/*

 * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.

 * Copyright (c) 2012, 2019, SAP SE. 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

 * questions.

 *

 */

#include "precompiled.hpp"

#include "asm/macroAssembler.inline.hpp"

#include "code/compiledIC.hpp"

#include "memory/resourceArea.hpp"

#include "nativeInst_ppc.hpp"

#include "oops/compressedOops.inline.hpp"

#include "oops/oop.hpp"

#include "runtime/handles.hpp"

#include "runtime/orderAccess.hpp"

#include "runtime/sharedRuntime.hpp"

#include "runtime/stubRoutines.hpp"

#include "utilities/ostream.hpp"

#ifdef COMPILER1

#include "c1/c1_Runtime1.hpp"

#endif

// We use an illtrap for marking a method as not_entrant or zombie iff !UseSIGTRAP

// Work around a C++ compiler bug which changes 'this'

bool NativeInstruction::is_sigill_zombie_not_entrant_at(address addr) {

  assert(!UseSIGTRAP, "precondition");

  if (*(int*)addr != 0 /*illtrap*/) return false;

  CodeBlob* cb = CodeCache::find_blob_unsafe(addr);

  if (cb == NULL || !cb->is_nmethod()) return false;

  nmethod *nm = (nmethod *)cb;

  // This method is not_entrant or zombie iff the illtrap instruction is

  // located at the verified entry point.

  return nm->verified_entry_point() == addr;

}

#ifdef ASSERT

void NativeInstruction::verify() {

  // Make sure code pattern is actually an instruction address.

  address addr = addr_at(0);

  if (addr == 0 || ((intptr_t)addr & 3) != 0) {

    fatal("not an instruction address");

  }

}

#endif // ASSERT

// Extract call destination from a NativeCall. The call might use a trampoline stub.

address NativeCall::destination() const {

  address addr = (address)this;

  address destination = Assembler::bxx_destination(addr);

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

  // Trampoline stubs are located behind the main code.

  if (destination > addr) {

    // Filter out recursive method invocation (call to verified/unverified entry point).

    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(nm);

    }

  }

  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. Thus, the displacement field must be

// instruction-word-aligned.

//

// 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()) ||

         CompiledICLocker::is_safe(addr_at(0)),

         "concurrent code patching");

  ResourceMark rm;

  int code_size = 1 * BytesPerInstWord;

  address addr_call = addr_at(0);

  assert(MacroAssembler::is_bl(*(int*)addr_call), "unexpected code at call-site");

  CodeBuffer cb(addr_call, code_size + 1);

  MacroAssembler* a = new MacroAssembler(&cb);

  // Patch the call.

  if (!ReoptimizeCallSequences || !a->is_within_range_of_b(dest, addr_call)) {

    address trampoline_stub_addr = get_trampoline();

    // We did not find a trampoline stub because the current codeblob

    // does not provide this information. The branch will be patched

    // later during a final fixup, when all necessary information is

    // available.

    if (trampoline_stub_addr == 0)

      return;

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

    NativeCallTrampolineStub_at(trampoline_stub_addr)->set_destination(dest);

    dest = trampoline_stub_addr;

  }

  OrderAccess::release();

  a->bl(dest);

  ICache::ppc64_flush_icache_bytes(addr_call, code_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");

  // There are no relocations available when the code gets relocated

  // because of CodeBuffer expansion.

  if (code->relocation_size() == 0)

    return NULL;

  address bl_destination = Assembler::bxx_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);

}

#ifdef ASSERT

void NativeCall::verify() {

  address addr = addr_at(0);

  if (!NativeCall::is_call_at(addr)) {

    tty->print_cr("not a NativeCall at " PTR_FORMAT, p2i(addr));

    // TODO: PPC port: Disassembler::decode(addr - 20, addr + 20, tty);

    fatal("not a NativeCall at " PTR_FORMAT, p2i(addr));

  }

}

#endif // ASSERT

#ifdef ASSERT

void NativeFarCall::verify() {

  address addr = addr_at(0);

  NativeInstruction::verify();

  if (!NativeFarCall::is_far_call_at(addr)) {

    tty->print_cr("not a NativeFarCall at " PTR_FORMAT, p2i(addr));

    // TODO: PPC port: Disassembler::decode(addr, 20, 20, tty);

    fatal("not a NativeFarCall at " PTR_FORMAT, p2i(addr));

  }

}

#endif // ASSERT

address NativeMovConstReg::next_instruction_address() const {

#ifdef ASSERT

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

  assert(!MacroAssembler::is_set_narrow_oop(addr_at(0), nm->content_begin()), "Should not patch narrow oop here");

#endif

  if (MacroAssembler::is_load_const_from_method_toc_at(addr_at(0))) {

    return addr_at(load_const_from_method_toc_instruction_size);

  } else {

    return addr_at(load_const_instruction_size);

  }

}

intptr_t NativeMovConstReg::data() const {

  address   addr = addr_at(0);

  if (MacroAssembler::is_load_const_at(addr)) {

    return MacroAssembler::get_const(addr);

  }

  CodeBlob* cb = CodeCache::find_blob_unsafe(addr);

  if (MacroAssembler::is_set_narrow_oop(addr, cb->content_begin())) {

    narrowOop no = (narrowOop)MacroAssembler::get_narrow_oop(addr, cb->content_begin());

    return cast_from_oop<intptr_t>(CompressedOops::decode(no));

  } else {

    assert(MacroAssembler::is_load_const_from_method_toc_at(addr), "must be load_const_from_pool");

    address ctable = cb->content_begin();

    int offset = MacroAssembler::get_offset_of_load_const_from_method_toc_at(addr);

    return *(intptr_t *)(ctable + offset);

  }

}

address NativeMovConstReg::set_data_plain(intptr_t data, CodeBlob *cb) {

  address addr         = instruction_address();

  address next_address = NULL;

  if (!cb) cb = CodeCache::find_blob(addr);

  if (cb != NULL && MacroAssembler::is_load_const_from_method_toc_at(addr)) {

    // A load from the method's TOC (ctable).

    assert(cb->is_nmethod(), "must be nmethod");

    const address ctable = cb->content_begin();

    const int toc_offset = MacroAssembler::get_offset_of_load_const_from_method_toc_at(addr);

    *(intptr_t *)(ctable + toc_offset) = data;

    next_address = addr + BytesPerInstWord;

  } else if (cb != NULL &&

             MacroAssembler::is_calculate_address_from_global_toc_at(addr, cb->content_begin())) {

    // A calculation relative to the global TOC.

    if (MacroAssembler::get_address_of_calculate_address_from_global_toc_at(addr, cb->content_begin()) !=

        (address)data) {

      const address inst2_addr = addr;

      const address inst1_addr =

        MacroAssembler::patch_calculate_address_from_global_toc_at(inst2_addr, cb->content_begin(),

                                                                   (address)data);

      assert(inst1_addr != NULL && inst1_addr < inst2_addr, "first instruction must be found");

      const int range = inst2_addr - inst1_addr + BytesPerInstWord;

      ICache::ppc64_flush_icache_bytes(inst1_addr, range);

    }

    next_address = addr + 1 * BytesPerInstWord;

  } else if (MacroAssembler::is_load_const_at(addr)) {

    // A normal 5 instruction load_const code sequence.

    if (MacroAssembler::get_const(addr) != (long)data) {

      // This is not mt safe, ok in methods like CodeBuffer::copy_code().

      MacroAssembler::patch_const(addr, (long)data);

      ICache::ppc64_flush_icache_bytes(addr, load_const_instruction_size);

    }

    next_address = addr + 5 * BytesPerInstWord;

  } else if (MacroAssembler::is_bl(* (int*) addr)) {

    // A single branch-and-link instruction.

    ResourceMark rm;

    const int code_size = 1 * BytesPerInstWord;

    CodeBuffer cb(addr, code_size + 1);

    MacroAssembler* a = new MacroAssembler(&cb);

    a->bl((address) data);

    ICache::ppc64_flush_icache_bytes(addr, code_size);

    next_address = addr + code_size;

  } else {

    ShouldNotReachHere();

  }

  return next_address;

}

void NativeMovConstReg::set_data(intptr_t data) {

  // Store the value into the instruction stream.

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

  address next_address = set_data_plain(data, cb);

  // Also store the value into an oop_Relocation cell, if any.

  if (cb && cb->is_nmethod()) {

    RelocIterator iter((nmethod *) cb, instruction_address(), next_address);

    oop* oop_addr = NULL;

    Metadata** metadata_addr = NULL;

    while (iter.next()) {

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

        oop_Relocation *r = iter.oop_reloc();

        if (oop_addr == NULL) {

          oop_addr = r->oop_addr();

          *oop_addr = cast_to_oop(data);

        } else {

          assert(oop_addr == r->oop_addr(), "must be only one set-oop here");

        }

      }

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

        metadata_Relocation *r = iter.metadata_reloc();

        if (metadata_addr == NULL) {

          metadata_addr = r->metadata_addr();

          *metadata_addr = (Metadata*)data;

        } else {

          assert(metadata_addr == r->metadata_addr(), "must be only one set-metadata here");

        }

      }

    }

  }

}

void NativeMovConstReg::set_narrow_oop(narrowOop data, CodeBlob *code /* = NULL */) {

  address   inst2_addr = addr_at(0);

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

  if (MacroAssembler::get_narrow_oop(inst2_addr, cb->content_begin()) == (long)data)

    return;

  const address inst1_addr =

    MacroAssembler::patch_set_narrow_oop(inst2_addr, cb->content_begin(), (long)data);

  assert(inst1_addr != NULL && inst1_addr < inst2_addr, "first instruction must be found");

  const int range = inst2_addr - inst1_addr + BytesPerInstWord;

  ICache::ppc64_flush_icache_bytes(inst1_addr, range);

}

// Do not use an assertion here. Let clients decide whether they only

// want this when assertions are enabled.

#ifdef ASSERT

void NativeMovConstReg::verify() {

  address   addr = addr_at(0);

  if (! MacroAssembler::is_load_const_at(addr) &&

      ! MacroAssembler::is_load_const_from_method_toc_at(addr)) {

    CodeBlob* cb = CodeCache::find_blob_unsafe(addr);   // find_nmethod() asserts if nmethod is zombie.

    if (! (cb != NULL && MacroAssembler::is_calculate_address_from_global_toc_at(addr, cb->content_begin())) &&

        ! (cb != NULL && MacroAssembler::is_set_narrow_oop(addr, cb->content_begin())) &&

        ! MacroAssembler::is_bl(*((int*) addr))) {

      tty->print_cr("not a NativeMovConstReg at " PTR_FORMAT, p2i(addr));

      // TODO: PPC port: Disassembler::decode(addr, 20, 20, tty);

      fatal("not a NativeMovConstReg at " PTR_FORMAT, p2i(addr));

    }

  }

}

#endif // ASSERT

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

  ResourceMark rm;

  int code_size = 1 * BytesPerInstWord;

  CodeBuffer cb(verified_entry, code_size + 1);

  MacroAssembler* a = new MacroAssembler(&cb);

#ifdef COMPILER2

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

#endif

  // Patch this nmethod atomically. Always use illtrap/trap in debug build.

  if (DEBUG_ONLY(false &&) a->is_within_range_of_b(dest, a->pc())) {

    a->b(dest);

  } else {

    // The signal handler will continue at dest=OptoRuntime::handle_wrong_method_stub().

    if (TrapBasedNotEntrantChecks) {

      // We use a special trap for marking a method as not_entrant or zombie.

      a->trap_zombie_not_entrant();

    } else {

      // We use an illtrap for marking a method as not_entrant or zombie.

      a->illtrap();

    }

  }

  ICache::ppc64_flush_icache_bytes(verified_entry, code_size);

}

#ifdef ASSERT

void NativeJump::verify() {

  address addr = addr_at(0);

  NativeInstruction::verify();

  if (!NativeJump::is_jump_at(addr)) {

    tty->print_cr("not a NativeJump at " PTR_FORMAT, p2i(addr));

    // TODO: PPC port: Disassembler::decode(addr, 20, 20, tty);

    fatal("not a NativeJump at " PTR_FORMAT, p2i(addr));

  }

}

#endif // ASSERT

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

  CodeBuffer cb(code_pos, BytesPerInstWord + 1);

  MacroAssembler a(&cb);

  a.b(entry);

  ICache::ppc64_flush_icache_bytes(code_pos, NativeGeneralJump::instruction_size);

}

// MT-safe patching of a jmp instruction.

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

  // Bytes beyond offset NativeGeneralJump::instruction_size are copied by caller.

  // Finally patch out the jump.

  volatile juint *jump_addr = (volatile juint*)instr_addr;

  // Release not needed because caller uses invalidate_range after copying the remaining bytes.

  *jump_addr = *((juint*)code_buffer); // atomically store code over branch instruction

  ICache::ppc64_flush_icache_bytes(instr_addr, NativeGeneralJump::instruction_size);

}

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

// Call trampoline stubs.

//

// Layout and instructions of a call trampoline stub:

//    0:  load the TOC (part 1)

//    4:  load the TOC (part 2)

//    8:  load the call target from the constant pool (part 1)

//  [12:  load the call target from the constant pool (part 2, optional)]

//   ..:  branch via CTR

//

address NativeCallTrampolineStub::encoded_destination_addr() const {

  address instruction_addr = addr_at(0 * BytesPerInstWord);

  if (!MacroAssembler::is_ld_largeoffset(instruction_addr)) {

    instruction_addr = addr_at(2 * BytesPerInstWord);

    assert(MacroAssembler::is_ld_largeoffset(instruction_addr),

           "must be a ld with large offset (from the constant pool)");

  }

  return instruction_addr;

}

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

  CodeBlob* cb = nm ? nm : CodeCache::find_blob_unsafe(addr_at(0));

  address ctable = cb->content_begin();

  return *(address*)(ctable + destination_toc_offset());

}

int NativeCallTrampolineStub::destination_toc_offset() const {

  return MacroAssembler::get_ld_largeoffset_offset(encoded_destination_addr());

}

void NativeCallTrampolineStub::set_destination(address new_destination) {

  CodeBlob* cb = CodeCache::find_blob(addr_at(0));

  address ctable = cb->content_begin();

  *(address*)(ctable + destination_toc_offset()) = new_destination;

}