Re: [RFC PATCH 03/12] powerpc/prom_init: Add the ESM call to prom_init

[Thiago Jung Bauermann <bauerman@linux.ibm.com>]

Hello Alexey,

Thanks for reviewing this patch!

Alexey Kardashevskiy <aik@ozlabs.ru> writes:

> On 21/05/2019 14:49, Thiago Jung Bauermann wrote:
>> @@ -1707,6 +1723,43 @@ static void __init prom_close_stdin(void)
>>  	}
>>  }
>>  
>> +#ifdef CONFIG_PPC_SVM
>> +static int prom_rtas_os_term_hcall(uint64_t args)
>
>
> This is just an rtas hcall, nothing special about "os-term".

Sorry, unfortunately I don't understand how we're treating os-term
especially. Do you mean that we should inline this function directly
into prom_rtas_os_term()?

>> +{
>> +	register uint64_t arg1 asm("r3") = 0xf000;
>> +	register uint64_t arg2 asm("r4") = args;
>> +
>> +	asm volatile("sc 1\n" : "=r" (arg1) :
>> +			"r" (arg1),
>> +			"r" (arg2) :);
>> +	return arg1;
>> +}
>> +
>> +static struct rtas_args __prombss os_term_args;
>> +
>> +static void __init prom_rtas_os_term(char *str)
>> +{
>> +	phandle rtas_node;
>> +	__be32 val;
>> +	u32 token;
>> +
>> +	prom_printf("%s: start...\n", __func__);
>> +	rtas_node = call_prom("finddevice", 1, 1, ADDR("/rtas"));
>> +	prom_printf("rtas_node: %x\n", rtas_node);
>> +	if (!PHANDLE_VALID(rtas_node))
>> +		return;
>> +
>> +	val = 0;
>> +	prom_getprop(rtas_node, "ibm,os-term", &val, sizeof(val));
>> +	token = be32_to_cpu(val);
>> +	prom_printf("ibm,os-term: %x\n", token);
>> +	if (token == 0)
>> +		prom_panic("Could not get token for ibm,os-term\n");
>> +	os_term_args.token = cpu_to_be32(token);
>> +	prom_rtas_os_term_hcall((uint64_t)&os_term_args);
>> +}
>> +#endif /* CONFIG_PPC_SVM */
>> +
>>  /*
>>   * Allocate room for and instantiate RTAS
>>   */

-- 
Thiago Jung Bauermann
IBM Linux Technology Center