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1
2/*--------------------------------------------------------------------*/
3/*--- The core dispatch loop, for jumping to a code address.       ---*/
4/*---                                      dispatch-mips64-linux.S ---*/
5/*--------------------------------------------------------------------*/
6
7/*
8  This file is part of Valgrind, a dynamic binary instrumentation
9  framework.
10
11  Copyright (C) 2000-2017 RT-RK
12     mips-valgrind@rt-rk.com
13
14  This program is free software; you can redistribute it and/or
15  modify it under the terms of the GNU General Public License as
16  published by the Free Software Foundation; either version 2 of the
17  License, or (at your option) any later version.
18
19  This program is distributed in the hope that it will be useful, but
20  WITHOUT ANY WARRANTY; without even the implied warranty of
21  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
22  General Public License for more details.
23
24   You should have received a copy of the GNU General Public License
25   along with this program; if not, write to the Free Software
26   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
27   02111-1307, USA.
28
29  The GNU General Public License is contained in the file COPYING.
30*/
31
32#include "pub_core_basics_asm.h"
33
34#if defined(VGP_mips64_linux)
35
36#include "pub_core_dispatch_asm.h"
37#include "pub_core_transtab_asm.h"
38#include "libvex_guest_offsets.h"	/* for OFFSET_mips_PC */
39
40
41/*------------------------------------------------------------*/
42/*---                                                      ---*/
43/*--- The dispatch loop.  VG_(disp_run_translations) is    ---*/
44/*--- used to run all translations,                        ---*/
45/*--- including no-redir ones.                             ---*/
46/*---                                                      ---*/
47/*------------------------------------------------------------*/
48
49/*----------------------------------------------------*/
50/*--- Entry and preamble (set everything up)       ---*/
51/*----------------------------------------------------*/
52
53/* signature:
54void VG_(disp_run_translations)( UWord* two_words,
55                                 void*  guest_state,
56                                 Addr   host_addr );
57*/
58
59.text
60.globl VG_(disp_run_translations)
61VG_(disp_run_translations):
62    /* a0 ($4) holds two_words   */
63    /* a1 ($5) holds guest_state */
64    /* a2 ($6) holds host_addr   */
65
66    /* New stack frame.  Stack must remain 16 aligned (at least) */
67    daddiu $29, -176
68
69    /* Save ra */
70    sd  $31, 72($29)
71
72    /* ... and s0 - s7 */
73    sd $16, 80($29)
74    sd $17, 88($29)
75    sd $18, 96($29)
76    sd $19, 104($29)
77    sd $20, 112($29)
78    sd $21, 120($29)
79    sd $22, 128($29)
80    sd $23, 136($29)
81
82    /* ... and gp, fp/s8 */
83    sd $28, 144($29)
84    sd $30, 152($29)
85
86    /* Save a0 ($4) on stack. In postamble it will be restored such that the
87       return values can be written */
88    sd $4, 160($29)
89
90    /* Load address of guest state into guest state register ($23) */
91    move $23, $5
92
93    /* and jump into the code cache.  Chained translations in
94           the code cache run, until for whatever reason, they can't
95           continue.  When that happens, the translation in question
96           will jump (or call) to one of the continuation points
97           VG_(cp_...) below. */
98    jr $6
99    /*NOTREACHED*/
100
101/*----------------------------------------------------*/
102/*--- Postamble and exit.                          ---*/
103/*----------------------------------------------------*/
104
105postamble:
106        /* At this point, $2 and $3 contain two
107           words to be returned to the caller.  $2
108           holds a TRC value, and $3 optionally may
109           hold another word (for CHAIN_ME exits, the
110           address of the place to patch.) */
111
112    /* Restore $4 from stack; holds address of two_words */
113    ld $4, 160($29)
114    sd  $2, 0($4)         /* Store $2 to two_words[0] */
115    sd  $3, 8($4)         /* Store $3 to two_words[1] */
116
117    /* Restore callee-saved registers... */
118
119    /* Restore ra */
120    ld $31, 72($29)
121
122    /* ... and s0 - s7 */
123    ld $16, 80($29)
124    ld $17, 88($29)
125    ld $18, 96($29)
126    ld $19, 104($29)
127    ld $20, 112($29)
128    ld $21, 120($29)
129    ld $22, 128($29)
130    ld $23, 136($29)
131
132    /* ... and gp, fp/s8 */
133    ld $28, 144($29)
134    ld $30, 152($29)
135
136    daddiu $29, 176   /* stack_size */
137    jr $31
138    nop
139
140/*----------------------------------------------------*/
141/*--- Continuation points                          ---*/
142/*----------------------------------------------------*/
143
144/* ------ Chain me to slow entry point ------ */
145.global VG_(disp_cp_chain_me_to_slowEP)
146VG_(disp_cp_chain_me_to_slowEP):
147        /* We got called.  The return address indicates
148           where the patching needs to happen.  Collect
149           the return address and, exit back to C land,
150           handing the caller the pair (Chain_me_S, RA) */
151        li $2, VG_TRC_CHAIN_ME_TO_SLOW_EP
152        move $3, $31
153        /* 8 = mkLoadImm_EXACTLY2or6
154           4 = jalr $9
155           4 = nop */
156        daddiu  $3, $3, -32
157        b    postamble
158
159/* ------ Chain me to slow entry point ------ */
160.global VG_(disp_cp_chain_me_to_fastEP)
161VG_(disp_cp_chain_me_to_fastEP):
162        /* We got called.  The return address indicates
163           where the patching needs to happen.  Collect
164           the return address and, exit back to C land,
165           handing the caller the pair (Chain_me_S, RA) */
166        li $2, VG_TRC_CHAIN_ME_TO_FAST_EP
167        move $3, $31
168        /* 8 = mkLoadImm_EXACTLY2or6
169           4 = jalr $9
170           4 = nop */
171        daddiu  $3, $3, -32
172        b    postamble
173
174/* ------ Indirect but boring jump ------ */
175.global VG_(disp_cp_xindir)
176VG_(disp_cp_xindir):
177        /* Where are we going? */
178        ld  $11, OFFSET_mips64_PC($23)
179
180        lw $13, vgPlain_stats__n_xindirs_32
181        addiu $13, $13, 0x1
182        sw $13, vgPlain_stats__n_xindirs_32
183
184        /* try a fast lookup in the translation cache */
185        /* t1 = VG_TT_FAST_HASH(addr) * sizeof(ULong*)
186                = (t8 >> 2 & VG_TT_FAST_MASK)  << 3 */
187
188        move $14, $11
189        li $12, VG_TT_FAST_MASK
190        srl $14, $14, 2
191        and $14, $14, $12
192        sll $14, $14, 3
193
194        /* t2 = (addr of VG_(tt_fast)) + t1 */
195        dla $13, VG_(tt_fast)
196        daddu $13, $13, $14
197
198        ld $12, 0($13) /* t3 = VG_(tt_fast)[hash] :: ULong* */
199        daddiu $13, $13, 8
200        ld $25, 0($13) /* little-endian, so comparing 1st 32bit word */
201        nop
202
203check:
204        bne $12, $11, fast_lookup_failed
205        /* run the translation */
206        jr $25
207        .long   0x0   /* persuade insn decoders not to speculate past here */
208
209fast_lookup_failed:
210        /* %PC is up to date */
211        /* back out decrement of the dispatch counter */
212        /* hold dispatch_ctr in t0 (r8) */
213        lw $13, vgPlain_stats__n_xindirs_32
214        addiu $13, $13, 0x1
215        sw $13, vgPlain_stats__n_xindirs_32
216        li $2, VG_TRC_INNER_FASTMISS
217        li $3, 0
218        b       postamble
219
220/* ------ Assisted jump ------ */
221        .global VG_(disp_cp_xassisted)
222VG_(disp_cp_xassisted):
223        /* guest-state-pointer contains the TRC. Put the value into the
224           return register */
225        move    $2, $23
226        move    $3, $0
227        b       postamble
228
229/* ------ Event check failed ------ */
230        .global VG_(disp_cp_evcheck_fail)
231VG_(disp_cp_evcheck_fail):
232        li      $2, VG_TRC_INNER_COUNTERZERO
233        move    $3, $0
234        b       postamble
235
236.size VG_(disp_run_translations), .-VG_(disp_run_translations)
237
238#endif // defined(VGP_mips64_linux)
239
240/* Let the linker know we don't need an executable stack */
241MARK_STACK_NO_EXEC
242
243/*--------------------------------------------------------------------*/
244/*--- end                                                          ---*/
245/*--------------------------------------------------------------------*/
246