From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:20:52 +0000
Subject: [PATCH] add new system file
---
kernel/drivers/pci/controller/pci-hyperv.c | 112 ++++++++++++++++++++++++++++---------------------------
1 files changed, 57 insertions(+), 55 deletions(-)
diff --git a/kernel/drivers/pci/controller/pci-hyperv.c b/kernel/drivers/pci/controller/pci-hyperv.c
index 4353443..2d6c77d 100644
--- a/kernel/drivers/pci/controller/pci-hyperv.c
+++ b/kernel/drivers/pci/controller/pci-hyperv.c
@@ -520,19 +520,10 @@
struct hv_pcidev_description func[];
};
-enum hv_pcichild_state {
- hv_pcichild_init = 0,
- hv_pcichild_requirements,
- hv_pcichild_resourced,
- hv_pcichild_ejecting,
- hv_pcichild_maximum
-};
-
struct hv_pci_dev {
/* List protected by pci_rescan_remove_lock */
struct list_head list_entry;
refcount_t refs;
- enum hv_pcichild_state state;
struct pci_slot *pci_slot;
struct hv_pcidev_description desc;
bool reported_missing;
@@ -1237,6 +1228,11 @@
pbus = pdev->bus;
hbus = container_of(pbus->sysdata, struct hv_pcibus_device, sysdata);
int_desc = data->chip_data;
+ if (!int_desc) {
+ dev_warn(&hbus->hdev->device, "%s() can not unmask irq %u\n",
+ __func__, data->irq);
+ return;
+ }
spin_lock_irqsave(&hbus->retarget_msi_interrupt_lock, flags);
@@ -1552,12 +1548,6 @@
}
hv_pci_onchannelcallback(hbus);
spin_unlock_irqrestore(&channel->sched_lock, flags);
-
- if (hpdev->state == hv_pcichild_ejecting) {
- dev_err_once(&hbus->hdev->device,
- "the device is being ejected\n");
- goto enable_tasklet;
- }
udelay(100);
}
@@ -2378,8 +2368,6 @@
hpdev = container_of(work, struct hv_pci_dev, wrk);
hbus = hpdev->hbus;
- WARN_ON(hpdev->state != hv_pcichild_ejecting);
-
/*
* Ejection can come before or after the PCI bus has been set up, so
* attempt to find it and tear down the bus state, if it exists. This
@@ -2438,7 +2426,6 @@
return;
}
- hpdev->state = hv_pcichild_ejecting;
get_pcichild(hpdev);
INIT_WORK(&hpdev->wrk, hv_eject_device_work);
get_hvpcibus(hbus);
@@ -2842,8 +2829,10 @@
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
@@ -2869,6 +2858,38 @@
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,
@@ -2911,6 +2932,24 @@
0, VM_PKT_DATA_INBAND, 0);
if (!ret)
ret = wait_for_response(hdev, &comp);
+
+ /*
+ * In the case of fast device addition/removal, it's possible that
+ * vmbus_sendpacket() or wait_for_response() returns -ENODEV but we
+ * already got a PCI_BUS_RELATIONS* message from the host and the
+ * channel callback already scheduled a work to hbus->wq, which can be
+ * running pci_devices_present_work() -> survey_child_resources() ->
+ * complete(&hbus->survey_event), even after hv_pci_query_relations()
+ * exits and the stack variable 'comp' is no longer valid; as a result,
+ * a hang or a page fault may happen when the complete() calls
+ * raw_spin_lock_irqsave(). Flush hbus->wq before we exit from
+ * hv_pci_query_relations() to avoid the issues. Note: if 'ret' is
+ * -ENODEV, there can't be any more work item scheduled to hbus->wq
+ * after the flush_workqueue(): see vmbus_onoffer_rescind() ->
+ * vmbus_reset_channel_cb(), vmbus_rescind_cleanup() ->
+ * channel->rescind = true.
+ */
+ flush_workqueue(hbus->wq);
return ret;
}
@@ -3107,7 +3146,6 @@
struct hv_pcibus_device *hbus;
u16 dom_req, dom;
char *name;
- bool enter_d0_retry = true;
int ret;
/*
@@ -3228,47 +3266,11 @@
if (ret)
goto free_fwnode;
-retry:
ret = hv_pci_query_relations(hdev);
if (ret)
goto free_irq_domain;
ret = hv_pci_enter_d0(hdev);
- /*
- * 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.
- * Since the hv_pci_bus_exit() call releases structures
- * of all its child devices, we need to start the retry from
- * hv_pci_query_relations() call, requesting host to send
- * the synchronous child device relations message before this
- * information is needed in hv_send_resources_allocated()
- * call later.
- */
- if (ret == -EPROTO && enter_d0_retry) {
- enter_d0_retry = false;
-
- dev_err(&hdev->device, "Retrying D0 Entry\n");
-
- /*
- * Hv_pci_bus_exit() calls hv_send_resources_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)
- goto retry;
-
- dev_err(&hdev->device,
- "Retrying D0 failed with ret %d\n", ret);
- }
if (ret)
goto free_irq_domain;
--
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