_set_device() helper to perform this
operation.

Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Acked-by: Linus Walleij <linusw@kernel.org>
Reviewed-by: Richard Cheng <icheng@nvidia.com>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
---
 drivers/pinctrl/cirrus/pinctrl-cs42l43.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pinctrl/cirrus/pinctrl-cs42l43.c b/drivers/pinctrl/cirrus/pinctrl-cs42l43.c
index 8990fab0446c..563070aba3d8 100644
--- a/drivers/pinctrl/cirrus/pinctrl-cs42l43.c
+++ b/drivers/pinctrl/cirrus/pinctrl-cs42l43.c
@@ -576,7 +576,7 @@ static int cs42l43_pin_probe(struct platform_device *pdev)
 				return ret;
 
 			if (!child->dev)
-				child->dev = priv->dev;
+				fw_devlink_set_device(child, priv->dev);
 			fwnode = child;
 		}
 	}
-- 
2.55.0

[PATCH v13 05/10] cxl/test: Use fw_devlink_set_device()

[Herve Codina]

The code set directly fwnode.dev field.

Use the dedicated fw_devlink_set_device() helper to perform this
operation.

Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Richard Cheng <icheng@nvidia.com>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
---
 tools/testing/cxl/test/cxl.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/cxl/test/cxl.c b/tools/testing/cxl/test/cxl.c
index 547ebc97bf59..e21e45fe1572 100644
--- a/tools/testing/cxl/test/cxl.c
+++ b/tools/testing/cxl/test/cxl.c
@@ -1678,7 +1678,7 @@ static void mock_companion(struct acpi_device *adev, struct device *dev)
 	device_initialize(&adev->dev);
 	fwnode_init(&adev->fwnode, NULL);
 	device_set_node(dev, &adev->fwnode);
-	adev->fwnode.dev = dev;
+	fw_devlink_set_device(&adev->fwnode, dev);
 }
 
 #ifndef SZ_64G
-- 
2.55.0

[PATCH v13 06/10] PCI: of: Use fw_devlink_set_device()

[Herve Codina]

The code set directly fwnode.dev field.

Use the dedicated fw_devlink_set_device() helper to perform this
operation.

Cc: stable@vger.kernel.org
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Richard Cheng <icheng@nvidia.com>
Acked-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
---
Cc stable because used by other patches with Fixes + Cc stable
---
 drivers/pci/of.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pci/of.c b/drivers/pci/of.c
index a51dff91b196..0f45c5b72458 100644
--- a/drivers/pci/of.c
+++ b/drivers/pci/of.c
@@ -882,7 +882,7 @@ void of_pci_make_host_bridge_node(struct pci_host_bridge *bridge)
 	 * bus. Avoid any new device creation.
 	 */
 	of_node_set_flag(np, OF_POPULATED);
-	np->fwnode.dev = &bridge->dev;
+	fw_devlink_set_device(&np->fwnode, &bridge->dev);
 	fwnode_dev_initialized(&np->fwnode, true);
 
 	ret = of_changeset_apply(cset);
-- 
2.55.0

[PATCH v13 07/10] PCI: of: Clear fwnode->dev during root bridge node removal and error path

[Herve Codina]

During the of_pci_make_host_bridge_node() call, an OF node is created
dynamically and its fwnode device (fwnode->dev) is set to the PCI root
bridge device using the fw_devlink_set_device(&np->fwnode, &bridge->dev)
call.

On removal, of_pci_remove_host_bridge_node() is called and calls
device_remove_of_node() which in turn set to NULL the related
dev->fwnode.

Later in the removal sequence, device_del() is called and runs its
cleanup logic:

    if (dev->fwnode && dev->fwnode->dev == dev)
        fw_devlink_set_device(dev->fwnode, NULL);

Because dev->fwnode has been cleared earlier, fw_devlink_set_device()
is not called and leaves fwnode->dev unchanged. This fwnode device
(fwnode->dev) becomes an dangling pointer.

If any reference to the OF node is held after this removal, the pointer
is still accessible using the OF node (np->fwnode.dev) but points to a
freed area.

The exact same issue is present in the of_pci_make_host_bridge_node()
error path leading to the exact same dangling fwnode->dev.

Avoid this dangling fwnode->dev pointer by clearing it in
of_pci_remove_host_bridge_node() and in of_pci_make_host_bridge_node()
error path.

Fixes: 1f340724419e ("PCI: of: Create device tree PCI host bridge node")
Cc: stable@vger.kernel.org
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Reviewed-by: Richard Cheng <icheng@nvidia.com>
Acked-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
---
 drivers/pci/of.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/of.c b/drivers/pci/of.c
index 0f45c5b72458..29b63a9090ae 100644
--- a/drivers/pci/of.c
+++ b/drivers/pci/of.c
@@ -822,6 +822,7 @@ void of_pci_remove_host_bridge_node(struct pci_host_bridge *bridge)
 	if (!np || !of_node_check_flag(np, OF_DYNAMIC))
 		return;
 
+	fw_devlink_set_device(&np->fwnode, NULL);
 	device_remove_of_node(&bridge->bus->dev);
 	device_remove_of_node(&bridge->dev);
 	of_changeset_revert(np->data);
@@ -887,7 +888,7 @@ void of_pci_make_host_bridge_node(struct pci_host_bridge *bridge)
 
 	ret = of_changeset_apply(cset);
 	if (ret)
-		goto out_free_node;
+		goto out_clear_devlink_dev;
 
 	np->data = cset;
 
@@ -909,6 +910,8 @@ void of_pci_make_host_bridge_node(struct pci_host_bridge *bridge)
 out_revert_cset:
 	np->data = NULL;
 	of_changeset_revert(cset);
+out_clear_devlink_dev:
+	fw_devlink_set_device(&np->fwnode, NULL);
 out_free_node:
 	of_node_put(np);
 out_destroy_cset:
-- 
2.55.0

[PATCH v13 08/10] PCI: of: Set fwnode device of newly created PCI device nodes

[Herve Codina]

Device-tree node can be created when CONFIG_PCI_DYNAMIC_OF_NODES. Those
nodes are created and filled based on PCI core information but the
fwnode device field is not set.

When later an overlay is applied, this confuses fw_devlink. Indeed,
without any device attached to the node, fw_devlink considers that this
node will never become a device. When this node is pointed as a
supplier, devlink looks at its ancestors in order to find a node with a
device that could be used as the supplier.

In the PCI use case, this leads to links that wrongly use the PCI root
bridge device as the supplier instead of the expected PCI device.

Setting the fwnode device to the device of the PCI device allows devlink
to use this device as a supplier and so, correct links are created.

Fixes: 407d1a51921e ("PCI: Create device tree node for bridge")
Cc: stable@vger.kernel.org
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Richard Cheng <icheng@nvidia.com>
Acked-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
---
 drivers/pci/of.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/of.c b/drivers/pci/of.c
index 29b63a9090ae..8914bfa25dc1 100644
--- a/drivers/pci/of.c
+++ b/drivers/pci/of.c
@@ -736,6 +736,7 @@ void of_pci_remove_node(struct pci_dev *pdev)
 	if (!np || !of_node_check_flag(np, OF_DYNAMIC))
 		return;
 
+	fw_devlink_set_device(&np->fwnode, NULL);
 	device_remove_of_node(&pdev->dev);
 	of_changeset_revert(np->data);
 	of_changeset_destroy(np->data);
@@ -788,9 +789,16 @@ void of_pci_make_dev_node(struct pci_dev *pdev)
 	if (ret)
 		goto out_free_node;
 
+	/*
+	 * Set the fwnode device in order to have fw_devlink creating links
+	 * pointing to this PCI device instead of walking up to the PCI host
+	 * bridge.
+	 */
+	fw_devlink_set_device(&np->fwnode, &pdev->dev);
+
 	ret = of_changeset_apply(cset);
 	if (ret)
-		goto out_free_node;
+		goto out_clear_devlink_dev;
 
 	np->data = cset;
 
@@ -805,6 +813,8 @@ void of_pci_make_dev_node(struct pci_dev *pdev)
 out_revert_cset:
 	np->data = NULL;
 	of_changeset_revert(cset);
+out_clear_devlink_dev:
+	fw_devlink_set_device(&np->fwnode, NULL);
 out_free_node:
 	of_node_put(np);
 out_destroy_cset:
-- 
2.55.0

[PATCH v13 09/10] PCI: of: Remove fwnode_dev_initialized() call for a PCI root bridge node

[Herve Codina]

During the instantiation of devices described by a device-tree overlay
applied on a PCI device, devlink displays the following kind of debug
messages instead of creating the expected links:
   'Not linking xxxx - might never become dev'

Without those expected links, the device removal order cannot be
correct.

Those debug traces are printed by fw_devlink_create_devlink(). In our
use case, they are all printed because the supplier of the link has at
least one of its ancestor with its fwnode flag FWNODE_FLAG_INITIALIZED
set.

The culprit ancestor is the PCI root bridge.

The fwnode related to the PCI root bridge is created dynamically by the
of_pci_make_host_bridge_node() function. During this creation
fwnode_dev_initialized() is called which set the FWNODE_FLAG_INITIALIZED
flag.

Calling fwnode_dev_initialized() tells devlink that the device related
to this node is handled out of the driver core. This is not correct in
our case. Indeed the device related to this firmware node is handled
using driver core mechanisms and is fully compliant devlink
expectations.

Simply remove the fwnode_dev_initialized() call. With that done, the
devlink debug messages are no more displayed and links that were missing
are correctly created.

Fixes: 1f340724419e ("PCI: of: Create device tree PCI host bridge node")
Cc: stable@vger.kernel.org
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Richard Cheng <icheng@nvidia.com>
---
 drivers/pci/of.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/pci/of.c b/drivers/pci/of.c
index 8914bfa25dc1..0a5797652e18 100644
--- a/drivers/pci/of.c
+++ b/drivers/pci/of.c
@@ -894,7 +894,6 @@ void of_pci_make_host_bridge_node(struct pci_host_bridge *bridge)
 	 */
 	of_node_set_flag(np, OF_POPULATED);
 	fw_devlink_set_device(&np->fwnode, &bridge->dev);
-	fwnode_dev_initialized(&np->fwnode, true);
 
 	ret = of_changeset_apply(cset);
 	if (ret)
-- 
2.55.0