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/*--- The core dispatch loop, for jumping to a code address. ---*/
/*--- dispatch-s390x-linux.S ---*/
This file is part of Valgrind, a dynamic binary instrumentation
Copyright IBM Corp. 2010-2013
Copyright (C) 2011-2013, Florian Krohm (
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307, USA.
The GNU General Public License is contained in the file COPYING.
/* Contributed by Florian Krohm and Christian Borntraeger */
#include "pub_core_basics_asm.h"
#include "pub_core_dispatch_asm.h"
#include "pub_core_transtab_asm.h"
#include "libvex_guest_offsets.h"
#include "libvex_s390x_common.h"
#if defined(VGA_s390x)
/*--- ---*/
/*--- The dispatch loop. VG_(disp_run_translations) is ---*/
/*--- used to run all translations, ---*/
/*--- including no-redir ones. ---*/
/*--- ---*/
/* Convenience definitions for readability */
#undef SP
#undef LR
/* Location of valgrind's saved FPC register */
/* Location of saved R2 register */
#define S390_LOC_SAVED_R2 S390_OFFSET_SAVED_R2(SP)
/*--- Entry and preamble (set everything up) ---*/
/* signature:
void VG_(disp_run_translations)( UWord* two_words,
void* guest_state,
Addr host_addr );
Return results are placed in two_words:
two_words[0] is set to the TRC
two_words[1] is set to the address to patch (in case two_words[0] is
VG_TRC_CHAIN_ME_TO_{SLOW,FAST}_EP). Otherwise, it is 0.
.align 4
.globl VG_(disp_run_translations)
.type VG_(disp_run_translations), @function
/* r2 holds two_words */
/* r3 holds pointer to guest_state */
/* r4 holds host_addr, i.e. the address of the translation to run */
/* Save gprs ABI: r6...r13 and r15 */
stmg %r6,%r15,48(SP)
/* New stack frame */
/* Save fprs: ABI: f8...f15 */
std %f8,160+0(SP)
std %f9,160+8(SP)
std %f10,160+16(SP)
std %f11,160+24(SP)
std %f12,160+32(SP)
std %f13,160+40(SP)
std %f14,160+48(SP)
std %f15,160+56(SP)
/* Load address of guest state into guest state register (r13) */
lgr %r13,%r3
/* Save R2 on stack. In postamble it will be restored such that the
return values can be written */
stg %r2,S390_LOC_SAVED_R2
/* Save valgrind's FPC on stack so postamble can restore
it later . */
stfpc S390_LOC_SAVED_FPC_V
/* Load the FPC the way the client code wants it. I.e. pull the
value from the guest state. */
lfpc OFFSET_s390x_fpc(%r13)
/* Jump into the code cache. Chained translations in
the code cache run, until for whatever reason, they can't
continue. When that happens, the translation in question
will jump (or call) to one of the continuation points
VG_(cp_...) below. */
br %r4
/*--- Postamble and return to C code. ---*/
/* At this point, %r0 and %r1 contain two
words to be returned to the caller. %r0
holds a TRC value, and %r1 optionally may
hold another word (for CHAIN_ME exits, the
address of the place to patch.) */
/* We're leaving. AMD has some code here to check invariants.
We don't have (need) that, as we save and restore the FPC register
whenever we switch between valgrind proper to client code. */
/* Restore valgrind's FPC, as client code may have changed it. */
/* Restore %r2 from stack; holds address of two_words */
lg %r2,S390_LOC_SAVED_R2
stg %r0,0(%r2) /* Store %r0 to two_words[0] */
stg %r1,8(%r2) /* Store %r1 to two_words[1] */
/* Restore callee-saved registers... */
/* Floating-point regs */
ld %f8,160+0(SP)
ld %f9,160+8(SP)
ld %f10,160+16(SP)
ld %f11,160+24(SP)
ld %f12,160+32(SP)
ld %f13,160+40(SP)
ld %f14,160+48(SP)
ld %f15,160+56(SP)
/* Remove stack frame */
/* General-purpose regs. This also restores the original link
register (r14) and stack pointer (r15). */
lmg %r6,%r15,48(SP)
/* Return */
br LR
/*--- Continuation points ---*/
/* ------ Chain me to slow entry point ------ */
.global VG_(disp_cp_chain_me_to_slowEP)
/* When we come here %r1 contains the address of the place to patch.
The return values (TRC, address-to-patch) are stored here in
%r0 and %r1, respectively */
j postamble
/* ------ Chain me to fast entry point ------ */
.global VG_(disp_cp_chain_me_to_fastEP)
/* Identical to VG_(disp_cp_chain_me_to_slowEP), except value of %r0. */
j postamble
/* ------ Indirect but boring jump ------ */
.global VG_(disp_cp_xindir)
/* Where are we going? */
lg %r2, OFFSET_s390x_IA(%r13)
/* Increment VG_(stats__n_xindirs_32) */
larl %r8, VG_(stats__n_xindirs_32)
l %r10,0(%r8)
ahi %r10,1
st %r10,0(%r8)
/* Try a fast lookup in the translation cache:
Compute offset (not index) into VT_(tt_fast):
offset = VG_TT_FAST_HASH(addr) * sizeof(FastCacheEntry)
with VG_TT_FAST_HASH(addr) == (addr >> 1) & VG_TT_FAST_MASK
and sizeof(FastCacheEntry) == 16
offset = ((addr >> 1) & VG_TT_FAST_MASK) << 4
which is
offset = ((addr & (VG_TT_FAST_MASK << 1) ) << 3
larl %r8, VG_(tt_fast)
llill %r5,(VG_TT_FAST_MASK << 1) & 0xffff
#if ((( VG_TT_FAST_MASK << 1) & 0xffff0000) >> 16 != 0)
iilh %r5,((VG_TT_FAST_MASK << 1) & 0xffff0000) >> 16
ngr %r5,%r2
sllg %r7,%r5,3
lg %r11, 8(%r8,%r7) /* .host */
cg %r2, 0(%r8,%r7) /* next guest address == .guest ? */
jne fast_lookup_failed
/* Found a match. Call .host.
r11 is an address. There we will find the instrumented client code.
That code may modify the guest state register r13. */
br %r11
.long 0x0 /* persuade insn decoders not to speculate past here */
/* Increment VG_(stats__n_xindir_misses_32) */
larl %r8, VG_(stats__n_xindir_misses_32)
l %r10,0(%r8)
ahi %r10,1
st %r10,0(%r8)
lghi %r1,0
j postamble
/* ------ Assisted jump ------ */
.global VG_(disp_cp_xassisted)
/* guest-state-pointer contains the TRC. Put the value into the
return register */
lgr %r0,%r13
lghi %r1,0
j postamble
/* ------ Event check failed ------ */
.global VG_(disp_cp_evcheck_fail)
lghi %r1,0
j postamble
.size VG_(disp_run_translations), .-VG_(disp_run_translations)
/* Let the linker know we don't need an executable stack */
.section .note.GNU-stack,"",@progbits
#endif /* VGA_s390x */
/*--- end dispatch-s390x-linux.S ---*/