HID: bpf: add hid_get/put_device() helpers

no code change, but this way we reduce code duplication and we
can export it later.

Link: https://lore.kernel.org/r/20240608-hid_bpf_struct_ops-v3-2-6ac6ade58329@kernel.org
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>

diff --git a/drivers/hid/bpf/hid_bpf_dispatch.c b/drivers/hid/bpf/hid_bpf_dispatch.c
index 55c9f82fdef0cf38fa3e893d409f668255faedd7..c8bb79ce2354f8c97dd5459f91f29f829c29cf28 100644 (file)
--- a/drivers/hid/bpf/hid_bpf_dispatch.c
+++ b/drivers/hid/bpf/hid_bpf_dispatch.c
@@ -150,6 +150,25 @@ static int device_match_id(struct device *dev, const void *id)
        return hdev->id == *(int *)id;
 }
 
+static struct hid_device *hid_get_device(unsigned int hid_id)
+{
+       struct device *dev;
+
+       if (!hid_ops)
+               return ERR_PTR(-EINVAL);
+
+       dev = bus_find_device(hid_ops->bus_type, NULL, &hid_id, device_match_id);
+       if (!dev)
+               return ERR_PTR(-EINVAL);
+
+       return to_hid_device(dev);
+}
+
+static void hid_put_device(struct hid_device *hid)
+{
+       put_device(&hid->dev);
+}
+
 static int __hid_bpf_allocate_data(struct hid_device *hdev, u8 **data, u32 *size)
 {
        u8 *alloc_data;
@@ -281,20 +300,14 @@ hid_bpf_attach_prog(unsigned int hid_id, int prog_fd, __u32 flags)
 {
        struct hid_device *hdev;
        struct bpf_prog *prog;
-       struct device *dev;
        int err, fd;
 
-       if (!hid_ops)
-               return -EINVAL;
-
        if ((flags & ~HID_BPF_FLAG_MASK))
                return -EINVAL;
 
-       dev = bus_find_device(hid_ops->bus_type, NULL, &hid_id, device_match_id);
-       if (!dev)
-               return -EINVAL;
-
-       hdev = to_hid_device(dev);
+       hdev = hid_get_device(hid_id);
+       if (IS_ERR(hdev))
+               return PTR_ERR(hdev);
 
        /*
         * take a ref on the prog itself, it will be released
@@ -317,7 +330,7 @@ hid_bpf_attach_prog(unsigned int hid_id, int prog_fd, __u32 flags)
  out_prog_put:
        bpf_prog_put(prog);
  out_dev_put:
-       put_device(dev);
+       hid_put_device(hdev);
        return err;
 }
 
@@ -333,20 +346,14 @@ hid_bpf_allocate_context(unsigned int hid_id)
 {
        struct hid_device *hdev;
        struct hid_bpf_ctx_kern *ctx_kern = NULL;
-       struct device *dev;
-
-       if (!hid_ops)
-               return NULL;
 
-       dev = bus_find_device(hid_ops->bus_type, NULL, &hid_id, device_match_id);
-       if (!dev)
+       hdev = hid_get_device(hid_id);
+       if (IS_ERR(hdev))
                return NULL;
 
-       hdev = to_hid_device(dev);
-
        ctx_kern = kzalloc(sizeof(*ctx_kern), GFP_KERNEL);
        if (!ctx_kern) {
-               put_device(dev);
+               hid_put_device(hdev);
                return NULL;
        }
 
@@ -373,7 +380,7 @@ hid_bpf_release_context(struct hid_bpf_ctx *ctx)
        kfree(ctx_kern);
 
        /* get_device() is called by bus_find_device() */
-       put_device(&hid->dev);
+       hid_put_device(hid);
 }
 
 static int