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Message-ID: <9acd96ab-7987-5cdc-e65b-9f055948eb4f@kernel.org>
Date:   Wed, 29 Mar 2023 11:21:11 +0300
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Subject: Re: [PATCH v7 3/3] remoteproc: k3-r5: Use separate compatible string
 for TI AM62x SoC family
Content-Language: en-US
To:     Devarsh Thakkar <devarsht@ti.com>,
        Mathieu Poirier <mathieu.poirier@linaro.org>
Cc:     andersson@kernel.org, devicetree@vger.kernel.org,
        p.zabel@pengutronix.de, linux-remoteproc@vger.kernel.org,
        robh+dt@kernel.org, linux-kernel@vger.kernel.org,
        krzysztof.kozlowski+dt@linaro.org, s-anna@ti.com, hnagalla@ti.com,
        praneeth@ti.com, nm@ti.com, vigneshr@ti.com, a-bhatia1@ti.com,
        j-luthra@ti.com
References: <20230310162544.3468365-1-devarsht@ti.com>
 <20230310162544.3468365-4-devarsht@ti.com> <20230317161757.GA2471094@p14s>
 <f08e550b-2f15-0f84-c0ca-05e0b803481a@kernel.org>
 <1a24f99a-99c1-bf00-e5e7-1085cfd8faf5@ti.com>
From:   Roger Quadros <rogerq@kernel.org>
In-Reply-To: <1a24f99a-99c1-bf00-e5e7-1085cfd8faf5@ti.com>
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On 28/03/2023 19:08, Devarsh Thakkar wrote:
> Hi Roger,
> 
> On 28/03/23 13:22, Roger Quadros wrote:
>> Hi Devarsh,
>>
>> On 17/03/2023 18:17, Mathieu Poirier wrote:
>>> On Fri, Mar 10, 2023 at 09:55:44PM +0530, Devarsh Thakkar wrote:
>>>> AM62 and AM62A SoCs use single core R5F which is a new scenario
>>>> different than the one being used with CLUSTER_MODE_SINGLECPU which is
>>>> for utilizing a single core from a set of cores available in R5F cluster
>>>> present in the SoC.
>>>>
>>>> To support this single core scenario map it with newly defined
>>>> CLUSTER_MODE_SINGLECORE and use it when compatible is set to
>>>> ti,am62-r5fss.
>>>>
>>>> Also set PROC_BOOT_CFG_FLAG_R5_SINGLE_CORE config for
>>>> CLUSTER_MODE_SINGLECORE too as it is required by R5 core when it is
>>>> being as general purpose core instead of device manager.
>>>>
>>>> Signed-off-by: Devarsh Thakkar <devarsht@ti.com>
>>>> ---
>>>> V2:
>>>> - Fix indentation and ordering issues as per review comments
>>>> V3:
>>>> - Change CLUSTER_MODE_NONE value to -1
>>>> V4:
>>>> - No change
>>>> V5:
>>>> - No change (fixing typo in email address)
>>>> V6:
>>>>     - Use CLUSTER_MODE_SINGLECORE for AM62x
>>>>     - Set PROC_BOOT_CFG_FLAG_R5_SINGLE_CORE for single core.
>>>> V7:
>>>>     - Simplify and rebase on top of base commit "[PATCH v7] remoteproc: k3-r5: Simplify cluster
>>>>       mode setting"
>>>> ---
>>>>   drivers/remoteproc/ti_k3_r5_remoteproc.c | 59 +++++++++++++++++++-----
>>>>   1 file changed, 48 insertions(+), 11 deletions(-)
>>>>
>>>> diff --git a/drivers/remoteproc/ti_k3_r5_remoteproc.c b/drivers/remoteproc/ti_k3_r5_remoteproc.c
>>>> index c2ec0f432921..df32f6bc4325 100644
>>>> --- a/drivers/remoteproc/ti_k3_r5_remoteproc.c
>>>> +++ b/drivers/remoteproc/ti_k3_r5_remoteproc.c
>>>> @@ -71,14 +71,16 @@ struct k3_r5_mem {
>>>>   /*
>>>>    * All cluster mode values are not applicable on all SoCs. The following
>>>>    * are the modes supported on various SoCs:
>>>> - *   Split mode      : AM65x, J721E, J7200 and AM64x SoCs
>>>> - *   LockStep mode   : AM65x, J721E and J7200 SoCs
>>>> - *   Single-CPU mode : AM64x SoCs only
>>>> + *   Split mode       : AM65x, J721E, J7200 and AM64x SoCs
>>>> + *   LockStep mode    : AM65x, J721E and J7200 SoCs
>>>> + *   Single-CPU mode  : AM64x SoCs only
>>>> + *   Single-Core mode : AM62x, AM62A SoCs
>>>>    */
>>>>   enum cluster_mode {
>>>>       CLUSTER_MODE_SPLIT = 0,
>>>>       CLUSTER_MODE_LOCKSTEP,
>>>>       CLUSTER_MODE_SINGLECPU,
>>>> +    CLUSTER_MODE_SINGLECORE
>>
>> What is the difference in device driver behaviour between
>> SINGLECPU and SINGLECORE?
>>
> Yeah there is quite a bit of common code flow between the two but the fundamental difference is that you use CLUSTER_MODE_SINGLECPU when

I still didn't get what is the difference between the two from SW point of view.
What happens if you just use CLUSTER_MODE_SINGLECPU for AM62 SoC?

> you have two R5F cores but you want to use only single R5F core albeit
> with using TCM of both the cores whereas CLUSTER_MODE_SINGLECORE is
> for the scenario where you have single core R5F's only.
> 
> Also the bindings for CLUSTER_MODE_SINGLECPU are already upstream so did
> not want to break them either : https://gitlab.com/linux-kernel/linux-next/-/blob/next-20230328/Documentation/devicetree/bindings/remoteproc/ti%2Ck3-r5f-rproc.yaml#L20.
> 
> Regards
> Devarsh
> 
>> If there is no difference then you should not introduce
>> a new enum. >
>>>>   };
>>>>     /**
>>>> @@ -86,11 +88,13 @@ enum cluster_mode {
>>>>    * @tcm_is_double: flag to denote the larger unified TCMs in certain modes
>>>>    * @tcm_ecc_autoinit: flag to denote the auto-initialization of TCMs for ECC
>>>>    * @single_cpu_mode: flag to denote if SoC/IP supports Single-CPU mode
>>>> + * @is_single_core: flag to denote if SoC/IP has only single core R5
>>>>    */
>>>>   struct k3_r5_soc_data {
>>>>       bool tcm_is_double;
>>>>       bool tcm_ecc_autoinit;
>>>>       bool single_cpu_mode;
>>>> +    bool is_single_core;
>>>>   };
>>>>     /**
>>>> @@ -838,7 +842,8 @@ static int k3_r5_rproc_configure(struct k3_r5_rproc *kproc)
>>>>         core0 = list_first_entry(&cluster->cores, struct k3_r5_core, elem);
>>>>       if (cluster->mode == CLUSTER_MODE_LOCKSTEP ||
>>>> -        cluster->mode == CLUSTER_MODE_SINGLECPU) {
>>>> +        cluster->mode == CLUSTER_MODE_SINGLECPU ||
>>>> +        cluster->mode == CLUSTER_MODE_SINGLECORE) {
>>>>           core = core0;
>>>>       } else {
>>>>           core = kproc->core;
>>>> @@ -877,7 +882,8 @@ static int k3_r5_rproc_configure(struct k3_r5_rproc *kproc)
>>>>            * with the bit configured, so program it only on
>>>>            * permitted cores
>>>>            */
>>>> -        if (cluster->mode == CLUSTER_MODE_SINGLECPU) {
>>>> +        if (cluster->mode == CLUSTER_MODE_SINGLECPU ||
>>>> +            cluster->mode == CLUSTER_MODE_SINGLECORE) {
>>>>               set_cfg = PROC_BOOT_CFG_FLAG_R5_SINGLE_CORE;
>>>>           } else {
>>>>               /*
>>>> @@ -1069,6 +1075,7 @@ static void k3_r5_adjust_tcm_sizes(struct k3_r5_rproc *kproc)
>>>>         if (cluster->mode == CLUSTER_MODE_LOCKSTEP ||
>>>>           cluster->mode == CLUSTER_MODE_SINGLECPU ||
>>>> +        cluster->mode == CLUSTER_MODE_SINGLECORE ||
>>>>           !cluster->soc_data->tcm_is_double)
>>>>           return;
>>>>   @@ -1145,6 +1152,8 @@ static int k3_r5_rproc_configure_mode(struct k3_r5_rproc *kproc)
>>>>       if (cluster->soc_data->single_cpu_mode) {
>>>>           mode = cfg & PROC_BOOT_CFG_FLAG_R5_SINGLE_CORE ?
>>>>                   CLUSTER_MODE_SINGLECPU : CLUSTER_MODE_SPLIT;
>>>> +    } else if (cluster->soc_data->is_single_core) {
>>>> +        mode = CLUSTER_MODE_SINGLECORE;
>>>
>>> I have commented twice on this before - whether it is soc_data->single_cpu_mode or
>>> soc_data->is_single_core, I don't want to see them used elsewhere than in a
>>> single function.  Either in probe() or another function, use them once to set
>>> cluster->mode and never again.
>>>
>>> I will silently drop any other patchset that doesn't address this.
>>>
>>>>       } else {
>>>>           mode = cfg & PROC_BOOT_CFG_FLAG_R5_LOCKSTEP ?
>>>>                   CLUSTER_MODE_LOCKSTEP : CLUSTER_MODE_SPLIT;
>>>> @@ -1264,9 +1273,12 @@ static int k3_r5_cluster_rproc_init(struct platform_device *pdev)
>>>>               goto err_add;
>>>>           }
>>>>   -        /* create only one rproc in lockstep mode or single-cpu mode */
>>>> +        /* create only one rproc in lockstep, single-cpu or
>>>> +         * single core mode
>>>> +         */
>>>>           if (cluster->mode == CLUSTER_MODE_LOCKSTEP ||
>>>> -            cluster->mode == CLUSTER_MODE_SINGLECPU)
>>>> +            cluster->mode == CLUSTER_MODE_SINGLECPU ||
>>>> +            cluster->mode == CLUSTER_MODE_SINGLECORE)
>>>>               break;
>>>>       }
>>>>   @@ -1709,19 +1721,33 @@ static int k3_r5_probe(struct platform_device *pdev)
>>>>           /*
>>>>            * default to most common efuse configurations - Split-mode on AM64x
>>>>            * and LockStep-mode on all others
>>>> +         * default to most common efuse configurations -
>>>> +         * Split-mode on AM64x
>>>> +         * Single core on AM62x
>>>> +         * LockStep-mode on all others
>>>>            */
>>>> -        cluster->mode = data->single_cpu_mode ?
>>>> +        if (!data->is_single_core)
>>>> +            cluster->mode = data->single_cpu_mode ?
>>>>                       CLUSTER_MODE_SPLIT : CLUSTER_MODE_LOCKSTEP;
>>>> +        else
>>>> +            cluster->mode = CLUSTER_MODE_SINGLECORE;
>>>>       }
>>>>   -    if (cluster->mode == CLUSTER_MODE_SINGLECPU && !data->single_cpu_mode) {
>>>> +    if  ((cluster->mode == CLUSTER_MODE_SINGLECPU && !data->single_cpu_mode) ||
>>>> +         (cluster->mode == CLUSTER_MODE_SINGLECORE && !data->is_single_core)) {
>>>>           dev_err(dev, "Cluster mode = %d is not supported on this SoC\n", cluster->mode);
>>>>           return -EINVAL;
>>>>       }
>>>>         num_cores = of_get_available_child_count(np);
>>>> -    if (num_cores != 2) {
>>>> -        dev_err(dev, "MCU cluster requires both R5F cores to be enabled, num_cores = %d\n",
>>>> +    if (num_cores != 2 && !data->is_single_core) {
>>>> +        dev_err(dev, "MCU cluster requires both R5F cores to be enabled but num_cores is set to = %d\n",
>>>> +            num_cores);
>>>> +        return -ENODEV;
>>>> +    }
>>>> +
>>>> +    if (num_cores != 1 && data->is_single_core) {
>>>> +        dev_err(dev, "SoC supports only single core R5 but num_cores is set to %d\n",
>>>>               num_cores);
>>>>           return -ENODEV;
>>>>       }
>>>> @@ -1763,18 +1789,28 @@ static const struct k3_r5_soc_data am65_j721e_soc_data = {
>>>>       .tcm_is_double = false,
>>>>       .tcm_ecc_autoinit = false,
>>>>       .single_cpu_mode = false,
>>>> +    .is_single_core = false,
>>>>   };
>>>>     static const struct k3_r5_soc_data j7200_j721s2_soc_data = {
>>>>       .tcm_is_double = true,
>>>>       .tcm_ecc_autoinit = true,
>>>>       .single_cpu_mode = false,
>>>> +    .is_single_core = false,
>>>>   };
>>>>     static const struct k3_r5_soc_data am64_soc_data = {
>>>>       .tcm_is_double = true,
>>>>       .tcm_ecc_autoinit = true,
>>>>       .single_cpu_mode = true,
>>>> +    .is_single_core = false,
>>>> +};
>>>> +
>>>> +static const struct k3_r5_soc_data am62_soc_data = {
>>>> +    .tcm_is_double = false,
>>>> +    .tcm_ecc_autoinit = true,
>>>> +    .single_cpu_mode = false,
>>>> +    .is_single_core = true,
>>>>   };
>>>>     static const struct of_device_id k3_r5_of_match[] = {
>>>> @@ -1782,6 +1818,7 @@ static const struct of_device_id k3_r5_of_match[] = {
>>>>       { .compatible = "ti,j721e-r5fss", .data = &am65_j721e_soc_data, },
>>>>       { .compatible = "ti,j7200-r5fss", .data = &j7200_j721s2_soc_data, },
>>>>       { .compatible = "ti,am64-r5fss",  .data = &am64_soc_data, },
>>>> +    { .compatible = "ti,am62-r5fss",  .data = &am62_soc_data, },
>>>>       { .compatible = "ti,j721s2-r5fss",  .data = &j7200_j721s2_soc_data, },
>>>>       { /* sentinel */ },
>>>>   };
>>>> -- 
>>>> 2.34.1
>>>>
>>

--
cheers,
-roger