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Subject: Re: [PATCH v8 04/22] s390/zcrypt: Integrate ap_asm.h into
 include/asm/ap.h.
To:     Cornelia Huck <cohuck@redhat.com>,
        Tony Krowiak <akrowiak@linux.vnet.ibm.com>
Cc:     linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org,
        kvm@vger.kernel.org, freude@de.ibm.com, schwidefsky@de.ibm.com,
        heiko.carstens@de.ibm.com, borntraeger@de.ibm.com,
        kwankhede@nvidia.com, bjsdjshi@linux.vnet.ibm.com,
        pbonzini@redhat.com, alex.williamson@redhat.com,
        pmorel@linux.vnet.ibm.com, alifm@linux.vnet.ibm.com,
        mjrosato@linux.vnet.ibm.com, jjherne@linux.vnet.ibm.com,
        thuth@redhat.com, pasic@linux.vnet.ibm.com, berrange@redhat.com,
        fiuczy@linux.vnet.ibm.com, buendgen@de.ibm.com,
        frankja@linux.ibm.com
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 <20180809110645.33b20c1f.cohuck@redhat.com>
From:   Tony Krowiak <akrowiak@linux.ibm.com>
Date:   Thu, 9 Aug 2018 11:18:05 -0400
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On 08/09/2018 05:06 AM, Cornelia Huck wrote:
> On Wed,  8 Aug 2018 10:44:14 -0400
> Tony Krowiak <akrowiak@linux.vnet.ibm.com> wrote:
>
>> From: Harald Freudenberger <freude@de.ibm.com>
>>
>> Move all the inline functions from the ap bus header
>> file ap_asm.h into the in-kernel api header file
>> arch/s390/include/asm/ap.h so that KVM can make use
>> of all the low level AP functions.
>>
>> Signed-off-by: Harald Freudenberger <freude@de.ibm.com>
>> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
> You should add your own s-o-b if you are sending on patches written by
> others (even if it does not matter in the end, when they are merged
> through a different path anyway.)

That's rather ironic given I was told in an internal review that I should
not sign off on patches I did not write.

>
>> ---
>>   arch/s390/include/asm/ap.h     |  284 ++++++++++++++++++++++++++++++++++++----
>>   drivers/s390/crypto/ap_asm.h   |  261 ------------------------------------
>>   drivers/s390/crypto/ap_bus.c   |   21 +---
>>   drivers/s390/crypto/ap_bus.h   |    1 +
>>   drivers/s390/crypto/ap_card.c  |    1 -
>>   drivers/s390/crypto/ap_queue.c |    1 -
>>   6 files changed, 259 insertions(+), 310 deletions(-)
>>   delete mode 100644 drivers/s390/crypto/ap_asm.h
>>
>> diff --git a/arch/s390/include/asm/ap.h b/arch/s390/include/asm/ap.h
>> index c1bedb4..046e044 100644
>> --- a/arch/s390/include/asm/ap.h
>> +++ b/arch/s390/include/asm/ap.h
>> @@ -47,6 +47,50 @@ struct ap_queue_status {
>>   };
>>   
>>   /**
>> + * ap_intructions_available() - Test if AP instructions are available.
>> + *
>> + * Returns 0 if the AP instructions are installed.
> Stumbled over this when I was looking at the usage in patch 7: if I see
> a function called '_available' return 0, I'd assume that whatever the
> function tests for is *not* available.
>
> Rather call this function ap_instructions_check_availability() (and
> keep the return code convention), or switch this to return 0 if not
> available and !0 if available?
>
>> + */
>> +static inline int ap_instructions_available(void)
>> +{
>> +	register unsigned long reg0 asm ("0") = AP_MKQID(0, 0);
>> +	register unsigned long reg1 asm ("1") = -ENODEV;
>> +	register unsigned long reg2 asm ("2");
>> +
>> +	asm volatile(
>> +		"   .long 0xb2af0000\n"		/* PQAP(TAPQ) */
>> +		"0: la    %0,0\n"
>> +		"1:\n"
>> +		EX_TABLE(0b, 1b)
>> +		: "+d" (reg1), "=d" (reg2)
>> +		: "d" (reg0)
>> +		: "cc");
>> +	return reg1;
>> +}