1 /*
   2  * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "asm/macroAssembler.inline.hpp"
  27 #include "gc/g1/g1BarrierSet.hpp"
  28 #include "gc/g1/g1BarrierSetAssembler.hpp"
  29 #include "gc/g1/g1BarrierSetRuntime.hpp"
  30 #include "gc/g1/g1CardTable.hpp"
  31 #include "gc/g1/g1ThreadLocalData.hpp"
  32 #include "gc/g1/heapRegion.hpp"
  33 #include "gc/shared/collectedHeap.hpp"
  34 #include "runtime/sharedRuntime.hpp"
  35 #include "runtime/thread.hpp"
  36 #include "interpreter/interp_masm.hpp"
  37 #include "runtime/sharedRuntime.hpp"
  38 #ifdef COMPILER1
  39 #include "c1/c1_LIRAssembler.hpp"
  40 #include "c1/c1_MacroAssembler.hpp"
  41 #include "gc/g1/c1/g1BarrierSetC1.hpp"
  42 #endif
  43 
  44 #define __ masm->
  45 
  46 void G1BarrierSetAssembler::gen_write_ref_array_pre_barrier(MacroAssembler* masm, DecoratorSet decorators,
  47                                                             Register addr, Register count, RegSet saved_regs) {
  48   bool dest_uninitialized = (decorators & IS_DEST_UNINITIALIZED) != 0;
  49   if (!dest_uninitialized) {
  50     __ push(saved_regs, sp);
  51     if (count == c_rarg0) {
  52       if (addr == c_rarg1) {
  53         // exactly backwards!!
  54         __ mov(rscratch1, c_rarg0);
  55         __ mov(c_rarg0, c_rarg1);
  56         __ mov(c_rarg1, rscratch1);
  57       } else {
  58         __ mov(c_rarg1, count);
  59         __ mov(c_rarg0, addr);
  60       }
  61     } else {
  62       __ mov(c_rarg0, addr);
  63       __ mov(c_rarg1, count);
  64     }
  65     if (UseCompressedOops) {
  66       __ call_VM_leaf(CAST_FROM_FN_PTR(address, G1BarrierSetRuntime::write_ref_array_pre_narrow_oop_entry), 2);
  67     } else {
  68       __ call_VM_leaf(CAST_FROM_FN_PTR(address, G1BarrierSetRuntime::write_ref_array_pre_oop_entry), 2);
  69     }
  70     __ pop(saved_regs, sp);
  71   }
  72 }
  73 
  74 void G1BarrierSetAssembler::gen_write_ref_array_post_barrier(MacroAssembler* masm, DecoratorSet decorators,
  75                                                              Register start, Register count, Register scratch, RegSet saved_regs) {
  76   __ push(saved_regs, sp);
  77   assert_different_registers(start, count, scratch);
  78   assert_different_registers(c_rarg0, count);
  79   __ mov(c_rarg0, start);
  80   __ mov(c_rarg1, count);
  81   __ call_VM_leaf(CAST_FROM_FN_PTR(address, G1BarrierSetRuntime::write_ref_array_post_entry), 2);
  82   __ pop(saved_regs, sp);
  83 }
  84 
  85 void G1BarrierSetAssembler::g1_write_barrier_pre(MacroAssembler* masm,
  86                                                  Register obj,
  87                                                  Register pre_val,
  88                                                  Register thread,
  89                                                  Register tmp,
  90                                                  bool tosca_live,
  91                                                  bool expand_call) {
  92   // If expand_call is true then we expand the call_VM_leaf macro
  93   // directly to skip generating the check by
  94   // InterpreterMacroAssembler::call_VM_leaf_base that checks _last_sp.
  95 
  96   assert(thread == rthread, "must be");
  97 
  98   Label done;
  99   Label runtime;
 100 
 101   assert_different_registers(obj, pre_val, tmp, rscratch1);
 102   assert(pre_val != noreg &&  tmp != noreg, "expecting a register");
 103 
 104   Address in_progress(thread, in_bytes(G1ThreadLocalData::satb_mark_queue_active_offset()));
 105   Address index(thread, in_bytes(G1ThreadLocalData::satb_mark_queue_index_offset()));
 106   Address buffer(thread, in_bytes(G1ThreadLocalData::satb_mark_queue_buffer_offset()));
 107 
 108   // Is marking active?
 109   if (in_bytes(SATBMarkQueue::byte_width_of_active()) == 4) {
 110     __ ldrw(tmp, in_progress);
 111   } else {
 112     assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "Assumption");
 113     __ ldrb(tmp, in_progress);
 114   }
 115   __ cbzw(tmp, done);
 116 
 117   // Do we need to load the previous value?
 118   if (obj != noreg) {
 119     __ load_heap_oop(pre_val, Address(obj, 0), noreg, noreg, AS_RAW);
 120   }
 121 
 122   // Is the previous value null?
 123   __ cbz(pre_val, done);
 124 
 125   // Can we store original value in the thread's buffer?
 126   // Is index == 0?
 127   // (The index field is typed as size_t.)
 128 
 129   __ ldr(tmp, index);                      // tmp := *index_adr
 130   __ cbz(tmp, runtime);                    // tmp == 0?
 131                                         // If yes, goto runtime
 132 
 133   __ sub(tmp, tmp, wordSize);              // tmp := tmp - wordSize
 134   __ str(tmp, index);                      // *index_adr := tmp
 135   __ ldr(rscratch1, buffer);
 136   __ add(tmp, tmp, rscratch1);             // tmp := tmp + *buffer_adr
 137 
 138   // Record the previous value
 139   __ str(pre_val, Address(tmp, 0));
 140   __ b(done);
 141 
 142   __ bind(runtime);
 143   // save the live input values
 144   RegSet saved = RegSet::of(pre_val);
 145   if (tosca_live) saved += RegSet::of(r0);
 146   if (obj != noreg) saved += RegSet::of(obj);
 147 
 148   __ push(saved, sp);
 149 
 150   // Calling the runtime using the regular call_VM_leaf mechanism generates
 151   // code (generated by InterpreterMacroAssember::call_VM_leaf_base)
 152   // that checks that the *(rfp+frame::interpreter_frame_last_sp) == NULL.
 153   //
 154   // If we care generating the pre-barrier without a frame (e.g. in the
 155   // intrinsified Reference.get() routine) then ebp might be pointing to
 156   // the caller frame and so this check will most likely fail at runtime.
 157   //
 158   // Expanding the call directly bypasses the generation of the check.
 159   // So when we do not have have a full interpreter frame on the stack
 160   // expand_call should be passed true.
 161 
 162   if (expand_call) {
 163     assert(pre_val != c_rarg1, "smashed arg");
 164     __ super_call_VM_leaf(CAST_FROM_FN_PTR(address, G1BarrierSetRuntime::write_ref_field_pre_entry), pre_val, thread);
 165   } else {
 166     __ call_VM_leaf(CAST_FROM_FN_PTR(address, G1BarrierSetRuntime::write_ref_field_pre_entry), pre_val, thread);
 167   }
 168 
 169   __ pop(saved, sp);
 170 
 171   __ bind(done);
 172 
 173 }
 174 
 175 void G1BarrierSetAssembler::g1_write_barrier_post(MacroAssembler* masm,
 176                                                   Register store_addr,
 177                                                   Register new_val,
 178                                                   Register thread,
 179                                                   Register tmp,
 180                                                   Register tmp2) {
 181   assert(thread == rthread, "must be");
 182   assert_different_registers(store_addr, new_val, thread, tmp, tmp2,
 183                              rscratch1);
 184   assert(store_addr != noreg && new_val != noreg && tmp != noreg
 185          && tmp2 != noreg, "expecting a register");
 186 
 187   Address queue_index(thread, in_bytes(G1ThreadLocalData::dirty_card_queue_index_offset()));
 188   Address buffer(thread, in_bytes(G1ThreadLocalData::dirty_card_queue_buffer_offset()));
 189 
 190   BarrierSet* bs = BarrierSet::barrier_set();
 191   CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(bs);
 192   CardTable* ct = ctbs->card_table();
 193 
 194   Label done;
 195   Label runtime;
 196 
 197   // Does store cross heap regions?
 198 
 199   __ eor(tmp, store_addr, new_val);
 200   __ lsr(tmp, tmp, HeapRegion::LogOfHRGrainBytes);
 201   __ cbz(tmp, done);
 202 
 203   // crosses regions, storing NULL?
 204 
 205   __ cbz(new_val, done);
 206 
 207   // storing region crossing non-NULL, is card already dirty?
 208 
 209   ExternalAddress cardtable((address) ct->byte_map_base());
 210   const Register card_addr = tmp;
 211 
 212   __ lsr(card_addr, store_addr, CardTable::card_shift);
 213 
 214   // get the address of the card
 215   __ load_byte_map_base(tmp2);
 216   __ add(card_addr, card_addr, tmp2);
 217   __ ldrb(tmp2, Address(card_addr));
 218   __ cmpw(tmp2, (int)G1CardTable::g1_young_card_val());
 219   __ br(Assembler::EQ, done);
 220 
 221   assert((int)CardTable::dirty_card_val() == 0, "must be 0");
 222 
 223   __ membar(Assembler::StoreLoad);
 224 
 225   __ ldrb(tmp2, Address(card_addr));
 226   __ cbzw(tmp2, done);
 227 
 228   // storing a region crossing, non-NULL oop, card is clean.
 229   // dirty card and log.
 230 
 231   __ strb(zr, Address(card_addr));
 232 
 233   __ ldr(rscratch1, queue_index);
 234   __ cbz(rscratch1, runtime);
 235   __ sub(rscratch1, rscratch1, wordSize);
 236   __ str(rscratch1, queue_index);
 237 
 238   __ ldr(tmp2, buffer);
 239   __ str(card_addr, Address(tmp2, rscratch1));
 240   __ b(done);
 241 
 242   __ bind(runtime);
 243   // save the live input values
 244   RegSet saved = RegSet::of(store_addr, new_val);
 245   __ push(saved, sp);
 246   __ call_VM_leaf(CAST_FROM_FN_PTR(address, G1BarrierSetRuntime::write_ref_field_post_entry), card_addr, thread);
 247   __ pop(saved, sp);
 248 
 249   __ bind(done);
 250 }
 251 
 252 void G1BarrierSetAssembler::load_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
 253                                     Register dst, Address src, Register tmp1, Register tmp_thread) {
 254   bool on_oop = type == T_OBJECT || type == T_ARRAY;
 255   bool on_weak = (decorators & ON_WEAK_OOP_REF) != 0;
 256   bool on_phantom = (decorators & ON_PHANTOM_OOP_REF) != 0;
 257   bool on_reference = on_weak || on_phantom;
 258   ModRefBarrierSetAssembler::load_at(masm, decorators, type, dst, src, tmp1, tmp_thread);
 259   if (on_oop && on_reference) {
 260     // LR is live.  It must be saved around calls.
 261     __ enter(); // barrier may call runtime
 262     // Generate the G1 pre-barrier code to log the value of
 263     // the referent field in an SATB buffer.
 264     g1_write_barrier_pre(masm /* masm */,
 265                          noreg /* obj */,
 266                          dst /* pre_val */,
 267                          rthread /* thread */,
 268                          tmp1 /* tmp */,
 269                          true /* tosca_live */,
 270                          true /* expand_call */);
 271     __ leave();
 272   }
 273 }
 274 
 275 void G1BarrierSetAssembler::oop_store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
 276                                          Address dst, Register val, Register tmp1, Register tmp2) {
 277   // flatten object address if needed
 278   if (dst.index() == noreg && dst.offset() == 0) {
 279     if (dst.base() != r3) {
 280       __ mov(r3, dst.base());
 281     }
 282   } else {
 283     __ lea(r3, dst);
 284   }
 285 
 286   g1_write_barrier_pre(masm,
 287                        r3 /* obj */,
 288                        tmp2 /* pre_val */,
 289                        rthread /* thread */,
 290                        tmp1  /* tmp */,
 291                        val != noreg /* tosca_live */,
 292                        false /* expand_call */);
 293 
 294   if (val == noreg) {
 295     BarrierSetAssembler::store_at(masm, decorators, type, Address(r3, 0), noreg, noreg, noreg);
 296   } else {
 297     // G1 barrier needs uncompressed oop for region cross check.
 298     Register new_val = val;
 299     if (UseCompressedOops) {
 300       new_val = rscratch2;
 301       __ mov(new_val, val);
 302     }
 303     BarrierSetAssembler::store_at(masm, decorators, type, Address(r3, 0), val, noreg, noreg);
 304     g1_write_barrier_post(masm,
 305                           r3 /* store_adr */,
 306                           new_val /* new_val */,
 307                           rthread /* thread */,
 308                           tmp1 /* tmp */,
 309                           tmp2 /* tmp2 */);
 310   }
 311 
 312 }
 313 
 314 #ifdef COMPILER1
 315 
 316 #undef __
 317 #define __ ce->masm()->
 318 
 319 void G1BarrierSetAssembler::gen_pre_barrier_stub(LIR_Assembler* ce, G1PreBarrierStub* stub) {
 320   G1BarrierSetC1* bs = (G1BarrierSetC1*)BarrierSet::barrier_set()->barrier_set_c1();
 321   // At this point we know that marking is in progress.
 322   // If do_load() is true then we have to emit the
 323   // load of the previous value; otherwise it has already
 324   // been loaded into _pre_val.
 325 
 326   __ bind(*stub->entry());
 327 
 328   assert(stub->pre_val()->is_register(), "Precondition.");
 329 
 330   Register pre_val_reg = stub->pre_val()->as_register();
 331 
 332   if (stub->do_load()) {
 333     ce->mem2reg(stub->addr(), stub->pre_val(), T_OBJECT, stub->patch_code(), stub->info(), false /*wide*/, false /*unaligned*/);
 334   }
 335   __ cbz(pre_val_reg, *stub->continuation());
 336   ce->store_parameter(stub->pre_val()->as_register(), 0);
 337   __ far_call(RuntimeAddress(bs->pre_barrier_c1_runtime_code_blob()->code_begin()));
 338   __ b(*stub->continuation());
 339 }
 340 
 341 void G1BarrierSetAssembler::gen_post_barrier_stub(LIR_Assembler* ce, G1PostBarrierStub* stub) {
 342   G1BarrierSetC1* bs = (G1BarrierSetC1*)BarrierSet::barrier_set()->barrier_set_c1();
 343   __ bind(*stub->entry());
 344   assert(stub->addr()->is_register(), "Precondition.");
 345   assert(stub->new_val()->is_register(), "Precondition.");
 346   Register new_val_reg = stub->new_val()->as_register();
 347   __ cbz(new_val_reg, *stub->continuation());
 348   ce->store_parameter(stub->addr()->as_pointer_register(), 0);
 349   __ far_call(RuntimeAddress(bs->post_barrier_c1_runtime_code_blob()->code_begin()));
 350   __ b(*stub->continuation());
 351 }
 352 
 353 #undef __
 354 
 355 #define __ sasm->
 356 
 357 void G1BarrierSetAssembler::generate_c1_pre_barrier_runtime_stub(StubAssembler* sasm) {
 358   __ prologue("g1_pre_barrier", false);
 359 
 360   // arg0 : previous value of memory
 361 
 362   BarrierSet* bs = BarrierSet::barrier_set();
 363 
 364   const Register pre_val = r0;
 365   const Register thread = rthread;
 366   const Register tmp = rscratch1;
 367 
 368   Address in_progress(thread, in_bytes(G1ThreadLocalData::satb_mark_queue_active_offset()));
 369   Address queue_index(thread, in_bytes(G1ThreadLocalData::satb_mark_queue_index_offset()));
 370   Address buffer(thread, in_bytes(G1ThreadLocalData::satb_mark_queue_buffer_offset()));
 371 
 372   Label done;
 373   Label runtime;
 374 
 375   // Is marking still active?
 376   if (in_bytes(SATBMarkQueue::byte_width_of_active()) == 4) {
 377     __ ldrw(tmp, in_progress);
 378   } else {
 379     assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "Assumption");
 380     __ ldrb(tmp, in_progress);
 381   }
 382   __ cbzw(tmp, done);
 383 
 384   // Can we store original value in the thread's buffer?
 385   __ ldr(tmp, queue_index);
 386   __ cbz(tmp, runtime);
 387 
 388   __ sub(tmp, tmp, wordSize);
 389   __ str(tmp, queue_index);
 390   __ ldr(rscratch2, buffer);
 391   __ add(tmp, tmp, rscratch2);
 392   __ load_parameter(0, rscratch2);
 393   __ str(rscratch2, Address(tmp, 0));
 394   __ b(done);
 395 
 396   __ bind(runtime);
 397   __ push_call_clobbered_registers();
 398   __ load_parameter(0, pre_val);
 399   __ call_VM_leaf(CAST_FROM_FN_PTR(address, G1BarrierSetRuntime::write_ref_field_pre_entry), pre_val, thread);
 400   __ pop_call_clobbered_registers();
 401   __ bind(done);
 402 
 403   __ epilogue();
 404 }
 405 
 406 void G1BarrierSetAssembler::generate_c1_post_barrier_runtime_stub(StubAssembler* sasm) {
 407   __ prologue("g1_post_barrier", false);
 408 
 409   // arg0: store_address
 410   Address store_addr(rfp, 2*BytesPerWord);
 411 
 412   BarrierSet* bs = BarrierSet::barrier_set();
 413   CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(bs);
 414   CardTable* ct = ctbs->card_table();
 415 
 416   Label done;
 417   Label runtime;
 418 
 419   // At this point we know new_value is non-NULL and the new_value crosses regions.
 420   // Must check to see if card is already dirty
 421 
 422   const Register thread = rthread;
 423 
 424   Address queue_index(thread, in_bytes(G1ThreadLocalData::dirty_card_queue_index_offset()));
 425   Address buffer(thread, in_bytes(G1ThreadLocalData::dirty_card_queue_buffer_offset()));
 426 
 427   const Register card_offset = rscratch2;
 428   // LR is free here, so we can use it to hold the byte_map_base.
 429   const Register byte_map_base = lr;
 430 
 431   assert_different_registers(card_offset, byte_map_base, rscratch1);
 432 
 433   __ load_parameter(0, card_offset);
 434   __ lsr(card_offset, card_offset, CardTable::card_shift);
 435   __ load_byte_map_base(byte_map_base);
 436   __ ldrb(rscratch1, Address(byte_map_base, card_offset));
 437   __ cmpw(rscratch1, (int)G1CardTable::g1_young_card_val());
 438   __ br(Assembler::EQ, done);
 439 
 440   assert((int)CardTable::dirty_card_val() == 0, "must be 0");
 441 
 442   __ membar(Assembler::StoreLoad);
 443   __ ldrb(rscratch1, Address(byte_map_base, card_offset));
 444   __ cbzw(rscratch1, done);
 445 
 446   // storing region crossing non-NULL, card is clean.
 447   // dirty card and log.
 448   __ strb(zr, Address(byte_map_base, card_offset));
 449 
 450   // Convert card offset into an address in card_addr
 451   Register card_addr = card_offset;
 452   __ add(card_addr, byte_map_base, card_addr);
 453 
 454   __ ldr(rscratch1, queue_index);
 455   __ cbz(rscratch1, runtime);
 456   __ sub(rscratch1, rscratch1, wordSize);
 457   __ str(rscratch1, queue_index);
 458 
 459   // Reuse LR to hold buffer_addr
 460   const Register buffer_addr = lr;
 461 
 462   __ ldr(buffer_addr, buffer);
 463   __ str(card_addr, Address(buffer_addr, rscratch1));
 464   __ b(done);
 465 
 466   __ bind(runtime);
 467   __ push_call_clobbered_registers();
 468   __ call_VM_leaf(CAST_FROM_FN_PTR(address, G1BarrierSetRuntime::write_ref_field_post_entry), card_addr, thread);
 469   __ pop_call_clobbered_registers();
 470   __ bind(done);
 471   __ epilogue();
 472 }
 473 
 474 #undef __
 475 
 476 #endif // COMPILER1