Merge tag 'pci-v5.8-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

[platform/kernel/linux-starfive.git] / drivers / pci / controller / pci-hyperv.c

diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
index 222ff56..bf40ff0 100644 (file)
--- 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;
 
@@ -2210,10 +2213,8 @@ static void hv_pci_devices_present(struct hv_pcibus_device *hbus,
        struct hv_dr_state *dr;
        int i;
 
-       dr = kzalloc(offsetof(struct hv_dr_state, func) +
-                    (sizeof(struct hv_pcidev_description) *
-                     (relations->device_count)), GFP_NOWAIT);
-
+       dr = kzalloc(struct_size(dr, func, relations->device_count),
+                    GFP_NOWAIT);
        if (!dr)
                return;
 
@@ -2247,10 +2248,8 @@ static void hv_pci_devices_present2(struct hv_pcibus_device *hbus,
        struct hv_dr_state *dr;
        int i;
 
-       dr = kzalloc(offsetof(struct hv_dr_state, func) +
-                    (sizeof(struct hv_pcidev_description) *
-                     (relations->device_count)), GFP_NOWAIT);
-
+       dr = kzalloc(struct_size(dr, func, relations->device_count),
+                    GFP_NOWAIT);
        if (!dr)
                return;
 
@@ -2444,9 +2443,8 @@ static void hv_pci_onchannelcallback(void *context)
 
                                bus_rel = (struct pci_bus_relations *)buffer;
                                if (bytes_recvd <
-                                   offsetof(struct pci_bus_relations, func) +
-                                   (sizeof(struct pci_function_description) *
-                                    (bus_rel->device_count))) {
+                                       struct_size(bus_rel, func,
+                                                   bus_rel->device_count)) {
                                        dev_err(&hbus->hdev->device,
                                                "bus relations too small\n");
                                        break;
@@ -2459,9 +2457,8 @@ static void hv_pci_onchannelcallback(void *context)
 
                                bus_rel2 = (struct pci_bus_relations2 *)buffer;
                                if (bytes_recvd <
-                                   offsetof(struct pci_bus_relations2, func) +
-                                   (sizeof(struct pci_function_description2) *
-                                    (bus_rel2->device_count))) {
+                                       struct_size(bus_rel2, func,
+                                                   bus_rel2->device_count)) {
                                        dev_err(&hbus->hdev->device,
                                                "bus relations v2 too small\n");
                                        break;
@@ -2748,6 +2745,8 @@ static void hv_free_config_window(struct hv_pcibus_device *hbus)
        vmbus_free_mmio(hbus->mem_config->start, PCI_CONFIG_MMIO_LENGTH);
 }
 
+static int hv_pci_bus_exit(struct hv_device *hdev, bool keep_devs);
+
 /**
  * hv_pci_enter_d0() - Bring the "bus" into the D0 power state
  * @hdev:      VMBus's tracking struct for this root PCI bus
@@ -2760,8 +2759,10 @@ static int hv_pci_enter_d0(struct hv_device *hdev)
        struct pci_bus_d0_entry *d0_entry;
        struct hv_pci_compl comp_pkt;
        struct pci_packet *pkt;
+       bool retry = true;
        int ret;
 
+enter_d0_retry:
        /*
         * Tell the host that the bus is ready to use, and moved into the
         * powered-on state.  This includes telling the host which region
@@ -2788,6 +2789,38 @@ static int hv_pci_enter_d0(struct hv_device *hdev)
        if (ret)
                goto exit;
 
+       /*
+        * In certain case (Kdump) the pci device of interest was
+        * not cleanly shut down and resource is still held on host
+        * side, the host could return invalid device status.
+        * We need to explicitly request host to release the resource
+        * and try to enter D0 again.
+        */
+       if (comp_pkt.completion_status < 0 && retry) {
+               retry = false;
+
+               dev_err(&hdev->device, "Retrying D0 Entry\n");
+
+               /*
+                * Hv_pci_bus_exit() calls hv_send_resource_released()
+                * to free up resources of its child devices.
+                * In the kdump kernel we need to set the
+                * wslot_res_allocated to 255 so it scans all child
+                * devices to release resources allocated in the
+                * normal kernel before panic happened.
+                */
+               hbus->wslot_res_allocated = 255;
+
+               ret = hv_pci_bus_exit(hdev, true);
+
+               if (ret == 0) {
+                       kfree(pkt);
+                       goto enter_d0_retry;
+               }
+               dev_err(&hdev->device,
+                       "Retrying D0 failed with ret %d\n", ret);
+       }
+
        if (comp_pkt.completion_status < 0) {
                dev_err(&hdev->device,
                        "PCI Pass-through VSP failed D0 Entry with status %x\n",
@@ -2859,7 +2892,7 @@ 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)
@@ -2912,6 +2945,8 @@ static int hv_send_resources_allocated(struct hv_device *hdev)
                                comp_pkt.completion_status);
                        break;
                }
+
+               hbus->wslot_res_allocated = wslot;
        }
 
        kfree(pkt);
@@ -2930,10 +2965,10 @@ 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;
@@ -2948,8 +2983,12 @@ 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;
 }
 
@@ -3049,6 +3088,7 @@ 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
@@ -3148,7 +3188,7 @@ 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)
@@ -3166,6 +3206,8 @@ 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:
@@ -3185,7 +3227,7 @@ free_bus:
        return ret;
 }
 
-static int hv_pci_bus_exit(struct hv_device *hdev, bool hibernating)
+static int hv_pci_bus_exit(struct hv_device *hdev, bool keep_devs)
 {
        struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
        struct {
@@ -3203,7 +3245,7 @@ static int hv_pci_bus_exit(struct hv_device *hdev, bool hibernating)
        if (hdev->channel->rescind)
                return 0;
 
-       if (!hibernating) {
+       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))