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Diffstat (limited to 'drivers/pci/pci-driver.c')
-rw-r--r--drivers/pci/pci-driver.c38
1 files changed, 30 insertions, 8 deletions
diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index 9042fdbd7244..25f0bc659164 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -19,6 +19,7 @@
#include <linux/cpu.h>
#include <linux/pm_runtime.h>
#include <linux/suspend.h>
+#include <linux/kexec.h>
#include "pci.h"
struct pci_dynid {
@@ -288,12 +289,27 @@ static int pci_call_probe(struct pci_driver *drv, struct pci_dev *dev,
int error, node;
struct drv_dev_and_id ddi = { drv, dev, id };
- /* Execute driver initialization on node where the device's
- bus is attached to. This way the driver likely allocates
- its local memory on the right node without any need to
- change it. */
+ /*
+ * Execute driver initialization on node where the device is
+ * attached. This way the driver likely allocates its local memory
+ * on the right node.
+ */
node = dev_to_node(&dev->dev);
- if (node >= 0) {
+
+ /*
+ * On NUMA systems, we are likely to call a PF probe function using
+ * work_on_cpu(). If that probe calls pci_enable_sriov() (which
+ * adds the VF devices via pci_bus_add_device()), we may re-enter
+ * this function to call the VF probe function. Calling
+ * work_on_cpu() again will cause a lockdep warning. Since VFs are
+ * always on the same node as the PF, we can work around this by
+ * avoiding work_on_cpu() when we're already on the correct node.
+ *
+ * Preemption is enabled, so it's theoretically unsafe to use
+ * numa_node_id(), but even if we run the probe function on the
+ * wrong node, it should be functionally correct.
+ */
+ if (node >= 0 && node != numa_node_id()) {
int cpu;
get_online_cpus();
@@ -305,6 +321,7 @@ static int pci_call_probe(struct pci_driver *drv, struct pci_dev *dev,
put_online_cpus();
} else
error = local_pci_probe(&ddi);
+
return error;
}
@@ -399,12 +416,17 @@ static void pci_device_shutdown(struct device *dev)
pci_msi_shutdown(pci_dev);
pci_msix_shutdown(pci_dev);
+#ifdef CONFIG_KEXEC
/*
- * Turn off Bus Master bit on the device to tell it to not
- * continue to do DMA. Don't touch devices in D3cold or unknown states.
+ * If this is a kexec reboot, turn off Bus Master bit on the
+ * device to tell it to not continue to do DMA. Don't touch
+ * devices in D3cold or unknown states.
+ * If it is not a kexec reboot, firmware will hit the PCI
+ * devices with big hammer and stop their DMA any way.
*/
- if (pci_dev->current_state <= PCI_D3hot)
+ if (kexec_in_progress && (pci_dev->current_state <= PCI_D3hot))
pci_clear_master(pci_dev);
+#endif
}
#ifdef CONFIG_PM
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