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

2024-08-14 Thread Mathieu Poirier
On Thu, Aug 08, 2024 at 01:11:27PM +0530, Beleswar Padhi wrote:
> 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 
> Acked-by: Andrew Davis 
> ---
>  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

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

2024-08-08 Thread Beleswar Padhi
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 
Acked-by: Andrew Davis 
---
 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