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MMU: Use VSID in segment register as additional TLB lookup key #12282

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merged 1 commit into from
Nov 12, 2023
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MMU: Use VSID in segment register as additional TLB lookup key #12282

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21 changes: 11 additions & 10 deletions Source/Core/Core/PowerPC/MMU.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1330,13 +1330,13 @@ enum class TLBLookupResult
};

static TLBLookupResult LookupTLBPageAddress(PowerPC::PowerPCState& ppc_state,
const XCheckTLBFlag flag, const u32 vpa, u32* paddr,
bool* wi)
const XCheckTLBFlag flag, const u32 vpa, const u32 vsid,
u32* paddr, bool* wi)
{
const u32 tag = vpa >> HW_PAGE_INDEX_SHIFT;
TLBEntry& tlbe = ppc_state.tlb[IsOpcodeFlag(flag)][tag & HW_PAGE_INDEX_MASK];

if (tlbe.tag[0] == tag)
if (tlbe.tag[0] == tag && tlbe.vsid[0] == vsid)
{
UPTE_Hi pte2(tlbe.pte[0]);

Expand All @@ -1359,7 +1359,7 @@ static TLBLookupResult LookupTLBPageAddress(PowerPC::PowerPCState& ppc_state,

return TLBLookupResult::Found;
}
if (tlbe.tag[1] == tag)
if (tlbe.tag[1] == tag && tlbe.vsid[1] == vsid)
{
UPTE_Hi pte2(tlbe.pte[1]);

Expand All @@ -1386,7 +1386,7 @@ static TLBLookupResult LookupTLBPageAddress(PowerPC::PowerPCState& ppc_state,
}

static void UpdateTLBEntry(PowerPC::PowerPCState& ppc_state, const XCheckTLBFlag flag, UPTE_Hi pte2,
const u32 address)
const u32 address, const u32 vsid)
{
if (IsNoExceptionFlag(flag))
return;
Expand All @@ -1398,6 +1398,7 @@ static void UpdateTLBEntry(PowerPC::PowerPCState& ppc_state, const XCheckTLBFlag
tlbe.paddr[index] = pte2.RPN << HW_PAGE_INDEX_SHIFT;
tlbe.pte[index] = pte2.Hex;
tlbe.tag[index] = tag;
tlbe.vsid[index] = vsid;
}

void MMU::InvalidateTLBEntry(u32 address)
Expand All @@ -1412,20 +1413,21 @@ void MMU::InvalidateTLBEntry(u32 address)
template <const XCheckTLBFlag flag>
MMU::TranslateAddressResult MMU::TranslatePageAddress(const EffectiveAddress address, bool* wi)
{
const auto sr = UReg_SR{m_ppc_state.sr[address.SR]};
const u32 VSID = sr.VSID; // 24 bit

// TLB cache
// This catches 99%+ of lookups in practice, so the actual page table entry code below doesn't
// benefit much from optimization.
u32 translated_address = 0;
const TLBLookupResult res =
LookupTLBPageAddress(m_ppc_state, flag, address.Hex, &translated_address, wi);
LookupTLBPageAddress(m_ppc_state, flag, address.Hex, VSID, &translated_address, wi);
if (res == TLBLookupResult::Found)
{
return TranslateAddressResult{TranslateAddressResultEnum::PAGE_TABLE_TRANSLATED,
translated_address};
}

const auto sr = UReg_SR{m_ppc_state.sr[address.SR]};

if (sr.T != 0)
return TranslateAddressResult{TranslateAddressResultEnum::DIRECT_STORE_SEGMENT, 0};

Expand All @@ -1439,7 +1441,6 @@ MMU::TranslateAddressResult MMU::TranslatePageAddress(const EffectiveAddress add

const u32 offset = address.offset; // 12 bit
const u32 page_index = address.page_index; // 16 bit
const u32 VSID = sr.VSID; // 24 bit
const u32 api = address.API; // 6 bit (part of page_index)

// hash function no 1 "xor" .360
Expand Down Expand Up @@ -1494,7 +1495,7 @@ MMU::TranslateAddressResult MMU::TranslatePageAddress(const EffectiveAddress add

// We already updated the TLB entry if this was caused by a C bit.
if (res != TLBLookupResult::UpdateC)
UpdateTLBEntry(m_ppc_state, flag, pte2, address.Hex);
UpdateTLBEntry(m_ppc_state, flag, pte2, address.Hex, VSID);

*wi = (pte2.WIMG & 0b1100) != 0;

Expand Down
1 change: 1 addition & 0 deletions Source/Core/Core/PowerPC/PowerPC.h
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Original file line number Diff line number Diff line change
Expand Up @@ -62,6 +62,7 @@ struct TLBEntry

WayArray tag{INVALID_TAG, INVALID_TAG};
WayArray paddr{};
WayArray vsid{};
WayArray pte{};
u32 recent = 0;

Expand Down
2 changes: 1 addition & 1 deletion Source/Core/Core/State.cpp
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Expand Up @@ -93,7 +93,7 @@ static size_t s_state_writes_in_queue;
static std::condition_variable s_state_write_queue_is_empty;

// Don't forget to increase this after doing changes on the savestate system
constexpr u32 STATE_VERSION = 163; // Last changed in PR 12217
constexpr u32 STATE_VERSION = 164; // Last changed in PR 12282

// Increase this if the StateExtendedHeader definition changes
constexpr u32 EXTENDED_HEADER_VERSION = 1; // Last changed in PR 12217
Expand Down