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

From: longli
Date: Mon Jan 13 2020 - 15:08:38 EST


From: Long Li <longli@xxxxxxxxxxxxx>

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@xxxxxxxxxxxxx>
Reviewed-by: Michael Kelley <mikelley@xxxxxxxxxxxxx>
---
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