1 /*

     2  * Copyright 1997-2006 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

    20  * CA 95054 USA or visit www.sun.com if you need additional information or

    21  * have any questions.

    22  *

    23  */

    24 

    25 #include "incls/_precompiled.incl"

    26 #include "incls/_icache.cpp.incl"

    27 

    28 // The flush stub function address

    29 AbstractICache::flush_icache_stub_t AbstractICache::_flush_icache_stub = NULL;

    30 

    31 void AbstractICache::initialize() {

    32   // Making this stub must be FIRST use of assembler

    33   ResourceMark rm;

    34 

    35   BufferBlob* b = BufferBlob::create("flush_icache_stub", ICache::stub_size);

    36   CodeBuffer c(b->instructions_begin(), b->instructions_size());

    37 

    38   ICacheStubGenerator g(&c);

    39   g.generate_icache_flush(&_flush_icache_stub);

    40 

    41   // The first use of flush_icache_stub must apply it to itself.

    42   // The StubCodeMark destructor in generate_icache_flush will

    43   // call Assembler::flush, which in turn will call invalidate_range,

    44   // which will in turn call the flush stub.  Thus we don't need an

    45   // explicit call to invalidate_range here.  This assumption is

    46   // checked in invalidate_range.

    47 }

    48 

    49 void AbstractICache::call_flush_stub(address start, int lines) {

    50   // The business with the magic number is just a little security.

    51   // We cannot call the flush stub when generating the flush stub

    52   // because it isn't there yet.  So, the stub also returns its third

    53   // parameter.  This is a cheap check that the stub was really executed.

    54   static int magic = 0xbaadbabe;

    55 

    56   int auto_magic = magic; // Make a local copy to avoid race condition

    57   int r = (*_flush_icache_stub)(start, lines, auto_magic);

    58   guarantee(r == auto_magic, "flush stub routine did not execute");

    59   ++magic;

    60 }

    61 

    62 void AbstractICache::invalidate_word(address addr) {

    63   // Because this is called for instruction patching on the fly, long after

    64   // bootstrapping, we execute the stub directly.  Account for a 4-byte word

    65   // spanning two cache lines by computing a start line address by rounding

    66   // addr down to a line_size boundary, and an end line address by adding

    67   // the word size - 1 and rounding the result down to a line_size boundary.

    68   // If we just added word size, we'd mistakenly flush the next cache line

    69   // if the word to be flushed started in the last 4 bytes of the line.

    70   // Doing that would segv if the next line weren't mapped.

    71 

    72   const int word_size_in_bytes = 4; // Always, regardless of platform

    73 

    74   intptr_t start_line = ((intptr_t)addr + 0) & ~(ICache::line_size - 1);

    75   intptr_t end_line   = ((intptr_t)addr + word_size_in_bytes - 1)

    76                                              & ~(ICache::line_size - 1);

    77   (*_flush_icache_stub)((address)start_line, start_line == end_line ? 1 : 2, 0);

    78 }

    79 

    80 void AbstractICache::invalidate_range(address start, int nbytes) {

    81   static bool firstTime = true;

    82   if (firstTime) {

    83     guarantee(start == CAST_FROM_FN_PTR(address, _flush_icache_stub),

    84               "first flush should be for flush stub");

    85     firstTime = false;

    86     return;

    87   }

    88   if (nbytes == 0) {

    89     return;

    90   }

    91   // Align start address to an icache line boundary and transform

    92   // nbytes to an icache line count.

    93   const uint line_offset = mask_address_bits(start, ICache::line_size-1);

    94   if (line_offset != 0) {

    95     start -= line_offset;

    96     nbytes += line_offset;

    97   }

    98   call_flush_stub(start, round_to(nbytes, ICache::line_size) >>

    99                          ICache::log2_line_size);

   100 }

   101 

   102 // For init.cpp

   103 void icache_init() {

   104   ICache::initialize();

   105 }