[PATCH v4 3/3] remoteproc: k3-dsp: Acquire mailbox handle during probe routine

Beleswar Padhi
2024-08-08T07:41:42Z

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>
---
drivers/remoteproc/ti_k3_dsp_remoteproc.c | 80 +++++++++--------------
1 file changed, 30 insertions(+), 50 deletions(-)

diff --git a/drivers/remoteproc/ti_k3_dsp_remoteproc.c b/drivers/remoteproc/ti_k3_dsp_remoteproc.c
index a22d41689a7d..9009367e2891 100644
--- 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[] = {
--
2.34.1