addr_range.hh revision 14047
1/* 2 * Copyright (c) 2012, 2014, 2017-2019 ARM Limited 3 * All rights reserved 4 * 5 * The license below extends only to copyright in the software and shall 6 * not be construed as granting a license to any other intellectual 7 * property including but not limited to intellectual property relating 8 * to a hardware implementation of the functionality of the software 9 * licensed hereunder. You may use the software subject to the license 10 * terms below provided that you ensure that this notice is replicated 11 * unmodified and in its entirety in all distributions of the software, 12 * modified or unmodified, in source code or in binary form. 13 * 14 * Copyright (c) 2002-2005 The Regents of The University of Michigan 15 * All rights reserved. 16 * 17 * Redistribution and use in source and binary forms, with or without 18 * modification, are permitted provided that the following conditions are 19 * met: redistributions of source code must retain the above copyright 20 * notice, this list of conditions and the following disclaimer; 21 * redistributions in binary form must reproduce the above copyright 22 * notice, this list of conditions and the following disclaimer in the 23 * documentation and/or other materials provided with the distribution; 24 * neither the name of the copyright holders nor the names of its 25 * contributors may be used to endorse or promote products derived from 26 * this software without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 31 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 32 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 33 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 34 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 35 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 36 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 37 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 38 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 39 * 40 * Authors: Nathan Binkert 41 * Steve Reinhardt 42 * Andreas Hansson 43 */ 44 45#ifndef __BASE_ADDR_RANGE_HH__ 46#define __BASE_ADDR_RANGE_HH__ 47 48#include <algorithm> 49#include <list> 50#include <vector> 51 52#include "base/bitfield.hh" 53#include "base/cprintf.hh" 54#include "base/logging.hh" 55#include "base/types.hh" 56 57/** 58 * The AddrRange class encapsulates an address range, and supports a 59 * number of tests to check if two ranges intersect, if a range 60 * contains a specific address etc. Besides a basic range, the 61 * AddrRange also support interleaved ranges, to stripe across cache 62 * banks, or memory controllers. The interleaving is implemented by 63 * allowing a number of bits of the address, at an arbitrary bit 64 * position, to be used as interleaving bits with an associated 65 * matching value. In addition, to prevent uniformly strided address 66 * patterns from a very biased interleaving, we also allow XOR-based 67 * hashing by specifying a set of bits to XOR with before matching. 68 * 69 * The AddrRange is also able to coalesce a number of interleaved 70 * ranges to a contiguous range. 71 */ 72class AddrRange 73{ 74 75 private: 76 77 /// Private fields for the start and end of the range 78 /// Both _start and _end are part of the range. 79 Addr _start; 80 Addr _end; 81 82 /** 83 * Each mask determines the bits we need to xor to get one bit of 84 * sel. The first (0) mask is used to get the LSB and the last for 85 * the MSB of sel. 86 */ 87 std::vector<Addr> masks; 88 89 /** The value to compare sel with. */ 90 uint8_t intlvMatch; 91 92 public: 93 94 AddrRange() 95 : _start(1), _end(0), intlvMatch(0) 96 {} 97 98 /** 99 * Construct an address range 100 * 101 * If the user provides a non empty vector of masks then the 102 * address range is interleaved. Each mask determines a set of 103 * bits that are xored to determine one bit of the sel value, 104 * starting from the least significant bit (i.e., masks[0] 105 * determines the least significant bit of sel, ...). If sel 106 * matches the provided _intlv_match then the address a is in the 107 * range. 108 * 109 * For example if the input mask is 110 * _masks = { 1 << 8 | 1 << 11 | 1 << 13, 111 * 1 << 15 | 1 << 17 | 1 << 19} 112 * 113 * Then a belongs to the address range if 114 * _start <= a < _end 115 * and 116 * sel == _intlv_match 117 * where 118 * sel[0] = a[8] ^ a[11] ^ a[13] 119 * sel[1] = a[15] ^ a[17] ^ a[19] 120 * 121 * @param _start The start address of this range 122 * @param _end The end address of this range (not included in the range) 123 * @param _masks The input vector of masks 124 * @param intlv_math The matching value of the xor operations 125 */ 126 AddrRange(Addr _start, Addr _end, const std::vector<Addr> &_masks, 127 uint8_t _intlv_match) 128 : _start(_start), _end(_end), masks(_masks), 129 intlvMatch(_intlv_match) 130 { 131 // sanity checks 132 fatal_if(!masks.empty() && _intlv_match >= ULL(1) << masks.size(), 133 "Match value %d does not fit in %d interleaving bits\n", 134 _intlv_match, masks.size()); 135 } 136 137 /** 138 * Legacy constructor of AddrRange 139 * 140 * If the user provides a non-zero value in _intlv_high_bit the 141 * address range is interleaved. 142 * 143 * An address a belongs to the address range if 144 * _start <= a < _end 145 * and 146 * sel == _intlv_match 147 * where 148 * sel = sel1 ^ sel2 149 * sel1 = a[_intlv_low_bit:_intlv_high_bit] 150 * sel2 = a[_xor_low_bit:_xor_high_bit] 151 * _intlv_low_bit = _intlv_high_bit - intv_bits 152 * _xor_low_bit = _xor_high_bit - intv_bits 153 * 154 * @param _start The start address of this range 155 * @param _end The end address of this range (not included in the range) 156 * @param _intlv_high_bit The MSB of the intlv bits (disabled if 0) 157 * @param _xor_high_bit The MSB of the xor bit (disabled if 0) 158 * @param intlv_math The matching value of the xor operations 159 */ 160 AddrRange(Addr _start, Addr _end, uint8_t _intlv_high_bit, 161 uint8_t _xor_high_bit, uint8_t _intlv_bits, 162 uint8_t _intlv_match) 163 : _start(_start), _end(_end), masks(_intlv_bits), 164 intlvMatch(_intlv_match) 165 { 166 // sanity checks 167 fatal_if(_intlv_bits && _intlv_match >= ULL(1) << _intlv_bits, 168 "Match value %d does not fit in %d interleaving bits\n", 169 _intlv_match, _intlv_bits); 170 171 // ignore the XOR bits if not interleaving 172 if (_intlv_bits && _xor_high_bit) { 173 if (_xor_high_bit == _intlv_high_bit) { 174 fatal("XOR and interleave high bit must be different\n"); 175 } else if (_xor_high_bit > _intlv_high_bit) { 176 if ((_xor_high_bit - _intlv_high_bit) < _intlv_bits) 177 fatal("XOR and interleave high bit must be at least " 178 "%d bits apart\n", _intlv_bits); 179 } else { 180 if ((_intlv_high_bit - _xor_high_bit) < _intlv_bits) { 181 fatal("Interleave and XOR high bit must be at least " 182 "%d bits apart\n", _intlv_bits); 183 } 184 } 185 } 186 187 for (auto i = 0; i < _intlv_bits; i++) { 188 uint8_t bit1 = _intlv_high_bit - i; 189 Addr mask = (1ULL << bit1); 190 if (_xor_high_bit) { 191 uint8_t bit2 = _xor_high_bit - i; 192 mask |= (1ULL << bit2); 193 } 194 masks[_intlv_bits - i - 1] = mask; 195 } 196 } 197 198 AddrRange(Addr _start, Addr _end) 199 : _start(_start), _end(_end), intlvMatch(0) 200 {} 201 202 /** 203 * Create an address range by merging a collection of interleaved 204 * ranges. 205 * 206 * @param ranges Interleaved ranges to be merged 207 */ 208 AddrRange(const std::vector<AddrRange>& ranges) 209 : _start(1), _end(0), intlvMatch(0) 210 { 211 if (!ranges.empty()) { 212 // get the values from the first one and check the others 213 _start = ranges.front()._start; 214 _end = ranges.front()._end; 215 masks = ranges.front().masks; 216 217 if (ranges.size() != (ULL(1) << masks.size())) 218 fatal("Got %d ranges spanning %d interleaving bits\n", 219 ranges.size(), masks.size()); 220 221 uint8_t match = 0; 222 for (const auto& r : ranges) { 223 if (!mergesWith(r)) 224 fatal("Can only merge ranges with the same start, end " 225 "and interleaving bits, %s %s\n", to_string(), 226 r.to_string()); 227 228 if (r.intlvMatch != match) 229 fatal("Expected interleave match %d but got %d when " 230 "merging\n", match, r.intlvMatch); 231 ++match; 232 } 233 masks.clear(); 234 } 235 } 236 237 /** 238 * Determine if the range is interleaved or not. 239 * 240 * @return true if interleaved 241 */ 242 bool interleaved() const { return masks.size() > 0; } 243 244 /** 245 * Determing the interleaving granularity of the range. 246 * 247 * @return The size of the regions created by the interleaving bits 248 */ 249 uint64_t granularity() const 250 { 251 if (interleaved()) { 252 auto combined_mask = 0; 253 for (auto mask: masks) { 254 combined_mask |= mask; 255 } 256 const uint8_t lowest_bit = ctz64(combined_mask); 257 return ULL(1) << lowest_bit; 258 } else { 259 return size(); 260 } 261 } 262 263 /** 264 * Determine the number of interleaved address stripes this range 265 * is part of. 266 * 267 * @return The number of stripes spanned by the interleaving bits 268 */ 269 uint32_t stripes() const { return ULL(1) << masks.size(); } 270 271 /** 272 * Get the size of the address range. For a case where 273 * interleaving is used we make the simplifying assumption that 274 * the size is a divisible by the size of the interleaving slice. 275 */ 276 Addr size() const 277 { 278 return (_end - _start + 1) >> masks.size(); 279 } 280 281 /** 282 * Determine if the range is valid. 283 */ 284 bool valid() const { return _start <= _end; } 285 286 /** 287 * Get the start address of the range. 288 */ 289 Addr start() const { return _start; } 290 291 /** 292 * Get the end address of the range. 293 */ 294 Addr end() const { return _end; } 295 296 /** 297 * Get a string representation of the range. This could 298 * alternatively be implemented as a operator<<, but at the moment 299 * that seems like overkill. 300 */ 301 std::string to_string() const 302 { 303 if (interleaved()) { 304 std::string str; 305 for (int i = 0; i < masks.size(); i++) { 306 str += " "; 307 Addr mask = masks[i]; 308 while (mask) { 309 auto bit = ctz64(mask); 310 mask &= ~(1ULL << bit); 311 str += csprintf("a[%d]^", bit); 312 } 313 str += csprintf("\b=%d", bits(intlvMatch, i)); 314 } 315 return csprintf("[%#llx:%#llx]%s", _start, _end, str); 316 } else { 317 return csprintf("[%#llx:%#llx]", _start, _end); 318 } 319 } 320 321 /** 322 * Determine if another range merges with the current one, i.e. if 323 * they are part of the same contigous range and have the same 324 * interleaving bits. 325 * 326 * @param r Range to evaluate merging with 327 * @return true if the two ranges would merge 328 */ 329 bool mergesWith(const AddrRange& r) const 330 { 331 return r._start == _start && r._end == _end && 332 r.masks == masks; 333 } 334 335 /** 336 * Determine if another range intersects this one, i.e. if there 337 * is an address that is both in this range and the other 338 * range. No check is made to ensure either range is valid. 339 * 340 * @param r Range to intersect with 341 * @return true if the intersection of the two ranges is not empty 342 */ 343 bool intersects(const AddrRange& r) const 344 { 345 if (_start > r._end || _end < r._start) 346 // start with the simple case of no overlap at all, 347 // applicable even if we have interleaved ranges 348 return false; 349 else if (!interleaved() && !r.interleaved()) 350 // if neither range is interleaved, we are done 351 return true; 352 353 // now it gets complicated, focus on the cases we care about 354 if (r.size() == 1) 355 // keep it simple and check if the address is within 356 // this range 357 return contains(r.start()); 358 else if (mergesWith(r)) 359 // restrict the check to ranges that belong to the 360 // same chunk 361 return intlvMatch == r.intlvMatch; 362 else 363 panic("Cannot test intersection of %s and %s\n", 364 to_string(), r.to_string()); 365 } 366 367 /** 368 * Determine if this range is a subset of another range, i.e. if 369 * every address in this range is also in the other range. No 370 * check is made to ensure either range is valid. 371 * 372 * @param r Range to compare with 373 * @return true if the this range is a subset of the other one 374 */ 375 bool isSubset(const AddrRange& r) const 376 { 377 if (interleaved()) 378 panic("Cannot test subset of interleaved range %s\n", to_string()); 379 380 // This address range is not interleaved and therefore it 381 // suffices to check the upper bound, the lower bound and 382 // whether it would fit in a continuous segment of the input 383 // addr range. 384 if (r.interleaved()) { 385 return r.contains(_start) && r.contains(_end) && 386 size() <= r.granularity(); 387 } else { 388 return _start >= r._start && _end <= r._end; 389 } 390 } 391 392 /** 393 * Determine if the range contains an address. 394 * 395 * @param a Address to compare with 396 * @return true if the address is in the range 397 */ 398 bool contains(const Addr& a) const 399 { 400 // check if the address is in the range and if there is either 401 // no interleaving, or with interleaving also if the selected 402 // bits from the address match the interleaving value 403 bool in_range = a >= _start && a <= _end; 404 if (in_range) { 405 auto sel = 0; 406 for (int i = 0; i < masks.size(); i++) { 407 Addr masked = a & masks[i]; 408 // The result of an xor operation is 1 if the number 409 // of bits set is odd or 0 othersize, thefore it 410 // suffices to count the number of bits set to 411 // determine the i-th bit of sel. 412 sel |= (popCount(masked) % 2) << i; 413 } 414 return sel == intlvMatch; 415 } 416 return false; 417 } 418 419 /** 420 * Remove the interleaving bits from an input address. 421 * 422 * This function returns a new address in a continous range [ 423 * start, start + size / intlv_bits). We can achieve this by 424 * discarding the LSB in each mask. 425 * 426 * e.g., if the input address is of the form: 427 * ------------------------------------ 428 * | a_high | x1 | a_mid | x0 | a_low | 429 * ------------------------------------ 430 * where x0 is the LSB set in masks[0] 431 * and x1 is the LSB set in masks[1] 432 * 433 * this function will return: 434 * --------------------------------- 435 * | 0 | a_high | a_mid | a_low | 436 * --------------------------------- 437 * 438 * @param the input address 439 * @return the new address 440 */ 441 inline Addr removeIntlvBits(Addr a) const 442 { 443 // Get the LSB set from each mask 444 int masks_lsb[masks.size()]; 445 for (int i = 0; i < masks.size(); i++) { 446 masks_lsb[i] = ctz64(masks[i]); 447 } 448 449 // we need to sort the list of bits we will discard as we 450 // discard them one by one starting. 451 std::sort(masks_lsb, masks_lsb + masks.size()); 452 453 for (int i = 0; i < masks.size(); i++) { 454 const int intlv_bit = masks_lsb[i]; 455 if (intlv_bit > 0) { 456 // on every iteration we remove one bit from the input 457 // address, and therefore the lowest invtl_bit has 458 // also shifted to the right by i positions. 459 a = insertBits(a >> 1, intlv_bit - i - 1, 0, a); 460 } else { 461 a >>= 1; 462 } 463 } 464 return a; 465 } 466 467 /** 468 * Determine the offset of an address within the range. 469 * 470 * This function returns the offset of the given address from the 471 * starting address discarding any bits that are used for 472 * interleaving. This way we can convert the input address to a 473 * new unique address in a continuous range that starts from 0. 474 * 475 * @param the input address 476 * @return the flat offset in the address range 477 */ 478 Addr getOffset(const Addr& a) const 479 { 480 bool in_range = a >= _start && a <= _end; 481 if (!in_range) { 482 return MaxAddr; 483 } 484 if (interleaved()) { 485 return removeIntlvBits(a) - removeIntlvBits(_start); 486 } else { 487 return a - _start; 488 } 489 } 490 491 /** 492 * Less-than operator used to turn an STL map into a binary search 493 * tree of non-overlapping address ranges. 494 * 495 * @param r Range to compare with 496 * @return true if the start address is less than that of the other range 497 */ 498 bool operator<(const AddrRange& r) const 499 { 500 if (_start != r._start) 501 return _start < r._start; 502 else 503 // for now assume that the end is also the same, and that 504 // we are looking at the same interleaving bits 505 return intlvMatch < r.intlvMatch; 506 } 507 508 bool operator==(const AddrRange& r) const 509 { 510 if (_start != r._start) return false; 511 if (_end != r._end) return false; 512 if (masks != r.masks) return false; 513 if (intlvMatch != r.intlvMatch) return false; 514 515 return true; 516 } 517 518 bool operator!=(const AddrRange& r) const 519 { 520 return !(*this == r); 521 } 522}; 523 524/** 525 * Convenience typedef for a collection of address ranges 526 */ 527typedef std::list<AddrRange> AddrRangeList; 528 529inline AddrRange 530RangeEx(Addr start, Addr end) 531{ return AddrRange(start, end - 1); } 532 533inline AddrRange 534RangeIn(Addr start, Addr end) 535{ return AddrRange(start, end); } 536 537inline AddrRange 538RangeSize(Addr start, Addr size) 539{ return AddrRange(start, start + size - 1); } 540 541#endif // __BASE_ADDR_RANGE_HH__ 542