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Date:   Fri, 23 Apr 2021 19:16:31 -0700
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Subject: [PATCH v2 2/2] pci: Support "removable" attribute for PCI devices
From:   Rajat Jain <rajatja@google.com>
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Alan Stern <stern@rowland.harvard.edu>,
        Rajat Jain <rajatja@google.com>, linux-kernel@vger.kernel.org,
        linux-pci@vger.kernel.org, linux-usb@vger.kernel.org,
        helgaas@kernel.org
Cc:     rajatxjain@gmail.com, jsbarnes@google.com, dtor@google.com
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

Export the already available info, to the userspace via the
device core, so that userspace can implement whatever policies it
wants to, for external removable devices.

Signed-off-by: Rajat Jain <rajatja@google.com>
---
v2: Add documentation

 Documentation/ABI/testing/sysfs-devices-removable |  3 ++-
 drivers/pci/pci-sysfs.c                           |  1 +
 drivers/pci/probe.c                               | 12 ++++++++++++
 3 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/Documentation/ABI/testing/sysfs-devices-removable b/Documentation/ABI/testing/sysfs-devices-removable
index e13dddd547b5..daac4f007619 100644
--- a/Documentation/ABI/testing/sysfs-devices-removable
+++ b/Documentation/ABI/testing/sysfs-devices-removable
@@ -14,4 +14,5 @@ Description:
 
 		Currently this is only supported by USB (which infers the
 		information from a combination of hub descriptor bits and
-		platform-specific data such as ACPI).
+		platform-specific data such as ACPI) and PCI (which gets this
+		from ACPI / device tree).
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index f8afd54ca3e1..9302f0076e73 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -1582,4 +1582,5 @@ static const struct attribute_group *pci_dev_attr_groups[] = {
 
 const struct device_type pci_dev_type = {
 	.groups = pci_dev_attr_groups,
+	.supports_removable = true,
 };
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 953f15abc850..d1cceee62e1b 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1575,6 +1575,16 @@ static void set_pcie_untrusted(struct pci_dev *dev)
 		dev->untrusted = true;
 }
 
+static void set_pci_dev_removable(struct pci_dev *dev)
+{
+	struct pci_dev *parent = pci_upstream_bridge(dev);
+	if (parent &&
+	    (parent->external_facing || dev_is_removable(&parent->dev)))
+		dev_set_removable(&dev->dev, DEVICE_REMOVABLE);
+	else
+		dev_set_removable(&dev->dev, DEVICE_FIXED);
+}
+
 /**
  * pci_ext_cfg_is_aliased - Is ext config space just an alias of std config?
  * @dev: PCI device
@@ -1819,6 +1829,8 @@ int pci_setup_device(struct pci_dev *dev)
 	/* "Unknown power state" */
 	dev->current_state = PCI_UNKNOWN;
 
+	set_pci_dev_removable(dev);
+
 	/* Early fixups, before probing the BARs */
 	pci_fixup_device(pci_fixup_early, dev);
 
-- 
2.31.1.498.g6c1eba8ee3d-goog