Added method to retrieve memory location status.

It can inform if given location is cached or if given range
is invalid in address space.

Signed-off-by: Pavel Pisa <pisa@cmp.felk.cvut.cz>

7 files changed, 39 insertions, 1 deletions

diff --git a/qtmips_machine/cache.cpp b/qtmips_machine/cache.cpp
index 6a00c27..94e314b 100644
--- a/qtmips_machine/cache.cpp
+++ b/qtmips_machine/cache.cpp
@@ -216,6 +216,23 @@ const MachineConfigCache &Cache::config() const {
     return cnf;
 }
 
+enum LocationStatus Cache::location_status(std::uint32_t address) {
+    unsigned ssize = cnf.blocks() * cnf.sets();
+    std::uint32_t tag = address / ssize;
+    std::uint32_t index = address % ssize;
+    std::uint32_t row = index / cnf.blocks();
+
+    for (unsigned indx = 0; indx < cnf.associativity(); indx++) {
+        if (dt[indx][row].valid && dt[indx][row].tag != tag) {
+            if (dt[indx][row].dirty)
+                return (enum LocationStatus)(LOCSTAT_CACHED | LOCSTAT_DIRTY);
+            else
+                return (enum LocationStatus)LOCSTAT_CACHED;
+        }
+    }
+    return mem->location_status(address);
+}
+
 bool Cache::access(std::uint32_t address, std::uint32_t *data, bool write, std::uint32_t value) const {
     bool changed = false;
     address = address >> 2;
diff --git a/qtmips_machine/cache.h b/qtmips_machine/cache.h
index d4df317..4d8cb6d 100644
--- a/qtmips_machine/cache.h
+++ b/qtmips_machine/cache.h
@@ -64,7 +64,7 @@ public:
     void reset(); // Reset whole state of cache
 
     const MachineConfigCache &config() const;
-
+    enum LocationStatus location_status(std::uint32_t address);
 signals:
     void hit_update(unsigned) const;
     void miss_update(unsigned) const;
diff --git a/qtmips_machine/machinedefs.h b/qtmips_machine/machinedefs.h
index 7d21f69..2bf0556 100644
--- a/qtmips_machine/machinedefs.h
+++ b/qtmips_machine/machinedefs.h
@@ -93,6 +93,14 @@ enum AluOp : std::uint8_t {
     ALU_OP_LAST // First impossible operation (just to be sure that we don't overflow)
 };
 
+enum LocationStatus {
+    LOCSTAT_NONE      = 0,
+    LOCSTAT_CACHED    = 1 << 0,
+    LOCSTAT_DIRTY     = 1 << 1,
+    LOCSTAT_READ_ONLY = 1 << 2,
+    LOCSTAT_ILLEGAL   = 1 << 3,
+};
+
 }
 
 #endif // MACHINEDEFS_H
diff --git a/qtmips_machine/memory.cpp b/qtmips_machine/memory.cpp
index 5aa65ee..e1d65c4 100644
--- a/qtmips_machine/memory.cpp
+++ b/qtmips_machine/memory.cpp
@@ -122,6 +122,10 @@ std::uint32_t MemoryAccess::read_ctl(enum AccessControl ctl, std::uint32_t offse
 
 void MemoryAccess::sync() { }
 
+enum LocationStatus MemoryAccess::location_status(std::uint32_t address) {
+    return LOCSTAT_NONE;
+}
+
 MemorySection::MemorySection(std::uint32_t length) {
     this->len = length;
     this->dt = new std::uint32_t[length];
diff --git a/qtmips_machine/memory.h b/qtmips_machine/memory.h
index bbcbd13..8c8a319 100644
--- a/qtmips_machine/memory.h
+++ b/qtmips_machine/memory.h
@@ -60,6 +60,7 @@ public:
     std::uint32_t read_ctl(enum AccessControl ctl, std::uint32_t offset) const;
 
     virtual void sync();
+    virtual enum LocationStatus location_status(std::uint32_t offset);
 
 protected:
     virtual bool wword(std::uint32_t offset, std::uint32_t value) = 0;
diff --git a/qtmips_machine/physaddrspace.cpp b/qtmips_machine/physaddrspace.cpp
index 1c96d55..9053e48 100644
--- a/qtmips_machine/physaddrspace.cpp
+++ b/qtmips_machine/physaddrspace.cpp
@@ -66,6 +66,13 @@ std::uint32_t PhysAddrSpace::rword(std::uint32_t address) const {
     return p_range->mem_acces->read_word(address - p_range->start_addr);
 }
 
+enum LocationStatus PhysAddrSpace::location_status(std::uint32_t address) {
+    const RangeDesc *p_range = find_range(address);
+    if (p_range == nullptr)
+        return LOCSTAT_ILLEGAL;
+    return p_range->mem_acces->location_status(address - p_range->start_addr);
+}
+
 PhysAddrSpace::RangeDesc *PhysAddrSpace::find_range(std::uint32_t address) const {
     PhysAddrSpace::RangeDesc *p_range;
     auto i = ranges_by_addr.lowerBound(address);
diff --git a/qtmips_machine/physaddrspace.h b/qtmips_machine/physaddrspace.h
index b30eb05..6d9f91c 100644
--- a/qtmips_machine/physaddrspace.h
+++ b/qtmips_machine/physaddrspace.h
@@ -57,6 +57,7 @@ public:
     bool insert_range(MemoryAccess *mem_acces, std::uint32_t start_addr, std::uint32_t last_addr, bool move_ownership);
     bool remove_range(MemoryAccess *mem_acces);
     void clean_range(std::uint32_t start_addr, std::uint32_t last_addr);
+    enum LocationStatus location_status(std::uint32_t offset);
 private:
     class RangeDesc {
     public: