[PATCH v4 2/3] remoteproc: k3-r5: Acquire mailbox handle during probe routine

Beleswar Padhi
2024-08-08T07:41:39Z

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>
---
drivers/remoteproc/ti_k3_r5_remoteproc.c | 78 +++++++++---------------
1 file changed, 30 insertions(+), 48 deletions(-)

diff --git a/drivers/remoteproc/ti_k3_r5_remoteproc.c b/drivers/remoteproc/ti_k3_r5_remoteproc.c
index 57067308b3c0..8a63a9360c0f 100644
--- 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 @@ static int k3_r5_rproc_start(struct rproc *rproc)
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 @@ static int k3_r5_rproc_stop(struct rproc *rproc)
/*
* 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);
--
2.34.1