[PATCH v3 2/2] firmware: zynqmp: Move permission to change config object message

Stefan Herbrechtsmeier stefan.herbrechtsmeier-oss at weidmueller.com
Wed May 17 16:11:31 CEST 2023


Am 17.05.2023 um 14:12 schrieb Michal Simek:
> On 5/16/23 16:05, Stefan Herbrechtsmeier wrote:
>> From: Stefan Herbrechtsmeier <stefan.herbrechtsmeier at weidmueller.com>
>>
>> Move the permission to change a config object message from
>> zynqmp_pmufw_load_config_object function to zynqmp_pmufw_node function
>> to simplify the code and check the permission only if required.
>>
>> Signed-off-by: Stefan Herbrechtsmeier 
>> <stefan.herbrechtsmeier at weidmueller.com>
>>
>> ---
>>
>> Changes in v4:
>> - Reword
>> - Move the check back to zynqmp_pmufw_node because the check need to be
>>    run after the config object load.
>> - Return error in zynqmp_pmufw_config_close and zynqmp_pmufw_node
>>
>> Changes in v3:
>> - Added
>>
>>   drivers/firmware/firmware-zynqmp.c | 36 ++++++++++++++----------------
>>   1 file changed, 17 insertions(+), 19 deletions(-)
>>
>> diff --git a/drivers/firmware/firmware-zynqmp.c 
>> b/drivers/firmware/firmware-zynqmp.c
>> index 2b1ad5d2c3..6dc745bd14 100644
>> --- a/drivers/firmware/firmware-zynqmp.c
>> +++ b/drivers/firmware/firmware-zynqmp.c
>> @@ -63,29 +63,32 @@ static unsigned int xpm_configobject_close[] = {
>>     int zynqmp_pmufw_config_close(void)
>>   {
>> -    zynqmp_pmufw_load_config_object(xpm_configobject_close,
>> -                    sizeof(xpm_configobject_close));
>> -    return 0;
>> +    return zynqmp_pmufw_load_config_object(xpm_configobject_close,
>> +                           sizeof(xpm_configobject_close));
>>   }
>>     int zynqmp_pmufw_node(u32 id)
>>   {
>> -    static bool skip_config;
>> -    int ret;
>> +    static bool checked;
>> +    static bool skip;
>
> I see interesting behavior in connection to these variables.
> I did this change and keep test variable to see behavior.
>
>
> diff --git a/drivers/firmware/firmware-zynqmp.c 
> b/drivers/firmware/firmware-zynqmp.c
> index 6dc745bd1424..becbea7b64ea 100644
> --- a/drivers/firmware/firmware-zynqmp.c
> +++ b/drivers/firmware/firmware-zynqmp.c
> @@ -67,10 +67,14 @@ int zynqmp_pmufw_config_close(void)
> sizeof(xpm_configobject_close));
>  }
>
> +static bool checked;
> +static bool skip;
> +
>  int zynqmp_pmufw_node(u32 id)
>  {
> -       static bool checked;
> -       static bool skip;
> +       static bool test;
> +
> +       printf("----------------%s, id %d, ch %d, skp %d - test %d\n", 
> __func__, id, checked, skip, test);
>
>         if (!checked) {
>                 checked = true;
> @@ -379,6 +391,9 @@ static int zynqmp_firmware_bind(struct udevice *dev)
>         int ret;
>         struct udevice *child;
>
> +       checked = 0;
> +       skip = 0;
> +
>         if ((IS_ENABLED(CONFIG_SPL_BUILD) &&
>              IS_ENABLED(CONFIG_SPL_POWER_DOMAIN) &&
>              IS_ENABLED(CONFIG_ZYNQMP_POWER_DOMAIN)) ||
>
>
> <debug_uart>
> zynqmp_power_domain zynqmp_power_domain: Request for id: 34
> zynqmp_pmufw_node, id 34, ch 0, skp 0 - test 255/815a2fa
> zynqmp_pmufw_node, id 11, ch 1, skp 0 - test 255/815a2fa
> -----------zynqmp_pmufw_node ACCESS OK
> --------------------zynqmp_pmufw_load_config_object
> --------------------zynqmp_pmufw_load_config_object44
> -----------zynqmp_pmufw_node ACCESS OK
> --------------------zynqmp_pmufw_load_config_object
> --------------------zynqmp_pmufw_load_config_object44
> zynqmp_power_domain zynqmp_power_domain: Domain ON for id: 34
> zynq_serial_setbrg: CLK 99999999
>
>
> U-Boot 2023.07-rc2-00053-gaf7817988644-dirty (May 17 2023 - 14:03:37 
> +0200)
>
> CPU:   ZynqMP
> Silicon: v3
> Chip:  xck26
> zynqmp_power_domain zynqmp_power_domain: Request for id: 38
> zynqmp_pmufw_node, id 38, ch 1, skp 0 - test 1/815a2fa
> -----------zynqmp_pmufw_node ACCESS OK
> --------------------zynqmp_pmufw_load_config_object
> --------------------zynqmp_pmufw_load_config_object44
> zynqmp_power_domain zynqmp_power_domain: Domain ON for id: 38
> Detected name: zynqmp-smk-k26-xcl2g-revA-sck-kv-g-revB
> Model: ZynqMP KV260 revB
> Board: Xilinx ZynqMP
> DRAM:  2 GiB (effective 4 GiB)
> zynqmp_power_domain zynqmp_power_domain: Request for id: 46
> zynqmp_pmufw_node, id 46, ch 0, skp 0 - test 0/7ffd42fa
> zynqmp_pmufw_node, id 11, ch 1, skp 0 - test 0/7ffd42fa
> -----------zynqmp_pmufw_node ACCESS OK
> --------------------zynqmp_pmufw_load_config_object
> --------------------zynqmp_pmufw_load_config_object44
> -----------zynqmp_pmufw_node ACCESS OK
> --------------------zynqmp_pmufw_load_config_object
> --------------------zynqmp_pmufw_load_config_object44
> zynqmp_power_domain zynqmp_power_domain: Domain ON for id: 46
> PMUFW:    v1.1
> zynqmp_power_domain zynqmp_power_domain: Request for id: 38
> zynqmp_pmufw_node, id 38, ch 1, skp 0 - test 1/7ffd42fa
> -----------zynqmp_pmufw_node ACCESS OK
>
>
> As you see test variable is in BSS section but it is not initialized 
> at this stage. If you look at arch/arm/lib/crt0_64.S debug uart is 
> called before calling board_init_f and bss is cleared before 
> board_init_r is called.

What does "but BSS and  initialized non-const data are still not 
available" mean? Could we use variables from the data section like 
"static bool check = true"?

> It means variables should be placed to different section or 
> initialized them directly from the code.

I think the zynqmp_power variable could have the same problem.

The initialization from the code doesn't work because the class is 
dynamic probed.
zynqmp_pmufw_node --> zynqmp_pmufw_load_config_object --> xilinx_pm_request
-(SPL)-> ipi_req --> do_pm_probe

Maybe we need to rework the driver to use private driver data and probe 
the driver early in the chain.

>>   -    if (skip_config)
>> -        return 0;
>> +    if (!checked) {
>> +        checked = true;
>>   -    /* Record power domain id */
>> -    xpm_configobject[NODE_ID_LOCATION] = id;
>> +        if (zynqmp_pmufw_node(NODE_OCM_BANK_0) == -EACCES) {
>> +            printf("PMUFW:  No permission to change config object\n");
>> +            skip = true;
>> +        }
>> +    }
>>   -    ret = zynqmp_pmufw_load_config_object(xpm_configobject,
>> -                          sizeof(xpm_configobject));
>> +    if (skip)
>> +        return -EACCES;
>>   -    if (ret == -EACCES && id == NODE_OCM_BANK_0)
>> -        skip_config = true;
>> +    /* Record power domain id */
>> +    xpm_configobject[NODE_ID_LOCATION] = id;
>>   -    return 0;
>> +    return zynqmp_pmufw_load_config_object(xpm_configobject,
>> +                           sizeof(xpm_configobject));
>>   }
>
> With this change there is also need to change
> drivers/power/domain/zynqmp-power-domain.c
>
> to handle return value for case that node is already configured.
> I would prefer to have separate error code for it just in case.
>
>  static int zynqmp_power_domain_request(struct power_domain 
> *power_domain)
>  {
> +       int ret = 0;
> +
>         dev_dbg(power_domain->dev, "Request for id: %ld\n", 
> power_domain->id);
>
> -       if (IS_ENABLED(CONFIG_ARCH_ZYNQMP))
> -               return zynqmp_pmufw_node(power_domain->id);
> +       if (IS_ENABLED(CONFIG_ARCH_ZYNQMP)) {
> +               ret = zynqmp_pmufw_node(power_domain->id);
> +               if (ret == -ENODEV)
> +                       ret = 0;
> +       }
>
> -       return 0;
> +       return ret;
>  }
>
Should I add a patch to the series before this patch?

>
>>     static int do_pm_probe(void)
>> @@ -250,8 +253,6 @@ int zynqmp_pmufw_load_config_object(const void 
>> *cfg_obj, size_t size)
>>       err = xilinx_pm_request(PM_SET_CONFIGURATION, 
>> (u32)(u64)cfg_obj, 0, 0,
>>                   0, ret_payload);
>>       if (err == XST_PM_NO_ACCESS) {
>> -        if (((u32 *)cfg_obj)[NODE_ID_LOCATION] == NODE_OCM_BANK_0)
>> -            printf("PMUFW:  No permission to change config object\n");
>>           return -EACCES;
>>       }
>>   @@ -295,9 +296,6 @@ static int zynqmp_power_probe(struct udevice *dev)
>>              ret >> ZYNQMP_PM_VERSION_MAJOR_SHIFT,
>>              ret & ZYNQMP_PM_VERSION_MINOR_MASK);
>>   -    if (IS_ENABLED(CONFIG_ARCH_ZYNQMP))
>> -        zynqmp_pmufw_node(NODE_OCM_BANK_0);
>> -
>>       return 0;
>>   };


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