Re: PCI range checking under qemu-system-sparc64

Mark Cave-Ayland <[email protected]>
Newsgroups gmane.os.freebsd.devel.sparc
Message-ID <[email protected]>
On 23/09/15 21:43, Marius Strobl wrote:

> On Wed, Sep 23, 2015 at 09:19:53AM +0100, Mark Cave-Ayland wrote:
>>
>> I've had a quick look through the relevant PDFs and the definitions I
>> have for tick/stick are this:
>>
>> tick:
>>   bit  63: NPT (Non-Privileged Trap enable - defaults to 1)
>>   bits 62 - 0: CPU cycle counter
>>
>> tick_cmpr:
>>   bit  63: Interrupt disable (1 = no interrupt)
>>   bits 62 - 0: counter compare value
>>
>> stick:
>>   bit  63: Reserved (reads 0, no write)
>>   bits 62 - 0: stick register count value
> 
> I cannot confirm that, the specification for the first sun4u CPU
> having a %stick register (UltraSPARC III, see 1, p. 6-105) up to
> the latest architecture specification (see 2, p. 60) say that bit
> 32 of %stick is NPT, just as with %tick. Same for the specification
> the Fujitsu SPARC64 processors follow (3, p. 90).

Interesting. The document I'm referring to in my local collection is the
UltraSPARC IIe specification which you can find a copy at
http://www.coris.org.uk/misc/Sundocs/USIIe_ext_1.1.pdf (see page 29). I
don't see this as necessarily being a conflict, it just seems that the
IIe allows unprivileged access to %stick.


ATB,

Mark.

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