microblaze: syscall interface

Fix the microblaze syscall interface.
Recent mainline kernels no longer carry userland code to invoke syscalls
and microblaze can use the uClibc generic code.

Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>

libc/sysdeps/linux/microblaze/bits/syscalls.h

@@ -4,12 +4,54 @@
 # error "Never use <bits/syscalls.h> directly; include <sys/syscall.h> instead."
 #endif
 
-#include <features.h>
 
-/* Do something very evil for now.  Until we create our own syscall
- * macros, short circuit bits/sysnum.h  and use asm/unistd.h instead */
-#warning "fixme -- add arch specific syscall macros.h"
-#include <asm/unistd.h>
+#ifndef __ASSEMBLER__
 
-#endif /* _BITS_SYSCALLS_H */
+#include <errno.h>
+
+#define INTERNAL_SYSCALL_NCS(name, err, nr, args...)			\
+	({								\
+		register int __ret __asm__("r3");			\
+		register int _scno __asm__("r12") = name;		\
+		LOAD_ARGS_##nr (args);					\
+		__asm__ __volatile__("brki	r14, 0x8"		\
+			      : "=r" (__ret)				\
+			      :  "r"(_scno) ASM_ARGS_##nr		\
+			      : __SYSCALL_CLOBBERS );			\
+		__ret;							\
+	})
+
+#define INTERNAL_SYSCALL_ERROR_P(val, err)		\
+	((unsigned int)(val) >= 0xfffff001U)
 
+#define LOAD_ARGS_0() do { } while(0)
+#define ASM_ARGS_0
+#define LOAD_ARGS_1(a1)				\
+	register int _a1 __asm__("r5") = (int)(a1);	\
+	LOAD_ARGS_0()
+#define ASM_ARGS_1	ASM_ARGS_0, "r"(_a1)
+#define LOAD_ARGS_2(a1, a2)				\
+	register int _a2 __asm__("r6") = (int)(a2);	\
+	LOAD_ARGS_1(a1)
+#define ASM_ARGS_2	ASM_ARGS_1, "r"(_a2)
+#define LOAD_ARGS_3(a1, a2, a3)				\
+	register int _a3 __asm__("r7") = (int)(a3);	\
+	LOAD_ARGS_2(a1, a2)
+#define ASM_ARGS_3	ASM_ARGS_2, "r"(_a3)
+#define LOAD_ARGS_4(a1, a2, a3, a4)			\
+	register int _a4 __asm__("r8") = (int)(a4);	\
+	LOAD_ARGS_3(a1, a2, a3)
+#define ASM_ARGS_4	ASM_ARGS_3, "r"(_a4)
+#define LOAD_ARGS_5(a1, a2, a3, a4, a5)			\
+	register int _a5 __asm__("r9") = (int)(a5);	\
+	LOAD_ARGS_4(a1, a2, a3, a4)
+#define ASM_ARGS_5	ASM_ARGS_4, "r"(_a5)
+#define LOAD_ARGS_6(a1, a2, a3, a4, a5, a6)		\
+	register int _a6 __asm__("r10") = (int)(a6);	\
+	LOAD_ARGS_5(a1, a2, a3, a4, a5)
+#define ASM_ARGS_6	ASM_ARGS_5, "r"(_a6)
+
+#define __SYSCALL_CLOBBERS "r4", "r14", "cc", "memory"
+
+#endif /* __ASSEMBLER__ */
+#endif /* _BITS_SYSCALLS_H */

libc/sysdeps/linux/microblaze/syscall.c

@@ -1,51 +0,0 @@
-/*
- * libc/sysdeps/linux/microblaze/syscall.c -- generic syscall function for linux/microblaze
- *
- *  Copyright (C) 2003  John Williams <jwilliams@itee.uq.edu.au>
- *  Copyright (C) 2002  NEC Corporation
- *  Copyright (C) 2002  Miles Bader <miles@gnu.org>
- *
- * This file is subject to the terms and conditions of the GNU Lesser
- * General Public License.  See the file COPYING.LIB in the main
- * directory of this archive for more details.
- *
- * Written by Miles Bader <miles@gnu.org>
- */
-
-#include <errno.h>
-#include <sys/syscall.h>
-
-typedef unsigned long arg_t;
-
-/* Invoke `system call' NUM, passing it the remaining arguments.
-   This is completely system-dependent, and not often useful.  */
-long
-syscall (long num, arg_t a1, arg_t a2, arg_t a3, arg_t a4, arg_t a5, arg_t a6)
-{
-  /* We don't know how many arguments are valid, so A5 and A6 are fetched
-     off the stack even for (the majority of) system calls with fewer
-     arguments; hopefully this won't cause any problems.  A1-A4 are in
-     registers, so they're OK.  */
-  register arg_t a __asm__ (SYSCALL_ARG0) = a1;
-  register arg_t b __asm__ (SYSCALL_ARG1) = a2;
-  register arg_t c __asm__ (SYSCALL_ARG2) = a3;
-  register arg_t d __asm__ (SYSCALL_ARG3) = a4;
-  register arg_t e __asm__ (SYSCALL_ARG4) = a5;
-  register arg_t f __asm__ (SYSCALL_ARG5) = a6;
-  register unsigned long syscall __asm__ (SYSCALL_NUM) = num;
-  register unsigned long ret __asm__ (SYSCALL_RET);
-	unsigned long ret_sav;
-
-  *((unsigned long *)0xFFFF4004) = (unsigned int)('+');
-  __asm__ ("brlid r17, 08x; nop;"
-       : "=r" (ret)
-       : "r" (syscall), "r" (a), "r" (b), "r" (c), "r" (d), "r" (e), "r" (f)
-       : SYSCALL_CLOBBERS);
-
-  ret_sav=ret;
-  *((unsigned long *)0xFFFF4004) = (unsigned int)('-');
-
-
-
-  __syscall_return (long, ret);
-}