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MMU: Fix SDR updates being silently dropped in some cases 

While 6xx_pem.pdf §7.6.1.1 mentions that the number of trailing
zeros in HTABORG must be equal to the number of trailing ones
in the mask (i.e. HTABORG must be properly aligned), this is actually
not a hard requirement. Real hardware will just OR the base address
anyway. Ignoring SDR changes would lead to incorrect emulation.

Logging a warning instead of dropping the SDR update silently is a
saner behaviour.
This commit is contained in:
Léo Lam 2021-04-06 01:35:56 +02:00
parent ac250f7c20
commit 960d957f4f
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GPG Key ID: 0DF30F9081000741
1 changed files with 8 additions and 6 deletions
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14
Source/Core/Core/PowerPC/MMU.cpp
View File

@ -980,14 +980,16 @@ void SDRUpdated()
{
u32 htabmask = SDR1_HTABMASK(PowerPC::ppcState.spr[SPR_SDR]);
if (!Common::IsValidLowMask(htabmask))
{
return;
}
WARN_LOG_FMT(POWERPC, "Invalid HTABMASK: 0b{:032b}", htabmask);
// While 6xx_pem.pdf §7.6.1.1 mentions that the number of trailing zeros in HTABORG
// must be equal to the number of trailing ones in the mask (i.e. HTABORG must be
// properly aligned), this is actually not a hard requirement. Real hardware will just OR
// the base address anyway. Ignoring SDR changes would lead to incorrect emulation.
u32 htaborg = SDR1_HTABORG(PowerPC::ppcState.spr[SPR_SDR]);
if (htaborg & htabmask)
{
return;
}
WARN_LOG_FMT(POWERPC, "Invalid HTABORG: htaborg=0x{:08x} htabmask=0x{:08x}", htaborg, htabmask);
PowerPC::ppcState.pagetable_base = htaborg << 16;
PowerPC::ppcState.pagetable_hashmask = ((htabmask << 10) | 0x3ff);
}