From: longli@linuxonhyperv.com
To: "K. Y. Srinivasan" <kys@microsoft.com>,
Haiyang Zhang <haiyangz@microsoft.com>,
Stephen Hemminger <sthemmin@microsoft.com>,
Wei Liu <wei.liu@kernel.org>,
Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
Rob Herring <robh@kernel.org>,
Bjorn Helgaas <bhelgaas@google.com>,
linux-hyperv@vger.kernel.org, linux-pci@vger.kernel.org,
linux-kernel@vger.kernel.org
Cc: Long Li <longli@microsoft.com>
Subject: [Patch v2 2/2] PCI: hv: Remove unused refcount and supporting functions for handling bus device removal
Date: Wed, 21 Apr 2021 22:45:46 -0700 [thread overview]
Message-ID: <1619070346-21557-2-git-send-email-longli@linuxonhyperv.com> (raw)
In-Reply-To: <1619070346-21557-1-git-send-email-longli@linuxonhyperv.com>
From: Long Li <longli@microsoft.com>
With the new method of flushing/stopping the workqueue before doing bus
removal, the old mechanisum of using refcount and wait for completion
is no longer needed. Remove those dead code.
Signed-off-by: Long Li <longli@microsoft.com>
---
drivers/pci/controller/pci-hyperv.c | 34 +++--------------------------
1 file changed, 3 insertions(+), 31 deletions(-)
diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
index fc948a2ed703..e6b4ee323068 100644
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -452,7 +452,6 @@ struct hv_pcibus_device {
/* Protocol version negotiated with the host */
enum pci_protocol_version_t protocol_version;
enum hv_pcibus_state state;
- refcount_t remove_lock;
struct hv_device *hdev;
resource_size_t low_mmio_space;
resource_size_t high_mmio_space;
@@ -460,7 +459,6 @@ struct hv_pcibus_device {
struct resource *low_mmio_res;
struct resource *high_mmio_res;
struct completion *survey_event;
- struct completion remove_event;
struct pci_bus *pci_bus;
spinlock_t config_lock; /* Avoid two threads writing index page */
spinlock_t device_list_lock; /* Protect lists below */
@@ -593,9 +591,6 @@ static void put_pcichild(struct hv_pci_dev *hpdev)
kfree(hpdev);
}
-static void get_hvpcibus(struct hv_pcibus_device *hv_pcibus);
-static void put_hvpcibus(struct hv_pcibus_device *hv_pcibus);
-
/*
* There is no good way to get notified from vmbus_onoffer_rescind(),
* so let's use polling here, since this is not a hot path.
@@ -2067,10 +2062,8 @@ static void pci_devices_present_work(struct work_struct *work)
}
spin_unlock_irqrestore(&hbus->device_list_lock, flags);
- if (!dr) {
- put_hvpcibus(hbus);
+ if (!dr)
return;
- }
/* First, mark all existing children as reported missing. */
spin_lock_irqsave(&hbus->device_list_lock, flags);
@@ -2153,7 +2146,6 @@ static void pci_devices_present_work(struct work_struct *work)
break;
}
- put_hvpcibus(hbus);
kfree(dr);
}
@@ -2194,12 +2186,10 @@ static int hv_pci_start_relations_work(struct hv_pcibus_device *hbus,
list_add_tail(&dr->list_entry, &hbus->dr_list);
spin_unlock_irqrestore(&hbus->device_list_lock, flags);
- if (pending_dr) {
+ if (pending_dr)
kfree(dr_wrk);
- } else {
- get_hvpcibus(hbus);
+ else
queue_work(hbus->wq, &dr_wrk->wrk);
- }
return 0;
}
@@ -2342,8 +2332,6 @@ static void hv_eject_device_work(struct work_struct *work)
put_pcichild(hpdev);
put_pcichild(hpdev);
/* hpdev has been freed. Do not use it any more. */
-
- put_hvpcibus(hbus);
}
/**
@@ -2367,7 +2355,6 @@ static void hv_pci_eject_device(struct hv_pci_dev *hpdev)
hpdev->state = hv_pcichild_ejecting;
get_pcichild(hpdev);
INIT_WORK(&hpdev->wrk, hv_eject_device_work);
- get_hvpcibus(hbus);
queue_work(hbus->wq, &hpdev->wrk);
}
@@ -2967,17 +2954,6 @@ static int hv_send_resources_released(struct hv_device *hdev)
return 0;
}
-static void get_hvpcibus(struct hv_pcibus_device *hbus)
-{
- refcount_inc(&hbus->remove_lock);
-}
-
-static void put_hvpcibus(struct hv_pcibus_device *hbus)
-{
- if (refcount_dec_and_test(&hbus->remove_lock))
- complete(&hbus->remove_event);
-}
-
#define HVPCI_DOM_MAP_SIZE (64 * 1024)
static DECLARE_BITMAP(hvpci_dom_map, HVPCI_DOM_MAP_SIZE);
@@ -3097,14 +3073,12 @@ static int hv_pci_probe(struct hv_device *hdev,
hbus->sysdata.domain = dom;
hbus->hdev = hdev;
- refcount_set(&hbus->remove_lock, 1);
INIT_LIST_HEAD(&hbus->children);
INIT_LIST_HEAD(&hbus->dr_list);
INIT_LIST_HEAD(&hbus->resources_for_children);
spin_lock_init(&hbus->config_lock);
spin_lock_init(&hbus->device_list_lock);
spin_lock_init(&hbus->retarget_msi_interrupt_lock);
- init_completion(&hbus->remove_event);
hbus->wq = alloc_ordered_workqueue("hv_pci_%x", 0,
hbus->sysdata.domain);
if (!hbus->wq) {
@@ -3332,8 +3306,6 @@ static int hv_pci_remove(struct hv_device *hdev)
hv_pci_free_bridge_windows(hbus);
irq_domain_remove(hbus->irq_domain);
irq_domain_free_fwnode(hbus->sysdata.fwnode);
- put_hvpcibus(hbus);
- wait_for_completion(&hbus->remove_event);
hv_put_dom_num(hbus->sysdata.domain);
--
2.27.0
next prev parent reply other threads:[~2021-04-22 5:46 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-22 5:45 [Patch v2 1/2] PCI: hv: Fix a race condition when removing the device longli
2021-04-22 5:45 ` longli [this message]
2021-04-23 7:18 ` [Patch v2 2/2] PCI: hv: Remove unused refcount and supporting functions for handling bus device removal Dexuan Cui
2021-04-23 18:40 ` Long Li
2021-04-25 2:57 ` Dexuan Cui
2021-04-23 7:09 ` [Patch v2 1/2] PCI: hv: Fix a race condition when removing the device Dexuan Cui
2021-04-23 18:32 ` Long Li
2021-04-23 18:41 ` Dexuan Cui
2021-04-23 18:49 ` Long Li
2021-04-25 2:24 ` Dexuan Cui
2021-04-25 4:53 ` Long Li
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