| /* |
| * Copyright 2019 Google, Inc. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are |
| * met: redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer; |
| * redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution; |
| * neither the name of the copyright holders nor the names of its |
| * contributors may be used to endorse or promote products derived from |
| * this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #ifndef __MEM_BACKDOOR_HH__ |
| #define __MEM_BACKDOOR_HH__ |
| |
| #include <cstdint> |
| #include <functional> |
| #include <memory> |
| |
| #include "base/addr_range.hh" |
| #include "base/callback.hh" |
| |
| namespace gem5 |
| { |
| |
| class MemBackdoor |
| { |
| public: |
| // Callbacks from this back door are set up using a callable which accepts |
| // a const reference to this back door as their only parameter. |
| typedef std::function<void(const MemBackdoor &backdoor)> CbFunction; |
| |
| public: |
| enum Flags |
| { |
| // How data is allowed to be accessed through this backdoor. |
| NoAccess = 0x0, |
| Readable = 0x1, |
| Writeable = 0x2 |
| }; |
| |
| // The range in the guest address space covered by this back door. |
| const AddrRange &range() const { return _range; } |
| void range(const AddrRange &r) { _range = r; } |
| |
| // A pointer to the data accessible through this back door. |
| uint8_t *ptr() const { return _ptr; } |
| void ptr(uint8_t *p) { _ptr = p; } |
| |
| /* |
| * Helper functions to make it easier to set/check particular flags. |
| */ |
| |
| bool readable() const { return _flags & Readable; } |
| void |
| readable(bool r) |
| { |
| if (r) |
| _flags = (Flags)(_flags | Readable); |
| else |
| _flags = (Flags)(_flags & ~Readable); |
| } |
| |
| bool writeable() const { return _flags & Writeable; } |
| void |
| writeable(bool w) |
| { |
| if (w) |
| _flags = (Flags)(_flags | Writeable); |
| else |
| _flags = (Flags)(_flags & ~Writeable); |
| } |
| |
| Flags flags() const { return _flags; } |
| void flags(Flags f) { _flags = f; } |
| |
| MemBackdoor(AddrRange r, uint8_t *p, Flags flags) : |
| _range(r), _ptr(p), _flags(flags) |
| {} |
| |
| MemBackdoor() : MemBackdoor(AddrRange(), nullptr, NoAccess) |
| {} |
| |
| // Set up a callable to be called when this back door is invalidated. This |
| // lets holders update their bookkeeping to remove any references to it, |
| // and/or to propogate that invalidation to other interested parties. |
| void |
| addInvalidationCallback(CbFunction func) |
| { |
| invalidationCallbacks.push_back([this,func](){ func(*this); }); |
| } |
| |
| // Notify and clear invalidation callbacks when the data in the backdoor |
| // structure is no longer valid/current. The backdoor might then be |
| // updated or even deleted without having to worry about stale data being |
| // used. |
| void |
| invalidate() |
| { |
| invalidationCallbacks.process(); |
| invalidationCallbacks.clear(); |
| } |
| |
| private: |
| CallbackQueue invalidationCallbacks; |
| |
| AddrRange _range; |
| uint8_t *_ptr; |
| Flags _flags; |
| }; |
| |
| typedef MemBackdoor *MemBackdoorPtr; |
| |
| class MemBackdoorReq |
| { |
| private: |
| AddrRange _range; |
| MemBackdoor::Flags _flags; |
| |
| public: |
| MemBackdoorReq(AddrRange r, MemBackdoor::Flags new_flags) : |
| _range(r), _flags(new_flags) |
| {} |
| |
| const AddrRange &range() const { return _range; } |
| |
| bool readable() const { return _flags & MemBackdoor::Readable; } |
| bool writeable() const { return _flags & MemBackdoor::Writeable; } |
| |
| MemBackdoor::Flags flags() const { return _flags; } |
| }; |
| |
| } // namespace gem5 |
| |
| #endif //__MEM_BACKDOOR_HH__ |