firmware: arm_scmi: Calculate virtio PDU max size dynamically

SCMI virtio transport maximum PDU size is currently hardcoded at build
time; this will not play well with the possibile retrieval of a different
size at run-time.

Make the virtio transport derive the maximum PDU size from the max_msg_size
provided by the SCMI core.

No functional change.

Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Message-Id: <20241028120151.1301177-3-cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

diff --git a/drivers/firmware/arm_scmi/transports/virtio.c b/drivers/firmware/arm_scmi/transports/virtio.c
index d349766bc0b267ee5ca44d31952353d89ad7a83a..41aea33776a9befb0c71d974429e237a66d54c8e 100644 (file)
--- a/drivers/firmware/arm_scmi/transports/virtio.c
+++ b/drivers/firmware/arm_scmi/transports/virtio.c
@@ -32,8 +32,8 @@
 
 #define VIRTIO_MAX_RX_TIMEOUT_MS       60000
 #define VIRTIO_SCMI_MAX_MSG_SIZE 128 /* Value may be increased. */
-#define VIRTIO_SCMI_MAX_PDU_SIZE \
-       (VIRTIO_SCMI_MAX_MSG_SIZE + SCMI_MSG_MAX_PROT_OVERHEAD)
+#define VIRTIO_SCMI_MAX_PDU_SIZE(ci) \
+       ((ci)->max_msg_size + SCMI_MSG_MAX_PROT_OVERHEAD)
 #define DESCRIPTORS_PER_TX_MSG 2
 
 /**
@@ -90,6 +90,7 @@ enum poll_states {
  * @input: SDU used for (delayed) responses and notifications
  * @list: List which scmi_vio_msg may be part of
  * @rx_len: Input SDU size in bytes, once input has been received
+ * @max_len: Maximumm allowed SDU size in bytes
  * @poll_idx: Last used index registered for polling purposes if this message
  *           transaction reply was configured for polling.
  * @poll_status: Polling state for this message.
@@ -102,6 +103,7 @@ struct scmi_vio_msg {
        struct scmi_msg_payld *input;
        struct list_head list;
        unsigned int rx_len;
+       unsigned int max_len;
        unsigned int poll_idx;
        enum poll_states poll_status;
        /* Lock to protect access to poll_status */
@@ -234,7 +236,7 @@ static int scmi_vio_feed_vq_rx(struct scmi_vio_channel *vioch,
        unsigned long flags;
        struct device *dev = &vioch->vqueue->vdev->dev;
 
-       sg_init_one(&sg_in, msg->input, VIRTIO_SCMI_MAX_PDU_SIZE);
+       sg_init_one(&sg_in, msg->input, msg->max_len);
 
        spin_lock_irqsave(&vioch->lock, flags);
 
@@ -439,9 +441,9 @@ static int virtio_chan_setup(struct scmi_chan_info *cinfo, struct device *dev,
                if (!msg)
                        return -ENOMEM;
 
+               msg->max_len = VIRTIO_SCMI_MAX_PDU_SIZE(cinfo);
                if (tx) {
-                       msg->request = devm_kzalloc(dev,
-                                                   VIRTIO_SCMI_MAX_PDU_SIZE,
+                       msg->request = devm_kzalloc(dev, msg->max_len,
                                                    GFP_KERNEL);
                        if (!msg->request)
                                return -ENOMEM;
@@ -449,8 +451,7 @@ static int virtio_chan_setup(struct scmi_chan_info *cinfo, struct device *dev,
                        refcount_set(&msg->users, 1);
                }
 
-               msg->input = devm_kzalloc(dev, VIRTIO_SCMI_MAX_PDU_SIZE,
-                                         GFP_KERNEL);
+               msg->input = devm_kzalloc(dev, msg->max_len, GFP_KERNEL);
                if (!msg->input)
                        return -ENOMEM;