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authorLukas Wunner <lukas@wunner.de>2025-04-25 11:24:22 +0200
committerKrzysztof Wilczyński <kwilczynski@kernel.org>2025-05-15 13:40:52 +0000
commitce45dc4bb22e96b59a07e19b67e915d99dd5281b (patch)
tree1aee9649ff974396d2dd52a59c39dfa1171e60a3
parent3be5fa236649da6404f1bca1491bf02d4b0d5cce (diff)
downloadpci-enumeration.tar.gz
PCI: Limit visibility of match_driver flag to PCI coreenumeration
Since commit 58d9a38f6fac ("PCI: Skip attaching driver in device_add()"), PCI enumeration is split into two steps: In the first step, all devices are published in sysfs with device_add(). In the second step, drivers are bound to the devices with device_attach(). To delay driver binding until the second step, a "bool match_driver" in struct pci_dev is used. Instead of a bool, use a bit in the "unsigned long priv_flags" to shrink struct pci_dev a little and prevent use of the bool outside the PCI core (as has happened with commit cbbc00be2ce3 ("iommu/amd: Prevent binding other PCI drivers to IOMMU PCI devices")). Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org> Link: https://patch.msgid.link/d22a9e5b81d6bd8dd1837607d6156679b3b1199c.1745572340.git.lukas@wunner.de
-rw-r--r--drivers/pci/bus.c4
-rw-r--r--drivers/pci/pci-driver.c2
-rw-r--r--drivers/pci/pci.h11
-rw-r--r--drivers/pci/probe.c1
-rw-r--r--include/linux/pci.h2
5 files changed, 15 insertions, 5 deletions
diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c
index b6851101ac3642..69048869ef1c37 100644
--- a/drivers/pci/bus.c
+++ b/drivers/pci/bus.c
@@ -369,7 +369,9 @@ void pci_bus_add_device(struct pci_dev *dev)
pdev->name);
}
- dev->match_driver = !dn || of_device_is_available(dn);
+ if (!dn || of_device_is_available(dn))
+ pci_dev_allow_binding(dev);
+
retval = device_attach(&dev->dev);
if (retval < 0 && retval != -EPROBE_DEFER)
pci_warn(dev, "device attach failed (%d)\n", retval);
diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index c8bd71a739f724..0c5bdb8c2c07b0 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -1507,7 +1507,7 @@ static int pci_bus_match(struct device *dev, const struct device_driver *drv)
struct pci_driver *pci_drv;
const struct pci_device_id *found_id;
- if (!pci_dev->match_driver)
+ if (pci_dev_binding_disallowed(pci_dev))
return 0;
pci_drv = (struct pci_driver *)to_pci_driver(drv);
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index b81e99cd4b62a3..de5d4ef943b291 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -557,6 +557,7 @@ static inline int pci_dev_set_disconnected(struct pci_dev *dev, void *unused)
#define PCI_DPC_RECOVERED 1
#define PCI_DPC_RECOVERING 2
#define PCI_DEV_REMOVED 3
+#define PCI_DEV_ALLOW_BINDING 7
static inline void pci_dev_assign_added(struct pci_dev *dev)
{
@@ -580,6 +581,16 @@ static inline bool pci_dev_test_and_set_removed(struct pci_dev *dev)
return test_and_set_bit(PCI_DEV_REMOVED, &dev->priv_flags);
}
+static inline void pci_dev_allow_binding(struct pci_dev *dev)
+{
+ set_bit(PCI_DEV_ALLOW_BINDING, &dev->priv_flags);
+}
+
+static inline bool pci_dev_binding_disallowed(struct pci_dev *dev)
+{
+ return !test_bit(PCI_DEV_ALLOW_BINDING, &dev->priv_flags);
+}
+
#ifdef CONFIG_PCIEAER
#include <linux/aer.h>
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 08971fca081935..4b8693ec9e4c67 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -2711,7 +2711,6 @@ void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
pci_set_msi_domain(dev);
/* Notifier could use PCI capabilities */
- dev->match_driver = false;
ret = device_add(&dev->dev);
WARN_ON(ret < 0);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index d26e6611bd0045..053d9dd494d459 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -423,8 +423,6 @@ struct pci_dev {
struct resource resource[DEVICE_COUNT_RESOURCE]; /* I/O and memory regions + expansion ROMs */
struct resource driver_exclusive_resource; /* driver exclusive resource ranges */
- bool match_driver; /* Skip attaching driver */
-
unsigned int transparent:1; /* Subtractive decode bridge */
unsigned int io_window:1; /* Bridge has I/O window */
unsigned int pref_window:1; /* Bridge has pref mem window */