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References: <20190521044912.1375-1-bauerman@linux.ibm.com> <20190521044912.1375-4-bauerman@linux.ibm.com> <3b45cc84-273b-b333-831c-85c501b7e78e@ozlabs.ru>
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From:   Thiago Jung Bauermann <bauerman@linux.ibm.com>
To:     Alexey Kardashevskiy <aik@ozlabs.ru>
Cc:     linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
        Anshuman Khandual <anshuman.linux@gmail.com>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Christoph Hellwig <hch@lst.de>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Mike Anderson <andmike@linux.ibm.com>,
        Paul Mackerras <paulus@samba.org>,
        Ram Pai <linuxram@us.ibm.com>,
        Claudio Carvalho <cclaudio@linux.ibm.com>
Subject: Re: [RFC PATCH 03/12] powerpc/prom_init: Add the ESM call to prom_init
In-reply-to: <3b45cc84-273b-b333-831c-85c501b7e78e@ozlabs.ru>
Date:   Fri, 28 Jun 2019 19:33:24 -0300
Message-ID: <87mui1732j.fsf@morokweng.localdomain>
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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