d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
c7f58afc39
freebsd-dev/sys/contrib/ia64/libuwx/src/uwx_context.c

345 lines
11 KiB
C
Raw Normal View History

This is beta4 of libuwx; an ia64 stack unwinder. This code is made available by Hewlett-Packard under the MIT license. The unwinder is small, clean and fast and needed little adaptation for use in the kernel. This import has embedded in it the changes needed to make it build in a kernel environment. To optimize the common case, the kernel will minimize the number of registers saved by not saving the preserved registers. In case access to preserved registers is needed (signal handling, ptrace) the kernel will unwind to the context of the syscall or exception. For this we need an unwinder. Approved by: re (blanket)
2003-05-15 05:04:44 +00:00
/*
* Copyright (c) 2002,2003 Hewlett-Packard Company
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*/
#include "uwx_env.h"
#include "uwx_context.h"
#include "uwx_scoreboard.h"
Upgrade Unwind Express (libuwx) to BETA 5. This upgrade includes all the fixes locally applied and submitted to the author. Not included in BETA 5, but part of this import are: o FreeBSD specific ifdefs to make this compile within a kernel. These are limited to include directives and defines. o Removal of unused variables, proper casts and initializations to allow building with -Werror. This happens in code so has a higher chance of causing future import conflicts but not enough to worry about it. I'm especially thankful that the author accepted the change to replace DISABLE_TRACE with UWX_TRACE_ENABLE so that we can use it in kernel config files without nasty mappings or indirections as that would make the integration less perfect. Thanks Cary!
2003-10-09 03:02:46 +00:00
#include "uwx_step.h"
This is beta4 of libuwx; an ia64 stack unwinder. This code is made available by Hewlett-Packard under the MIT license. The unwinder is small, clean and fast and needed little adaptation for use in the kernel. This import has embedded in it the changes needed to make it build in a kernel environment. To optimize the common case, the kernel will minimize the number of registers saved by not saving the preserved registers. In case access to preserved registers is needed (signal handling, ptrace) the kernel will unwind to the context of the syscall or exception. For this we need an unwinder. Approved by: re (blanket)
2003-05-15 05:04:44 +00:00
#include "uwx_trace.h"
int uwx_init_context(
struct uwx_env *env,
uint64_t ip,
uint64_t sp,
uint64_t bsp,
uint64_t cfm)
{
int i;
if (env == 0)
return UWX_ERR_NOENV;
env->context.special[UWX_REG_IP] = ip;
env->context.special[UWX_REG_SP] = sp;
env->context.special[UWX_REG_BSP] = bsp;
env->context.special[UWX_REG_CFM] = cfm;
for (i = UWX_REG_RP; i < NSPECIALREG; i++)
env->context.special[i] = 0;
for (i = 0; i < NPRESERVEDGR; i++)
env->context.gr[i] = 0;
env->context.valid_regs = VALID_BASIC4;
Upgrade Unwind Express (libuwx) to BETA 5. This upgrade includes all the fixes locally applied and submitted to the author. Not included in BETA 5, but part of this import are: o FreeBSD specific ifdefs to make this compile within a kernel. These are limited to include directives and defines. o Removal of unused variables, proper casts and initializations to allow building with -Werror. This happens in code so has a higher chance of causing future import conflicts but not enough to worry about it. I'm especially thankful that the author accepted the change to replace DISABLE_TRACE with UWX_TRACE_ENABLE so that we can use it in kernel config files without nasty mappings or indirections as that would make the integration less perfect. Thanks Cary!
2003-10-09 03:02:46 +00:00
env->context.valid_frs = 0;
This is beta4 of libuwx; an ia64 stack unwinder. This code is made available by Hewlett-Packard under the MIT license. The unwinder is small, clean and fast and needed little adaptation for use in the kernel. This import has embedded in it the changes needed to make it build in a kernel environment. To optimize the common case, the kernel will minimize the number of registers saved by not saving the preserved registers. In case access to preserved registers is needed (signal handling, ptrace) the kernel will unwind to the context of the syscall or exception. For this we need an unwinder. Approved by: re (blanket)
2003-05-15 05:04:44 +00:00
env->rstate = 0;
(void)uwx_init_history(env);
return UWX_OK;
}
int uwx_get_reg(struct uwx_env *env, int regid, uint64_t *valp)
{
int status;
int sor;
int rrb_gr;
uint64_t bsp;
int n;
if (env == 0)
return UWX_ERR_NOENV;
status = UWX_OK;
Upgrade Unwind Express (libuwx) to BETA 5. This upgrade includes all the fixes locally applied and submitted to the author. Not included in BETA 5, but part of this import are: o FreeBSD specific ifdefs to make this compile within a kernel. These are limited to include directives and defines. o Removal of unused variables, proper casts and initializations to allow building with -Werror. This happens in code so has a higher chance of causing future import conflicts but not enough to worry about it. I'm especially thankful that the author accepted the change to replace DISABLE_TRACE with UWX_TRACE_ENABLE so that we can use it in kernel config files without nasty mappings or indirections as that would make the integration less perfect. Thanks Cary!
2003-10-09 03:02:46 +00:00
if (regid == UWX_REG_GR(12))
regid = UWX_REG_SP;
This is beta4 of libuwx; an ia64 stack unwinder. This code is made available by Hewlett-Packard under the MIT license. The unwinder is small, clean and fast and needed little adaptation for use in the kernel. This import has embedded in it the changes needed to make it build in a kernel environment. To optimize the common case, the kernel will minimize the number of registers saved by not saving the preserved registers. In case access to preserved registers is needed (signal handling, ptrace) the kernel will unwind to the context of the syscall or exception. For this we need an unwinder. Approved by: re (blanket)
2003-05-15 05:04:44 +00:00
if (regid < NSPECIALREG && (env->context.valid_regs & (1 << regid)))
*valp = env->context.special[regid];
Upgrade Unwind Express (libuwx) to BETA 5. This upgrade includes all the fixes locally applied and submitted to the author. Not included in BETA 5, but part of this import are: o FreeBSD specific ifdefs to make this compile within a kernel. These are limited to include directives and defines. o Removal of unused variables, proper casts and initializations to allow building with -Werror. This happens in code so has a higher chance of causing future import conflicts but not enough to worry about it. I'm especially thankful that the author accepted the change to replace DISABLE_TRACE with UWX_TRACE_ENABLE so that we can use it in kernel config files without nasty mappings or indirections as that would make the integration less perfect. Thanks Cary!
2003-10-09 03:02:46 +00:00
else if (regid == UWX_REG_PSP || regid == UWX_REG_RP ||
regid == UWX_REG_PFS) {
status = uwx_restore_markers(env);
if (status != UWX_OK)
return status;
*valp = env->context.special[regid];
}
This is beta4 of libuwx; an ia64 stack unwinder. This code is made available by Hewlett-Packard under the MIT license. The unwinder is small, clean and fast and needed little adaptation for use in the kernel. This import has embedded in it the changes needed to make it build in a kernel environment. To optimize the common case, the kernel will minimize the number of registers saved by not saving the preserved registers. In case access to preserved registers is needed (signal handling, ptrace) the kernel will unwind to the context of the syscall or exception. For this we need an unwinder. Approved by: re (blanket)
2003-05-15 05:04:44 +00:00
else if (regid >= UWX_REG_GR(4) && regid <= UWX_REG_GR(7) &&
(env->context.valid_regs &
(1 << (regid - UWX_REG_GR(4) + VALID_GR_SHIFT))) )
*valp = env->context.gr[regid - UWX_REG_GR(4)];
else if (regid >= UWX_REG_GR(32) && regid <= UWX_REG_GR(127)) {
if (env->copyin == 0)
return UWX_ERR_NOCALLBACKS;
bsp = env->context.special[UWX_REG_BSP];
TRACE_C_GET_REG(regid, bsp)
regid -= UWX_REG_GR(32);
sor = (((int) env->context.special[UWX_REG_CFM] >> 14) & 0x0f) * 8;
rrb_gr = ((int) env->context.special[UWX_REG_CFM] >> 18) & 0x7f;
if (sor != 0 && rrb_gr != 0 && regid < sor) {
TRACE_C_ROTATE_GR(regid, sor, rrb_gr, (regid+rrb_gr)%sor)
regid = (regid + rrb_gr) % sor;
}
bsp = uwx_add_to_bsp(bsp, regid);
n = (*env->copyin)(UWX_COPYIN_RSTACK, (char *)valp,
bsp, DWORDSZ, env->cb_token);
if (n != DWORDSZ)
status = UWX_ERR_COPYIN_RSTK;
}
else if (regid == UWX_REG_GR(0))
*valp = 0;
else if (regid >= UWX_REG_BR(1) && regid <= UWX_REG_BR(5) &&
(env->context.valid_regs &
(1 << (regid - UWX_REG_BR(1) + VALID_BR_SHIFT))) )
*valp = env->context.br[regid - UWX_REG_BR(1)];
Upgrade Unwind Express (libuwx) to BETA 5. This upgrade includes all the fixes locally applied and submitted to the author. Not included in BETA 5, but part of this import are: o FreeBSD specific ifdefs to make this compile within a kernel. These are limited to include directives and defines. o Removal of unused variables, proper casts and initializations to allow building with -Werror. This happens in code so has a higher chance of causing future import conflicts but not enough to worry about it. I'm especially thankful that the author accepted the change to replace DISABLE_TRACE with UWX_TRACE_ENABLE so that we can use it in kernel config files without nasty mappings or indirections as that would make the integration less perfect. Thanks Cary!
2003-10-09 03:02:46 +00:00
else if (regid >= UWX_REG_FR(2) && regid <= UWX_REG_FR(5) &&
(env->context.valid_frs & (1 << (regid - UWX_REG_FR(2)))) ) {
This is beta4 of libuwx; an ia64 stack unwinder. This code is made available by Hewlett-Packard under the MIT license. The unwinder is small, clean and fast and needed little adaptation for use in the kernel. This import has embedded in it the changes needed to make it build in a kernel environment. To optimize the common case, the kernel will minimize the number of registers saved by not saving the preserved registers. In case access to preserved registers is needed (signal handling, ptrace) the kernel will unwind to the context of the syscall or exception. For this we need an unwinder. Approved by: re (blanket)
2003-05-15 05:04:44 +00:00
valp[0] = env->context.fr[regid - UWX_REG_FR(2)].part0;
valp[1] = env->context.fr[regid - UWX_REG_FR(2)].part1;
}
Upgrade Unwind Express (libuwx) to BETA 5. This upgrade includes all the fixes locally applied and submitted to the author. Not included in BETA 5, but part of this import are: o FreeBSD specific ifdefs to make this compile within a kernel. These are limited to include directives and defines. o Removal of unused variables, proper casts and initializations to allow building with -Werror. This happens in code so has a higher chance of causing future import conflicts but not enough to worry about it. I'm especially thankful that the author accepted the change to replace DISABLE_TRACE with UWX_TRACE_ENABLE so that we can use it in kernel config files without nasty mappings or indirections as that would make the integration less perfect. Thanks Cary!
2003-10-09 03:02:46 +00:00
else if (regid >= UWX_REG_FR(16) && regid <= UWX_REG_FR(31) &&
(env->context.valid_frs & (1 << (regid - UWX_REG_FR(16) + 4))) ) {
This is beta4 of libuwx; an ia64 stack unwinder. This code is made available by Hewlett-Packard under the MIT license. The unwinder is small, clean and fast and needed little adaptation for use in the kernel. This import has embedded in it the changes needed to make it build in a kernel environment. To optimize the common case, the kernel will minimize the number of registers saved by not saving the preserved registers. In case access to preserved registers is needed (signal handling, ptrace) the kernel will unwind to the context of the syscall or exception. For this we need an unwinder. Approved by: re (blanket)
2003-05-15 05:04:44 +00:00
valp[0] = env->context.fr[regid - UWX_REG_FR(16) + 4].part0;
valp[1] = env->context.fr[regid - UWX_REG_FR(16) + 4].part1;
}
else if ( (regid < NSPECIALREG) ||
(regid >= UWX_REG_GR(1) && regid <= UWX_REG_GR(31)) ||
(regid >= UWX_REG_BR(0) && regid <= UWX_REG_BR(7)) ) {
if (env->copyin == 0)
return UWX_ERR_NOCALLBACKS;
n = (*env->copyin)(UWX_COPYIN_REG, (char *)valp,
regid, DWORDSZ, env->cb_token);
if (n != DWORDSZ)
status = UWX_ERR_COPYIN_REG;
}
Upgrade Unwind Express (libuwx) to BETA 5. This upgrade includes all the fixes locally applied and submitted to the author. Not included in BETA 5, but part of this import are: o FreeBSD specific ifdefs to make this compile within a kernel. These are limited to include directives and defines. o Removal of unused variables, proper casts and initializations to allow building with -Werror. This happens in code so has a higher chance of causing future import conflicts but not enough to worry about it. I'm especially thankful that the author accepted the change to replace DISABLE_TRACE with UWX_TRACE_ENABLE so that we can use it in kernel config files without nasty mappings or indirections as that would make the integration less perfect. Thanks Cary!
2003-10-09 03:02:46 +00:00
else if (regid >= UWX_REG_FR(2) && regid <= UWX_REG_FR(127)) {
This is beta4 of libuwx; an ia64 stack unwinder. This code is made available by Hewlett-Packard under the MIT license. The unwinder is small, clean and fast and needed little adaptation for use in the kernel. This import has embedded in it the changes needed to make it build in a kernel environment. To optimize the common case, the kernel will minimize the number of registers saved by not saving the preserved registers. In case access to preserved registers is needed (signal handling, ptrace) the kernel will unwind to the context of the syscall or exception. For this we need an unwinder. Approved by: re (blanket)
2003-05-15 05:04:44 +00:00
if (env->copyin == 0)
return UWX_ERR_NOCALLBACKS;
n = (*env->copyin)(UWX_COPYIN_REG, (char *)valp,
regid, 2*DWORDSZ, env->cb_token);
if (n != 2*DWORDSZ)
status = UWX_ERR_COPYIN_REG;
}
else if (regid == UWX_REG_FR(0)) {
valp[0] = 0;
valp[1] = 0;
}
else if (regid == UWX_REG_FR(1)) {
valp[0] = 0x000000000000ffffULL;
valp[1] = 0x8000000000000000ULL;
}
else
status = UWX_ERR_BADREGID;
return status;
}
int uwx_get_nat(struct uwx_env *env, int regid, int *natp)
{
int status;
int sor;
int rrb_gr;
uint64_t bsp;
uint64_t natcollp;
uint64_t natcoll;
int n;
if (env == 0)
return UWX_ERR_NOENV;
status = UWX_OK;
if (regid >= UWX_REG_GR(4) && regid <= UWX_REG_GR(7) &&
(env->context.valid_regs &
(1 << (regid - UWX_REG_GR(4) + VALID_GR_SHIFT))) ) {
*natp = (env->context.special[UWX_REG_PRIUNAT] >>
(regid - UWX_REG_GR(4)) ) & 0x01;
}
else if (regid >= UWX_REG_GR(32) && regid <= UWX_REG_GR(127)) {
if (env->copyin == 0)
return UWX_ERR_NOCALLBACKS;
bsp = env->context.special[UWX_REG_BSP];
regid -= UWX_REG_GR(32);
sor = (((int) env->context.special[UWX_REG_CFM] >> 14) & 0x0f) * 8;
rrb_gr = ((int) env->context.special[UWX_REG_CFM] >> 18) & 0x7f;
if (sor != 0 && rrb_gr != 0 && regid < sor) {
regid = (regid + rrb_gr) % sor;
}
bsp = uwx_add_to_bsp(bsp, regid);
natcollp = bsp | 0x01f8;
if (natcollp >= bsp)
n = (*env->copyin)(UWX_COPYIN_REG, (char *)&natcoll,
Upgrade Unwind Express (libuwx) to BETA 5. This upgrade includes all the fixes locally applied and submitted to the author. Not included in BETA 5, but part of this import are: o FreeBSD specific ifdefs to make this compile within a kernel. These are limited to include directives and defines. o Removal of unused variables, proper casts and initializations to allow building with -Werror. This happens in code so has a higher chance of causing future import conflicts but not enough to worry about it. I'm especially thankful that the author accepted the change to replace DISABLE_TRACE with UWX_TRACE_ENABLE so that we can use it in kernel config files without nasty mappings or indirections as that would make the integration less perfect. Thanks Cary!
2003-10-09 03:02:46 +00:00
(uint64_t)UWX_REG_AR_RNAT, DWORDSZ, env->cb_token);
This is beta4 of libuwx; an ia64 stack unwinder. This code is made available by Hewlett-Packard under the MIT license. The unwinder is small, clean and fast and needed little adaptation for use in the kernel. This import has embedded in it the changes needed to make it build in a kernel environment. To optimize the common case, the kernel will minimize the number of registers saved by not saving the preserved registers. In case access to preserved registers is needed (signal handling, ptrace) the kernel will unwind to the context of the syscall or exception. For this we need an unwinder. Approved by: re (blanket)
2003-05-15 05:04:44 +00:00
else
n = (*env->copyin)(UWX_COPYIN_RSTACK, (char *)&natcoll,
bsp, DWORDSZ, env->cb_token);
if (n != DWORDSZ)
return UWX_ERR_COPYIN_RSTK;
*natp = (int)(natcoll >> (((int)bsp >> 3) & 0x3f)) & 0x01;
}
else if (regid == UWX_REG_GR(0))
*natp = 0;
else
status = UWX_ERR_BADREGID;
return status;
}
int uwx_get_spill_loc(struct uwx_env *env, int regid, uint64_t *dispp)
{
int status;
int sor;
int rrb_gr;
uint64_t bsp;
if (env == 0)
return UWX_ERR_NOENV;
status = UWX_OK;
Upgrade Unwind Express (libuwx) to BETA 5. This upgrade includes all the fixes locally applied and submitted to the author. Not included in BETA 5, but part of this import are: o FreeBSD specific ifdefs to make this compile within a kernel. These are limited to include directives and defines. o Removal of unused variables, proper casts and initializations to allow building with -Werror. This happens in code so has a higher chance of causing future import conflicts but not enough to worry about it. I'm especially thankful that the author accepted the change to replace DISABLE_TRACE with UWX_TRACE_ENABLE so that we can use it in kernel config files without nasty mappings or indirections as that would make the integration less perfect. Thanks Cary!
2003-10-09 03:02:46 +00:00
if (regid == UWX_REG_GR(12))
regid = UWX_REG_SP;
This is beta4 of libuwx; an ia64 stack unwinder. This code is made available by Hewlett-Packard under the MIT license. The unwinder is small, clean and fast and needed little adaptation for use in the kernel. This import has embedded in it the changes needed to make it build in a kernel environment. To optimize the common case, the kernel will minimize the number of registers saved by not saving the preserved registers. In case access to preserved registers is needed (signal handling, ptrace) the kernel will unwind to the context of the syscall or exception. For this we need an unwinder. Approved by: re (blanket)
2003-05-15 05:04:44 +00:00
if (regid < NSPECIALREG)
*dispp = env->history.special[regid];
else if (regid >= UWX_REG_GR(4) && regid <= UWX_REG_GR(7))
*dispp = env->history.gr[regid - UWX_REG_GR(4)];
else if (regid >= UWX_REG_GR(32) && regid <= UWX_REG_GR(127)) {
bsp = env->context.special[UWX_REG_BSP];
regid -= UWX_REG_GR(32);
sor = (((int) env->context.special[UWX_REG_CFM] >> 14) & 0x0f) * 8;
rrb_gr = ((int) env->context.special[UWX_REG_CFM] >> 18) & 0x7f;
if (sor != 0 && rrb_gr != 0 && regid < sor)
regid = (regid + rrb_gr) % sor;
bsp = uwx_add_to_bsp(bsp, regid);
*dispp = UWX_DISP_RSTK(bsp);
}
else if (regid >= UWX_REG_BR(1) && regid <= UWX_REG_GR(5))
*dispp = env->history.br[regid - UWX_REG_BR(1)];
else if (regid >= UWX_REG_FR(2) && regid <= UWX_REG_FR(5))
*dispp = env->history.fr[regid - UWX_REG_FR(2)];
else if (regid >= UWX_REG_FR(16) && regid <= UWX_REG_FR(31))
*dispp = env->history.fr[regid - UWX_REG_FR(16) + 4];
else if ( (regid >= UWX_REG_GR(1) && regid <= UWX_REG_GR(31)) ||
(regid >= UWX_REG_BR(0) && regid <= UWX_REG_BR(7)) ||
(regid >= UWX_REG_FR(2) && regid <= UWX_REG_FR(127)) )
*dispp = UWX_DISP_REG(regid);
else
status = UWX_ERR_BADREGID;
return status;
}
int uwx_set_reg(struct uwx_env *env, int regid, uint64_t val)
{
int status;
if (env == 0)
return UWX_ERR_NOENV;
Upgrade Unwind Express (libuwx) to BETA 5. This upgrade includes all the fixes locally applied and submitted to the author. Not included in BETA 5, but part of this import are: o FreeBSD specific ifdefs to make this compile within a kernel. These are limited to include directives and defines. o Removal of unused variables, proper casts and initializations to allow building with -Werror. This happens in code so has a higher chance of causing future import conflicts but not enough to worry about it. I'm especially thankful that the author accepted the change to replace DISABLE_TRACE with UWX_TRACE_ENABLE so that we can use it in kernel config files without nasty mappings or indirections as that would make the integration less perfect. Thanks Cary!
2003-10-09 03:02:46 +00:00
if (regid == UWX_REG_GR(12))
regid = UWX_REG_SP;
This is beta4 of libuwx; an ia64 stack unwinder. This code is made available by Hewlett-Packard under the MIT license. The unwinder is small, clean and fast and needed little adaptation for use in the kernel. This import has embedded in it the changes needed to make it build in a kernel environment. To optimize the common case, the kernel will minimize the number of registers saved by not saving the preserved registers. In case access to preserved registers is needed (signal handling, ptrace) the kernel will unwind to the context of the syscall or exception. For this we need an unwinder. Approved by: re (blanket)
2003-05-15 05:04:44 +00:00
if (regid < NSPECIALREG) {
env->context.special[regid] = val;
env->context.valid_regs |= 1 << regid;
status = UWX_OK;
}
else if (regid >= UWX_REG_GR(4) && regid <= UWX_REG_GR(7)) {
env->context.gr[regid - UWX_REG_GR(4)] = val;
env->context.valid_regs |=
1 << (regid - UWX_REG_GR(4) + VALID_GR_SHIFT);
status = UWX_OK;
}
else if (regid >= UWX_REG_GR(32) && regid <= UWX_REG_GR(127)) {
status = UWX_ERR_BADREGID;
}
else if (regid >= UWX_REG_BR(1) && regid <= UWX_REG_BR(5)) {
env->context.br[regid - UWX_REG_BR(1)] = val;
env->context.valid_regs |=
1 << (regid - UWX_REG_BR(1) + VALID_BR_SHIFT);
status = UWX_OK;
}
else
status = UWX_ERR_BADREGID;
return status;
}
int uwx_set_fr(struct uwx_env *env, int regid, uint64_t *val)
{
if (regid >= UWX_REG_FR(2) && regid <= UWX_REG_FR(5))
regid -= UWX_REG_FR(2);
else if (regid >= UWX_REG_FR(16) && regid <= UWX_REG_FR(31))
regid -= UWX_REG_FR(16) - 4;
else
return UWX_ERR_BADREGID;
env->context.fr[regid].part0 = val[0];
env->context.fr[regid].part1 = val[1];
env->context.valid_frs |= 1 << regid;
env->nsbreg = NSBREG;
return UWX_OK;
}
uint64_t uwx_add_to_bsp(uint64_t bsp, int nslots)
{
int bias;
/*
* Here's a picture of the backing store as modeled in
* the computations below. "X" marks NaT collections at
* every 0x1f8 mod 0x200 address.
*
* To make the NaT adjustments easier, we bias the current bsp
* by enough slots to place it at the previous NaT collection.
* Then we need to add the bias to the number of slots,
* then add 1 for every 63 slots to account for NaT collections.
* Then we can remove the bias again and add the adjusted
* number of slots to the bsp.
*
* 0 1f8 3f8
* +---------------------------------------------------------------+
* | X X|
* +---------------------------------------------------------------+
* <-------- bias -------->
* <--- nslots --->
* ^
* |
* bsp
* <------- adjusted (nslots + bias) ------->
* When subtracting from bsp, we bias the bsp in the opposite
* direction so that it is at the next NaT collection.
*
* 0 1f8 3f8
* +---------------------------------------------------------------+
* | X X|
* +---------------------------------------------------------------+
* <------- bias ------->
* <--- nslots --->
* ^
* |
* bsp
* <------ adjusted (nslots + bias) ------>
*/
if (nslots > 0) {
bias = ((unsigned int)bsp & 0x1f8) / DWORDSZ;
nslots += (nslots + bias) / 63;
}
else if (nslots < 0) {
bias = (0x1f8 - ((unsigned int)bsp & 0x1f8)) / DWORDSZ;
nslots -= (-nslots + bias) / 63;
}
return bsp + nslots * DWORDSZ;
}
Reference in New Issue Copy Permalink