nolibc: add support for s390
authorSven Schnelle <svens@linux.ibm.com>
Mon, 9 Jan 2023 08:09:07 +0000 (09:09 +0100)
committerPaul E. McKenney <paulmck@kernel.org>
Mon, 9 Jan 2023 17:36:05 +0000 (09:36 -0800)
Use arch-x86_64 as a template. Not really different, but
we have our own mmap syscall which takes a structure instead
of discrete arguments.

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
tools/include/nolibc/arch-s390.h [new file with mode: 0644]
tools/include/nolibc/arch.h
tools/include/nolibc/sys.h

diff --git a/tools/include/nolibc/arch-s390.h b/tools/include/nolibc/arch-s390.h
new file mode 100644 (file)
index 0000000..76bc8fd
--- /dev/null
@@ -0,0 +1,222 @@
+/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
+/*
+ * s390 specific definitions for NOLIBC
+ */
+
+#ifndef _NOLIBC_ARCH_S390_H
+#define _NOLIBC_ARCH_S390_H
+#include <asm/unistd.h>
+
+/* O_* macros for fcntl/open are architecture-specific */
+#define O_RDONLY            0
+#define O_WRONLY            1
+#define O_RDWR              2
+#define O_CREAT          0x40
+#define O_EXCL           0x80
+#define O_NOCTTY        0x100
+#define O_TRUNC         0x200
+#define O_APPEND        0x400
+#define O_NONBLOCK      0x800
+#define O_DIRECTORY   0x10000
+
+/* The struct returned by the stat() syscall, equivalent to stat64(). The
+ * syscall returns 116 bytes and stops in the middle of __unused.
+ */
+
+struct sys_stat_struct {
+       unsigned long   st_dev;
+       unsigned long   st_ino;
+       unsigned long   st_nlink;
+       unsigned int    st_mode;
+       unsigned int    st_uid;
+       unsigned int    st_gid;
+       unsigned int    __pad1;
+       unsigned long   st_rdev;
+       unsigned long   st_size;
+       unsigned long   st_atime;
+       unsigned long   st_atime_nsec;
+       unsigned long   st_mtime;
+       unsigned long   st_mtime_nsec;
+       unsigned long   st_ctime;
+       unsigned long   st_ctime_nsec;
+       unsigned long   st_blksize;
+       long            st_blocks;
+       unsigned long   __unused[3];
+};
+
+/* Syscalls for s390:
+ *   - registers are 64-bit
+ *   - syscall number is passed in r1
+ *   - arguments are in r2-r7
+ *   - the system call is performed by calling the svc instruction
+ *   - syscall return value is in r2
+ *   - r1 and r2 are clobbered, others are preserved.
+ *
+ * Link s390 ABI: https://github.com/IBM/s390x-abi
+ *
+ */
+
+#define my_syscall0(num)                                               \
+({                                                                     \
+       register long _num __asm__ ("1") = (num);                       \
+       register long _rc __asm__ ("2");                                \
+                                                                       \
+       __asm__  volatile (                                             \
+               "svc 0\n"                                               \
+               : "=d"(_rc)                                             \
+               : "d"(_num)                                             \
+               : "memory", "cc"                                        \
+               );                                                      \
+       _rc;                                                            \
+})
+
+#define my_syscall1(num, arg1)                                         \
+({                                                                     \
+       register long _num __asm__ ("1") = (num);                       \
+       register long _arg1 __asm__ ("2") = (long)(arg1);               \
+                                                                       \
+       __asm__  volatile (                                             \
+               "svc 0\n"                                               \
+               : "+d"(_arg1)                                           \
+               : "d"(_num)                                             \
+               : "memory", "cc"                                        \
+               );                                                      \
+       _arg1;                                                          \
+})
+
+#define my_syscall2(num, arg1, arg2)                                   \
+({                                                                     \
+       register long _num __asm__ ("1") = (num);                       \
+       register long _arg1 __asm__ ("2") = (long)(arg1);               \
+       register long _arg2 __asm__ ("3") = (long)(arg2);               \
+                                                                       \
+       __asm__  volatile (                                             \
+               "svc 0\n"                                               \
+               : "+d"(_arg1)                                           \
+               : "d"(_arg2), "d"(_num)                                 \
+               : "memory", "cc"                                        \
+               );                                                      \
+       _arg1;                                                          \
+})
+
+#define my_syscall3(num, arg1, arg2, arg3)                             \
+({                                                                     \
+       register long _num __asm__ ("1") = (num);                       \
+       register long _arg1 __asm__ ("2") = (long)(arg1);               \
+       register long _arg2 __asm__ ("3") = (long)(arg2);               \
+       register long _arg3 __asm__ ("4") = (long)(arg3);               \
+                                                                       \
+       __asm__  volatile (                                             \
+               "svc 0\n"                                               \
+               : "+d"(_arg1)                                           \
+               : "d"(_arg2), "d"(_arg3), "d"(_num)                     \
+               : "memory", "cc"                                        \
+               );                                                      \
+       _arg1;                                                          \
+})
+
+#define my_syscall4(num, arg1, arg2, arg3, arg4)                       \
+({                                                                     \
+       register long _num __asm__ ("1") = (num);                       \
+       register long _arg1 __asm__ ("2") = (long)(arg1);               \
+       register long _arg2 __asm__ ("3") = (long)(arg2);               \
+       register long _arg3 __asm__ ("4") = (long)(arg3);               \
+       register long _arg4 __asm__ ("5") = (long)(arg4);               \
+                                                                       \
+       __asm__  volatile (                                             \
+               "svc 0\n"                                               \
+               : "+d"(_arg1)                                           \
+               : "d"(_arg2), "d"(_arg3), "d"(_arg4), "d"(_num)         \
+               : "memory", "cc"                                        \
+               );                                                      \
+       _arg1;                                                          \
+})
+
+#define my_syscall5(num, arg1, arg2, arg3, arg4, arg5)                 \
+({                                                                     \
+       register long _num __asm__ ("1") = (num);                       \
+       register long _arg1 __asm__ ("2") = (long)(arg1);               \
+       register long _arg2 __asm__ ("3") = (long)(arg2);               \
+       register long _arg3 __asm__ ("4") = (long)(arg3);               \
+       register long _arg4 __asm__ ("5") = (long)(arg4);               \
+       register long _arg5 __asm__ ("6") = (long)(arg5);               \
+                                                                       \
+       __asm__  volatile (                                             \
+               "svc 0\n"                                               \
+               : "+d"(_arg1)                                           \
+               : "d"(_arg2), "d"(_arg3), "d"(_arg4), "d"(_arg5),       \
+                 "d"(_num)                                             \
+               : "memory", "cc"                                        \
+               );                                                      \
+       _arg1;                                                          \
+})
+
+#define my_syscall6(num, arg1, arg2, arg3, arg4, arg5, arg6)           \
+({                                                                     \
+       register long _num __asm__ ("1") = (num);                       \
+       register long _arg1 __asm__ ("2") = (long)(arg1);               \
+       register long _arg2 __asm__ ("3") = (long)(arg2);               \
+       register long _arg3 __asm__ ("4") = (long)(arg3);               \
+       register long _arg4 __asm__ ("5") = (long)(arg4);               \
+       register long _arg5 __asm__ ("6") = (long)(arg5);               \
+       register long _arg6 __asm__ ("7") = (long)(arg6);               \
+                                                                       \
+       __asm__  volatile (                                             \
+               "svc 0\n"                                               \
+               : "+d"(_arg1)                                           \
+               : "d"(_arg2), "d"(_arg3), "d"(_arg4), "d"(_arg5),       \
+                 "d"(_arg6), "d"(_num)                                 \
+               : "memory", "cc"                                        \
+               );                                                      \
+       _arg1;                                                          \
+})
+
+/* startup code */
+__asm__ (".section .text\n"
+        ".weak _start\n"
+        "_start:\n"
+        "lg    %r2,0(%r15)\n"          /* argument count */
+        "la    %r3,8(%r15)\n"          /* argument pointers */
+
+        "xgr   %r0,%r0\n"              /* r0 will be our NULL value */
+        /* search for envp */
+        "lgr   %r4,%r3\n"              /* start at argv */
+        "0:\n"
+        "clg   %r0,0(%r4)\n"           /* entry zero? */
+        "la    %r4,8(%r4)\n"           /* advance pointer */
+        "jnz   0b\n"                   /* no -> test next pointer */
+                                       /* yes -> r4 now contains start of envp */
+
+        "aghi  %r15,-160\n"            /* allocate new stackframe */
+        "xc    0(8,%r15),0(%r15)\n"    /* clear backchain */
+        "brasl %r14,main\n"            /* ret value of main is arg to exit */
+        "lghi  %r1,1\n"                /* __NR_exit */
+        "svc   0\n"
+        "");
+
+struct s390_mmap_arg_struct {
+       unsigned long addr;
+       unsigned long len;
+       unsigned long prot;
+       unsigned long flags;
+       unsigned long fd;
+       unsigned long offset;
+};
+
+static __attribute__((unused))
+void *sys_mmap(void *addr, size_t length, int prot, int flags, int fd,
+              off_t offset)
+{
+       struct s390_mmap_arg_struct args = {
+               .addr = (unsigned long)addr,
+               .len = (unsigned long)length,
+               .prot = prot,
+               .flags = flags,
+               .fd = fd,
+               .offset = (unsigned long)offset
+       };
+
+       return (void *)my_syscall1(__NR_mmap, &args);
+}
+#define sys_mmap sys_mmap
+#endif // _NOLIBC_ARCH_S390_H
index 4c69923..78b067a 100644 (file)
@@ -27,6 +27,8 @@
 #include "arch-mips.h"
 #elif defined(__riscv)
 #include "arch-riscv.h"
+#elif defined(__s390x__)
+#include "arch-s390.h"
 #endif
 
 #endif /* _NOLIBC_ARCH_H */
index 78473d3..a42d7c4 100644 (file)
@@ -686,6 +686,7 @@ int mknod(const char *path, mode_t mode, dev_t dev)
 #define MAP_FAILED ((void *)-1)
 #endif
 
+#ifndef sys_mmap
 static __attribute__((unused))
 void *sys_mmap(void *addr, size_t length, int prot, int flags, int fd,
               off_t offset)
@@ -707,6 +708,7 @@ void *sys_mmap(void *addr, size_t length, int prot, int flags, int fd,
        return (void *)my_syscall6(n, addr, length, prot, flags, fd, offset);
 #endif
 }
+#endif
 
 static __attribute__((unused))
 void *mmap(void *addr, size_t length, int prot, int flags, int fd, off_t offset)