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kern: implement KPageTableImpl merge

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This commit is contained in:
Michael Scire 2024-10-10 13:25:37 -07:00
parent 104be247da
commit e2f068548b
2 changed files with 73 additions and 4 deletions
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2
libraries/libmesosphere/include/mesosphere/arch/arm64/kern_k_page_table_entry.hpp
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@ -224,7 +224,7 @@ namespace ams::kern::arch::arm64 {
constexpr ALWAYS_INLINE decltype(auto) RemoveTableEntries(size_t num) { return this->SetTableNumEntries(this->GetTableNumEntries() - num); }
constexpr ALWAYS_INLINE u64 GetEntryTemplateForMerge() const {
constexpr u64 BaseMask = (0xFFF0000000000FFFul & ~static_cast<u64>((0x1ul << 52) | ExtensionFlag_TestTableMask | ExtensionFlag_DisableMergeHead | ExtensionFlag_DisableMergeHeadAndBody | ExtensionFlag_DisableMergeTail));
constexpr u64 BaseMask = (0xFFFF000000000FFFul & ~static_cast<u64>((0x1ul << 52) | ExtensionFlag_TestTableMask | ExtensionFlag_DisableMergeHead | ExtensionFlag_DisableMergeHeadAndBody | ExtensionFlag_DisableMergeTail));
return m_attributes & BaseMask;
}

75
libraries/libmesosphere/source/arch/arm64/kern_k_page_table_impl.cpp
View file

@ -167,9 +167,78 @@ namespace ams::kern::arch::arm64 {
}
bool KPageTableImpl::MergePages(KVirtualAddress *out, TraversalContext *context) {
/* TODO */
MESOSPHERE_UNUSED(out, context);
MESOSPHERE_PANIC("page tables");
/* We want to upgrade the pages by one step. */
if (context->is_contiguous) {
/* We can't merge an L1 table. */
if (context->level == EntryLevel_L1) {
return false;
}
/* We want to upgrade a contiguous mapping in a table to a block. */
PageTableEntry *pte = reinterpret_cast<PageTableEntry *>(util::AlignDown(reinterpret_cast<uintptr_t>(context->level_entries[context->level]), BlocksPerTable * sizeof(PageTableEntry)));
const KPhysicalAddress phys_addr = GetBlock(pte, context->level);
/* First, check that all entries are valid for us to merge. */
const u64 entry_template = pte->GetEntryTemplateForMerge();
for (size_t i = 0; i < BlocksPerTable; ++i) {
if (!pte[i].IsForMerge(entry_template | GetInteger(phys_addr + (i << (PageBits + LevelBits * context->level))) | PageTableEntry::ContigType_Contiguous | pte->GetTestTableMask())) {
return false;
}
if (i > 0 && pte[i].IsHeadOrHeadAndBodyMergeDisabled()) {
return false;
}
if (i < BlocksPerTable - 1 && pte[i].IsTailMergeDisabled()) {
return false;
}
}
/* The entries are valid for us to merge, so merge them. */
const auto *head_pte = pte;
const auto *tail_pte = pte + BlocksPerTable - 1;
const auto sw_reserved_bits = PageTableEntry::EncodeSoftwareReservedBits(head_pte->IsHeadMergeDisabled(), head_pte->IsHeadAndBodyMergeDisabled(), tail_pte->IsTailMergeDisabled());
*context->level_entries[context->level + 1] = PageTableEntry(PageTableEntry::BlockTag{}, phys_addr, PageTableEntry(entry_template), sw_reserved_bits, false, false);
/* Update our context. */
context->is_contiguous = false;
context->level = static_cast<EntryLevel>(util::ToUnderlying(context->level) + 1);
/* Set the output to the table we just freed. */
*out = KVirtualAddress(pte);
} else {
/* We want to upgrade a non-contiguous mapping to a contiguous mapping. */
PageTableEntry *pte = reinterpret_cast<PageTableEntry *>(util::AlignDown(reinterpret_cast<uintptr_t>(context->level_entries[context->level]), BlocksPerContiguousBlock * sizeof(PageTableEntry)));
const KPhysicalAddress phys_addr = GetBlock(pte, context->level);
/* First, check that all entries are valid for us to merge. */
const u64 entry_template = pte->GetEntryTemplateForMerge();
for (size_t i = 0; i < BlocksPerContiguousBlock; ++i) {
if (!pte[i].IsForMerge(entry_template | GetInteger(phys_addr + (i << (PageBits + LevelBits * context->level))) | pte->GetTestTableMask())) {
return false;
}
if (i > 0 && pte[i].IsHeadOrHeadAndBodyMergeDisabled()) {
return false;
}
if (i < BlocksPerContiguousBlock - 1 && pte[i].IsTailMergeDisabled()) {
return false;
}
}
/* The entries are valid for us to merge, so merge them. */
const auto *head_pte = pte;
const auto *tail_pte = pte + BlocksPerContiguousBlock - 1;
const auto sw_reserved_bits = PageTableEntry::EncodeSoftwareReservedBits(head_pte->IsHeadMergeDisabled(), head_pte->IsHeadAndBodyMergeDisabled(), tail_pte->IsTailMergeDisabled());
for (size_t i = 0; i < BlocksPerContiguousBlock; ++i) {
pte[i] = PageTableEntry(PageTableEntry::BlockTag{}, phys_addr + (i << (PageBits + LevelBits * context->level)), PageTableEntry(entry_template), sw_reserved_bits, true, context->level == EntryLevel_L3);
}
/* Update our context. */
context->level_entries[context->level] = pte;
context->is_contiguous = true;
}
return true;
}
void KPageTableImpl::SeparatePages(TraversalEntry *entry, TraversalContext *context, KProcessAddress address, PageTableEntry *pte) const {