nds32: add NPTL/TLS, *context function, libm changes and code cleanup

This commit includes following features.
1. Support NPTL/TLS
2. Add libm function which is used to handle FP rounding and excpetions
   (ex: fclrexcpt,fedisblxcpti,feenablxcpt... )
3. Add *context function for operating user context
   (ex: setcontext,getcontext,makecontext... )
4. Change the return flow from signal handler
5. Cleanup of old code

The testsuite only has 2 errors, tst-cpuclock1 and tst-cputimer1,
which are related to timing accuracy. (math and locale tests are disabled)

Signed-off-by: Vincent Ren-Wei Chen <vincentc@andestech.com>

1 files changed, 144 insertions, 56 deletions

diff --git a/libc/sysdeps/linux/nds32/clone.S b/libc/sysdeps/linux/nds32/clone.S
index 5dba17896..1ed77fb2e 100644
--- a/libc/sysdeps/linux/nds32/clone.S
+++ b/libc/sysdeps/linux/nds32/clone.S
@@ -1,92 +1,180 @@
 /*
- * Copyright (C) 2016 Andes Technology, Inc.
+ * Copyright (C) 2016-2017 Andes Technology, Inc.
  * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
  */
 
+/* Copyright (C) 2010-2014 Free Software Foundation, Inc.
+   Contributed by Pat Beirne <patb@corelcomputer.com>
+
+   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, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
 /* clone() is even more special than fork() as it mucks with stacks
    and invokes a function in the right context after its all over.  */
 
 #include <sysdep.h>
-#include <sys/syscall.h>
 #define _ERRNO_H	1
 #include <bits/errno.h>
 
-/*
-       int clone(int (*fn)(void *), void *child_stack, int flags, void *arg);
-       _syscall2(int, clone, int, flags, void *, child_stack)
-*/
+#ifdef RESET_PID
+#include <tcb-offsets.h>
+#endif
+
+#define CLONE_VM      0x00000100
+#define CLONE_THREAD  0x00010000
+
+/* int clone(int (*fn)(void *), void *child_stack, int flags, void *arg);
+   _syscall2(int, clone, int, flags, void *, child_stack)  */
 
 ENTRY(__clone)
+#ifdef __NDS32_ABI_2FP_PLUS__
+	lwi	$r4, [$sp]
+	lwi	$r5, [$sp+4]
+#endif
 #ifdef PIC
 	/* set GP register to parent only, cause child's $SP will be $r1. */
 	pushm	$fp, $gp
-#ifndef __NDS32_N1213_43U1H__
-	mfusr $r15, $PC
-#endif
-	sethi	$gp,	hi20(_GLOBAL_OFFSET_TABLE_+4)
-	ori	$gp,	$gp,	lo12(_GLOBAL_OFFSET_TABLE_+8)
-	add	$gp,	$gp,	$r15
-#endif
-        /* sanity check arguments.  */
-        beqz    $r0, 1f
-        bnez    $r1, 2f
+	cfi_adjust_cfa_offset(8)
+	cfi_rel_offset(fp, 0)
+	cfi_rel_offset(gp, 4)
+	mfusr	$r15, $pc
+	sethi	$gp, hi20(_GLOBAL_OFFSET_TABLE_+4)
+	ori	$gp, $gp, lo12(_GLOBAL_OFFSET_TABLE_+8)
+	add	$gp, $gp, $r15
+#endif /* PIC  */
+
+	/* sanity check arguments.  */
+	beqz	$r0, 1f
+	bnez	$r1, 2f
 
 1:
-        movi    $r0, -EINVAL
+	movi	$r0, -EINVAL
+
 5:
 #ifdef PIC
-		  /* restore GP register, only in parent's stack */
-		  popm	$fp, $gp
-        la      $r15, C_SYMBOL_NAME(__syscall_error@PLT)
-        jr      $r15
-#else
-        b       C_SYMBOL_NAME(__syscall_error)
-#endif
+	/* restore GP register, only in parent's stack  */
+	la	$r15, C_SYMBOL_NAME(__syscall_error@PLT)
+	push	$lp
+	cfi_adjust_cfa_offset(4)
+	cfi_rel_offset(lp, 0)
+	addi	$sp, $sp, -4
+	cfi_adjust_cfa_offset(4)
+	jral	$r15
+	addi	$sp, $sp, 4
+	cfi_adjust_cfa_offset(-4)
+	pop	$lp
+	cfi_adjust_cfa_offset(-4)
+	cfi_restore(lp)
+	popm	$fp, $gp
+	cfi_adjust_cfa_offset(-8)
+	cfi_restore(fp)
+	cfi_restore(gp)
+	ret
+#else /* ! PIC  */
+	la	$r15, C_SYMBOL_NAME(__syscall_error)
+	jr	$r15
+#endif /* ! PIC  */
 
 2:
-	/* Child's $SP will be $r1, push to child's stack only. */
+	/* Child's $sp will be $r1, make $sp 8-byte alignment */
+	bitci	$r1, $r1, 7
+	/* push to child's stack only.  */
 	addi	$r1, $r1, -4
-        swi.p   $r3, [$r1], -4  ! arg
-        swi     $r0, [$r1]  ! fn
+	swi.p	$r3, [$r1], -4			! arg
+	swi	$r0, [$r1]			! fn
+
+	/* do the system call  */
+	or	$r0, $r2, $r2			! move $r0, $r2
+
+	move    $r3, $r5
+	move    $r5, $r2                        ! Use $r5 to backup $r2
+						! The pt_regs is placed in $r5 in kerenl (sys_clone_wrapper)
+	move    $r2, $r4
 
-        /* do the system call */
-        or      $r0, $r2, $r2   ! move r0, r2
-        __do_syscall(clone)
-	!syscall (__NR_clone)
-        beqz    $r0, 4f
-        bltz    $r0, 5b
+#ifdef __NDS32_ABI_2FP_PLUS__
+# ifdef PIC
+       lwi     $r4, [$sp+#0x10]
+# else
+       lwi     $r4, [$sp+#0x8]
+# endif
+#else
+# ifdef PIC
+       lwi     $r4, [$sp+#0x8]
+# else
+       lwi     $r4, [$sp]
+# endif
+#endif
+
+	__do_syscall(clone)
+	beqz    $r0, 4f
+	bltz    $r0, 5b
 
-        ! parent
+
+10:
 #ifdef PIC
-	/* restore GP register, only in parent's stack */
+	/* restore GP register, only in parent's stack  */
 	popm	$fp, $gp
-#endif
-        ret
+	cfi_adjust_cfa_offset(-8)
+	cfi_restore(gp)
+	cfi_restore(fp)
+#endif /* PIC  */
+	ret
 
+#ifdef RESET_PID
 4:
-	/* Only in child's stack. */
-        pop     $r1  ! fn
-        pop     $r0  ! arg
-#if defined(NDS32_ABI_2) || defined(NDS32_ABI_2FP)
+	cfi_undefined(lp)
+	movi	$r0, CLONE_THREAD		! Skip when CLONE_THREAD is set.
+	and	$r0, $r5, $r0
+	bnez	$r0, 8f
+	movi    $r0, CLONE_VM			! Value = -1 when CLONE_VM is set.
+	and	$r0, $r5, $r0
+	beqz	$r0, 6f
+	movi	$r0, -1
+	j	7f
+6:
+        __do_syscall(getpid) ! __do_syscall(gettid) ! __do_syscall(getpid)
+7:
+	swi     $r0, [$r25 + PID_OFFSET]
+        swi     $r0, [$r25 + TID_OFFSET]
+8:
 #else
-	addi	$sp, $sp, -24
-#endif
-	! use r15 in case _exit is PIC
-#ifdef __NDS32_N1213_43U1H__
-        or      $r15, $r1, $r1   ! move r15, r2
+4:
 #endif
-        bral    $r1
-#if defined(NDS32_ABI_2) || defined(NDS32_ABI_2FP)
-#else
+	/* Only in child's stack.  */
+	pop	$r1				! fn
+	pop	$r0				! arg
+
+
+#if !defined(__NDS32_ABI_2__) && !defined(__NDS32_ABI_2FP_PLUS__)
+	addi	$sp, $sp, -24
+#endif /* !defined(__NDS32_ABI_2__) && !defined(__NDS32_ABI_2FP_PLUS__)  */
+
+	! use $r15 in case _exit is PIC
+	bral	$r1
+
+#if !defined(__NDS32_ABI_2__) && !defined(__NDS32_ABI_2FP_PLUS__)
 	addi	$sp, $sp, 24
-#endif
-	! use r15 in case _exit is PIC
+#endif /* !defined(__NDS32_ABI_2__) && !defined(__NDS32_ABI_2FP_PLUS__)  */
+
+	! use $r15 in case _exit is PIC
 #ifdef PIC
-        la      $r15, C_SYMBOL_NAME(_exit@PLT)
-        jr      $r15
-#else
-        b       C_SYMBOL_NAME(_exit)
-#endif
+	la	$r15, C_SYMBOL_NAME(_exit@PLT)
+#else /* ! PIC  */
+	la	$r15, C_SYMBOL_NAME(_exit)
+#endif /* ! PIC  */
+	jr	$r15
 
 
 PSEUDO_END (__clone)