src/hotspot/cpu/riscv/icache_riscv.cpp

/*
 * Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2020, 2022, Huawei Technologies Co., Ltd. All rights reserved.
 * Copyright (c) 2023, Rivos 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 "asm/macroAssembler.hpp"
#include "riscv_flush_icache.hpp"
#include "runtime/java.hpp"
#include "runtime/icache.hpp"

#define __ _masm->

static int icache_flush(address addr, int lines, int magic) {
  // To make a store to instruction memory visible to all RISC-V harts,
  // the writing hart has to execute a data FENCE before requesting that
  // all remote RISC-V harts execute a FENCE.I.

  // We need to make sure stores happens before the I/D cache synchronization.
  __asm__ volatile("fence rw, rw" : : : "memory");

  RiscvFlushIcache::flush((uintptr_t)addr, ((uintptr_t)lines) << ICache::log2_line_size);

  return magic;
}

void ICacheStubGenerator::generate_icache_flush(ICache::flush_icache_stub_t* flush_icache_stub) {
  // Only riscv_flush_icache is supported as I-cache synchronization.
  // We must make sure the VM can execute such without error.
  if (!RiscvFlushIcache::test()) {
    vm_exit_during_initialization("Unable to synchronize I-cache");
  }

  address start = (address)icache_flush;
  *flush_icache_stub = (ICache::flush_icache_stub_t)start;

  // ICache::invalidate_range() contains explicit condition that the first
  // call is invoked on the generated icache flush stub code range.
  ICache::invalidate_range(start, 0);

  {
    StubCodeMark mark(this, "ICache", "fake_stub_for_inlined_icache_flush");
    __ ret();
  }
}

#undef __