remoteproc: k3-dsp: 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>
Acked-by: Andrew Davis <afd@ti.com>
Link: https://lore.kernel.org/r/20240808074127.2688131-4-b-padhi@ti.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>

diff --git a/drivers/remoteproc/ti_k3_dsp_remoteproc.c b/drivers/remoteproc/ti_k3_dsp_remoteproc.c
index a22d41689a7d2368e32435c42106652ba83c56fc..9009367e2891a2f6117a6b6a7925f1e244b9a3fc 100644 (file)
--- a/drivers/remoteproc/ti_k3_dsp_remoteproc.c
+++ b/drivers/remoteproc/ti_k3_dsp_remoteproc.c
@@ -115,6 +115,10 @@ static void k3_dsp_rproc_mbox_callback(struct mbox_client *client, void *data)
        const char *name = kproc->rproc->name;
        u32 msg = omap_mbox_message(data);
 
+       /* Do not forward messages from a detached core */
+       if (kproc->rproc->state == RPROC_DETACHED)
+               return;
+
        dev_dbg(dev, "mbox msg: 0x%x\n", msg);
 
        switch (msg) {
@@ -155,6 +159,10 @@ static void k3_dsp_rproc_kick(struct rproc *rproc, int vqid)
        mbox_msg_t msg = (mbox_msg_t)vqid;
        int ret;
 
+       /* Do not forward messages 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)
@@ -230,12 +238,9 @@ static int k3_dsp_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;
@@ -315,32 +320,23 @@ static int k3_dsp_rproc_start(struct rproc *rproc)
        u32 boot_addr;
        int ret;
 
-       ret = k3_dsp_rproc_request_mbox(rproc);
-       if (ret)
-               return ret;
-
        boot_addr = rproc->bootaddr;
        if (boot_addr & (kproc->data->boot_align_addr - 1)) {
                dev_err(dev, "invalid boot address 0x%x, must be aligned on a 0x%x boundary\n",
                        boot_addr, kproc->data->boot_align_addr);
-               ret = -EINVAL;
-               goto put_mbox;
+               return -EINVAL;
        }
 
        dev_dbg(dev, "booting DSP core using boot addr = 0x%x\n", boot_addr);
        ret = ti_sci_proc_set_config(kproc->tsp, boot_addr, 0, 0);
        if (ret)
-               goto put_mbox;
+               return ret;
 
        ret = k3_dsp_rproc_release(kproc);
        if (ret)
-               goto put_mbox;
+               return ret;
 
        return 0;
-
-put_mbox:
-       mbox_free_channel(kproc->mbox);
-       return ret;
 }
 
 /*
@@ -353,8 +349,6 @@ static int k3_dsp_rproc_stop(struct rproc *rproc)
 {
        struct k3_dsp_rproc *kproc = rproc->priv;
 
-       mbox_free_channel(kproc->mbox);
-
        k3_dsp_rproc_reset(kproc);
 
        return 0;
@@ -363,42 +357,22 @@ static int k3_dsp_rproc_stop(struct rproc *rproc)
 /*
  * Attach to a running DSP remote processor (IPC-only mode)
  *
- * This rproc 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 DSP core. This callback is invoked only in IPC-only
- * mode.
+ * This rproc 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 DSP core. This callback
+ * is invoked only in IPC-only mode and exists because rproc_validate() checks
+ * for its existence.
  */
-static int k3_dsp_rproc_attach(struct rproc *rproc)
-{
-       struct k3_dsp_rproc *kproc = rproc->priv;
-       struct device *dev = kproc->dev;
-       int ret;
-
-       ret = k3_dsp_rproc_request_mbox(rproc);
-       if (ret)
-               return ret;
-
-       dev_info(dev, "DSP initialized in IPC-only mode\n");
-       return 0;
-}
+static int k3_dsp_rproc_attach(struct rproc *rproc) { return 0; }
 
 /*
  * Detach from a running DSP remote processor (IPC-only mode)
  *
- * This rproc detach callback performs the opposite operation to attach callback
- * and only needs to release the mailbox, the DSP core is not stopped and will
- * be left to continue to run its booted firmware. This callback is invoked only
- * in IPC-only mode.
+ * This rproc detach callback is a NOP. The DSP core is not stopped and will be
+ * left to continue to run its booted firmware. This callback is invoked only in
+ * IPC-only mode and exists for sanity sake.
  */
-static int k3_dsp_rproc_detach(struct rproc *rproc)
-{
-       struct k3_dsp_rproc *kproc = rproc->priv;
-       struct device *dev = kproc->dev;
-
-       mbox_free_channel(kproc->mbox);
-       dev_info(dev, "DSP deinitialized in IPC-only mode\n");
-       return 0;
-}
+static int k3_dsp_rproc_detach(struct rproc *rproc) { return 0; }
 
 /*
  * This function implements the .get_loaded_rsc_table() callback and is used
@@ -697,6 +671,10 @@ static int k3_dsp_rproc_probe(struct platform_device *pdev)
        kproc->dev = dev;
        kproc->data = data;
 
+       ret = k3_dsp_rproc_request_mbox(rproc);
+       if (ret)
+               return ret;
+
        kproc->ti_sci = devm_ti_sci_get_by_phandle(dev, "ti,sci");
        if (IS_ERR(kproc->ti_sci))
                return dev_err_probe(dev, PTR_ERR(kproc->ti_sci),
@@ -789,6 +767,8 @@ static void k3_dsp_rproc_remove(struct platform_device *pdev)
                if (ret)
                        dev_err(dev, "failed to detach proc (%pe)\n", ERR_PTR(ret));
        }
+
+       mbox_free_channel(kproc->mbox);
 }
 
 static const struct k3_dsp_mem_data c66_mems[] = {