Once a PCI device's memory settings have been fixed through a static
enumeration profile, do not allow other parts of the PCI subsystem
to reset those settings. Specifically,
pci_reassigndev_resource_alignment() will remove the memory behind a
bridge if there are no devices downstream. With static enumeration,
devices may appear downstream later on, after the initial scan. Thus,
do not remove resources explicitly set by the static enumeration
profile.
Signed-off-by: Jason Tang <jason.tang2@xxxxxxx>
---
drivers/pci/pci.h | 12 ++++++++++++
drivers/pci/pci_static_enum.c | 4 ++++
drivers/pci/probe.c | 3 ++-
include/linux/pci.h | 4 ++++
4 files changed, 22 insertions(+), 1 deletion(-)
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index db710ac..6233998 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -336,6 +336,14 @@ static inline unsigned char pci_bus_subordinate(struct pci_bus *bus)
{
return bus->subordinate;
}
+/**
+ * pci_static_enum_set() - return %true if @dev's bridge and BAR
+ * settings have been set by a static enumeration profile
+ */
+static inline bool pci_static_enum_set(struct pci_dev *dev)
+{
+ return dev->is_static_enum;
+}
#else
static inline void pci_static_enum_set_opt(const char *str) { return; }
static inline int pci_static_enum_exists(void) { return 0; }
@@ -350,6 +358,10 @@ static inline unsigned char pci_bus_subordinate(struct pci_bus *bus)
{
return 0;
}
+static inline bool pci_static_enum_set(struct pci_dev *dev)
+{
+ return false;
+}
#endif
#endif /* DRIVERS_PCI_H */
diff --git a/drivers/pci/pci_static_enum.c b/drivers/pci/pci_static_enum.c
index 14626cd..7b78a85 100644
--- a/drivers/pci/pci_static_enum.c
+++ b/drivers/pci/pci_static_enum.c
@@ -372,6 +372,8 @@ static void pci_static_enum_set_bridge_memory(struct pci_dev *dev, struct pci_st
memory */
if (root)
pci_walk_bus(root, pci_static_enum_invalidate, setting);
+
+ dev->is_static_enum = 1;
}
/**
@@ -515,6 +517,8 @@ static void pci_static_enum_set_mmio_bars(struct pci_dev *dev, struct pci_static
reg = PCI_BASE_ADDRESS_0 + (pos << 2);
pci_static_enum_reset_mmio_bar(dev, setting, reg);
}
+
+ dev->is_static_enum = 1;
}
/**
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 418fb59..5bbc11d 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1553,7 +1553,8 @@ void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
pci_fixup_device(pci_fixup_header, dev);
/* moved out from quirk header fixup code */
- pci_reassigndev_resource_alignment(dev);
+ if (!pci_static_enum_set(dev))
+ pci_reassigndev_resource_alignment(dev);
/* Clear the state_saved flag. */
dev->state_saved = false;
diff --git a/include/linux/pci.h b/include/linux/pci.h
index b82503b..aa208f0 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -334,6 +334,10 @@ struct pci_dev {
unsigned int multifunction:1;/* Part of multi-function device */
/* keep track of device state */
unsigned int is_added:1;
+#ifdef CONFIG_PCI_STATIC_ENUMERATION
+ unsigned int is_static_enum:1; /* static enumeration applied */
+#endif
+
unsigned int is_busmaster:1; /* device is busmaster */
unsigned int no_msi:1; /* device may not use msi */
unsigned int no_64bit_msi:1; /* device may only use 32-bit MSIs */
--
1.7.9.5
--
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