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[PowerPC64LE] Fix sleeping on POWER8.

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Due to enter_idle_powerx fabricating a MSR from scratch, it is necessary
for it to care about the endianness, so we don't accidentally switch
endian the first time we idle a thread.

Took about five seconds to spot after seeing an unmangled backtrace.

The hard bit was needing to temporarily set up a mutex to sort out the
logjam that happens when every thread simultaneously wakes up in the wrong
endian due to the panic IPI and panics, leaving what I can best describe as
"alphabet soup" on the console.

Luckily, I already had a patch sitting around to do that.

This brings POWER8 up to equivilence with POWER9 on PPC64LE.

Sponsored by:	Tag1 Consulting, Inc.
This commit is contained in:
Brandon Bergren 2020-09-23 02:28:19 +00:00
parent bceb5a2c8d
commit 93a5341930
1 changed files with 4 additions and 0 deletions
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4
sys/powerpc/powerpc/cpu_subr64.S
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@ -71,7 +71,11 @@ ENTRY(enter_idle_powerx)
/* Set MSR */
li %r3,0
#ifdef __LITTLE_ENDIAN__
ori %r3,%r3,(PSL_ME | PSL_RI | PSL_LE)
#else
ori %r3,%r3,(PSL_ME | PSL_RI)
#endif
li %r8,0x9 /* PSL_SF and PSL_HV */
insrdi %r3,%r8,4,0
mtsrr1 %r3