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-rw-r--r--drivers/pci/pci.c40
-rw-r--r--include/linux/pci.h2
2 files changed, 38 insertions, 4 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index cab05f31223f..e9d4fd861ba1 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -3271,7 +3271,8 @@ static int pci_parent_bus_reset(struct pci_dev *dev, int probe)
{
struct pci_dev *pdev;
- if (pci_is_root_bus(dev->bus) || dev->subordinate || !dev->bus->self)
+ if (pci_is_root_bus(dev->bus) || dev->subordinate ||
+ !dev->bus->self || dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET)
return -ENOTTY;
list_for_each_entry(pdev, &dev->bus->devices, bus_list)
@@ -3305,7 +3306,8 @@ static int pci_dev_reset_slot_function(struct pci_dev *dev, int probe)
{
struct pci_dev *pdev;
- if (dev->subordinate || !dev->slot)
+ if (dev->subordinate || !dev->slot ||
+ dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET)
return -ENOTTY;
list_for_each_entry(pdev, &dev->bus->devices, bus_list)
@@ -3557,6 +3559,20 @@ int pci_try_reset_function(struct pci_dev *dev)
}
EXPORT_SYMBOL_GPL(pci_try_reset_function);
+/* Do any devices on or below this bus prevent a bus reset? */
+static bool pci_bus_resetable(struct pci_bus *bus)
+{
+ struct pci_dev *dev;
+
+ list_for_each_entry(dev, &bus->devices, bus_list) {
+ if (dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET ||
+ (dev->subordinate && !pci_bus_resetable(dev->subordinate)))
+ return false;
+ }
+
+ return true;
+}
+
/* Lock devices from the top of the tree down */
static void pci_bus_lock(struct pci_bus *bus)
{
@@ -3607,6 +3623,22 @@ unlock:
return 0;
}
+/* Do any devices on or below this slot prevent a bus reset? */
+static bool pci_slot_resetable(struct pci_slot *slot)
+{
+ struct pci_dev *dev;
+
+ list_for_each_entry(dev, &slot->bus->devices, bus_list) {
+ if (!dev->slot || dev->slot != slot)
+ continue;
+ if (dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET ||
+ (dev->subordinate && !pci_bus_resetable(dev->subordinate)))
+ return false;
+ }
+
+ return true;
+}
+
/* Lock devices from the top of the tree down */
static void pci_slot_lock(struct pci_slot *slot)
{
@@ -3728,7 +3760,7 @@ static int pci_slot_reset(struct pci_slot *slot, int probe)
{
int rc;
- if (!slot)
+ if (!slot || !pci_slot_resetable(slot))
return -ENOTTY;
if (!probe)
@@ -3820,7 +3852,7 @@ EXPORT_SYMBOL_GPL(pci_try_reset_slot);
static int pci_bus_reset(struct pci_bus *bus, int probe)
{
- if (!bus->self)
+ if (!bus->self || !pci_bus_resetable(bus))
return -ENOTTY;
if (probe)
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 360a966a97a5..44627f1df4ca 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -175,6 +175,8 @@ enum pci_dev_flags {
PCI_DEV_FLAGS_DMA_ALIAS_DEVFN = (__force pci_dev_flags_t) (1 << 4),
/* Use a PCIe-to-PCI bridge alias even if !pci_is_pcie */
PCI_DEV_FLAG_PCIE_BRIDGE_ALIAS = (__force pci_dev_flags_t) (1 << 5),
+ /* Do not use bus resets for device */
+ PCI_DEV_FLAGS_NO_BUS_RESET = (__force pci_dev_flags_t) (1 << 6),
};
enum pci_irq_reroute_variant {