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PCI: hv: Fix hv_pci_remove() for hot-remove

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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 <decui@microsoft.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Jake Oshins <jakeo@microsoft.com>
Acked-by: K. Y. Srinivasan <kys@microsoft.com>
CC: Haiyang Zhang <haiyangz@microsoft.com>
CC: Vitaly Kuznetsov <vkuznets@redhat.com>
This commit is contained in:
Dexuan Cui 2016-11-10 07:18:47 +00:00 committed by Bjorn Helgaas
parent 8286e96d95
commit 17978524a6
1 changed files with 33 additions and 20 deletions
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53
drivers/pci/host/pci-hyperv.c
View file

@ -2266,24 +2266,32 @@ static int hv_pci_probe(struct hv_device *hdev,
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);