On 10/31/2016 09:40 AM, Artyom Tarasenko wrote:
* The "Remove asi helper code handled inline" patch retains the code within
ldda to handle asis that must be handled out of line. This fixes the
FreeBSD 10.3 boot problem. While the UA2007 spec (and thus sun4v?) doesn't
allow for such, it would seem that US2 hardware does.
What ASI was failing? It may still be a part of sun4v CPUs if it's
described in UST1/UST2 supplements.
0x00000000c08e5680: clr %g4
0x00000000c08e5684: mov 1, %g1
0x00000000c08e5688: sllx %g1, 0x24, %o5
0x00000000c08e568c: mov -1, %g1
0x00000000c08e5690: sllx %g1, 0x23, %g1
0x00000000c08e5694: xor %g1, -128, %o4
0x00000000c08e5698: ldda [ %g4 ] #ASI_IC_TAG, %g0 ****
0x00000000c08e569c: mov %g1, %g2
0x00000000c08e56a0: and %g1, %o5, %g1
0x00000000c08e56a4: brz,a %g1, 0xc08e56dc
So indeed it would appear that FreeBSD does in fact want the half of the result
that would get stored into %g1. As far as I can see they could have achieved
the same result with
ldxa [%g4] #ASI_IC_TAG, %g1
srl %g1, 0, %g1
to stay within the nominal spec.
r~
