[PATCH] media: dvb_ca_en50221: simplify ca allocation

[Rosen Penev]

Use a flexible array member to combine allocations and simplify memory
handling slightly.

Add __counted_by for extra runtime analysis. Move counting variable
assignment after allocation as done by kzalloc_flex for GCC >= 15.

Signed-off-by: Rosen Penev <ros...@gmail.com>
---
 drivers/media/dvb-core/dvb_ca_en50221.c | 20 ++++++--------------
 1 file changed, 6 insertions(+), 14 deletions(-)

diff --git a/drivers/media/dvb-core/dvb_ca_en50221.c 
b/drivers/media/dvb-core/dvb_ca_en50221.c
index 1b91ebb8f667..a792feb076ef 100644
--- a/drivers/media/dvb-core/dvb_ca_en50221.c
+++ b/drivers/media/dvb-core/dvb_ca_en50221.c
@@ -125,9 +125,6 @@ struct dvb_ca_private {
        /* number of slots supported by this CA interface */
        unsigned int slot_count;
 
-       /* information on each slot */
-       struct dvb_ca_slot *slot_info;
-
        /* wait queues for read() and write() operations */
        wait_queue_head_t wait_queue;
 
@@ -157,6 +154,9 @@ struct dvb_ca_private {
 
        /* Whether the device is disconnected */
        int exit;
+
+       /* information on each slot */
+       struct dvb_ca_slot slot_info[] __counted_by(slot_count);
 };
 
 static void dvb_ca_private_free(struct dvb_ca_private *ca)
@@ -167,7 +167,6 @@ static void dvb_ca_private_free(struct dvb_ca_private *ca)
        for (i = 0; i < ca->slot_count; i++)
                vfree(ca->slot_info[i].rx_buffer.data);
 
-       kfree(ca->slot_info);
        kfree(ca);
 }
 
@@ -1880,20 +1879,15 @@ int dvb_ca_en50221_init(struct dvb_adapter *dvb_adapter,
                return -EINVAL;
 
        /* initialise the system data */
-       ca = kzalloc_obj(*ca);
+       ca = kzalloc_flex(*ca, slot_info, slot_count);
        if (!ca) {
                ret = -ENOMEM;
                goto exit;
        }
+       ca->slot_count = slot_count;
        kref_init(&ca->refcount);
        ca->pub = pubca;
        ca->flags = flags;
-       ca->slot_count = slot_count;
-       ca->slot_info = kzalloc_objs(struct dvb_ca_slot, slot_count);
-       if (!ca->slot_info) {
-               ret = -ENOMEM;
-               goto free_ca;
-       }
        init_waitqueue_head(&ca->wait_queue);
        ca->open = 0;
        ca->wakeup = 0;
@@ -1904,7 +1898,7 @@ int dvb_ca_en50221_init(struct dvb_adapter *dvb_adapter,
        ret = dvb_register_device(dvb_adapter, &ca->dvbdev, &dvbdev_ca, ca,
                                  DVB_DEVICE_CA, 0);
        if (ret)
-               goto free_slot_info;
+               goto free_ca;
 
        /* now initialise each slot */
        for (i = 0; i < slot_count; i++) {
@@ -1939,8 +1933,6 @@ int dvb_ca_en50221_init(struct dvb_adapter *dvb_adapter,
 
 unregister_device:
        dvb_unregister_device(ca->dvbdev);
-free_slot_info:
-       kfree(ca->slot_info);
 free_ca:
        kfree(ca);
 exit:
-- 
2.53.0