diff options
Diffstat (limited to 'libc/sysdeps/linux/xtensa/pread_write.c')
| -rw-r--r-- | libc/sysdeps/linux/xtensa/pread_write.c | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/xtensa/pread_write.c b/libc/sysdeps/linux/xtensa/pread_write.c new file mode 100644 index 000000000..9e8813210 --- /dev/null +++ b/libc/sysdeps/linux/xtensa/pread_write.c @@ -0,0 +1,193 @@ +/* vi: set sw=4 ts=4: */ +/* + * Copyright (C) 2000-2006 Erik Andersen <andersen@uclibc.org> + * + * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball. + */ +/* + * Based in part on the files + * ./sysdeps/unix/sysv/linux/pwrite.c, + * ./sysdeps/unix/sysv/linux/pread.c, + * sysdeps/posix/pread.c + * sysdeps/posix/pwrite.c + * from GNU libc 2.2.5, but reworked considerably... + */ + +#include <sys/syscall.h> +#include <unistd.h> +#include <stdint.h> +#include <endian.h> + +extern __typeof(pread) __libc_pread; +extern __typeof(pwrite) __libc_pwrite; +#ifdef __UCLIBC_HAS_LFS__ +extern __typeof(pread64) __libc_pread64; +extern __typeof(pwrite64) __libc_pwrite64; +#endif + +#include <bits/kernel_types.h> + +#ifdef __NR_pread + +# define __NR___syscall_pread __NR_pread +/* On Xtensa, 64-bit values are aligned in even/odd register pairs. */ +static inline _syscall6(ssize_t, __syscall_pread, int, fd, void *, buf, + size_t, count, int, pad, off_t, offset_hi, off_t, offset_lo); + +ssize_t __libc_pread(int fd, void *buf, size_t count, off_t offset) +{ + return __syscall_pread(fd, buf, count, 0, __LONG_LONG_PAIR(offset >> 31, offset)); +} +weak_alias(__libc_pread,pread) + +# ifdef __UCLIBC_HAS_LFS__ +ssize_t __libc_pread64(int fd, void *buf, size_t count, off64_t offset) +{ + uint32_t low = offset & 0xffffffff; + uint32_t high = offset >> 32; + return __syscall_pread(fd, buf, count, 0, __LONG_LONG_PAIR(high, low)); +} +weak_alias(__libc_pread64,pread64) +# endif /* __UCLIBC_HAS_LFS__ */ + +#endif /* __NR_pread */ + +#ifdef __NR_pwrite + +# define __NR___syscall_pwrite __NR_pwrite +/* On Xtensa, 64-bit values are aligned in even/odd register pairs. */ +static inline _syscall6(ssize_t, __syscall_pwrite, int, fd, const void *, buf, + size_t, count, int, pad, off_t, offset_hi, off_t, offset_lo); + +ssize_t __libc_pwrite(int fd, const void *buf, size_t count, off_t offset) +{ + return __syscall_pwrite(fd, buf, count, 0, __LONG_LONG_PAIR(offset >> 31, offset)); +} +weak_alias(__libc_pwrite,pwrite) + +# ifdef __UCLIBC_HAS_LFS__ +ssize_t __libc_pwrite64(int fd, const void *buf, size_t count, off64_t offset) +{ + uint32_t low = offset & 0xffffffff; + uint32_t high = offset >> 32; + return __syscall_pwrite(fd, buf, count, 0, __LONG_LONG_PAIR(high, low)); +} +weak_alias(__libc_pwrite64,pwrite64) +# endif /* __UCLIBC_HAS_LFS__ */ +#endif /* __NR_pwrite */ + +#if ! defined __NR_pread || ! defined __NR_pwrite +libc_hidden_proto(read) +libc_hidden_proto(write) +libc_hidden_proto(lseek) + +static ssize_t __fake_pread_write(int fd, void *buf, + size_t count, off_t offset, int do_pwrite) +{ + int save_errno; + ssize_t result; + off_t old_offset; + + /* Since we must not change the file pointer preserve the + * value so that we can restore it later. */ + if ((old_offset=lseek(fd, 0, SEEK_CUR)) == (off_t) -1) + return -1; + + /* Set to wanted position. */ + if (lseek(fd, offset, SEEK_SET) == (off_t) -1) + return -1; + + if (do_pwrite == 1) { + /* Write the data. */ + result = write(fd, buf, count); + } else { + /* Read the data. */ + result = read(fd, buf, count); + } + + /* Now we have to restore the position. If this fails we + * have to return this as an error. */ + save_errno = errno; + if (lseek(fd, old_offset, SEEK_SET) == (off_t) -1) + { + if (result == -1) + __set_errno(save_errno); + return -1; + } + __set_errno(save_errno); + return(result); +} + +# ifdef __UCLIBC_HAS_LFS__ +libc_hidden_proto(lseek64) + +static ssize_t __fake_pread_write64(int fd, void *buf, + size_t count, off64_t offset, int do_pwrite) +{ + int save_errno; + ssize_t result; + off64_t old_offset; + + /* Since we must not change the file pointer preserve the + * value so that we can restore it later. */ + if ((old_offset=lseek64(fd, 0, SEEK_CUR)) == (off64_t) -1) + return -1; + + /* Set to wanted position. */ + if (lseek64(fd, offset, SEEK_SET) == (off64_t) -1) + return -1; + + if (do_pwrite == 1) { + /* Write the data. */ + result = write(fd, buf, count); + } else { + /* Read the data. */ + result = read(fd, buf, count); + } + + /* Now we have to restore the position. */ + save_errno = errno; + if (lseek64(fd, old_offset, SEEK_SET) == (off64_t) -1) { + if (result == -1) + __set_errno (save_errno); + return -1; + } + __set_errno (save_errno); + return result; +} +# endif /* __UCLIBC_HAS_LFS__ */ +#endif /* ! defined __NR_pread || ! defined __NR_pwrite */ + +#ifndef __NR_pread +ssize_t __libc_pread(int fd, void *buf, size_t count, off_t offset) +{ + return __fake_pread_write(fd, buf, count, offset, 0); +} +weak_alias(__libc_pread,pread) + +# ifdef __UCLIBC_HAS_LFS__ +ssize_t __libc_pread64(int fd, void *buf, size_t count, off64_t offset) +{ + return __fake_pread_write64(fd, buf, count, offset, 0); +} +weak_alias(__libc_pread64,pread64) +# endif /* __UCLIBC_HAS_LFS__ */ +#endif /* ! __NR_pread */ + +#ifndef __NR_pwrite +ssize_t __libc_pwrite(int fd, const void *buf, size_t count, off_t offset) +{ + /* we won't actually be modifying the buffer, + *just cast it to get rid of warnings */ + return __fake_pread_write(fd, (void*)buf, count, offset, 1); +} +weak_alias(__libc_pwrite,pwrite) + +# ifdef __UCLIBC_HAS_LFS__ +ssize_t __libc_pwrite64(int fd, const void *buf, size_t count, off64_t offset) +{ + return __fake_pread_write64(fd, (void*)buf, count, offset, 1); +} +weak_alias(__libc_pwrite64,pwrite64) +# endif /* __UCLIBC_HAS_LFS__ */ +#endif /* ! __NR_pwrite */ |