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Message-ID: <74e13b7a-67d3-efbd-6de5-01b6c71be8f4@ti.com>
Date:   Wed, 7 Dec 2022 16:21:07 +0530
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Subject: Re: [EXTERNAL] Re: [PATCH v10 3/6] remoteproc: pru: Add enum for PRU
 Core Indentifiers.
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From:   Md Danish Anwar <a0501179@ti.com>
To:     Roger Quadros <rogerq@kernel.org>,
        MD Danish Anwar <danishanwar@ti.com>,
        Mathieu Poirier <mathieu.poirier@linaro.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Rob Herring <robh+dt@kernel.org>
CC:     Suman Anna <s-anna@ti.com>, "Andrew F . Davis" <afd@ti.com>,
        <nm@ti.com>, <vigneshr@ti.com>, <srk@ti.com>,
        <linux-remoteproc@vger.kernel.org>, <devicetree@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>
References: <20221201110500.4017889-1-danishanwar@ti.com>
 <20221201110500.4017889-4-danishanwar@ti.com>
 <a32f817e-6b61-7666-94f9-cf11f1f2e0a8@kernel.org>
 <15846a05-acb7-126e-eb4f-4057c77ce696@ti.com>
In-Reply-To: <15846a05-acb7-126e-eb4f-4057c77ce696@ti.com>
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Hi Roger,

On 01/12/22 19:13, Md Danish Anwar wrote:
> Hi Roger,
> 
> On 01/12/22 5:28 pm, Roger Quadros wrote:
>> Danish,
>>
>> On 01/12/2022 13:04, MD Danish Anwar wrote:
>>> Introducing enum pruss_pru_id for PRU Core Identifiers.
>>> PRUSS_PRU0 indicates PRU Core 0.
>>> PRUSS_PRU1 indicates PRU Core 1.
>>> PRUSS_NUM_PRUS indicates the total number of PRU Cores.
>>>
>>> Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
>>> ---
>>>   drivers/remoteproc/pru_rproc.c | 16 ++++++++++++----
>>>   include/linux/pruss.h          | 19 +++++++++++++++++--
>>>   2 files changed, 29 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/drivers/remoteproc/pru_rproc.c b/drivers/remoteproc/pru_rproc.c
>>> index b4498a505108..7d4ed39b3772 100644
>>> --- a/drivers/remoteproc/pru_rproc.c
>>> +++ b/drivers/remoteproc/pru_rproc.c
>>> @@ -186,6 +186,7 @@ static struct rproc *__pru_rproc_get(struct device_node
>>> *np, int index)
>>>    * pru_rproc_get() - get the PRU rproc instance from a device node
>>>    * @np: the user/client device node
>>>    * @index: index to use for the ti,prus property
>>> + * @pru_id: optional pointer to return the PRU remoteproc processor id
>>>    *
>>>    * This function looks through a client device node's "ti,prus" property at
>>>    * index @index and returns the rproc handle for a valid PRU remote
>>> processor if
>>> @@ -193,13 +194,17 @@ static struct rproc *__pru_rproc_get(struct
>>> device_node *np, int index)
>>>    * time. Caller must call pru_rproc_put() when done with using the rproc, not
>>>    * required if the function returns a failure.
>>>    *
>>> + * When optional @pru_id pointer is passed the PRU remoteproc processor id is
>>> + * returned.
>>> + *
>>>    * Return: rproc handle on success, and an ERR_PTR on failure using one
>>>    * of the following error values
>>>    *    -ENODEV if device is not found
>>>    *    -EBUSY if PRU is already acquired by anyone
>>>    *    -EPROBE_DEFER is PRU device is not probed yet
>>>    */
>>> -struct rproc *pru_rproc_get(struct device_node *np, int index)
>>> +struct rproc *pru_rproc_get(struct device_node *np, int index,
>>> +                enum pruss_pru_id *pru_id)
>>
>> You just introduced pru_rproc_get() in the previous patch and are
>> now updating it here.
>>
> 
> That's because there is dependency between these two patches. The enum
> pruss_pru_id is declared inside linux/pruss.h file which is introduced in
> pru_rproc_get() patch. But pru_rproc_get() and pru_rproc_put() APIs use the
> enum as function argument. So I decided to keep pru_rproc_get() patch as second
> patch of this series(as it introduces <linux/pruss.h> where eventually the enum
> will be introduced).
> 
> Then I kept the enum introduction patch as third patch of the series and with
> this patch I modified pru_rproc_get() API by adding pru_id field in the
> function argument.
> 
>> Instead, what you need to do is, first introduce enum pruss_pru_id
>> and make any changes to code using hardcoded values for PRU ID.
>> This patch will have to introduce <linux/pruss.h> as it doesn't exist yet.
> 

I will be posting this series again with your suggestion by keeping enum patch
first and then the pru_rproc_get() patch.

> This also came to my mind. But I thought introduction of enum pruss_pru_id
> patch should just introduce the enum and modify APIs which uses the enum
> accordingly. I wanted to keep the introduction of <linux/pruss.h> file with the
> pru_rproc_get() patch as it was. That's why I kept pru_rproc_get() patch ahead
> of enum patch.
> 
>> Hopefully this clears the chicken/egg situation.
>>
>> Then introduce pru_rproc_get() patch with the final desired arguments.
>>
>>>   {
>>>       struct rproc *rproc;
>>>       struct pru_rproc *pru;
>>> @@ -226,6 +231,9 @@ struct rproc *pru_rproc_get(struct device_node *np, int
>>> index)
>>>         mutex_unlock(&pru->lock);
>>>   +    if (pru_id)
>>> +        *pru_id = pru->id;
>>> +
>>>       return rproc;
>>>     err_no_rproc_handle:
>>> @@ -556,7 +564,7 @@ static void *pru_d_da_to_va(struct pru_rproc *pru, u32
>>> da, size_t len)
>>>       dram0 = pruss->mem_regions[PRUSS_MEM_DRAM0];
>>>       dram1 = pruss->mem_regions[PRUSS_MEM_DRAM1];
>>>       /* PRU1 has its local RAM addresses reversed */
>>> -    if (pru->id == 1)
>>> +    if (pru->id == PRUSS_PRU1)
>>>           swap(dram0, dram1);
>>>       shrd_ram = pruss->mem_regions[PRUSS_MEM_SHRD_RAM2];
>>>   @@ -865,14 +873,14 @@ static int pru_rproc_set_id(struct pru_rproc *pru)
>>>       case RTU0_IRAM_ADDR_MASK:
>>>           fallthrough;
>>>       case PRU0_IRAM_ADDR_MASK:
>>> -        pru->id = 0;
>>> +        pru->id = PRUSS_PRU0;
>>>           break;
>>>       case TX_PRU1_IRAM_ADDR_MASK:
>>>           fallthrough;
>>>       case RTU1_IRAM_ADDR_MASK:
>>>           fallthrough;
>>>       case PRU1_IRAM_ADDR_MASK:
>>> -        pru->id = 1;
>>> +        pru->id = PRUSS_PRU1;
>>>           break;
>>>       default:
>>>           ret = -EINVAL;
>>> diff --git a/include/linux/pruss.h b/include/linux/pruss.h
>>> index 5c5d14b1249d..efe89c586b4b 100644
>>> --- a/include/linux/pruss.h
>>> +++ b/include/linux/pruss.h
>>> @@ -14,17 +14,32 @@
>>>     #define PRU_RPROC_DRVNAME "pru-rproc"
>>>   +/**
>>> + * enum pruss_pru_id - PRU core identifiers
>>> + * @PRUSS_PRU0: PRU Core 0.
>>> + * @PRUSS_PRU1: PRU Core 1.
>>> + * @PRUSS_NUM_PRUS: Total number of PRU Cores available.
>>> + *
>>> + */
>>> +
>>> +enum pruss_pru_id {
>>> +    PRUSS_PRU0 = 0,
>>> +    PRUSS_PRU1,
>>> +    PRUSS_NUM_PRUS,
>>> +};
>>> +
>>>   struct device_node;
>>>     #if IS_ENABLED(CONFIG_PRU_REMOTEPROC)
>>>   -struct rproc *pru_rproc_get(struct device_node *np, int index);
>>> +struct rproc *pru_rproc_get(struct device_node *np, int index,
>>> +                enum pruss_pru_id *pru_id);
>>>   void pru_rproc_put(struct rproc *rproc);
>>>     #else
>>>     static inline struct rproc *
>>> -pru_rproc_get(struct device_node *np, int index)
>>> +pru_rproc_get(struct device_node *np, int index, enum pruss_pru_id *pru_id)
>>>   {
>>>       return ERR_PTR(-EOPNOTSUPP);
>>>   }
>>
>> -- 
>> cheers,
>> -roger
> 
> Thanks,
> Danish.

Thanks,
Danish.