Merge tag 'pci-v5.14-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaa...

[sfrench/cifs-2.6.git] / drivers / pci / controller / pci-hyperv.c

diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
index bebe3eeebc4e1abb09092627657bded8d018e203..a53bd8728d0d3e2bc7fb95309b7c5f2bdff672e1 100644 (file)
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -444,7 +444,6 @@ enum hv_pcibus_state {
        hv_pcibus_probed,
        hv_pcibus_installed,
        hv_pcibus_removing,
-       hv_pcibus_removed,
        hv_pcibus_maximum
 };
 
@@ -453,7 +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;
@@ -461,7 +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 +590,6 @@ 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.
@@ -2064,10 +2058,8 @@ 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);
@@ -2150,7 +2142,6 @@ static void pci_devices_present_work(struct work_struct *work)
                break;
        }
 
-       put_hvpcibus(hbus);
        kfree(dr);
 }
 
@@ -2191,12 +2182,10 @@ 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;
 }
@@ -2339,8 +2328,6 @@ 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);
 }
 
 /**
@@ -2364,7 +2351,6 @@ 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);
 }
 
@@ -2964,17 +2950,6 @@ 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);
 
@@ -3094,14 +3069,12 @@ 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) {
@@ -3243,8 +3216,9 @@ static int hv_pci_bus_exit(struct hv_device *hdev, bool keep_devs)
                struct pci_packet teardown_packet;
                u8 buffer[sizeof(struct pci_message)];
        } pkt;
-       struct hv_dr_state *dr;
        struct hv_pci_compl comp_pkt;
+       struct hv_pci_dev *hpdev, *tmp;
+       unsigned long flags;
        int ret;
 
        /*
@@ -3256,9 +3230,16 @@ static int hv_pci_bus_exit(struct hv_device *hdev, bool keep_devs)
 
        if (!keep_devs) {
                /* Delete any children which might still exist. */
-               dr = kzalloc(sizeof(*dr), GFP_KERNEL);
-               if (dr && hv_pci_start_relations_work(hbus, dr))
-                       kfree(dr);
+               spin_lock_irqsave(&hbus->device_list_lock, flags);
+               list_for_each_entry_safe(hpdev, tmp, &hbus->children, list_entry) {
+                       list_del(&hpdev->list_entry);
+                       if (hpdev->pci_slot)
+                               pci_destroy_slot(hpdev->pci_slot);
+                       /* For the two refs got in new_pcichild_device() */
+                       put_pcichild(hpdev);
+                       put_pcichild(hpdev);
+               }
+               spin_unlock_irqrestore(&hbus->device_list_lock, flags);
        }
 
        ret = hv_send_resources_released(hdev);
@@ -3301,13 +3282,23 @@ static int hv_pci_remove(struct hv_device *hdev)
 
        hbus = hv_get_drvdata(hdev);
        if (hbus->state == hv_pcibus_installed) {
+               tasklet_disable(&hdev->channel->callback_event);
+               hbus->state = hv_pcibus_removing;
+               tasklet_enable(&hdev->channel->callback_event);
+               destroy_workqueue(hbus->wq);
+               hbus->wq = NULL;
+               /*
+                * At this point, no work is running or can be scheduled
+                * on hbus-wq. We can't race with hv_pci_devices_present()
+                * or hv_pci_eject_device(), it's safe to proceed.
+                */
+
                /* Remove the bus from PCI's point of view. */
                pci_lock_rescan_remove();
                pci_stop_root_bus(hbus->pci_bus);
                hv_pci_remove_slots(hbus);
                pci_remove_root_bus(hbus->pci_bus);
                pci_unlock_rescan_remove();
-               hbus->state = hv_pcibus_removed;
        }
 
        ret = hv_pci_bus_exit(hdev, false);
@@ -3320,9 +3311,6 @@ 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);
-       destroy_workqueue(hbus->wq);
 
        hv_put_dom_num(hbus->sysdata.domain);