firmware: arm_scmi: Use dedicated devices to initialize channels
authorCristian Marussi <cristian.marussi@arm.com>
Thu, 22 Dec 2022 18:50:42 +0000 (18:50 +0000)
committerSudeep Holla <sudeep.holla@arm.com>
Thu, 19 Jan 2023 09:43:48 +0000 (09:43 +0000)
Refactor channels initialization to use dedicated transport devices
instead of using devices borrowed from the SCMI drivers.

Initialize all channels, as described in the device tree, upfront during
SCMI core stack probe phase and free all of them, including the underlying
devices, when the SCMI core is removed.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Link: https://lore.kernel.org/r/20221222185049.737625-3-cristian.marussi@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
drivers/firmware/arm_scmi/common.h
drivers/firmware/arm_scmi/driver.c
drivers/firmware/arm_scmi/mailbox.c
drivers/firmware/arm_scmi/optee.c
drivers/firmware/arm_scmi/smc.c
drivers/firmware/arm_scmi/virtio.c

index 16db1e177123d08476c0adab6f8f5f8fb74dffa2..136bfd30f99c8227a5099f939f99fcd9654639e5 100644 (file)
@@ -229,7 +229,6 @@ extern const struct scmi_desc scmi_optee_desc;
 #endif
 
 void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr, void *priv);
-void scmi_free_channel(struct scmi_chan_info *cinfo, struct idr *idr, int id);
 
 /* shmem related declarations */
 struct scmi_shared_mem;
index f1ebadffdfe4c32fd931492180814ee880256777..f85b34e69d010bfeacc40837f57f91a5207f9b5a 100644 (file)
@@ -1987,23 +1987,20 @@ static int scmi_xfer_info_init(struct scmi_info *sinfo)
        return ret;
 }
 
-static int scmi_chan_setup(struct scmi_info *info, struct device *dev,
+static int scmi_chan_setup(struct scmi_info *info, struct device_node *of_node,
                           int prot_id, bool tx)
 {
        int ret, idx;
+       char name[32];
        struct scmi_chan_info *cinfo;
        struct idr *idr;
+       struct scmi_device *tdev = NULL;
 
        /* Transmit channel is first entry i.e. index 0 */
        idx = tx ? 0 : 1;
        idr = tx ? &info->tx_idr : &info->rx_idr;
 
-       /* check if already allocated, used for multiple device per protocol */
-       cinfo = idr_find(idr, prot_id);
-       if (cinfo)
-               return 0;
-
-       if (!info->desc->ops->chan_available(dev->of_node, idx)) {
+       if (!info->desc->ops->chan_available(of_node, idx)) {
                cinfo = idr_find(idr, SCMI_PROTOCOL_BASE);
                if (unlikely(!cinfo)) /* Possible only if platform has no Rx */
                        return -EINVAL;
@@ -2014,27 +2011,49 @@ static int scmi_chan_setup(struct scmi_info *info, struct device *dev,
        if (!cinfo)
                return -ENOMEM;
 
-       cinfo->dev = dev;
        cinfo->rx_timeout_ms = info->desc->max_rx_timeout_ms;
 
+       /* Create a unique name for this transport device */
+       snprintf(name, 32, "__scmi_transport_device_%s_%02X",
+                idx ? "rx" : "tx", prot_id);
+       /* Create a uniquely named, dedicated transport device for this chan */
+       tdev = scmi_device_create(of_node, info->dev, prot_id, name);
+       if (!tdev) {
+               devm_kfree(info->dev, cinfo);
+               return -EINVAL;
+       }
+       of_node_get(of_node);
+
+       cinfo->dev = &tdev->dev;
        ret = info->desc->ops->chan_setup(cinfo, info->dev, tx);
-       if (ret)
+       if (ret) {
+               of_node_put(of_node);
+               scmi_device_destroy(tdev);
+               devm_kfree(info->dev, cinfo);
                return ret;
+       }
 
        if (tx && is_polling_required(cinfo, info)) {
                if (is_transport_polling_capable(info))
-                       dev_info(dev,
+                       dev_info(&tdev->dev,
                                 "Enabled polling mode TX channel - prot_id:%d\n",
                                 prot_id);
                else
-                       dev_warn(dev,
+                       dev_warn(&tdev->dev,
                                 "Polling mode NOT supported by transport.\n");
        }
 
 idr_alloc:
        ret = idr_alloc(idr, cinfo, prot_id, prot_id + 1, GFP_KERNEL);
        if (ret != prot_id) {
-               dev_err(dev, "unable to allocate SCMI idr slot err %d\n", ret);
+               dev_err(info->dev,
+                       "unable to allocate SCMI idr slot err %d\n", ret);
+               /* Destroy channel and device only if created by this call. */
+               if (tdev) {
+                       of_node_put(of_node);
+                       scmi_device_destroy(tdev);
+                       devm_kfree(info->dev, cinfo);
+               }
                return ret;
        }
 
@@ -2043,13 +2062,14 @@ idr_alloc:
 }
 
 static inline int
-scmi_txrx_setup(struct scmi_info *info, struct device *dev, int prot_id)
+scmi_txrx_setup(struct scmi_info *info, struct device_node *of_node,
+               int prot_id)
 {
-       int ret = scmi_chan_setup(info, dev, prot_id, true);
+       int ret = scmi_chan_setup(info, of_node, prot_id, true);
 
        if (!ret) {
                /* Rx is optional, report only memory errors */
-               ret = scmi_chan_setup(info, dev, prot_id, false);
+               ret = scmi_chan_setup(info, of_node, prot_id, false);
                if (ret && ret != -ENOMEM)
                        ret = 0;
        }
@@ -2057,6 +2077,54 @@ scmi_txrx_setup(struct scmi_info *info, struct device *dev, int prot_id)
        return ret;
 }
 
+/**
+ * scmi_channels_setup  - Helper to initialize all required channels
+ *
+ * @info: The SCMI instance descriptor.
+ *
+ * Initialize all the channels found described in the DT against the underlying
+ * configured transport using custom defined dedicated devices instead of
+ * borrowing devices from the SCMI drivers; this way channels are initialized
+ * upfront during core SCMI stack probing and are no more coupled with SCMI
+ * devices used by SCMI drivers.
+ *
+ * Note that, even though a pair of TX/RX channels is associated to each
+ * protocol defined in the DT, a distinct freshly initialized channel is
+ * created only if the DT node for the protocol at hand describes a dedicated
+ * channel: in all the other cases the common BASE protocol channel is reused.
+ *
+ * Return: 0 on Success
+ */
+static int scmi_channels_setup(struct scmi_info *info)
+{
+       int ret;
+       struct device_node *child, *top_np = info->dev->of_node;
+
+       /* Initialize a common generic channel at first */
+       ret = scmi_txrx_setup(info, top_np, SCMI_PROTOCOL_BASE);
+       if (ret)
+               return ret;
+
+       for_each_available_child_of_node(top_np, child) {
+               u32 prot_id;
+
+               if (of_property_read_u32(child, "reg", &prot_id))
+                       continue;
+
+               if (!FIELD_FIT(MSG_PROTOCOL_ID_MASK, prot_id))
+                       dev_err(info->dev,
+                               "Out of range protocol %d\n", prot_id);
+
+               ret = scmi_txrx_setup(info, child, prot_id);
+               if (ret) {
+                       of_node_put(child);
+                       return ret;
+               }
+       }
+
+       return 0;
+}
+
 /**
  * scmi_get_protocol_device  - Helper to get/create an SCMI device.
  *
@@ -2106,14 +2174,6 @@ scmi_get_protocol_device(struct device_node *np, struct scmi_info *info,
                return NULL;
        }
 
-       if (scmi_txrx_setup(info, &sdev->dev, prot_id)) {
-               dev_err(&sdev->dev, "failed to setup transport\n");
-               scmi_device_destroy(sdev);
-               mutex_unlock(&scmi_syspower_mtx);
-
-               return NULL;
-       }
-
        if (prot_id == SCMI_PROTOCOL_SYSTEM)
                scmi_syspower_registered = true;
 
@@ -2347,19 +2407,39 @@ void scmi_protocol_device_unrequest(const struct scmi_device_id *id_table)
        mutex_unlock(&scmi_requested_devices_mtx);
 }
 
-static int scmi_cleanup_txrx_channels(struct scmi_info *info)
+static int scmi_chan_destroy(int id, void *p, void *idr)
 {
-       int ret;
-       struct idr *idr = &info->tx_idr;
+       struct scmi_chan_info *cinfo = p;
+
+       if (cinfo->dev) {
+               struct scmi_device *sdev = to_scmi_dev(cinfo->dev);
 
-       ret = idr_for_each(idr, info->desc->ops->chan_free, idr);
-       idr_destroy(&info->tx_idr);
+               of_node_put(cinfo->dev->of_node);
+               scmi_device_destroy(sdev);
+               cinfo->dev = NULL;
+       }
 
-       idr = &info->rx_idr;
-       ret = idr_for_each(idr, info->desc->ops->chan_free, idr);
-       idr_destroy(&info->rx_idr);
+       idr_remove(idr, id);
 
-       return ret;
+       return 0;
+}
+
+static void scmi_cleanup_channels(struct scmi_info *info, struct idr *idr)
+{
+       /* At first free all channels at the transport layer ... */
+       idr_for_each(idr, info->desc->ops->chan_free, idr);
+
+       /* ...then destroy all underlying devices */
+       idr_for_each(idr, scmi_chan_destroy, idr);
+
+       idr_destroy(idr);
+}
+
+static void scmi_cleanup_txrx_channels(struct scmi_info *info)
+{
+       scmi_cleanup_channels(info, &info->tx_idr);
+
+       scmi_cleanup_channels(info, &info->rx_idr);
 }
 
 static int scmi_probe(struct platform_device *pdev)
@@ -2411,7 +2491,8 @@ static int scmi_probe(struct platform_device *pdev)
                        return ret;
        }
 
-       ret = scmi_txrx_setup(info, dev, SCMI_PROTOCOL_BASE);
+       /* Setup all channels described in the DT at first */
+       ret = scmi_channels_setup(info);
        if (ret)
                return ret;
 
@@ -2481,14 +2562,9 @@ clear_txrx_setup:
        return ret;
 }
 
-void scmi_free_channel(struct scmi_chan_info *cinfo, struct idr *idr, int id)
-{
-       idr_remove(idr, id);
-}
-
 static int scmi_remove(struct platform_device *pdev)
 {
-       int ret, id;
+       int id;
        struct scmi_info *info = platform_get_drvdata(pdev);
        struct device_node *child;
 
@@ -2510,9 +2586,7 @@ static int scmi_remove(struct platform_device *pdev)
        idr_destroy(&info->active_protocols);
 
        /* Safe to free channels since no more users */
-       ret = scmi_cleanup_txrx_channels(info);
-       if (ret)
-               dev_warn(&pdev->dev, "Failed to cleanup SCMI channels.\n");
+       scmi_cleanup_txrx_channels(info);
 
        return 0;
 }
index c33dcadafea86b75b08053b35d754fc7788bdca8..0d9c9538b7f4175e0139563649ff2c687721f72e 100644 (file)
@@ -120,8 +120,6 @@ static int mailbox_chan_free(int id, void *p, void *data)
                smbox->cinfo = NULL;
        }
 
-       scmi_free_channel(cinfo, data, id);
-
        return 0;
 }
 
index 5a11091c72da3f71b69180f8f8745d0db206fde8..929720387102e6b85ffd709affdb9365f7ab27f0 100644 (file)
@@ -481,8 +481,6 @@ static int scmi_optee_chan_free(int id, void *p, void *data)
        cinfo->transport_info = NULL;
        channel->cinfo = NULL;
 
-       scmi_free_channel(cinfo, data, id);
-
        return 0;
 }
 
index 122128d56d2f27ef2733b5f5aef43a1f1f9fe459..93272e4bbd12b96629129c0ec8635231b6f2e247 100644 (file)
@@ -171,8 +171,6 @@ static int smc_chan_free(int id, void *p, void *data)
        cinfo->transport_info = NULL;
        scmi_info->cinfo = NULL;
 
-       scmi_free_channel(cinfo, data, id);
-
        return 0;
 }
 
index a917eca7d902401bda9a8105a23ebe45fc3eaeab..d68c01cb7aa009fe47570a07cdec1040e5230249 100644 (file)
@@ -489,8 +489,6 @@ static int virtio_chan_free(int id, void *p, void *data)
        virtio_break_device(vioch->vqueue->vdev);
        scmi_vio_channel_cleanup_sync(vioch);
 
-       scmi_free_channel(cinfo, data, id);
-
        return 0;
 }