/*

 * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.

 * Copyright (c) 2014, 2018, Red Hat Inc. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

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 */

#include "precompiled.hpp"

#include "asm/macroAssembler.hpp"

#include "memory/resourceArea.hpp"

#include "nativeInst_aarch64.hpp"

#include "oops/oop.inline.hpp"

#include "runtime/handles.hpp"

#include "runtime/sharedRuntime.hpp"

#include "runtime/stubRoutines.hpp"

#include "utilities/ostream.hpp"

#ifdef COMPILER1

#include "c1/c1_Runtime1.hpp"

#endif

void NativeCall::verify() { ; }

address NativeCall::destination() const {

  address addr = (address)this;

  address destination = instruction_address() + displacement();

  // Do we use a trampoline stub for this call?

  CodeBlob* cb = CodeCache::find_blob_unsafe(addr);   // Else we get assertion if nmethod is zombie.

  assert(cb && cb->is_nmethod(), "sanity");

  nmethod *nm = (nmethod *)cb;

  if (nm->stub_contains(destination) && is_NativeCallTrampolineStub_at(destination)) {

    // Yes we do, so get the destination from the trampoline stub.

    const address trampoline_stub_addr = destination;

    destination = nativeCallTrampolineStub_at(trampoline_stub_addr)->destination();

  }

  return destination;

}

// Similar to replace_mt_safe, but just changes the destination. The

// important thing is that free-running threads are able to execute this

// call instruction at all times.

//

// Used in the runtime linkage of calls; see class CompiledIC.

//

// Add parameter assert_lock to switch off assertion

// during code generation, where no patching lock is needed.

void NativeCall::set_destination_mt_safe(address dest, bool assert_lock) {

  assert(!assert_lock ||

         (Patching_lock->is_locked() || SafepointSynchronize::is_at_safepoint()),

         "concurrent code patching");

  ResourceMark rm;

  int code_size = NativeInstruction::instruction_size;

  address addr_call = addr_at(0);

  assert(NativeCall::is_call_at(addr_call), "unexpected code at call site");

  // Patch the constant in the call's trampoline stub.

  address trampoline_stub_addr = get_trampoline();

  if (trampoline_stub_addr != NULL) {

    assert (! is_NativeCallTrampolineStub_at(dest), "chained trampolines");

    nativeCallTrampolineStub_at(trampoline_stub_addr)->set_destination(dest);

  }

  // Patch the call.

  if (Assembler::reachable_from_branch_at(addr_call, dest)) {

    set_destination(dest);

  } else {

    assert (trampoline_stub_addr != NULL, "we need a trampoline");

    set_destination(trampoline_stub_addr);

  }

  ICache::invalidate_range(addr_call, instruction_size);

}

address NativeCall::get_trampoline() {

  address call_addr = addr_at(0);

  CodeBlob *code = CodeCache::find_blob(call_addr);

  assert(code != NULL, "Could not find the containing code blob");

  address bl_destination

    = MacroAssembler::pd_call_destination(call_addr);

  if (code->contains(bl_destination) &&

      is_NativeCallTrampolineStub_at(bl_destination))

    return bl_destination;

  // If the codeBlob is not a nmethod, this is because we get here from the

  // CodeBlob constructor, which is called within the nmethod constructor.

  return trampoline_stub_Relocation::get_trampoline_for(call_addr, (nmethod*)code);

}

// Inserts a native call instruction at a given pc

void NativeCall::insert(address code_pos, address entry) { Unimplemented(); }

//-------------------------------------------------------------------

void NativeMovConstReg::verify() {

  // make sure code pattern is actually mov reg64, imm64 instructions

}

intptr_t NativeMovConstReg::data() const {

  // das(uint64_t(instruction_address()),2);

  address addr = MacroAssembler::target_addr_for_insn(instruction_address());

  if (maybe_cpool_ref(instruction_address())) {

    return *(intptr_t*)addr;

  } else {

    return (intptr_t)addr;

  }

}

void NativeMovConstReg::set_data(intptr_t x) {

  if (maybe_cpool_ref(instruction_address())) {

    address addr = MacroAssembler::target_addr_for_insn(instruction_address());

    *(intptr_t*)addr = x;

  } else {

    // Store x into the instruction stream.

    MacroAssembler::pd_patch_instruction(instruction_address(), (address)x);

    ICache::invalidate_range(instruction_address(), instruction_size);

  }

  // Find and replace the oop/metadata corresponding to this

  // instruction in oops section.

  CodeBlob* cb = CodeCache::find_blob(instruction_address());

  nmethod* nm = cb->as_nmethod_or_null();

  if (nm != NULL) {

    RelocIterator iter(nm, instruction_address(), next_instruction_address());

    while (iter.next()) {

      if (iter.type() == relocInfo::oop_type) {

        oop* oop_addr = iter.oop_reloc()->oop_addr();

        *oop_addr = cast_to_oop(x);

        break;

      } else if (iter.type() == relocInfo::metadata_type) {

        Metadata** metadata_addr = iter.metadata_reloc()->metadata_addr();

        *metadata_addr = (Metadata*)x;

        break;

      }

    }

  }

}

void NativeMovConstReg::print() {

  tty->print_cr(PTR_FORMAT ": mov reg, " INTPTR_FORMAT,

                p2i(instruction_address()), data());

}

//-------------------------------------------------------------------

address NativeMovRegMem::instruction_address() const      { return addr_at(instruction_offset); }

int NativeMovRegMem::offset() const  {

  address pc = instruction_address();

  unsigned insn = *(unsigned*)pc;

  if (Instruction_aarch64::extract(insn, 28, 24) == 0b10000) {

    address addr = MacroAssembler::target_addr_for_insn(pc);

    return *addr;

  } else {

    return (int)(intptr_t)MacroAssembler::target_addr_for_insn(instruction_address());

  }

}

void NativeMovRegMem::set_offset(int x) {

  address pc = instruction_address();

  unsigned insn = *(unsigned*)pc;

  if (maybe_cpool_ref(pc)) {

    address addr = MacroAssembler::target_addr_for_insn(pc);

    *(long*)addr = x;

  } else {

    MacroAssembler::pd_patch_instruction(pc, (address)intptr_t(x));

    ICache::invalidate_range(instruction_address(), instruction_size);

  }

}

void NativeMovRegMem::verify() {

#ifdef ASSERT

  address dest = MacroAssembler::target_addr_for_insn(instruction_address());

#endif

}

//--------------------------------------------------------------------------------

void NativeJump::verify() { ; }

void NativeJump::check_verified_entry_alignment(address entry, address verified_entry) {

}

address NativeJump::jump_destination() const          {

  address dest = MacroAssembler::target_addr_for_insn(instruction_address());

  // We use jump to self as the unresolved address which the inline

  // cache code (and relocs) know about

  // return -1 if jump to self

  dest = (dest == (address) this) ? (address) -1 : dest;

  return dest;

}

void NativeJump::set_jump_destination(address dest) {

  // We use jump to self as the unresolved address which the inline

  // cache code (and relocs) know about

  if (dest == (address) -1)

    dest = instruction_address();

  MacroAssembler::pd_patch_instruction(instruction_address(), dest);

  ICache::invalidate_range(instruction_address(), instruction_size);

};

//-------------------------------------------------------------------

address NativeGeneralJump::jump_destination() const {

  NativeMovConstReg* move = nativeMovConstReg_at(instruction_address());

  address dest = (address) move->data();

  // We use jump to self as the unresolved address which the inline

  // cache code (and relocs) know about

  // return -1 if jump to self

  dest = (dest == (address) this) ? (address) -1 : dest;

  return dest;

}

void NativeGeneralJump::set_jump_destination(address dest) {

  NativeMovConstReg* move = nativeMovConstReg_at(instruction_address());

  // We use jump to self as the unresolved address which the inline

  // cache code (and relocs) know about

  if (dest == (address) -1) {

    dest = instruction_address();

  }

  move->set_data((uintptr_t) dest);

};

//-------------------------------------------------------------------

bool NativeInstruction::is_safepoint_poll() {

  // a safepoint_poll is implemented in two steps as either

  //

  // adrp(reg, polling_page);

  // ldr(zr, [reg, #offset]);

  //

  // or

  //

  // mov(reg, polling_page);

  // ldr(zr, [reg, #offset]);

  //

  // or

  //

  // ldr(reg, [rthread, #offset]);

  // ldr(zr, [reg, #offset]);

  //

  // however, we cannot rely on the polling page address load always

  // directly preceding the read from the page. C1 does that but C2

  // has to do the load and read as two independent instruction

  // generation steps. that's because with a single macro sequence the

  // generic C2 code can only add the oop map before the mov/adrp and

  // the trap handler expects an oop map to be associated with the

  // load. with the load scheuled as a prior step the oop map goes

  // where it is needed.

  //

  // so all we can do here is check that marked instruction is a load

  // word to zr

  return is_ldrw_to_zr(address(this));

}

bool NativeInstruction::is_adrp_at(address instr) {

  unsigned insn = *(unsigned*)instr;

  return (Instruction_aarch64::extract(insn, 31, 24) & 0b10011111) == 0b10010000;

}

bool NativeInstruction::is_ldr_literal_at(address instr) {

  unsigned insn = *(unsigned*)instr;

  return (Instruction_aarch64::extract(insn, 29, 24) & 0b011011) == 0b00011000;

}

bool NativeInstruction::is_ldrw_to_zr(address instr) {

  unsigned insn = *(unsigned*)instr;

  return (Instruction_aarch64::extract(insn, 31, 22) == 0b1011100101 &&

          Instruction_aarch64::extract(insn, 4, 0) == 0b11111);

}

bool NativeInstruction::is_general_jump() {

  if (is_movz()) {

    NativeInstruction* inst1 = nativeInstruction_at(addr_at(instruction_size * 1));

    if (inst1->is_movk()) {

      NativeInstruction* inst2 = nativeInstruction_at(addr_at(instruction_size * 2));

      if (inst2->is_movk()) {

        NativeInstruction* inst3 = nativeInstruction_at(addr_at(instruction_size * 3));

        if (inst3->is_blr()) {

          return true;

        }

      }

    }

  }

  return false;

}

bool NativeInstruction::is_movz() {

  return Instruction_aarch64::extract(int_at(0), 30, 23) == 0b10100101;

}

bool NativeInstruction::is_movk() {

  return Instruction_aarch64::extract(int_at(0), 30, 23) == 0b11100101;

}

bool NativeInstruction::is_sigill_zombie_not_entrant() {

  return uint_at(0) == 0xd4bbd5a1; // dcps1 #0xdead

}

void NativeIllegalInstruction::insert(address code_pos) {

  *(juint*)code_pos = 0xd4bbd5a1; // dcps1 #0xdead

}

//-------------------------------------------------------------------

// MT-safe inserting of a jump over a jump or a nop (used by

// nmethod::make_not_entrant_or_zombie)

void NativeJump::patch_verified_entry(address entry, address verified_entry, address dest) {

  assert(dest == SharedRuntime::get_handle_wrong_method_stub(), "expected fixed destination of patch");

  assert(nativeInstruction_at(verified_entry)->is_jump_or_nop()

         || nativeInstruction_at(verified_entry)->is_sigill_zombie_not_entrant(),

         "Aarch64 cannot replace non-jump with jump");

  // Patch this nmethod atomically.

  if (Assembler::reachable_from_branch_at(verified_entry, dest)) {

    ptrdiff_t disp = dest - verified_entry;

    guarantee(disp < 1 << 27 && disp > - (1 << 27), "branch overflow");

    unsigned int insn = (0b000101 << 26) | ((disp >> 2) & 0x3ffffff);

    *(unsigned int*)verified_entry = insn;

  } else {

    // We use an illegal instruction for marking a method as

    // not_entrant or zombie.

    NativeIllegalInstruction::insert(verified_entry);

  }

  ICache::invalidate_range(verified_entry, instruction_size);

}

void NativeGeneralJump::verify() {  }

void NativeGeneralJump::insert_unconditional(address code_pos, address entry) {

  NativeGeneralJump* n_jump = (NativeGeneralJump*)code_pos;

  CodeBuffer cb(code_pos, instruction_size);

  MacroAssembler a(&cb);

  a.br(rscratch1);

  ICache::invalidate_range(code_pos, instruction_size);

}

// MT-safe patching of a long jump instruction.

void NativeGeneralJump::replace_mt_safe(address instr_addr, address code_buffer) {

  ShouldNotCallThis();

}

address NativeCallTrampolineStub::destination(nmethod *nm) const {

  return ptr_at(data_offset);

}

void NativeCallTrampolineStub::set_destination(address new_destination) {

  set_ptr_at(data_offset, new_destination);

  OrderAccess::release();

}

// Generate a trampoline for a branch to dest.  If there's no need for a

// trampoline, simply patch the call directly to dest.

address NativeCall::trampoline_jump(CodeBuffer &cbuf, address dest) {

  MacroAssembler a(&cbuf);

  address stub = NULL;

  if (a.far_branches()

      && ! is_NativeCallTrampolineStub_at(instruction_address() + displacement())) {

    stub = a.emit_trampoline_stub(instruction_address() - cbuf.insts()->start(), dest);

  }

  if (stub == NULL) {

    // If we generated no stub, patch this call directly to dest.

    // This will happen if we don't need far branches or if there

    // already was a trampoline.

    set_destination(dest);

  }

  return stub;

}