> Subject: Re: [Patch v3 2/2] PCI: hv: Remove unused refcount and supporting
> functions for handling bus device removal
>
> On Wed, May 12, 2021 at 01:06:49AM -0700, longli@xxxxxxxxxxxxxxxxx
> wrote:
> > From: Long Li <longli@xxxxxxxxxxxxx>
> >
> > With the new method of flushing/stopping the workqueue before doing
> > bus removal, the old mechanism of using refcount and wait for
> > completion is no longer needed. Remove those dead code.
> >
> > Signed-off-by: Long Li <longli@xxxxxxxxxxxxx>
> > ---
> > drivers/pci/controller/pci-hyperv.c | 34
> > +++--------------------------
> > 1 file changed, 3 insertions(+), 31 deletions(-)
>
> I'd be grateful if in the future you can send threaded patch series so that
> tools like b4 can detect the thread and create the mbox accordingly.
>
> No need to resend this one (maybe I need to trim patch(2) Subject).
Will do next time. Thank you!
Long
>
> Thanks,
> Lorenzo
>
> > diff --git a/drivers/pci/controller/pci-hyperv.c
> > b/drivers/pci/controller/pci-hyperv.c
> > index c6122a1b0c46..9499ae3275fe 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) {
> > @@ -3341,8 +3315,6 @@ 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
> >
