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/* Copyright (C) 2011 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Chris Metcalf <cmetcalf@tilera.com>, 2011.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library. If not, see
<http://www.gnu.org/licenses/>. */
#include <sysdep.h>
#include <asm/errno.h>
#include <arch/spr_def.h>
#include <arch/abi.h>
#include "ucontext_i.h"
/* PL to return to via iret in setcontext */
#define RETURN_PL 0
/* int setcontext (const ucontext_t *ucp) */
.text
ENTRY (__setcontext)
FEEDBACK_ENTER(__setcontext)
/* See if this is a true signal context (flags == 0).
If so, restore by invoking rt_sigreturn(). */
#if UC_FLAGS_OFFSET != 0
# error "Add offset to r0 prior to load."
#endif
LD_PTR r10, r0
{
BEQZ r10, .Lsigreturn
addi r10, r10, -1 /* Confirm that it has value "1". */
}
BNEZ r10, .Lbadcontext
/* Save lr and r0 briefly on the stack and set the signal mask:
rt_sigprocmask (SIG_SETMASK, &ucp->uc_sigmask, NULL, _NSIG / 8). */
{
ST sp, lr
ADDI_PTR r11, sp, -(2 * REGSIZE)
move r10, sp
}
ADDI_PTR sp, sp, -(3 * REGSIZE)
cfi_def_cfa_offset (3 * REGSIZE)
cfi_offset (lr, 0)
{
ST r11, r10
ADDI_PTR r10, sp, (2 * REGSIZE)
}
{
ST r10, r0
ADDLI_PTR r1, r0, UC_SIGMASK_OFFSET
}
cfi_offset (r0, -REGSIZE)
{
movei r3, _NSIG / 8
movei r2, 0
}
{
movei r0, SIG_SETMASK
moveli TREG_SYSCALL_NR_NAME, __NR_rt_sigprocmask
}
swint1
ADDI_PTR r11, sp, 2 * REGSIZE /* Restore uc_context to r11. */
{
LD r11, r11
ADDI_PTR sp, sp, 3 * REGSIZE
}
cfi_def_cfa_offset (0)
LD lr, sp
{
ADDI_PTR r10, r11, UC_REG(0)
BNEZ r1, .Lsyscall_error
}
/* Restore the argument registers; note they will be random
unless makecontext() has been called. */
{ LD r0, r10; ADDI_PTR r10, r10, REGSIZE }
{ LD r1, r10; ADDI_PTR r10, r10, REGSIZE }
{ LD r2, r10; ADDI_PTR r10, r10, REGSIZE }
{ LD r3, r10; ADDI_PTR r10, r10, REGSIZE }
{ LD r4, r10; ADDI_PTR r10, r10, REGSIZE }
{ LD r5, r10; ADDI_PTR r10, r10, REGSIZE }
{ LD r6, r10; ADDI_PTR r10, r10, REGSIZE }
{ LD r7, r10; ADDI_PTR r10, r10, REGSIZE }
{ LD r8, r10; ADDI_PTR r10, r10, REGSIZE }
{ LD r9, r10; ADDLI_PTR r10, r10, UC_REG(30) - UC_REG(9) }
/* Restore the callee-saved GPRs. */
{ LD r30, r10; ADDI_PTR r10, r10, REGSIZE }
{ LD r31, r10; ADDI_PTR r10, r10, REGSIZE }
{ LD r32, r10; ADDI_PTR r10, r10, REGSIZE }
{ LD r33, r10; ADDI_PTR r10, r10, REGSIZE }
{ LD r34, r10; ADDI_PTR r10, r10, REGSIZE }
{ LD r35, r10; ADDI_PTR r10, r10, REGSIZE }
{ LD r36, r10; ADDI_PTR r10, r10, REGSIZE }
{ LD r37, r10; ADDI_PTR r10, r10, REGSIZE }
{ LD r38, r10; ADDI_PTR r10, r10, REGSIZE }
{ LD r39, r10; ADDI_PTR r10, r10, REGSIZE }
{ LD r40, r10; ADDI_PTR r10, r10, REGSIZE }
{ LD r41, r10; ADDI_PTR r10, r10, REGSIZE }
{ LD r42, r10; ADDI_PTR r10, r10, REGSIZE }
{ LD r43, r10; ADDI_PTR r10, r10, REGSIZE }
{ LD r44, r10; ADDI_PTR r10, r10, REGSIZE }
{ LD r45, r10; ADDI_PTR r10, r10, REGSIZE }
{ LD r46, r10; ADDI_PTR r10, r10, REGSIZE }
{ LD r47, r10; ADDI_PTR r10, r10, REGSIZE }
{ LD r48, r10; ADDI_PTR r10, r10, REGSIZE }
{ LD r49, r10; ADDI_PTR r10, r10, REGSIZE }
{ LD r50, r10; ADDI_PTR r10, r10, REGSIZE }
{ LD r51, r10; ADDI_PTR r10, r10, REGSIZE }
{ LD r52, r10; ADDI_PTR r10, r10, REGSIZE * 2 }
/* Skip tp since it must not change for a given thread. */
{ LD sp, r10; ADDI_PTR r10, r10, REGSIZE }
{ LD lr, r10; ADDI_PTR r10, r10, REGSIZE }
{ LD r11, r10; ADDI_PTR r10, r10, REGSIZE }
/* Construct an iret context; we set ICS so we can validly load
EX_CONTEXT for iret without being interrupted halfway through. */
{
LD r12, r10
movei r13, 1
}
{
mtspr INTERRUPT_CRITICAL_SECTION, r13
shli r12, r12, SPR_EX_CONTEXT_0_1__ICS_SHIFT
}
{
mtspr EX_CONTEXT_0_0, r11
ori r12, r12, RETURN_PL
}
mtspr EX_CONTEXT_0_1, r12
iret
jrp lr /* keep the backtracer happy */
.Lsigreturn:
/* This is a context obtained from a signal handler.
Perform a full restore by pushing the context
passed onto a simulated signal frame on the stack
and call the signal return syscall as if a signal
handler exited normally. */
{
ADDLI_PTR sp, sp, -(C_ABI_SAVE_AREA_SIZE + SI_MAX_SIZE + UC_SIZE)
ADDLI_PTR r1, sp, -UC_SIZE
}
cfi_def_cfa_offset (C_ABI_SAVE_AREA_SIZE + SI_MAX_SIZE + UC_SIZE)
moveli r2, UC_SIZE / REGSIZE
0: {
LD r10, r0
ADDI_PTR r0, r0, REGSIZE
}
{
ST r1, r10
ADDI_PTR r1, r1, REGSIZE
addi r2, r2, -1
}
BNEZ r2, 0b
moveli TREG_SYSCALL_NR_NAME, __NR_rt_sigreturn
swint1
/* Restore the stack and fall through to the error
path. Successful rt_sigreturn never returns to
its calling place. */
ADDLI_PTR sp, sp, (C_ABI_SAVE_AREA_SIZE + SI_MAX_SIZE + UC_SIZE)
cfi_def_cfa_offset (0)
.Lsyscall_error:
j SYSCALL_ERROR_NAME
.Lbadcontext:
{
movei r1, EINVAL
j SYSCALL_ERROR_NAME
}
END (__setcontext)
.hidden __setcontext
weak_alias (__setcontext, setcontext)
ENTRY (__startcontext)
FEEDBACK_ENTER(__startcontext)
BEQZ r30, 1f
{
move r0, r30
jal __setcontext
}
1: j HIDDEN_JUMPTARGET(exit)
END (__startcontext)
.hidden __startcontext
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