HID: hyperv: Use in-place iterator API in the channel callback

[ Upstream commit 6a297c90efa68b2864483193b8bfb0d19478600c ]

Simplify the ring buffer handling with the in-place API.

Also avoid the dynamic allocation and the memory leak in the channel
callback function.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/hid/hid-hyperv.c b/drivers/hid/hid-hyperv.c
index 704049e..4d1496f 100644 (file)
--- a/drivers/hid/hid-hyperv.c
+++ b/drivers/hid/hid-hyperv.c
@@ -322,60 +322,24 @@ static void mousevsc_on_receive(struct hv_device *device,
 
 static void mousevsc_on_channel_callback(void *context)
 {
-       const int packet_size = 0x100;
-       int ret;
        struct hv_device *device = context;
-       u32 bytes_recvd;
-       u64 req_id;
        struct vmpacket_descriptor *desc;
-       unsigned char   *buffer;
-       int     bufferlen = packet_size;
-
-       buffer = kmalloc(bufferlen, GFP_ATOMIC);
-       if (!buffer)
-               return;
-
-       do {
-               ret = vmbus_recvpacket_raw(device->channel, buffer,
-                                       bufferlen, &bytes_recvd, &req_id);
-
-               switch (ret) {
-               case 0:
-                       if (bytes_recvd <= 0) {
-                               kfree(buffer);
-                               return;
-                       }
-                       desc = (struct vmpacket_descriptor *)buffer;
-
-                       switch (desc->type) {
-                       case VM_PKT_COMP:
-                               break;
-
-                       case VM_PKT_DATA_INBAND:
-                               mousevsc_on_receive(device, desc);
-                               break;
-
-                       default:
-                               pr_err("unhandled packet type %d, tid %llx len %d\n",
-                                       desc->type, req_id, bytes_recvd);
-                               break;
-                       }
 
+       foreach_vmbus_pkt(desc, device->channel) {
+               switch (desc->type) {
+               case VM_PKT_COMP:
                        break;
 
-               case -ENOBUFS:
-                       kfree(buffer);
-                       /* Handle large packet */
-                       bufferlen = bytes_recvd;
-                       buffer = kmalloc(bytes_recvd, GFP_ATOMIC);
-
-                       if (!buffer)
-                               return;
+               case VM_PKT_DATA_INBAND:
+                       mousevsc_on_receive(device, desc);
+                       break;
 
+               default:
+                       pr_err("Unhandled packet type %d, tid %llx len %d\n",
+                              desc->type, desc->trans_id, desc->len8 * 8);
                        break;
                }
-       } while (1);
-
+       }
 }
 
 static int mousevsc_connect_to_vsp(struct hv_device *device)