Update Linux to v5.4.148
Sourced from [1]
[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.4.148.tar.gz
Change-Id: Ib3d26c5ba9b022e2e03533005c4fed4d7c30b61b
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c
index 0608aae..0153abd 100644
--- a/drivers/pci/p2pdma.c
+++ b/drivers/pci/p2pdma.c
@@ -292,10 +292,41 @@ static const struct pci_p2pdma_whitelist_entry {
{}
};
+/*
+ * This lookup function tries to find the PCI device corresponding to a given
+ * host bridge.
+ *
+ * It assumes the host bridge device is the first PCI device in the
+ * bus->devices list and that the devfn is 00.0. These assumptions should hold
+ * for all the devices in the whitelist above.
+ *
+ * This function is equivalent to pci_get_slot(host->bus, 0), however it does
+ * not take the pci_bus_sem lock seeing __host_bridge_whitelist() must not
+ * sleep.
+ *
+ * For this to be safe, the caller should hold a reference to a device on the
+ * bridge, which should ensure the host_bridge device will not be freed
+ * or removed from the head of the devices list.
+ */
+static struct pci_dev *pci_host_bridge_dev(struct pci_host_bridge *host)
+{
+ struct pci_dev *root;
+
+ root = list_first_entry_or_null(&host->bus->devices,
+ struct pci_dev, bus_list);
+
+ if (!root)
+ return NULL;
+ if (root->devfn != PCI_DEVFN(0, 0))
+ return NULL;
+
+ return root;
+}
+
static bool __host_bridge_whitelist(struct pci_host_bridge *host,
bool same_host_bridge)
{
- struct pci_dev *root = pci_get_slot(host->bus, PCI_DEVFN(0, 0));
+ struct pci_dev *root = pci_host_bridge_dev(host);
const struct pci_p2pdma_whitelist_entry *entry;
unsigned short vendor, device;
@@ -304,7 +335,6 @@ static bool __host_bridge_whitelist(struct pci_host_bridge *host,
vendor = root->vendor;
device = root->device;
- pci_dev_put(root);
for (entry = pci_p2pdma_whitelist; entry->vendor; entry++) {
if (vendor != entry->vendor || device != entry->device)