libc_sh: Add a sysdep header for sh

A new sysdep header for sh (ported from NPTL branch) to provide some
useful macros in asm code:
ENTRY: an entry point visible from C
PSEUDO: a wrapper for syscall with proper errno checking
SYSCALL_ERROR_HANDLER: errno check (suitable for TLS)

This will help in NPTL integration.

Signed-off-by: Carmelo Amoroso <carmelo.amoroso@st.com>

libc/sysdeps/linux/sh/sysdep.h

@@ -0,0 +1,277 @@
+/* Assembler macros for SH.
+   Copyright (C) 1999, 2000, 2005 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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.  */
+
+#include <common/sysdep.h>
+
+#include <features.h>
+#include <libc-internal.h>
+
+#ifdef	__ASSEMBLER__
+
+/* Syntactic details of assembler.  */
+
+#define ALIGNARG(log2) log2
+/* For ELF we need the `.type' directive to make shared libs work right.  */
+#define ASM_TYPE_DIRECTIVE(name,typearg) .type name,@##typearg;
+#define ASM_SIZE_DIRECTIVE(name) .size name,.-name
+
+#ifdef SHARED
+#define PLTJMP(_x)	_x##@PLT
+#else
+#define PLTJMP(_x)	_x
+#endif
+
+/* Define an entry point visible from C.  */
+#define	ENTRY(name)							      \
+  ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME(name);				      \
+  ASM_TYPE_DIRECTIVE (C_SYMBOL_NAME(name),function)			      \
+  .align ALIGNARG(5);							      \
+  C_LABEL(name)								      \
+  cfi_startproc;							      \
+  CALL_MCOUNT
+
+#undef	END
+#define END(name)							      \
+  cfi_endproc;								      \
+  ASM_SIZE_DIRECTIVE(C_SYMBOL_NAME(name))
+
+/* If compiled for profiling, call `mcount' at the start of each function.  */
+#ifdef	PROF
+#define CALL_MCOUNT					\
+	mov.l	1f,r1;					\
+	sts.l	pr,@-r15;				\
+	cfi_adjust_cfa_offset (4);			\
+	cfi_rel_offset (pr, 0);				\
+	mova	2f,r0;					\
+	jmp	@r1;					\
+	 lds	r0,pr;					\
+	.align	2;					\
+1:	.long	mcount;					\
+2:	lds.l	@r15+,pr;				\
+	cfi_adjust_cfa_offset (-4);			\
+	cfi_restore (pr)
+
+#else
+#define CALL_MCOUNT		/* Do nothing.  */
+#endif
+
+#ifdef	__UCLIBC_UNDERSCORES__
+/* Since C identifiers are not normally prefixed with an underscore
+   on this system, the asm identifier `syscall_error' intrudes on the
+   C name space.  Make sure we use an innocuous name.  */
+#define	syscall_error	__syscall_error
+#define mcount		_mcount
+#endif
+
+/* For Linux we can use the system call table in the header file
+	/usr/include/asm/unistd.h
+   of the kernel.  But these symbols do not follow the SYS_* syntax
+   so we have to redefine the `SYS_ify' macro here.  */
+#undef SYS_ify
+#define SYS_ify(syscall_name)	(__NR_##syscall_name)
+
+#define ret	rts ; nop
+/* The sh move insn is s, d.  */
+#define MOVE(x,y)	mov x , y
+
+/* Linux uses a negative return value to indicate syscall errors,
+   unlike most Unices, which use the condition codes' carry flag.
+
+   Since version 2.1 the return value of a system call might be
+   negative even if the call succeeded.  E.g., the `lseek' system call
+   might return a large offset.  Therefore we must not anymore test
+   for < 0, but test for a real error by making sure the value in R0
+   is a real error number.  Linus said he will make sure the no syscall
+   returns a value in -1 .. -4095 as a valid result so we can savely
+   test with -4095.  */
+
+#define _IMM1 #-1
+#define _IMM12 #-12
+#undef	PSEUDO
+#define	PSEUDO(name, syscall_name, args) \
+ .text; \
+ ENTRY (name); \
+    DO_CALL (syscall_name, args); \
+    mov r0,r1; \
+    mov _IMM12,r2; \
+    shad r2,r1; \
+    not r1,r1; \
+    tst r1,r1; \
+    bf .Lpseudo_end; \
+    SYSCALL_ERROR_HANDLER; \
+ .Lpseudo_end:
+
+#undef	PSEUDO_END
+#define	PSEUDO_END(name) \
+  END (name)
+
+#undef	PSEUDO_NOERRNO
+#define	PSEUDO_NOERRNO(name, syscall_name, args) \
+ .text; \
+ ENTRY (name); \
+    DO_CALL (syscall_name, args)
+
+#undef	PSEUDO_END_NOERRNO
+#define	PSEUDO_END_NOERRNO(name) \
+  END (name)
+
+#define ret_NOERRNO ret
+
+#define	PSEUDO_ERRVAL(name, syscall_name, args) \
+ .text; \
+ ENTRY (name); \
+    DO_CALL (syscall_name, args);
+
+#undef	PSEUDO_END_ERRVAL
+#define	PSEUDO_END_ERRVAL(name) \
+  END (name)
+
+#define ret_ERRVAL ret
+
+#ifndef PIC
+# define SYSCALL_ERROR_HANDLER	\
+	mov.l 0f,r1; \
+	jmp @r1; \
+	 mov r0,r4; \
+	.align 2; \
+     0: .long __syscall_error
+
+#include <libc/sysdeps/linux/sh/syscall_error.S>
+#else
+# ifdef RTLD_PRIVATE_ERRNO
+
+#  define SYSCALL_ERROR_HANDLER	\
+	neg r0,r1; \
+	mov.l 0f,r12; \
+	mova 0f,r0; \
+	add r0,r12; \
+	mov.l 1f,r0; \
+	mov.l r1,@(r0,r12)
+	bra .Lpseudo_end; \
+	 mov _IMM1,r0; \
+	.align 2; \
+     0: .long _GLOBAL_OFFSET_TABLE_; \
+     1: .long rtld_errno@GOTOFF
+
+# elif defined _LIBC_REENTRANT
+
+#  if USE___THREAD
+
+#   ifndef NOT_IN_libc
+#    define SYSCALL_ERROR_ERRNO __libc_errno
+#   else
+#    define SYSCALL_ERROR_ERRNO errno
+#   endif
+#   define SYSCALL_ERROR_HANDLER \
+	neg r0,r1; \
+	mov r12,r2; \
+	mov.l 0f,r12; \
+	mova 0f,r0; \
+	add r0,r12; \
+	mov.l 1f,r0; \
+	stc gbr, r4; \
+	mov.l @(r0,r12),r0; \
+	bra .Lskip; \
+	add r4,r0; \
+	.align 2; \
+	1: .long SYSCALL_ERROR_ERRNO@GOTTPOFF; \
+	.Lskip: \
+	mov r2,r12; \
+	mov.l r1,@r0; \
+	bra .Lpseudo_end; \
+	mov _IMM1,r0; \
+	.align 2; \
+	0: .long _GLOBAL_OFFSET_TABLE_
+#  else
+
+#   define SYSCALL_ERROR_HANDLER \
+	neg r0,r1; \
+	mov.l r14,@-r15; \
+	mov.l r12,@-r15; \
+	mov.l r1,@-r15; \
+	mov.l 0f,r12; \
+	mova 0f,r0; \
+	add r0,r12; \
+	sts.l pr,@-r15; \
+	mov r15,r14; \
+	mov.l 1f,r1; \
+	bsrf r1; \
+         nop; \
+     2: mov r14,r15; \
+	lds.l @r15+,pr; \
+	mov.l @r15+,r1; \
+	mov.l r1,@r0; \
+	mov.l @r15+,r12; \
+	mov.l @r15+,r14; \
+	bra .Lpseudo_end; \
+	 mov _IMM1,r0; \
+	.align 2; \
+     0: .long _GLOBAL_OFFSET_TABLE_; \
+     1: .long PLTJMP(C_SYMBOL_NAME(__errno_location))-(2b-.)
+/* A quick note: it is assumed that the call to `__errno_location' does
+   not modify the stack!  */
+#  endif
+# else
+
+/* Store (-r0) into errno through the GOT.  */
+#  define SYSCALL_ERROR_HANDLER						      \
+	neg r0,r1; \
+	mov r12,r2; \
+	mov.l 0f,r12; \
+	mova 0f,r0; \
+	add r0,r12; \
+	mov.l 1f,r0; \
+	mov.l @(r0,r12),r0; \
+	mov r2,r12; \
+	mov.l r1,@r0; \
+	bra .Lpseudo_end; \
+	 mov _IMM1,r0; \
+	.align 2; \
+     0: .long _GLOBAL_OFFSET_TABLE_; \
+     1: .long errno@GOT
+# endif	/* _LIBC_REENTRANT */
+#endif	/* PIC */
+
+# ifdef __SH4__
+#  define SYSCALL_INST_PAD \
+	or r0,r0; or r0,r0; or r0,r0; or r0,r0; or r0,r0
+# else
+#  define SYSCALL_INST_PAD
+# endif
+
+#define SYSCALL_INST0	trapa #0x10
+#define SYSCALL_INST1	trapa #0x11
+#define SYSCALL_INST2	trapa #0x12
+#define SYSCALL_INST3	trapa #0x13
+#define SYSCALL_INST4	trapa #0x14
+#define SYSCALL_INST5	mov.l @(0,r15),r0; trapa #0x15
+#define SYSCALL_INST6	mov.l @(0,r15),r0; mov.l @(4,r15),r1; trapa #0x16
+
+#undef	DO_CALL
+#define DO_CALL(syscall_name, args)	\
+    mov.l 1f,r3;			\
+    SYSCALL_INST##args;			\
+    SYSCALL_INST_PAD;			\
+    bra 2f;				\
+     nop;				\
+    .align 2;				\
+ 1: .long SYS_ify (syscall_name);	\
+ 2:
+
+#endif	/* __ASSEMBLER__ */