From 17978524a636d007e6b929304ae3eb5ea0371019 Mon Sep 17 00:00:00 2001 From: Dexuan Cui Date: Thu, 10 Nov 2016 07:18:47 +0000 Subject: [PATCH] PCI: hv: Fix hv_pci_remove() for hot-remove 1. We don't really need such a big on-stack buffer when sending the teardown_packet: vmbus_sendpacket() here only uses sizeof(struct pci_message). 2. In the hot-remove case (PCI_EJECT), after we send PCI_EJECTION_COMPLETE to the host, the host will send a RESCIND_CHANNEL message to us and the host won't access the per-channel ringbuffer any longer, so we needn't send PCI_RESOURCES_RELEASED/PCI_BUS_D0EXIT to the host, and we shouldn't expect the host's completion message of PCI_BUS_D0EXIT, which will never come. 3. We should send PCI_BUS_D0EXIT after hv_send_resources_released(). Signed-off-by: Dexuan Cui Signed-off-by: Bjorn Helgaas Reviewed-by: Jake Oshins Acked-by: K. Y. Srinivasan CC: Haiyang Zhang CC: Vitaly Kuznetsov --- drivers/pci/host/pci-hyperv.c | 53 +++++++++++++++++++++++++++---------------- 1 file changed, 33 insertions(+), 20 deletions(-) diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c index 9ea63b4..b174746 100644 --- a/drivers/pci/host/pci-hyperv.c +++ b/drivers/pci/host/pci-hyperv.c @@ -2266,24 +2266,32 @@ free_bus: return ret; } -/** - * hv_pci_remove() - Remove routine for this VMBus channel - * @hdev: VMBus's tracking struct for this root PCI bus - * - * Return: 0 on success, -errno on failure - */ -static int hv_pci_remove(struct hv_device *hdev) +static void hv_pci_bus_exit(struct hv_device *hdev) { - int ret; - struct hv_pcibus_device *hbus; - union { + struct hv_pcibus_device *hbus = hv_get_drvdata(hdev); + struct { struct pci_packet teardown_packet; - u8 buffer[0x100]; + u8 buffer[sizeof(struct pci_message)]; } pkt; struct pci_bus_relations relations; struct hv_pci_compl comp_pkt; + int ret; - hbus = hv_get_drvdata(hdev); + /* + * After the host sends the RESCIND_CHANNEL message, it doesn't + * access the per-channel ringbuffer any longer. + */ + if (hdev->channel->rescind) + return; + + /* Delete any children which might still exist. */ + memset(&relations, 0, sizeof(relations)); + hv_pci_devices_present(hbus, &relations); + + ret = hv_send_resources_released(hdev); + if (ret) + dev_err(&hdev->device, + "Couldn't send resources released packet(s)\n"); memset(&pkt.teardown_packet, 0, sizeof(pkt.teardown_packet)); init_completion(&comp_pkt.host_event); @@ -2298,7 +2306,19 @@ static int hv_pci_remove(struct hv_device *hdev) VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED); if (!ret) wait_for_completion_timeout(&comp_pkt.host_event, 10 * HZ); +} + +/** + * hv_pci_remove() - Remove routine for this VMBus channel + * @hdev: VMBus's tracking struct for this root PCI bus + * + * Return: 0 on success, -errno on failure + */ +static int hv_pci_remove(struct hv_device *hdev) +{ + struct hv_pcibus_device *hbus; + hbus = hv_get_drvdata(hdev); if (hbus->state == hv_pcibus_installed) { /* Remove the bus from PCI's point of view. */ pci_lock_rescan_remove(); @@ -2307,17 +2327,10 @@ static int hv_pci_remove(struct hv_device *hdev) pci_unlock_rescan_remove(); } - ret = hv_send_resources_released(hdev); - if (ret) - dev_err(&hdev->device, - "Couldn't send resources released packet(s)\n"); + hv_pci_bus_exit(hdev); vmbus_close(hdev->channel); - /* Delete any children which might still exist. */ - memset(&relations, 0, sizeof(relations)); - hv_pci_devices_present(hbus, &relations); - iounmap(hbus->cfg_addr); hv_free_config_window(hbus); pci_free_resource_list(&hbus->resources_for_children); -- 2.7.4