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kern: allocate all TTBR0 pages during init, use procidx as asid

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Michael Scire 2024-10-09 14:04:15 -07:00 • committed by SciresM
parent c3fa42d958
commit a72e39d657
9 changed files with 72 additions and 110 deletions
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103
libraries/libmesosphere/source/arch/arm64/kern_k_page_table.cpp
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@ -85,77 +85,6 @@ namespace ams::kern::arch::arm64 {
return (static_cast<u64>(asid) << 48) | (static_cast<u64>(GetInteger(table)));
}
class KPageTableAsidManager {
private:
using WordType = u32;
static constexpr u8 ReservedAsids[] = { 0 };
static constexpr size_t NumReservedAsids = util::size(ReservedAsids);
static constexpr size_t BitsPerWord = BITSIZEOF(WordType);
static constexpr size_t AsidCount = 0x100;
static constexpr size_t NumWords = AsidCount / BitsPerWord;
static constexpr WordType FullWord = ~WordType(0u);
private:
WordType m_state[NumWords];
KLightLock m_lock;
u8 m_hint;
private:
constexpr bool TestImpl(u8 asid) const {
return m_state[asid / BitsPerWord] & (1u << (asid % BitsPerWord));
}
constexpr void ReserveImpl(u8 asid) {
MESOSPHERE_ASSERT(!this->TestImpl(asid));
m_state[asid / BitsPerWord] |= (1u << (asid % BitsPerWord));
}
constexpr void ReleaseImpl(u8 asid) {
MESOSPHERE_ASSERT(this->TestImpl(asid));
m_state[asid / BitsPerWord] &= ~(1u << (asid % BitsPerWord));
}
constexpr u8 FindAvailable() const {
for (size_t i = 0; i < util::size(m_state); i++) {
if (m_state[i] == FullWord) {
continue;
}
const WordType clear_bit = (m_state[i] + 1) ^ (m_state[i]);
return BitsPerWord * i + BitsPerWord - 1 - ClearLeadingZero(clear_bit);
}
if (m_state[util::size(m_state)-1] == FullWord) {
MESOSPHERE_PANIC("Unable to reserve ASID");
}
__builtin_unreachable();
}
static constexpr ALWAYS_INLINE WordType ClearLeadingZero(WordType value) {
return __builtin_clzll(value) - (BITSIZEOF(unsigned long long) - BITSIZEOF(WordType));
}
public:
constexpr KPageTableAsidManager() : m_state(), m_lock(), m_hint() {
for (size_t i = 0; i < NumReservedAsids; i++) {
this->ReserveImpl(ReservedAsids[i]);
}
}
u8 Reserve() {
KScopedLightLock lk(m_lock);
if (this->TestImpl(m_hint)) {
m_hint = this->FindAvailable();
}
this->ReserveImpl(m_hint);
return m_hint++;
}
void Release(u8 asid) {
KScopedLightLock lk(m_lock);
this->ReleaseImpl(asid);
}
};
KPageTableAsidManager g_asid_manager;
}
ALWAYS_INLINE void KPageTable::NoteUpdated() const {
@ -184,6 +113,7 @@ namespace ams::kern::arch::arm64 {
this->OnKernelTableSinglePageUpdated(virt_addr);
}
void KPageTable::Initialize(s32 core_id) {
/* Nothing actually needed here. */
MESOSPHERE_UNUSED(core_id);
@ -194,38 +124,29 @@ namespace ams::kern::arch::arm64 {
m_asid = 0;
m_manager = Kernel::GetSystemSystemResource().GetPageTableManagerPointer();
/* Allocate a page for ttbr. */
/* NOTE: It is a postcondition of page table manager allocation that the page is all-zero. */
const u64 asid_tag = (static_cast<u64>(m_asid) << 48ul);
const KVirtualAddress page = m_manager->Allocate();
MESOSPHERE_ASSERT(page != Null<KVirtualAddress>);
m_ttbr = GetInteger(KPageTableBase::GetLinearMappedPhysicalAddress(page)) | asid_tag;
/* Initialize the base page table. */
MESOSPHERE_R_ABORT_UNLESS(KPageTableBase::InitializeForKernel(true, table, start, end));
R_SUCCEED();
}
Result KPageTable::InitializeForProcess(ams::svc::CreateProcessFlag flags, bool from_back, KMemoryManager::Pool pool, KProcessAddress code_address, size_t code_size, KSystemResource *system_resource, KResourceLimit *resource_limit) {
/* Get an ASID */
m_asid = g_asid_manager.Reserve();
ON_RESULT_FAILURE { g_asid_manager.Release(m_asid); };
Result KPageTable::InitializeForProcess(ams::svc::CreateProcessFlag flags, bool from_back, KMemoryManager::Pool pool, KProcessAddress code_address, size_t code_size, KSystemResource *system_resource, KResourceLimit *resource_limit, size_t process_index) {
/* Determine our ASID */
m_asid = process_index + 1;
MESOSPHERE_ABORT_UNLESS(0 < m_asid && m_asid < util::size(s_ttbr0_entries));
/* Set our manager. */
m_manager = system_resource->GetPageTableManagerPointer();
/* Allocate a new table, and set our ttbr value. */
const KVirtualAddress new_table = m_manager->Allocate();
R_UNLESS(new_table != Null<KVirtualAddress>, svc::ResultOutOfResource());
m_ttbr = EncodeTtbr(GetPageTablePhysicalAddress(new_table), m_asid);
ON_RESULT_FAILURE_2 { m_manager->Free(new_table); };
/* Get the virtual address of our L1 table. */
const KPhysicalAddress ttbr0_phys = KPhysicalAddress(s_ttbr0_entries[m_asid] & UINT64_C(0xFFFFFFFFFFFE));
const KVirtualAddress ttbr0_virt = KMemoryLayout::GetLinearVirtualAddress(ttbr0_phys);
/* Initialize our base table. */
const size_t as_width = GetAddressSpaceWidth(flags);
const KProcessAddress as_start = 0;
const KProcessAddress as_end = (1ul << as_width);
R_TRY(KPageTableBase::InitializeForProcess(flags, from_back, pool, GetVoidPointer(new_table), as_start, as_end, code_address, code_size, system_resource, resource_limit));
R_TRY(KPageTableBase::InitializeForProcess(flags, from_back, pool, GetVoidPointer(ttbr0_virt), as_start, as_end, code_address, code_size, system_resource, resource_limit));
/* Note that we've updated the table (since we created it). */
this->NoteUpdated();
@ -329,20 +250,16 @@ namespace ams::kern::arch::arm64 {
}
}
/* Free the L1 table. */
/* Clear the L1 table. */
{
const KVirtualAddress l1_table = reinterpret_cast<uintptr_t>(impl.Finalize());
ClearPageTable(l1_table);
this->GetPageTableManager().Free(l1_table);
}
/* Perform inherited finalization. */
KPageTableBase::Finalize();
}
/* Release our asid. */
g_asid_manager.Release(m_asid);
R_SUCCEED();
}