On 11/18/20 6:50 PM, Cornelia Huck wrote:
> On Tue, 17 Nov 2020 10:42:13 -0500
> Janosch Frank <frankja@xxxxxxxxxxxxx> wrote:
>
>> Availability of SIE is announced via a feature bit in a SCLP info CPU
>> entry. Let's add a framework that allows us to easily check for such
>> facilities.
>>
>> Signed-off-by: Janosch Frank <frankja@xxxxxxxxxxxxx>
>> ---
>> lib/s390x/io.c | 1 +
>> lib/s390x/sclp.c | 19 +++++++++++++++++++
>> lib/s390x/sclp.h | 15 +++++++++++++++
>> 3 files changed, 35 insertions(+)
>
> (...)
Btw. I also wanted to add this to the struct sclp_facilities:
u64 reserved : 63:
>
>> +void sclp_facilities_setup(void)
>> +{
>> + unsigned short cpu0_addr = stap();
>> + CPUEntry *cpu;
>> + int i;
>> +
>> + assert(read_info);
>> +
>> + cpu = (void *)read_info + read_info->offset_cpu;
>> + for (i = 0; i < read_info->entries_cpu; i++, cpu++) {
>> + if (cpu->address == cpu0_addr) {
>> + sclp_facilities.has_sief2 = test_bit_inv(SCLP_CPU_FEATURE_SIEF2_BIT, (void *)&cpu->address);
>
> Can you wrap this? This line is really overlong.
Sure
>
> (Also, just to understand: Is sief2 only indicated for cpu0, and not
> for the other cpus?)
That's an excellent question I don't know the answer to.
I had a look at the kernel's implementation of this and that's what
they're doing so I figured they had a reason for it.
The documentation doesn't seem to say anything about that, but there's a
lot of it I haven't yet read.
>
>> + break;
>> + }
>> + }
>> +}
>> +
>> /* Perform service call. Return 0 on success, non-zero otherwise. */
>> int sclp_service_call(unsigned int command, void *sccb)
>> {
>
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