diff options
Diffstat (limited to 'drivers/pci/pci-driver.c')
| -rw-r--r-- | drivers/pci/pci-driver.c | 38 |
1 files changed, 30 insertions, 8 deletions
diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index 9042fdbd724..25f0bc65916 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 |