2024-05-30 09:08:18

by Beleswar Padhi

[permalink] [raw]
Subject: [PATCH 2/3] remoteproc: k3-r5: Acquire mailbox handle during probe

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 <[email protected]>
---
drivers/remoteproc/ti_k3_r5_remoteproc.c | 66 ++++++++----------------
1 file changed, 21 insertions(+), 45 deletions(-)

diff --git a/drivers/remoteproc/ti_k3_r5_remoteproc.c b/drivers/remoteproc/ti_k3_r5_remoteproc.c
index 26362a509ae3..157e8fd57665 100644
--- a/drivers/remoteproc/ti_k3_r5_remoteproc.c
+++ b/drivers/remoteproc/ti_k3_r5_remoteproc.c
@@ -391,6 +391,7 @@ static int k3_r5_rproc_request_mbox(struct rproc *rproc)
struct mbox_client *client = &kproc->client;
struct device *dev = kproc->dev;
int ret;
+ long err;

client->dev = dev;
client->tx_done = NULL;
@@ -400,10 +401,9 @@ static int k3_r5_rproc_request_mbox(struct rproc *rproc)

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;
+ err = PTR_ERR(kproc->mbox);
+ dev_err(dev, "mbox_request_channel failed: %ld\n", err);
+ return (err == -EPROBE_DEFER) ? -EPROBE_DEFER : -EBUSY;
}

/*
@@ -552,10 +552,6 @@ 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 +560,7 @@ 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;
+ goto out;

/* unhalt/run all applicable cores */
if (cluster->mode == CLUSTER_MODE_LOCKSTEP) {
@@ -581,12 +577,12 @@ static int k3_r5_rproc_start(struct rproc *rproc)
dev_err(dev, "%s: can not start core 1 before core 0\n",
__func__);
ret = -EPERM;
- goto put_mbox;
+ goto out;
}

ret = k3_r5_core_run(core);
if (ret)
- goto put_mbox;
+ goto out;
}

return 0;
@@ -596,8 +592,7 @@ 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);
+out:
return ret;
}

@@ -658,8 +653,6 @@ static int k3_r5_rproc_stop(struct rproc *rproc)
goto out;
}

- mbox_free_channel(kproc->mbox);
-
return 0;

unroll_core_halt:
@@ -674,42 +667,21 @@ 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 for sanity sake.
*/
-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
@@ -1277,6 +1249,10 @@ 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 err_config;
--
2.34.1



2024-05-30 14:18:19

by Andrew Davis

[permalink] [raw]
Subject: Re: [PATCH 2/3] remoteproc: k3-r5: Acquire mailbox handle during probe

On 5/30/24 4:07 AM, 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 <[email protected]>
> ---
> drivers/remoteproc/ti_k3_r5_remoteproc.c | 66 ++++++++----------------
> 1 file changed, 21 insertions(+), 45 deletions(-)
>
> diff --git a/drivers/remoteproc/ti_k3_r5_remoteproc.c b/drivers/remoteproc/ti_k3_r5_remoteproc.c
> index 26362a509ae3..157e8fd57665 100644
> --- a/drivers/remoteproc/ti_k3_r5_remoteproc.c
> +++ b/drivers/remoteproc/ti_k3_r5_remoteproc.c
> @@ -391,6 +391,7 @@ static int k3_r5_rproc_request_mbox(struct rproc *rproc)
> struct mbox_client *client = &kproc->client;
> struct device *dev = kproc->dev;
> int ret;
> + long err;
>
> client->dev = dev;
> client->tx_done = NULL;
> @@ -400,10 +401,9 @@ static int k3_r5_rproc_request_mbox(struct rproc *rproc)
>
> 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;
> + err = PTR_ERR(kproc->mbox);
> + dev_err(dev, "mbox_request_channel failed: %ld\n", err);
> + return (err == -EPROBE_DEFER) ? -EPROBE_DEFER : -EBUSY;

Why turn all other errors into EBUSY? If you just return the error as-is you
can simply make these 3 lines just:

return dev_err_probe(dev, PTR_ERR(kproc->mbox), "mbox_request_channel failed\n");

> }
>
> /*
> @@ -552,10 +552,6 @@ 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 +560,7 @@ 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;
> + goto out;

The label "out" doesn't do anything, just directly `return ret;` here and
in the other cases below.

>
> /* unhalt/run all applicable cores */
> if (cluster->mode == CLUSTER_MODE_LOCKSTEP) {
> @@ -581,12 +577,12 @@ static int k3_r5_rproc_start(struct rproc *rproc)
> dev_err(dev, "%s: can not start core 1 before core 0\n",
> __func__);
> ret = -EPERM;
> - goto put_mbox;
> + goto out;
> }
>
> ret = k3_r5_core_run(core);
> if (ret)
> - goto put_mbox;
> + goto out;
> }
>
> return 0;
> @@ -596,8 +592,7 @@ 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);
> +out:
> return ret;
> }
>
> @@ -658,8 +653,6 @@ static int k3_r5_rproc_stop(struct rproc *rproc)
> goto out;
> }
>
> - mbox_free_channel(kproc->mbox);
> -
> return 0;
>
> unroll_core_halt:
> @@ -674,42 +667,21 @@ 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 for sanity sake.
> */
> -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; }

Do we still need to disable the mbox channel somehow here to prevent
receiving more messages from the detached core?

>
> /*
> * This function implements the .get_loaded_rsc_table() callback and is used
> @@ -1277,6 +1249,10 @@ static int k3_r5_cluster_rproc_init(struct platform_device *pdev)
> kproc->rproc = rproc;
> core->rproc = rproc;
>
> + ret = k3_r5_rproc_request_mbox(rproc);

Now that we get the channel here in init you'll want to add a matching
mbox_free_channel() call to k3_r5_cluster_rproc_exit().

Andrew

> + if (ret)
> + return ret;
> +
> ret = k3_r5_rproc_configure_mode(kproc);
> if (ret < 0)
> goto err_config;

2024-06-04 05:24:20

by Beleswar Padhi

[permalink] [raw]
Subject: Re: [PATCH 2/3] remoteproc: k3-r5: Acquire mailbox handle during probe

Hi Andrew,

On 30/05/24 19:46, Andrew Davis wrote:
> On 5/30/24 4:07 AM, 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 <[email protected]>
>> ---
>>   drivers/remoteproc/ti_k3_r5_remoteproc.c | 66 ++++++++----------------
>>   1 file changed, 21 insertions(+), 45 deletions(-)
>>
>> diff --git a/drivers/remoteproc/ti_k3_r5_remoteproc.c
>> b/drivers/remoteproc/ti_k3_r5_remoteproc.c
>> index 26362a509ae3..157e8fd57665 100644
>> --- a/drivers/remoteproc/ti_k3_r5_remoteproc.c
>> +++ b/drivers/remoteproc/ti_k3_r5_remoteproc.c
>> @@ -391,6 +391,7 @@ static int k3_r5_rproc_request_mbox(struct rproc
>> *rproc)
>>       struct mbox_client *client = &kproc->client;
>>       struct device *dev = kproc->dev;
>>       int ret;
>> +    long err;
>>         client->dev = dev;
>>       client->tx_done = NULL;
>> @@ -400,10 +401,9 @@ static int k3_r5_rproc_request_mbox(struct rproc
>> *rproc)
>>         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;
>> +        err = PTR_ERR(kproc->mbox);
>> +        dev_err(dev, "mbox_request_channel failed: %ld\n", err);
>> +        return (err == -EPROBE_DEFER) ? -EPROBE_DEFER : -EBUSY;
>
> Why turn all other errors into EBUSY? If you just return the error
> as-is you
> can simply make these 3 lines just:
>
> return dev_err_probe(dev, PTR_ERR(kproc->mbox), "mbox_request_channel
> failed\n");
>
>>       }
>>         /*
>> @@ -552,10 +552,6 @@ 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 +560,7 @@ 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;
>> +        goto out;
>
> The label "out" doesn't do anything, just directly `return ret;` here and
> in the other cases below.
>
>>         /* unhalt/run all applicable cores */
>>       if (cluster->mode == CLUSTER_MODE_LOCKSTEP) {
>> @@ -581,12 +577,12 @@ static int k3_r5_rproc_start(struct rproc *rproc)
>>               dev_err(dev, "%s: can not start core 1 before core 0\n",
>>                   __func__);
>>               ret = -EPERM;
>> -            goto put_mbox;
>> +            goto out;
>>           }
>>             ret = k3_r5_core_run(core);
>>           if (ret)
>> -            goto put_mbox;
>> +            goto out;
>>       }
>>         return 0;
>> @@ -596,8 +592,7 @@ 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);
>> +out:
>>       return ret;
>>   }
>>   @@ -658,8 +653,6 @@ static int k3_r5_rproc_stop(struct rproc *rproc)
>>               goto out;
>>       }
>>   -    mbox_free_channel(kproc->mbox);
>> -
>>       return 0;
>>     unroll_core_halt:
>> @@ -674,42 +667,21 @@ 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 for
>> sanity sake.
>>    */
>> -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; }
>
> Do we still need to disable the mbox channel somehow here to prevent
> receiving more messages from the detached core?
>
>>     /*
>>    * This function implements the .get_loaded_rsc_table() callback
>> and is used
>> @@ -1277,6 +1249,10 @@ static int k3_r5_cluster_rproc_init(struct
>> platform_device *pdev)
>>           kproc->rproc = rproc;
>>           core->rproc = rproc;
>>   +        ret = k3_r5_rproc_request_mbox(rproc);
>
> Now that we get the channel here in init you'll want to add a matching
> mbox_free_channel() call to k3_r5_cluster_rproc_exit().
>
> Andrew


Thanks for the review! I have sent out v2 addressing these comments:

https://lore.kernel.org/all/[email protected]/

>
>> +        if (ret)
>> +            return ret;
>> +
>>           ret = k3_r5_rproc_configure_mode(kproc);
>>           if (ret < 0)
>>               goto err_config;