diff options
| -rw-r--r-- | drivers/pci/controller/pci-hyperv.c | 40 |
1 files changed, 38 insertions, 2 deletions
diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c index e6fac0187722..92092a47d3af 100644 --- a/drivers/pci/controller/pci-hyperv.c +++ b/drivers/pci/controller/pci-hyperv.c @@ -2739,6 +2739,8 @@ static void hv_free_config_window(struct hv_pcibus_device *hbus) vmbus_free_mmio(hbus->mem_config->start, PCI_CONFIG_MMIO_LENGTH); } +static int hv_pci_bus_exit(struct hv_device *hdev, bool keep_devs); + /** * hv_pci_enter_d0() - Bring the "bus" into the D0 power state * @hdev: VMBus's tracking struct for this root PCI bus @@ -2751,8 +2753,10 @@ static int hv_pci_enter_d0(struct hv_device *hdev) struct pci_bus_d0_entry *d0_entry; struct hv_pci_compl comp_pkt; struct pci_packet *pkt; + bool retry = true; int ret; +enter_d0_retry: /* * Tell the host that the bus is ready to use, and moved into the * powered-on state. This includes telling the host which region @@ -2779,6 +2783,38 @@ static int hv_pci_enter_d0(struct hv_device *hdev) if (ret) goto exit; + /* + * In certain case (Kdump) the pci device of interest was + * not cleanly shut down and resource is still held on host + * side, the host could return invalid device status. + * We need to explicitly request host to release the resource + * and try to enter D0 again. + */ + if (comp_pkt.completion_status < 0 && retry) { + retry = false; + + dev_err(&hdev->device, "Retrying D0 Entry\n"); + + /* + * Hv_pci_bus_exit() calls hv_send_resource_released() + * to free up resources of its child devices. + * In the kdump kernel we need to set the + * wslot_res_allocated to 255 so it scans all child + * devices to release resources allocated in the + * normal kernel before panic happened. + */ + hbus->wslot_res_allocated = 255; + + ret = hv_pci_bus_exit(hdev, true); + + if (ret == 0) { + kfree(pkt); + goto enter_d0_retry; + } + dev_err(&hdev->device, + "Retrying D0 failed with ret %d\n", ret); + } + if (comp_pkt.completion_status < 0) { dev_err(&hdev->device, "PCI Pass-through VSP failed D0 Entry with status %x\n", @@ -3185,7 +3221,7 @@ free_bus: return ret; } -static int hv_pci_bus_exit(struct hv_device *hdev, bool hibernating) +static int hv_pci_bus_exit(struct hv_device *hdev, bool keep_devs) { struct hv_pcibus_device *hbus = hv_get_drvdata(hdev); struct { @@ -3203,7 +3239,7 @@ static int hv_pci_bus_exit(struct hv_device *hdev, bool hibernating) if (hdev->channel->rescind) return 0; - if (!hibernating) { + if (!keep_devs) { /* Delete any children which might still exist. */ dr = kzalloc(sizeof(*dr), GFP_KERNEL); if (dr && hv_pci_start_relations_work(hbus, dr)) |