table_walker.hh revision 8733
1/* 2 * Copyright (c) 2010 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 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions are 16 * met: redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer; 18 * redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution; 21 * neither the name of the copyright holders nor the names of its 22 * contributors may be used to endorse or promote products derived from 23 * this software without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 26 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 27 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 28 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 29 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 30 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 31 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 35 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 36 * 37 * Authors: Ali Saidi 38 */ 39 40#ifndef __ARCH_ARM_TABLE_WALKER_HH__ 41#define __ARCH_ARM_TABLE_WALKER_HH__ 42 43#include <list> 44 45#include "arch/arm/miscregs.hh" 46#include "arch/arm/tlb.hh" 47#include "mem/mem_object.hh" 48#include "mem/request.hh" 49#include "params/ArmTableWalker.hh" 50#include "sim/eventq.hh" 51#include "sim/fault_fwd.hh" 52 53class DmaPort; 54class ThreadContext; 55 56namespace ArmISA { 57class Translation; 58class TLB; 59 60class TableWalker : public MemObject 61{ 62 public: 63 struct L1Descriptor { 64 /** Type of page table entry ARM DDI 0406B: B3-8*/ 65 enum EntryType { 66 Ignore, 67 PageTable, 68 Section, 69 Reserved 70 }; 71 72 /** The raw bits of the entry */ 73 uint32_t data; 74 75 /** This entry has been modified (access flag set) and needs to be 76 * written back to memory */ 77 bool _dirty; 78 79 EntryType type() const 80 { 81 return (EntryType)(data & 0x3); 82 } 83 84 /** Is the page a Supersection (16MB)?*/ 85 bool supersection() const 86 { 87 return bits(data, 18); 88 } 89 90 /** Return the physcal address of the entry, bits in position*/ 91 Addr paddr() const 92 { 93 if (supersection()) 94 panic("Super sections not implemented\n"); 95 return mbits(data, 31, 20); 96 } 97 /** Return the physcal address of the entry, bits in position*/ 98 Addr paddr(Addr va) const 99 { 100 if (supersection()) 101 panic("Super sections not implemented\n"); 102 return mbits(data, 31, 20) | mbits(va, 19, 0); 103 } 104 105 106 /** Return the physical frame, bits shifted right */ 107 Addr pfn() const 108 { 109 if (supersection()) 110 panic("Super sections not implemented\n"); 111 return bits(data, 31, 20); 112 } 113 114 /** Is the translation global (no asid used)? */ 115 bool global() const 116 { 117 return bits(data, 17); 118 } 119 120 /** Is the translation not allow execution? */ 121 bool xn() const 122 { 123 return bits(data, 4); 124 } 125 126 /** Three bit access protection flags */ 127 uint8_t ap() const 128 { 129 return (bits(data, 15) << 2) | bits(data, 11, 10); 130 } 131 132 /** Domain Client/Manager: ARM DDI 0406B: B3-31 */ 133 uint8_t domain() const 134 { 135 return bits(data, 8, 5); 136 } 137 138 /** Address of L2 descriptor if it exists */ 139 Addr l2Addr() const 140 { 141 return mbits(data, 31, 10); 142 } 143 144 /** Memory region attributes: ARM DDI 0406B: B3-32. 145 * These bits are largly ignored by M5 and only used to 146 * provide the illusion that the memory system cares about 147 * anything but cachable vs. uncachable. 148 */ 149 uint8_t texcb() const 150 { 151 return bits(data, 2) | bits(data, 3) << 1 | bits(data, 14, 12) << 2; 152 } 153 154 /** If the section is shareable. See texcb() comment. */ 155 bool shareable() const 156 { 157 return bits(data, 16); 158 } 159 160 /** Set access flag that this entry has been touched. Mark 161 * the entry as requiring a writeback, in the future. 162 */ 163 void setAp0() 164 { 165 data |= 1 << 10; 166 _dirty = true; 167 } 168 169 /** This entry needs to be written back to memory */ 170 bool dirty() const 171 { 172 return _dirty; 173 } 174 }; 175 176 /** Level 2 page table descriptor */ 177 struct L2Descriptor { 178 179 /** The raw bits of the entry. */ 180 uint32_t data; 181 182 /** This entry has been modified (access flag set) and needs to be 183 * written back to memory */ 184 bool _dirty; 185 186 /** Is the entry invalid */ 187 bool invalid() const 188 { 189 return bits(data, 1, 0) == 0; 190 } 191 192 /** What is the size of the mapping? */ 193 bool large() const 194 { 195 return bits(data, 1) == 0; 196 } 197 198 /** Is execution allowed on this mapping? */ 199 bool xn() const 200 { 201 return large() ? bits(data, 15) : bits(data, 0); 202 } 203 204 /** Is the translation global (no asid used)? */ 205 bool global() const 206 { 207 return !bits(data, 11); 208 } 209 210 /** Three bit access protection flags */ 211 uint8_t ap() const 212 { 213 return bits(data, 5, 4) | (bits(data, 9) << 2); 214 } 215 216 /** Memory region attributes: ARM DDI 0406B: B3-32 */ 217 uint8_t texcb() const 218 { 219 return large() ? 220 (bits(data, 2) | (bits(data, 3) << 1) | (bits(data, 14, 12) << 2)) : 221 (bits(data, 2) | (bits(data, 3) << 1) | (bits(data, 8, 6) << 2)); 222 } 223 224 /** Return the physical frame, bits shifted right */ 225 Addr pfn() const 226 { 227 return large() ? bits(data, 31, 16) : bits(data, 31, 12); 228 } 229 230 /** Return complete physical address given a VA */ 231 Addr paddr(Addr va) const 232 { 233 if (large()) 234 return mbits(data, 31, 16) | mbits(va, 15, 0); 235 else 236 return mbits(data, 31, 12) | mbits(va, 11, 0); 237 } 238 239 /** If the section is shareable. See texcb() comment. */ 240 bool shareable() const 241 { 242 return bits(data, 10); 243 } 244 245 /** Set access flag that this entry has been touched. Mark 246 * the entry as requiring a writeback, in the future. 247 */ 248 void setAp0() 249 { 250 data |= 1 << 4; 251 _dirty = true; 252 } 253 254 /** This entry needs to be written back to memory */ 255 bool dirty() const 256 { 257 return _dirty; 258 } 259 260 }; 261 262 struct WalkerState //: public SimObject 263 { 264 /** Thread context that we're doing the walk for */ 265 ThreadContext *tc; 266 267 /** Request that is currently being serviced */ 268 RequestPtr req; 269 270 /** Context ID that we're servicing the request under */ 271 uint8_t contextId; 272 273 /** Translation state for delayed requests */ 274 TLB::Translation *transState; 275 276 /** The fault that we are going to return */ 277 Fault fault; 278 279 /** The virtual address that is being translated */ 280 Addr vaddr; 281 282 /** Cached copy of the sctlr as it existed when translation began */ 283 SCTLR sctlr; 284 285 /** Width of the base address held in TTRB0 */ 286 uint32_t N; 287 288 /** If the access is a write */ 289 bool isWrite; 290 291 /** If the access is a fetch (for execution, and no-exec) must be checked?*/ 292 bool isFetch; 293 294 /** If the mode is timing or atomic */ 295 bool timing; 296 297 /** If the atomic mode should be functional */ 298 bool functional; 299 300 /** Save mode for use in delayed response */ 301 BaseTLB::Mode mode; 302 303 L1Descriptor l1Desc; 304 L2Descriptor l2Desc; 305 306 /** Whether L1/L2 descriptor response is delayed in timing mode */ 307 bool delayed; 308 309 TableWalker *tableWalker; 310 311 void doL1Descriptor(); 312 void doL2Descriptor(); 313 314 std::string name() const {return tableWalker->name();} 315 }; 316 317 318 /** Queue of requests that need processing first level translation */ 319 std::list<WalkerState *> stateQueueL1; 320 321 /** Queue of requests that have passed first level translation and 322 * require an additional level. */ 323 std::list<WalkerState *> stateQueueL2; 324 325 /** Queue of requests that have passed are waiting because the walker is 326 * currently busy. */ 327 std::list<WalkerState *> pendingQueue;; 328 329 330 /** Port to issue translation requests from */ 331 DmaPort *port; 332 333 /** TLB that is initiating these table walks */ 334 TLB *tlb; 335 336 /** Cached copy of the sctlr as it existed when translation began */ 337 SCTLR sctlr; 338 339 WalkerState *currState; 340 341 /** If a timing translation is currently in progress */ 342 bool pending; 343 344 public: 345 typedef ArmTableWalkerParams Params; 346 TableWalker(const Params *p); 347 virtual ~TableWalker(); 348 349 const Params * 350 params() const 351 { 352 return dynamic_cast<const Params *>(_params); 353 } 354 355 virtual unsigned int drain(Event *de); 356 virtual void resume(); 357 virtual Port *getPort(const std::string &if_name, int idx = -1); 358 359 Fault walk(RequestPtr req, ThreadContext *tc, uint8_t cid, TLB::Mode mode, 360 TLB::Translation *_trans, bool timing, bool functional = false); 361 362 void setTlb(TLB *_tlb) { tlb = _tlb; } 363 void memAttrs(ThreadContext *tc, TlbEntry &te, SCTLR sctlr, 364 uint8_t texcb, bool s); 365 366 private: 367 368 void doL1Descriptor(); 369 void doL1DescriptorWrapper(); 370 EventWrapper<TableWalker, &TableWalker::doL1DescriptorWrapper> doL1DescEvent; 371 372 void doL2Descriptor(); 373 void doL2DescriptorWrapper(); 374 EventWrapper<TableWalker, &TableWalker::doL2DescriptorWrapper> doL2DescEvent; 375 376 Fault processWalk(); 377 void processWalkWrapper(); 378 EventWrapper<TableWalker, &TableWalker::processWalkWrapper> doProcessEvent; 379 380 void nextWalk(ThreadContext *tc); 381}; 382 383 384} // namespace ArmISA 385 386#endif //__ARCH_ARM_TABLE_WALKER_HH__ 387 388