RE: [Patch v4 1/2] PCI: hv: Decouple the func definition in hv_dr_state from VSP message

[Long Li <longli@microsoft.com>]

Hi Lorenzo,

Can you take a look at this patch?

Thanks

Long

>Subject: [Patch v4 1/2] PCI: hv: Decouple the func definition in hv_dr_state from
>VSP message
>
>From: Long Li <longli@microsoft.com>
>
>hv_dr_state is used to find present PCI devices on the bus. The structure reuses
>struct pci_function_description from VSP message to describe a device.
>
>To prepare support for pci_function_description v2, decouple this dependence in
>hv_dr_state so it can work with both v1 and v2 VSP messages.
>
>There is no functionality change.
>
>Signed-off-by: Long Li <longli@microsoft.com>
>Reviewed-by: Michael Kelley <mikelley@microsoft.com>
>---
>Changes
>v2: Changed some spaces to tabs, changed failure code to -ENOMEM
>v3: Revised comment for function hv_pci_devices_present(), reformatted patch
>title
>v4: Fixed spelling
>
> drivers/pci/controller/pci-hyperv.c | 101 +++++++++++++++++++---------
> 1 file changed, 70 insertions(+), 31 deletions(-)
>
>diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-
>hyperv.c
>index f1f300218fab..3b3e1967cf08 100644
>--- a/drivers/pci/controller/pci-hyperv.c
>+++ b/drivers/pci/controller/pci-hyperv.c
>@@ -507,10 +507,24 @@ struct hv_dr_work {
> 	struct hv_pcibus_device *bus;
> };
>
>+struct hv_pcidev_description {
>+	u16	v_id;	/* vendor ID */
>+	u16	d_id;	/* device ID */
>+	u8	rev;
>+	u8	prog_intf;
>+	u8	subclass;
>+	u8	base_class;
>+	u32	subsystem_id;
>+	union	win_slot_encoding win_slot;
>+	u32	ser;	/* serial number */
>+	u32	flags;
>+	u16	virtual_numa_node;
>+};
>+
> struct hv_dr_state {
> 	struct list_head list_entry;
> 	u32 device_count;
>-	struct pci_function_description func[0];
>+	struct hv_pcidev_description func[0];
> };
>
> enum hv_pcichild_state {
>@@ -527,7 +541,7 @@ struct hv_pci_dev {
> 	refcount_t refs;
> 	enum hv_pcichild_state state;
> 	struct pci_slot *pci_slot;
>-	struct pci_function_description desc;
>+	struct hv_pcidev_description desc;
> 	bool reported_missing;
> 	struct hv_pcibus_device *hbus;
> 	struct work_struct wrk;
>@@ -1862,7 +1876,7 @@ static void q_resource_requirements(void *context,
>struct pci_response *resp,
>  * Return: Pointer to the new tracking struct
>  */
> static struct hv_pci_dev *new_pcichild_device(struct hv_pcibus_device *hbus,
>-		struct pci_function_description *desc)
>+		struct hv_pcidev_description *desc)
> {
> 	struct hv_pci_dev *hpdev;
> 	struct pci_child_message *res_req;
>@@ -1973,7 +1987,7 @@ static void pci_devices_present_work(struct
>work_struct *work)  {
> 	u32 child_no;
> 	bool found;
>-	struct pci_function_description *new_desc;
>+	struct hv_pcidev_description *new_desc;
> 	struct hv_pci_dev *hpdev;
> 	struct hv_pcibus_device *hbus;
> 	struct list_head removed;
>@@ -2090,43 +2104,26 @@ static void pci_devices_present_work(struct
>work_struct *work)
> 	put_hvpcibus(hbus);
> 	kfree(dr);
> }
>-
> /**
>- * hv_pci_devices_present() - Handles list of new children
>+ * hv_pci_start_relations_work() - Queue work to start device discovery
>  * @hbus:	Root PCI bus, as understood by this driver
>- * @relations:	Packet from host listing children
>+ * @dr:		The list of children returned from host
>  *
>- * This function is invoked whenever a new list of devices for
>- * this bus appears.
>+ * Return:  0 on success, -errno on failure
>  */
>-static void hv_pci_devices_present(struct hv_pcibus_device *hbus,
>-				   struct pci_bus_relations *relations)
>+static int hv_pci_start_relations_work(struct hv_pcibus_device *hbus,
>+				       struct hv_dr_state *dr)
> {
>-	struct hv_dr_state *dr;
> 	struct hv_dr_work *dr_wrk;
>-	unsigned long flags;
> 	bool pending_dr;
>+	unsigned long flags;
>
> 	dr_wrk = kzalloc(sizeof(*dr_wrk), GFP_NOWAIT);
> 	if (!dr_wrk)
>-		return;
>-
>-	dr = kzalloc(offsetof(struct hv_dr_state, func) +
>-		     (sizeof(struct pci_function_description) *
>-		      (relations->device_count)), GFP_NOWAIT);
>-	if (!dr)  {
>-		kfree(dr_wrk);
>-		return;
>-	}
>+		return -ENOMEM;
>
> 	INIT_WORK(&dr_wrk->wrk, pci_devices_present_work);
> 	dr_wrk->bus = hbus;
>-	dr->device_count = relations->device_count;
>-	if (dr->device_count != 0) {
>-		memcpy(dr->func, relations->func,
>-		       sizeof(struct pci_function_description) *
>-		       dr->device_count);
>-	}
>
> 	spin_lock_irqsave(&hbus->device_list_lock, flags);
> 	/*
>@@ -2144,6 +2141,47 @@ static void hv_pci_devices_present(struct
>hv_pcibus_device *hbus,
> 		get_hvpcibus(hbus);
> 		queue_work(hbus->wq, &dr_wrk->wrk);
> 	}
>+
>+	return 0;
>+}
>+
>+/**
>+ * hv_pci_devices_present() - Handle list of new children
>+ * @hbus:	Root PCI bus, as understood by this driver
>+ * @relations:	Packet from host listing children
>+ *
>+ * Process a new list of devices on the bus. The list of devices is
>+ * discovered by VSP and sent to us via VSP message PCI_BUS_RELATIONS,
>+ * whenever a new list of devices for this bus appears.
>+ */
>+static void hv_pci_devices_present(struct hv_pcibus_device *hbus,
>+				   struct pci_bus_relations *relations) {
>+	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);
>+
>+	if (!dr)
>+		return;
>+
>+	dr->device_count = relations->device_count;
>+	for (i = 0; i < dr->device_count; i++) {
>+		dr->func[i].v_id = relations->func[i].v_id;
>+		dr->func[i].d_id = relations->func[i].d_id;
>+		dr->func[i].rev = relations->func[i].rev;
>+		dr->func[i].prog_intf = relations->func[i].prog_intf;
>+		dr->func[i].subclass = relations->func[i].subclass;
>+		dr->func[i].base_class = relations->func[i].base_class;
>+		dr->func[i].subsystem_id = relations->func[i].subsystem_id;
>+		dr->func[i].win_slot = relations->func[i].win_slot;
>+		dr->func[i].ser = relations->func[i].ser;
>+	}
>+
>+	if (hv_pci_start_relations_work(hbus, dr))
>+		kfree(dr);
> }
>
> /**
>@@ -3018,7 +3056,7 @@ static void hv_pci_bus_exit(struct hv_device *hdev)
> 		struct pci_packet teardown_packet;
> 		u8 buffer[sizeof(struct pci_message)];
> 	} pkt;
>-	struct pci_bus_relations relations;
>+	struct hv_dr_state *dr;
> 	struct hv_pci_compl comp_pkt;
> 	int ret;
>
>@@ -3030,8 +3068,9 @@ static void hv_pci_bus_exit(struct hv_device *hdev)
> 		return;
>
> 	/* Delete any children which might still exist. */
>-	memset(&relations, 0, sizeof(relations));
>-	hv_pci_devices_present(hbus, &relations);
>+	dr = kzalloc(sizeof(*dr), GFP_KERNEL);
>+	if (dr && hv_pci_start_relations_work(hbus, dr))
>+		kfree(dr);
>
> 	ret = hv_send_resources_released(hdev);
> 	if (ret)
>--
>2.17.1