remoteproc: k3-r5: Acquire mailbox handle during probe routine

Acquire the mailbox handle during device probe and do not release handle
in stop/detach routine or error paths. This removes the redundant
requests for mbox handle later during rproc start/attach. This also
allows to defer remoteproc driver's probe if mailbox is not probed yet.

Signed-off-by: Beleswar Padhi <b-padhi@ti.com>
Link: https://lore.kernel.org/r/20240808074127.2688131-3-b-padhi@ti.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>

diff --git a/drivers/remoteproc/ti_k3_r5_remoteproc.c b/drivers/remoteproc/ti_k3_r5_remoteproc.c
index 5706730..8a63a93 100644 (file)
--- a/drivers/remoteproc/ti_k3_r5_remoteproc.c
+++ b/drivers/remoteproc/ti_k3_r5_remoteproc.c
@@ -194,6 +194,10 @@ static void k3_r5_rproc_mbox_callback(struct mbox_client *client, void *data)
        const char *name = kproc->rproc->name;
        u32 msg = omap_mbox_message(data);
 
+       /* Do not forward message from a detached core */
+       if (kproc->rproc->state == RPROC_DETACHED)
+               return;
+
        dev_dbg(dev, "mbox msg: 0x%x\n", msg);
 
        switch (msg) {
@@ -229,6 +233,10 @@ static void k3_r5_rproc_kick(struct rproc *rproc, int vqid)
        mbox_msg_t msg = (mbox_msg_t)vqid;
        int ret;
 
+       /* Do not forward message to a detached core */
+       if (kproc->rproc->state == RPROC_DETACHED)
+               return;
+
        /* send the index of the triggered virtqueue in the mailbox payload */
        ret = mbox_send_message(kproc->mbox, (void *)msg);
        if (ret < 0)
@@ -399,12 +407,9 @@ static int k3_r5_rproc_request_mbox(struct rproc *rproc)
        client->knows_txdone = false;
 
        kproc->mbox = mbox_request_channel(client, 0);
-       if (IS_ERR(kproc->mbox)) {
-               ret = -EBUSY;
-               dev_err(dev, "mbox_request_channel failed: %ld\n",
-                       PTR_ERR(kproc->mbox));
-               return ret;
-       }
+       if (IS_ERR(kproc->mbox))
+               return dev_err_probe(dev, PTR_ERR(kproc->mbox),
+                                    "mbox_request_channel failed\n");
 
        /*
         * Ping the remote processor, this is only for sanity-sake for now;
@@ -552,10 +557,6 @@ static int k3_r5_rproc_start(struct rproc *rproc)
        u32 boot_addr;
        int ret;
 
-       ret = k3_r5_rproc_request_mbox(rproc);
-       if (ret)
-               return ret;
-
        boot_addr = rproc->bootaddr;
        /* TODO: add boot_addr sanity checking */
        dev_dbg(dev, "booting R5F core using boot addr = 0x%x\n", boot_addr);
@@ -564,7 +565,7 @@ static int k3_r5_rproc_start(struct rproc *rproc)
        core = kproc->core;
        ret = ti_sci_proc_set_config(core->tsp, boot_addr, 0, 0);
        if (ret)
-               goto put_mbox;
+               return ret;
 
        /* unhalt/run all applicable cores */
        if (cluster->mode == CLUSTER_MODE_LOCKSTEP) {
@@ -580,13 +581,12 @@ static int k3_r5_rproc_start(struct rproc *rproc)
                if (core != core0 && core0->rproc->state == RPROC_OFFLINE) {
                        dev_err(dev, "%s: can not start core 1 before core 0\n",
                                __func__);
-                       ret = -EPERM;
-                       goto put_mbox;
+                       return -EPERM;
                }
 
                ret = k3_r5_core_run(core);
                if (ret)
-                       goto put_mbox;
+                       return ret;
        }
 
        return 0;
@@ -596,8 +596,6 @@ unroll_core_run:
                if (k3_r5_core_halt(core))
                        dev_warn(core->dev, "core halt back failed\n");
        }
-put_mbox:
-       mbox_free_channel(kproc->mbox);
        return ret;
 }
 
@@ -658,8 +656,6 @@ static int k3_r5_rproc_stop(struct rproc *rproc)
                        goto out;
        }
 
-       mbox_free_channel(kproc->mbox);
-
        return 0;
 
 unroll_core_halt:
@@ -674,42 +670,22 @@ out:
 /*
  * Attach to a running R5F remote processor (IPC-only mode)
  *
- * The R5F attach callback only needs to request the mailbox, the remote
- * processor is already booted, so there is no need to issue any TI-SCI
- * commands to boot the R5F cores in IPC-only mode. This callback is invoked
- * only in IPC-only mode.
+ * The R5F attach callback is a NOP. The remote processor is already booted, and
+ * all required resources have been acquired during probe routine, so there is
+ * no need to issue any TI-SCI commands to boot the R5F cores in IPC-only mode.
+ * This callback is invoked only in IPC-only mode and exists because
+ * rproc_validate() checks for its existence.
  */
-static int k3_r5_rproc_attach(struct rproc *rproc)
-{
-       struct k3_r5_rproc *kproc = rproc->priv;
-       struct device *dev = kproc->dev;
-       int ret;
-
-       ret = k3_r5_rproc_request_mbox(rproc);
-       if (ret)
-               return ret;
-
-       dev_info(dev, "R5F core initialized in IPC-only mode\n");
-       return 0;
-}
+static int k3_r5_rproc_attach(struct rproc *rproc) { return 0; }
 
 /*
  * Detach from a running R5F remote processor (IPC-only mode)
  *
- * The R5F detach callback performs the opposite operation to attach callback
- * and only needs to release the mailbox, the R5F cores are not stopped and
- * will be left in booted state in IPC-only mode. This callback is invoked
- * only in IPC-only mode.
+ * The R5F detach callback is a NOP. The R5F cores are not stopped and will be
+ * left in booted state in IPC-only mode. This callback is invoked only in
+ * IPC-only mode and exists for sanity sake.
  */
-static int k3_r5_rproc_detach(struct rproc *rproc)
-{
-       struct k3_r5_rproc *kproc = rproc->priv;
-       struct device *dev = kproc->dev;
-
-       mbox_free_channel(kproc->mbox);
-       dev_info(dev, "R5F core deinitialized in IPC-only mode\n");
-       return 0;
-}
+static int k3_r5_rproc_detach(struct rproc *rproc) { return 0; }
 
 /*
  * This function implements the .get_loaded_rsc_table() callback and is used
@@ -1278,6 +1254,10 @@ static int k3_r5_cluster_rproc_init(struct platform_device *pdev)
                kproc->rproc = rproc;
                core->rproc = rproc;
 
+               ret = k3_r5_rproc_request_mbox(rproc);
+               if (ret)
+                       return ret;
+
                ret = k3_r5_rproc_configure_mode(kproc);
                if (ret < 0)
                        goto out;
@@ -1392,6 +1372,8 @@ static void k3_r5_cluster_rproc_exit(void *data)
                        }
                }
 
+               mbox_free_channel(kproc->mbox);
+
                rproc_del(rproc);
 
                k3_r5_reserved_mem_exit(kproc);