base: Add classes that encapsulate a channel address

There are cases where the memory system needs to reason about
channel-local addresses. These are currently represented using the
Addr and AddrRange classes. This is not ideal since it doesn't provide
any type safety when working with global addresses and channel-local
addresses. This is particularly problematic when porting existing
components to work in multi-channel configurations.

This changeset introduces the new ChannelAddr and ChannelAddrRange
classes. These classes encapsulate channel-local addresses in a
contiguous address space. These can, for example, be used in a memory
controller to represent a flat address space when calculating timings
or in a sectored cache.

Change-Id: I45d4061ebc8507a10d0a4577b28796dc5ec7a469
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/21600
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>

1 files changed, 193 insertions, 0 deletions

diff --git a/src/base/channel_addr.hh b/src/base/channel_addr.hh
new file mode 100644
index 000000000..abb01be59
--- /dev/null
+++ b/src/base/channel_addr.hh
@@ -0,0 +1,193 @@
+/*
+ * Copyright (c) 2019 ARM Limited
+ * All rights reserved
+ *
+ * The license below extends only to copyright in the software and shall
+ * not be construed as granting a license to any other intellectual
+ * property including but not limited to intellectual property relating
+ * to a hardware implementation of the functionality of the software
+ * licensed hereunder.  You may use the software subject to the license
+ * terms below provided that you ensure that this notice is replicated
+ * unmodified and in its entirety in all distributions of the software,
+ * modified or unmodified, in source code or in binary form.
+ *
+ * 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.
+ *
+ * Authors: Andreas Sandberg
+ */
+
+#ifndef __BASE_CHANNEL_ADDR_HH__
+#define __BASE_CHANNEL_ADDR_HH__
+
+#include <ostream>
+
+#include "base/addr_range.hh"
+
+/**
+ * Class holding a guest address in a contiguous channel-local address
+ * space.
+ */
+class ChannelAddr
+{
+  public:
+    using Type = Addr;
+
+    /** Explicit constructor assigning a value. */
+    explicit constexpr ChannelAddr(Type _a) : a(_a) { }
+
+    /** Converting back to the value type. */
+    explicit constexpr operator Type() const { return a; }
+
+    /** Converting back to the value type. */
+    constexpr Type value() const { return a; }
+
+    constexpr ChannelAddr() : a(0) { }
+
+    ChannelAddr(const AddrRange &range, Addr _a)
+        : a(range.removeIntlvBits(_a)) {}
+
+    ChannelAddr(const ChannelAddr &) = default;
+    ChannelAddr &operator=(const ChannelAddr &) = default;
+
+
+    Addr getPA(const AddrRange &range) const {
+        return range.addIntlvBits(a);
+    }
+
+    constexpr ChannelAddr operator|(const Type b) const {
+        return ChannelAddr(a | b);
+    }
+    constexpr ChannelAddr operator&(const Type b) const {
+        return ChannelAddr(a & b);
+    }
+
+    constexpr ChannelAddr operator>>(const int b) const {
+        return ChannelAddr(a >> b);
+    }
+
+    constexpr ChannelAddr operator<<(const int b) const {
+        return ChannelAddr(a << b);
+    }
+
+    constexpr ChannelAddr operator*(const Type &b) const {
+        return ChannelAddr(a * b);
+    }
+
+    constexpr ChannelAddr operator/(const Type &b) const {
+        return ChannelAddr(a / b);
+    }
+
+    constexpr ChannelAddr operator+(const Type &b) const {
+        return ChannelAddr(a + b);
+    }
+
+    constexpr ChannelAddr operator-(const Type &b) const {
+        return ChannelAddr(a - b);
+    }
+
+    constexpr ChannelAddr operator|(const ChannelAddr &b) const {
+        return ChannelAddr(a | b.a);
+    }
+
+    constexpr ChannelAddr operator&(const ChannelAddr &b) const {
+        return ChannelAddr(a & b.a);
+    }
+
+    constexpr ChannelAddr operator^(const ChannelAddr &b) const {
+        return ChannelAddr(a ^ b.a);
+    }
+
+    constexpr ChannelAddr operator+(const ChannelAddr &b) const {
+        return ChannelAddr(a + b.a);
+    }
+
+    constexpr ChannelAddr operator-(const ChannelAddr &b) const {
+        return ChannelAddr(a - b.a);
+    }
+
+    constexpr bool operator>(const ChannelAddr &b) const { return a > b.a; }
+    constexpr bool operator>=(const ChannelAddr &b) const { return a >= b.a; }
+    constexpr bool operator<(const ChannelAddr &b) const { return a < b.a; }
+    constexpr bool operator<=(const ChannelAddr &b) const { return a <= b.a; }
+    constexpr bool operator==(const ChannelAddr &b) const { return a == b.a; }
+    constexpr bool operator!=(const ChannelAddr &b) const { return a != b.a; }
+
+  private:
+    /** Member holding the actual value. */
+    Type a;
+};
+
+/**
+ * The ChanneelAddrRange class describes a contiguous range of
+ * addresses in a contiguous channel-local address space.
+ */
+class ChannelAddrRange
+{
+  public:
+    constexpr ChannelAddrRange()
+        : ChannelAddrRange(ChannelAddr(1), ChannelAddr(0)) {}
+
+    constexpr ChannelAddrRange(ChannelAddr start, ChannelAddr end)
+        : _start(start), _end(end) {}
+
+    ChannelAddrRange(AddrRange ch_range, Addr start, Addr end);
+    ChannelAddrRange(AddrRange ch_range, AddrRange range);
+
+    constexpr ChannelAddrRange(const ChannelAddrRange &) = default;
+
+    constexpr ChannelAddr size() const { return _end - _start + 1; }
+
+    constexpr bool valid() const { return _start <= _end; }
+
+    constexpr ChannelAddr start() const { return _start; }
+    constexpr ChannelAddr end() const { return _end; }
+
+    constexpr bool contains(ChannelAddr a) const {
+        return a >= _start && a <= _end;
+    }
+
+  protected:
+    ChannelAddr _start;
+    ChannelAddr _end;
+};
+
+namespace std
+{
+    template<>
+    struct hash<ChannelAddr>
+    {
+        typedef ChannelAddr argument_type;
+        typedef std::size_t result_type;
+
+        result_type
+        operator()(argument_type const &a) const noexcept {
+            return std::hash<ChannelAddr::Type>{}(
+                static_cast<argument_type::Type>(a));
+        }
+    };
+}
+
+std::ostream &operator<<(std::ostream &out, const ChannelAddr &addr);
+
+#endif // __BASE_CHANNEL_ADDR_HH__