Input: hyperv-keyboard: Use in-place iterator API in the channel callback

BugLink: https://bugs.launchpad.net/bugs/1843463
[ Upstream commit d09bc83640d524b8467a660db7b1d15e6562a1de ]

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: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/drivers/input/serio/hyperv-keyboard.c b/drivers/input/serio/hyperv-keyboard.c
index 55288a026e4e2919ab06a18b18b810b5d628dd59..c137ffa6fdec8a6badb8708596915fb4cd3a0084 100644 (file)
--- a/drivers/input/serio/hyperv-keyboard.c
+++ b/drivers/input/serio/hyperv-keyboard.c
@@ -245,40 +245,17 @@ static void hv_kbd_handle_received_packet(struct hv_device *hv_dev,
 
 static void hv_kbd_on_channel_callback(void *context)
 {
+       struct vmpacket_descriptor *desc;
        struct hv_device *hv_dev = context;
-       void *buffer;
-       int bufferlen = 0x100; /* Start with sensible size */
        u32 bytes_recvd;
        u64 req_id;
-       int error;
 
-       buffer = kmalloc(bufferlen, GFP_ATOMIC);
-       if (!buffer)
-               return;
-
-       while (1) {
-               error = vmbus_recvpacket_raw(hv_dev->channel, buffer, bufferlen,
-                                            &bytes_recvd, &req_id);
-               switch (error) {
-               case 0:
-                       if (bytes_recvd == 0) {
-                               kfree(buffer);
-                               return;
-                       }
-
-                       hv_kbd_handle_received_packet(hv_dev, buffer,
-                                                     bytes_recvd, req_id);
-                       break;
+       foreach_vmbus_pkt(desc, hv_dev->channel) {
+               bytes_recvd = desc->len8 * 8;
+               req_id = desc->trans_id;
 
-               case -ENOBUFS:
-                       kfree(buffer);
-                       /* Handle large packet */
-                       bufferlen = bytes_recvd;
-                       buffer = kmalloc(bytes_recvd, GFP_ATOMIC);
-                       if (!buffer)
-                               return;
-                       break;
-               }
+               hv_kbd_handle_received_packet(hv_dev, desc, bytes_recvd,
+                                             req_id);
        }
 }