diff options
Diffstat (limited to 'drivers/pci/host/pci-hyperv.c')
-rw-r--r-- | drivers/pci/host/pci-hyperv.c | 92 |
1 files changed, 73 insertions, 19 deletions
diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c index 6b8d060d07de..1cdc12938b24 100644 --- a/drivers/pci/host/pci-hyperv.c +++ b/drivers/pci/host/pci-hyperv.c @@ -457,7 +457,6 @@ struct hv_pcibus_device { spinlock_t device_list_lock; /* Protect lists below */ void __iomem *cfg_addr; - struct semaphore enum_sem; struct list_head resources_for_children; struct list_head children; @@ -471,6 +470,8 @@ struct hv_pcibus_device { struct retarget_msi_interrupt retarget_msi_interrupt_params; spinlock_t retarget_msi_interrupt_lock; + + struct workqueue_struct *wq; }; /* @@ -530,6 +531,8 @@ struct hv_pci_compl { s32 completion_status; }; +static void hv_pci_onchannelcallback(void *context); + /** * hv_pci_generic_compl() - Invoked for a completion packet * @context: Set up by the sender of the packet. @@ -674,6 +677,31 @@ static void _hv_pcifront_read_config(struct hv_pci_dev *hpdev, int where, } } +static u16 hv_pcifront_get_vendor_id(struct hv_pci_dev *hpdev) +{ + u16 ret; + unsigned long flags; + void __iomem *addr = hpdev->hbus->cfg_addr + CFG_PAGE_OFFSET + + PCI_VENDOR_ID; + + spin_lock_irqsave(&hpdev->hbus->config_lock, flags); + + /* Choose the function to be read. (See comment above) */ + writel(hpdev->desc.win_slot.slot, hpdev->hbus->cfg_addr); + /* Make sure the function was chosen before we start reading. */ + mb(); + /* Read from that function's config space. */ + ret = readw(addr); + /* + * mb() is not required here, because the spin_unlock_irqrestore() + * is a barrier. + */ + + spin_unlock_irqrestore(&hpdev->hbus->config_lock, flags); + + return ret; +} + /** * _hv_pcifront_write_config() - Internal PCI config write * @hpdev: The PCI driver's representation of the device @@ -1116,8 +1144,37 @@ static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg) * Since this function is called with IRQ locks held, can't * do normal wait for completion; instead poll. */ - while (!try_wait_for_completion(&comp.comp_pkt.host_event)) + while (!try_wait_for_completion(&comp.comp_pkt.host_event)) { + /* 0xFFFF means an invalid PCI VENDOR ID. */ + if (hv_pcifront_get_vendor_id(hpdev) == 0xFFFF) { + dev_err_once(&hbus->hdev->device, + "the device has gone\n"); + goto free_int_desc; + } + + /* + * When the higher level interrupt code calls us with + * interrupt disabled, we must poll the channel by calling + * the channel callback directly when channel->target_cpu is + * the current CPU. When the higher level interrupt code + * calls us with interrupt enabled, let's add the + * local_bh_disable()/enable() to avoid race. + */ + local_bh_disable(); + + if (hbus->hdev->channel->target_cpu == smp_processor_id()) + hv_pci_onchannelcallback(hbus); + + local_bh_enable(); + + if (hpdev->state == hv_pcichild_ejecting) { + dev_err_once(&hbus->hdev->device, + "the device is being ejected\n"); + goto free_int_desc; + } + udelay(100); + } if (comp.comp_pkt.completion_status < 0) { dev_err(&hbus->hdev->device, @@ -1600,12 +1657,8 @@ static struct hv_pci_dev *get_pcichild_wslot(struct hv_pcibus_device *hbus, * It must also treat the omission of a previously observed device as * notification that the device no longer exists. * - * Note that this function is a work item, and it may not be - * invoked in the order that it was queued. Back to back - * updates of the list of present devices may involve queuing - * multiple work items, and this one may run before ones that - * were sent later. As such, this function only does something - * if is the last one in the queue. + * Note that this function is serialized with hv_eject_device_work(), + * because both are pushed to the ordered workqueue hbus->wq. */ static void pci_devices_present_work(struct work_struct *work) { @@ -1626,11 +1679,6 @@ static void pci_devices_present_work(struct work_struct *work) INIT_LIST_HEAD(&removed); - if (down_interruptible(&hbus->enum_sem)) { - put_hvpcibus(hbus); - return; - } - /* Pull this off the queue and process it if it was the last one. */ spin_lock_irqsave(&hbus->device_list_lock, flags); while (!list_empty(&hbus->dr_list)) { @@ -1647,7 +1695,6 @@ static void pci_devices_present_work(struct work_struct *work) spin_unlock_irqrestore(&hbus->device_list_lock, flags); if (!dr) { - up(&hbus->enum_sem); put_hvpcibus(hbus); return; } @@ -1734,7 +1781,6 @@ static void pci_devices_present_work(struct work_struct *work) break; } - up(&hbus->enum_sem); put_hvpcibus(hbus); kfree(dr); } @@ -1780,7 +1826,7 @@ static void hv_pci_devices_present(struct hv_pcibus_device *hbus, spin_unlock_irqrestore(&hbus->device_list_lock, flags); get_hvpcibus(hbus); - schedule_work(&dr_wrk->wrk); + queue_work(hbus->wq, &dr_wrk->wrk); } /** @@ -1858,7 +1904,7 @@ static void hv_pci_eject_device(struct hv_pci_dev *hpdev) get_pcichild(hpdev, hv_pcidev_ref_pnp); INIT_WORK(&hpdev->wrk, hv_eject_device_work); get_hvpcibus(hpdev->hbus); - schedule_work(&hpdev->wrk); + queue_work(hpdev->hbus->wq, &hpdev->wrk); } /** @@ -2471,13 +2517,18 @@ static int hv_pci_probe(struct hv_device *hdev, spin_lock_init(&hbus->config_lock); spin_lock_init(&hbus->device_list_lock); spin_lock_init(&hbus->retarget_msi_interrupt_lock); - sema_init(&hbus->enum_sem, 1); init_completion(&hbus->remove_event); + hbus->wq = alloc_ordered_workqueue("hv_pci_%x", 0, + hbus->sysdata.domain); + if (!hbus->wq) { + ret = -ENOMEM; + goto free_bus; + } ret = vmbus_open(hdev->channel, pci_ring_size, pci_ring_size, NULL, 0, hv_pci_onchannelcallback, hbus); if (ret) - goto free_bus; + goto destroy_wq; hv_set_drvdata(hdev, hbus); @@ -2546,6 +2597,8 @@ free_config: hv_free_config_window(hbus); close: vmbus_close(hdev->channel); +destroy_wq: + destroy_workqueue(hbus->wq); free_bus: free_page((unsigned long)hbus); return ret; @@ -2625,6 +2678,7 @@ static int hv_pci_remove(struct hv_device *hdev) irq_domain_free_fwnode(hbus->sysdata.fwnode); put_hvpcibus(hbus); wait_for_completion(&hbus->remove_event); + destroy_workqueue(hbus->wq); free_page((unsigned long)hbus); return 0; } |