+FORCEINLINE
+ULONG
+Fast486GetPageTableEntry(PFAST486_STATE State,
+ ULONG VirtualAddress,
+ BOOLEAN MarkAsDirty)
+{
+ ULONG PdeIndex = GET_ADDR_PDE(VirtualAddress);
+ ULONG PteIndex = GET_ADDR_PTE(VirtualAddress);
+ FAST486_PAGE_DIR DirectoryEntry;
+ FAST486_PAGE_TABLE TableEntry;
+ ULONG PageDirectory = State->ControlRegisters[FAST486_REG_CR3];
+
+ if ((State->Tlb != NULL)
+ && (State->Tlb[VirtualAddress >> 12] != INVALID_TLB_FIELD))
+ {
+ /* Return the cached entry */
+ return State->Tlb[VirtualAddress >> 12];
+ }
+
+ /* Read the directory entry */
+ State->MemReadCallback(State,
+ PageDirectory + PdeIndex * sizeof(ULONG),
+ &DirectoryEntry.Value,
+ sizeof(DirectoryEntry));
+
+ /* Make sure it is present */
+ if (!DirectoryEntry.Present) return 0;
+
+ /* Was the directory entry accessed before? */
+ if (!DirectoryEntry.Accessed)
+ {
+ /* Well, it is now */
+ DirectoryEntry.Accessed = TRUE;
+
+ /* Write back the directory entry */
+ State->MemWriteCallback(State,
+ PageDirectory + PdeIndex * sizeof(ULONG),
+ &DirectoryEntry.Value,
+ sizeof(DirectoryEntry));
+ }
+
+ /* Read the table entry */
+ State->MemReadCallback(State,
+ (DirectoryEntry.TableAddress << 12)
+ + PteIndex * sizeof(ULONG),
+ &TableEntry.Value,
+ sizeof(TableEntry));
+
+ /* Make sure it is present */
+ if (!TableEntry.Present) return 0;
+
+ if (MarkAsDirty) TableEntry.Dirty = TRUE;
+
+ /* Was the table entry accessed before? */
+ if (!TableEntry.Accessed)
+ {
+ /* Well, it is now */
+ TableEntry.Accessed = TRUE;
+
+ /* Write back the table entry */
+ State->MemWriteCallback(State,
+ (DirectoryEntry.TableAddress << 12)
+ + PteIndex * sizeof(ULONG),
+ &TableEntry.Value,
+ sizeof(TableEntry));
+ }
+
+ /*
+ * The resulting permissions depend on the permissions
+ * in the page directory table too
+ */
+ TableEntry.Writeable &= DirectoryEntry.Writeable;
+ TableEntry.Usermode &= DirectoryEntry.Usermode;
+
+ if (State->Tlb != NULL)
+ {
+ /* Set the TLB entry */
+ State->Tlb[VirtualAddress >> 12] = TableEntry.Value;
+ }
+
+ /* Return the table entry */
+ return TableEntry.Value;
+}
+
+FORCEINLINE
+BOOLEAN
+Fast486ReadLinearMemory(PFAST486_STATE State,
+ ULONG LinearAddress,
+ PVOID Buffer,
+ ULONG Size)
+{
+ INT Cpl = Fast486GetCurrentPrivLevel(State);
+
+ /* Check if paging is enabled */
+ if (State->ControlRegisters[FAST486_REG_CR0] & FAST486_CR0_PG)
+ {
+ ULONG Page;
+ FAST486_PAGE_TABLE TableEntry;
+
+ for (Page = PAGE_ALIGN(LinearAddress);
+ Page <= PAGE_ALIGN(LinearAddress + Size - 1);
+ Page += PAGE_SIZE)
+ {
+ ULONG PageOffset = 0, PageLength = PAGE_SIZE;
+
+ /* Get the table entry */
+ TableEntry.Value = Fast486GetPageTableEntry(State, Page, FALSE);
+
+ if (!TableEntry.Present || (!TableEntry.Usermode && (Cpl > 0)))
+ {
+ /* Exception */
+ Fast486ExceptionWithErrorCode(State,
+ FAST486_EXCEPTION_PF,
+ TableEntry.Value & 0x07);
+ return FALSE;
+ }
+
+ /* Check if this is the first page */
+ if (Page == PAGE_ALIGN(LinearAddress))
+ {
+ /* Start copying from the offset from the beginning of the page */
+ PageOffset = PAGE_OFFSET(LinearAddress);
+ }
+
+ /* Check if this is the last page */
+ if (Page == PAGE_ALIGN(LinearAddress + Size - 1))
+ {
+ /* Copy only a part of the page */
+ PageLength = PAGE_OFFSET(LinearAddress + Size);
+ }
+
+ /* Read the memory */
+ State->MemReadCallback(State,
+ (TableEntry.Address << 12) | PageOffset,
+ Buffer,
+ PageLength);
+ }
+ }
+ else
+ {
+ /* Read the memory */
+ State->MemReadCallback(State, LinearAddress, Buffer, Size);
+ }
+
+ return TRUE;
+}
+
+FORCEINLINE
+BOOLEAN
+Fast486WriteLinearMemory(PFAST486_STATE State,
+ ULONG LinearAddress,
+ PVOID Buffer,
+ ULONG Size)
+{
+ INT Cpl = Fast486GetCurrentPrivLevel(State);
+
+ /* Check if paging is enabled */
+ if (State->ControlRegisters[FAST486_REG_CR0] & FAST486_CR0_PG)
+ {
+ ULONG Page;
+ FAST486_PAGE_TABLE TableEntry;
+
+ for (Page = PAGE_ALIGN(LinearAddress);
+ Page <= PAGE_ALIGN(LinearAddress + Size - 1);
+ Page += PAGE_SIZE)
+ {
+ ULONG PageOffset = 0, PageLength = PAGE_SIZE;
+
+ /* Get the table entry */
+ TableEntry.Value = Fast486GetPageTableEntry(State, Page, TRUE);
+
+ if ((!TableEntry.Present || (!TableEntry.Usermode && (Cpl > 0)))
+ || ((State->ControlRegisters[FAST486_REG_CR0] & FAST486_CR0_WP)
+ && !TableEntry.Writeable))
+ {
+ /* Exception */
+ Fast486ExceptionWithErrorCode(State,
+ FAST486_EXCEPTION_PF,
+ TableEntry.Value & 0x07);
+ return FALSE;
+ }
+
+ /* Check if this is the first page */
+ if (Page == PAGE_ALIGN(LinearAddress))
+ {
+ /* Start copying from the offset from the beginning of the page */
+ PageOffset = PAGE_OFFSET(LinearAddress);
+ }
+
+ /* Check if this is the last page */
+ if (Page == PAGE_ALIGN(LinearAddress + Size - 1))
+ {
+ /* Copy only a part of the page */
+ PageLength = PAGE_OFFSET(LinearAddress + Size);
+ }
+
+ /* Write the memory */
+ State->MemWriteCallback(State,
+ (TableEntry.Address << 12) | PageOffset,
+ Buffer,
+ PageLength);
+ }
+ }
+ else
+ {
+ /* Write the memory */
+ State->MemWriteCallback(State, LinearAddress, Buffer, Size);
+ }
+
+ return TRUE;
+}
+
projects / reactos.git / commitdiff