[PATCH v2 1/2] PCI: hv: Fix the PCI HyperV probe failure path to release resource properly

[Wei Hu]

Some error cases in hv_pci_probe() were not handled. Fix these error
paths to release the resourses and clean up the state properly.

Signed-off-by: Wei Hu <w...@microsoft.com>
---
 drivers/pci/controller/pci-hyperv.c | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/controller/pci-hyperv.c 
b/drivers/pci/controller/pci-hyperv.c
index e15022ff63e3..e6fac0187722 100644
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -480,6 +480,9 @@ struct hv_pcibus_device {
 
        struct workqueue_struct *wq;
 
+       /* Highest slot of child device with resources allocated */
+       int wslot_res_allocated;
+
        /* hypercall arg, must not cross page boundary */
        struct hv_retarget_device_interrupt retarget_msi_interrupt_params;
 
@@ -2847,7 +2850,7 @@ static int hv_send_resources_allocated(struct hv_device 
*hdev)
        struct hv_pci_dev *hpdev;
        struct pci_packet *pkt;
        size_t size_res;
-       u32 wslot;
+       int wslot;
        int ret;
 
        size_res = (hbus->protocol_version < PCI_PROTOCOL_VERSION_1_2)
@@ -2900,6 +2903,8 @@ static int hv_send_resources_allocated(struct hv_device 
*hdev)
                                comp_pkt.completion_status);
                        break;
                }
+
+               hbus->wslot_res_allocated = wslot;
        }
 
        kfree(pkt);
@@ -2918,10 +2923,10 @@ static int hv_send_resources_released(struct hv_device 
*hdev)
        struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
        struct pci_child_message pkt;
        struct hv_pci_dev *hpdev;
-       u32 wslot;
+       int wslot;
        int ret;
 
-       for (wslot = 0; wslot < 256; wslot++) {
+       for (wslot = hbus->wslot_res_allocated; wslot >= 0; wslot--) {
                hpdev = get_pcichild_wslot(hbus, wslot);
                if (!hpdev)
                        continue;
@@ -2936,8 +2941,12 @@ static int hv_send_resources_released(struct hv_device 
*hdev)
                                       VM_PKT_DATA_INBAND, 0);
                if (ret)
                        return ret;
+
+               hbus->wslot_res_allocated = wslot - 1;
        }
 
+       hbus->wslot_res_allocated = -1;
+
        return 0;
 }
 
@@ -3037,6 +3046,7 @@ static int hv_pci_probe(struct hv_device *hdev,
        if (!hbus)
                return -ENOMEM;
        hbus->state = hv_pcibus_init;
+       hbus->wslot_res_allocated = -1;
 
        /*
         * The PCI bus "domain" is what is called "segment" in ACPI and other
@@ -3136,7 +3146,7 @@ static int hv_pci_probe(struct hv_device *hdev,
 
        ret = hv_pci_allocate_bridge_windows(hbus);
        if (ret)
-               goto free_irq_domain;
+               goto exit_d0;
 
        ret = hv_send_resources_allocated(hdev);
        if (ret)
@@ -3154,6 +3164,8 @@ static int hv_pci_probe(struct hv_device *hdev,
 
 free_windows:
        hv_pci_free_bridge_windows(hbus);
+exit_d0:
+       (void) hv_pci_bus_exit(hdev, true);
 free_irq_domain:
        irq_domain_remove(hbus->irq_domain);
 free_fwnode:
-- 
2.20.1