/*
* Copyright (c) 2012, 2014, 2017-2019 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.
*
* Copyright (c) 2002-2005 The Regents of The University of Michigan
* All rights reserved.
*
* 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: Nathan Binkert
* Steve Reinhardt
* Andreas Hansson
*/
#ifndef __BASE_ADDR_RANGE_HH__
#define __BASE_ADDR_RANGE_HH__
#include <algorithm>
#include <list>
#include <vector>
#include "base/bitfield.hh"
#include "base/cprintf.hh"
#include "base/logging.hh"
#include "base/types.hh"
/**
* The AddrRange class encapsulates an address range, and supports a
* number of tests to check if two ranges intersect, if a range
* contains a specific address etc. Besides a basic range, the
* AddrRange also support interleaved ranges, to stripe across cache
* banks, or memory controllers. The interleaving is implemented by
* allowing a number of bits of the address, at an arbitrary bit
* position, to be used as interleaving bits with an associated
* matching value. In addition, to prevent uniformly strided address
* patterns from a very biased interleaving, we also allow XOR-based
* hashing by specifying a set of bits to XOR with before matching.
*
* The AddrRange is also able to coalesce a number of interleaved
* ranges to a contiguous range.
*/
class AddrRange
{
private:
/// Private fields for the start and end of the range
/// _start is the beginning of the range (inclusive).
/// _end is not part of the range.
Addr _start;
Addr _end;
/**
* Each mask determines the bits we need to xor to get one bit of
* sel. The first (0) mask is used to get the LSB and the last for
* the MSB of sel.
*/
std::vector<Addr> masks;
/** The value to compare sel with. */
uint8_t intlvMatch;
public:
AddrRange()
: _start(1), _end(0), intlvMatch(0)
{}
/**
* Construct an address range
*
* If the user provides a non empty vector of masks then the
* address range is interleaved. Each mask determines a set of
* bits that are xored to determine one bit of the sel value,
* starting from the least significant bit (i.e., masks[0]
* determines the least significant bit of sel, ...). If sel
* matches the provided _intlv_match then the address a is in the
* range.
*
* For example if the input mask is
* _masks = { 1 << 8 | 1 << 11 | 1 << 13,
* 1 << 15 | 1 << 17 | 1 << 19}
*
* Then a belongs to the address range if
* _start <= a < _end
* and
* sel == _intlv_match
* where
* sel[0] = a[8] ^ a[11] ^ a[13]
* sel[1] = a[15] ^ a[17] ^ a[19]
*
* @param _start The start address of this range
* @param _end The end address of this range (not included in the range)
* @param _masks The input vector of masks
* @param intlv_match The matching value of the xor operations
*/
AddrRange(Addr _start, Addr _end, const std::vector<Addr> &_masks,
uint8_t _intlv_match)
: _start(_start), _end(_end), masks(_masks),
intlvMatch(_intlv_match)
{
// sanity checks
fatal_if(!masks.empty() && _intlv_match >= ULL(1) << masks.size(),
"Match value %d does not fit in %d interleaving bits\n",
_intlv_match, masks.size());
}
/**
* Legacy constructor of AddrRange
*
* If the user provides a non-zero value in _intlv_high_bit the
* address range is interleaved.
*
* An address a belongs to the address range if
* _start <= a < _end
* and
* sel == _intlv_match
* where
* sel = sel1 ^ sel2
* sel1 = a[_intlv_low_bit:_intlv_high_bit]
* sel2 = a[_xor_low_bit:_xor_high_bit]
* _intlv_low_bit = _intlv_high_bit - intv_bits
* _xor_low_bit = _xor_high_bit - intv_bits
*
* @param _start The start address of this range
* @param _end The end address of this range (not included in the range)
* @param _intlv_high_bit The MSB of the intlv bits (disabled if 0)
* @param _xor_high_bit The MSB of the xor bit (disabled if 0)
* @param _intlv_bits the size, in bits, of the intlv and xor bits
* @param intlv_match The matching value of the xor operations
*/
AddrRange(Addr _start, Addr _end, uint8_t _intlv_high_bit,
uint8_t _xor_high_bit, uint8_t _intlv_bits,
uint8_t _intlv_match)
: _start(_start), _end(_end), masks(_intlv_bits),
intlvMatch(_intlv_match)
{
// sanity checks
fatal_if(_intlv_bits && _intlv_match >= ULL(1) << _intlv_bits,
"Match value %d does not fit in %d interleaving bits\n",
_intlv_match, _intlv_bits);
// ignore the XOR bits if not interleaving
if (_intlv_bits && _xor_high_bit) {
if (_xor_high_bit == _intlv_high_bit) {
fatal("XOR and interleave high bit must be different\n");
} else if (_xor_high_bit > _intlv_high_bit) {
if ((_xor_high_bit - _intlv_high_bit) < _intlv_bits)
fatal("XOR and interleave high bit must be at least "
"%d bits apart\n", _intlv_bits);
} else {
if ((_intlv_high_bit - _xor_high_bit) < _intlv_bits) {
fatal("Interleave and XOR high bit must be at least "
"%d bits apart\n", _intlv_bits);
}
}
}
for (auto i = 0; i < _intlv_bits; i++) {
uint8_t bit1 = _intlv_high_bit - i;
Addr mask = (1ULL << bit1);
if (_xor_high_bit) {
uint8_t bit2 = _xor_high_bit - i;
mask |= (1ULL << bit2);
}
masks[_intlv_bits - i - 1] = mask;
}
}
AddrRange(Addr _start, Addr _end)
: _start(_start), _end(_end), intlvMatch(0)
{}
/**
* Create an address range by merging a collection of interleaved
* ranges.
*
* @param ranges Interleaved ranges to be merged
*/
AddrRange(const std::vector<AddrRange>& ranges)
: _start(1), _end(0), intlvMatch(0)
{
if (!ranges.empty()) {
// get the values from the first one and check the others
_start = ranges.front()._start;
_end = ranges.front()._end;
masks = ranges.front().masks;
intlvMatch = ranges.front().intlvMatch;
}
// either merge if got all ranges or keep this equal to the single
// interleaved range
if (ranges.size() > 1) {
if (ranges.size() != (ULL(1) << masks.size()))
fatal("Got %d ranges spanning %d interleaving bits\n",
ranges.size(), masks.size());
uint8_t match = 0;
for (const auto& r : ranges) {
if (!mergesWith(r))
fatal("Can only merge ranges with the same start, end "
"and interleaving bits, %s %s\n", to_string(),
r.to_string());
if (r.intlvMatch != match)
fatal("Expected interleave match %d but got %d when "
"merging\n", match, r.intlvMatch);
++match;
}
masks.clear();
intlvMatch = 0;
}
}
/**
* Determine if the range is interleaved or not.
*
* @return true if interleaved
*/
bool interleaved() const { return masks.size() > 0; }
/**
* Determing the interleaving granularity of the range.
*
* @return The size of the regions created by the interleaving bits
*/
uint64_t granularity() const
{
if (interleaved()) {
auto combined_mask = 0;
for (auto mask: masks) {
combined_mask |= mask;
}
const uint8_t lowest_bit = ctz64(combined_mask);
return ULL(1) << lowest_bit;
} else {
return size();
}
}
/**
* Determine the number of interleaved address stripes this range
* is part of.
*
* @return The number of stripes spanned by the interleaving bits
*/
uint32_t stripes() const { return ULL(1) << masks.size(); }
/**
* Get the size of the address range. For a case where
* interleaving is used we make the simplifying assumption that
* the size is a divisible by the size of the interleaving slice.
*/
Addr size() const
{
return (_end - _start) >> masks.size();
}
/**
* Determine if the range is valid.
*/
bool valid() const { return _start <= _end; }
/**
* Get the start address of the range.
*/
Addr start() const { return _start; }
/**
* Get the end address of the range.
*/
Addr end() const { return _end; }
/**
* Get a string representation of the range. This could
* alternatively be implemented as a operator<<, but at the moment
* that seems like overkill.
*/
std::string to_string() const
{
if (interleaved()) {
std::string str;
for (int i = 0; i < masks.size(); i++) {
str += " ";
Addr mask = masks[i];
while (mask) {
auto bit = ctz64(mask);
mask &= ~(1ULL << bit);
str += csprintf("a[%d]^", bit);
}
str += csprintf("\b=%d", bits(intlvMatch, i));
}
return csprintf("[%#llx:%#llx]%s", _start, _end, str);
} else {
return csprintf("[%#llx:%#llx]", _start, _end);
}
}
/**
* Determine if another range merges with the current one, i.e. if
* they are part of the same contigous range and have the same
* interleaving bits.
*
* @param r Range to evaluate merging with
* @return true if the two ranges would merge
*/
bool mergesWith(const AddrRange& r) const
{
return r._start == _start && r._end == _end &&
r.masks == masks;
}
/**
* Determine if another range intersects this one, i.e. if there
* is an address that is both in this range and the other
* range. No check is made to ensure either range is valid.
*
* @param r Range to intersect with
* @return true if the intersection of the two ranges is not empty
*/
bool intersects(const AddrRange& r) const
{
if (_start >= r._end || _end <= r._start)
// start with the simple case of no overlap at all,
// applicable even if we have interleaved ranges
return false;
else if (!interleaved() && !r.interleaved())
// if neither range is interleaved, we are done
return true;
// now it gets complicated, focus on the cases we care about
if (r.size() == 1)
// keep it simple and check if the address is within
// this range
return contains(r.start());
else if (mergesWith(r))
// restrict the check to ranges that belong to the
// same chunk
return intlvMatch == r.intlvMatch;
else
panic("Cannot test intersection of %s and %s\n",
to_string(), r.to_string());
}
/**
* Determine if this range is a subset of another range, i.e. if
* every address in this range is also in the other range. No
* check is made to ensure either range is valid.
*
* @param r Range to compare with
* @return true if the this range is a subset of the other one
*/
bool isSubset(const AddrRange& r) const
{
if (interleaved())
panic("Cannot test subset of interleaved range %s\n", to_string());
// This address range is not interleaved and therefore it
// suffices to check the upper bound, the lower bound and
// whether it would fit in a continuous segment of the input
// addr range.
if (r.interleaved()) {
return r.contains(_start) && r.contains(_end) &&
size() <= r.granularity();
} else {
return _start >= r._start && _end <= r._end;
}
}
/**
* Determine if the range contains an address.
*
* @param a Address to compare with
* @return true if the address is in the range
*/
bool contains(const Addr& a) const
{
// check if the address is in the range and if there is either
// no interleaving, or with interleaving also if the selected
// bits from the address match the interleaving value
bool in_range = a >= _start && a < _end;
if (in_range) {
auto sel = 0;
for (int i = 0; i < masks.size(); i++) {
Addr masked = a & masks[i];
// The result of an xor operation is 1 if the number
// of bits set is odd or 0 othersize, thefore it
// suffices to count the number of bits set to
// determine the i-th bit of sel.
sel |= (popCount(masked) % 2) << i;
}
return sel == intlvMatch;
}
return false;
}
/**
* Remove the interleaving bits from an input address.
*
* This function returns a new address in a continous range [
* start, start + size / intlv_bits). We can achieve this by
* discarding the LSB in each mask.
*
* e.g., if the input address is of the form:
* ------------------------------------
* | a_high | x1 | a_mid | x0 | a_low |
* ------------------------------------
* where x0 is the LSB set in masks[0]
* and x1 is the LSB set in masks[1]
*
* this function will return:
* ---------------------------------
* | 0 | a_high | a_mid | a_low |
* ---------------------------------
*
* @param a the input address
* @return the new address
*/
inline Addr removeIntlvBits(Addr a) const
{
// Get the LSB set from each mask
int masks_lsb[masks.size()];
for (int i = 0; i < masks.size(); i++) {
masks_lsb[i] = ctz64(masks[i]);
}
// we need to sort the list of bits we will discard as we
// discard them one by one starting.
std::sort(masks_lsb, masks_lsb + masks.size());
for (int i = 0; i < masks.size(); i++) {
const int intlv_bit = masks_lsb[i];
if (intlv_bit > 0) {
// on every iteration we remove one bit from the input
// address, and therefore the lowest invtl_bit has
// also shifted to the right by i positions.
a = insertBits(a >> 1, intlv_bit - i - 1, 0, a);
} else {
a >>= 1;
}
}
return a;
}
/**
* This method adds the interleaving bits removed by
* removeIntlvBits.
*/
inline Addr addIntlvBits(Addr a) const
{
// Get the LSB set from each mask
int masks_lsb[masks.size()];
for (int i = 0; i < masks.size(); i++) {
masks_lsb[i] = ctz64(masks[i]);
}
// Add bits one-by-one from the LSB side.
std::sort(masks_lsb, masks_lsb + masks.size());
for (int i = 0; i < masks.size(); i++) {
const int intlv_bit = masks_lsb[i];
if (intlv_bit > 0) {
// on every iteration we add one bit from the input
// address, and therefore the lowest invtl_bit has
// also shifted to the left by i positions.
a = insertBits(a << 1, intlv_bit + i - 1, 0, a);
} else {
a <<= 1;
}
}
for (int i = 0; i < masks.size(); i++) {
const int lsb = ctz64(masks[i]);
const Addr intlv_bit = bits(intlvMatch, i);
// Calculate the mask ignoring the LSB
const Addr masked = a & masks[i] & ~(1 << lsb);
// Set the LSB of the mask to whatever satisfies the selector bit
a = insertBits(a, lsb, intlv_bit ^ popCount(masked));
}
return a;
}
/**
* Determine the offset of an address within the range.
*
* This function returns the offset of the given address from the
* starting address discarding any bits that are used for
* interleaving. This way we can convert the input address to a
* new unique address in a continuous range that starts from 0.
*
* @param the input address
* @return the flat offset in the address range
*/
Addr getOffset(const Addr& a) const
{
bool in_range = a >= _start && a < _end;
if (!in_range) {
return MaxAddr;
}
if (interleaved()) {
return removeIntlvBits(a) - removeIntlvBits(_start);
} else {
return a - _start;
}
}
/**
* Less-than operator used to turn an STL map into a binary search
* tree of non-overlapping address ranges.
*
* @param r Range to compare with
* @return true if the start address is less than that of the other range
*/
bool operator<(const AddrRange& r) const
{
if (_start != r._start)
return _start < r._start;
else
// for now assume that the end is also the same, and that
// we are looking at the same interleaving bits
return intlvMatch < r.intlvMatch;
}
bool operator==(const AddrRange& r) const
{
if (_start != r._start) return false;
if (_end != r._end) return false;
if (masks != r.masks) return false;
if (intlvMatch != r.intlvMatch) return false;
return true;
}
bool operator!=(const AddrRange& r) const
{
return !(*this == r);
}
};
/**
* Convenience typedef for a collection of address ranges
*/
typedef std::list<AddrRange> AddrRangeList;
inline AddrRange
RangeEx(Addr start, Addr end)
{ return AddrRange(start, end); }
inline AddrRange
RangeIn(Addr start, Addr end)
{ return AddrRange(start, end + 1); }
inline AddrRange
RangeSize(Addr start, Addr size)
{ return AddrRange(start, start + size); }
#endif // __BASE_ADDR_RANGE_HH__