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Annotation of embedaddon/pciutils/lib/pread.h, revision 1.1.1.1

1.1       misho       1: /*
                      2:  *     The PCI Library -- Portable interface to pread() and pwrite()
                      3:  *
                      4:  *     Copyright (c) 1997--2003 Martin Mares <mj@ucw.cz>
                      5:  *
                      6:  *     Can be freely distributed and used under the terms of the GNU GPL.
                      7:  */
                      8: 
                      9: /*
                     10:  *  We'd like to use pread/pwrite for configuration space accesses, but
                     11:  *  unfortunately it isn't simple at all since all libc's until glibc 2.1
                     12:  *  don't define it.
                     13:  */
                     14: 
                     15: #if defined(__GLIBC__) && __GLIBC__ == 2 && __GLIBC_MINOR__ > 0
                     16: /* glibc 2.1 or newer -> pread/pwrite supported automatically */
                     17: 
                     18: #elif defined(i386) && defined(__GLIBC__)
                     19: /* glibc 2.0 on i386 -> call syscalls directly */
                     20: #include <asm/unistd.h>
                     21: #include <syscall-list.h>
                     22: #ifndef SYS_pread
                     23: #define SYS_pread 180
                     24: #endif
                     25: static int pread(unsigned int fd, void *buf, size_t size, loff_t where)
                     26: { return syscall(SYS_pread, fd, buf, size, where); }
                     27: #ifndef SYS_pwrite
                     28: #define SYS_pwrite 181
                     29: #endif
                     30: static int pwrite(unsigned int fd, void *buf, size_t size, loff_t where)
                     31: { return syscall(SYS_pwrite, fd, buf, size, where); }
                     32: 
                     33: #elif defined(i386)
                     34: /* old libc on i386 -> call syscalls directly the old way */
                     35: #include <asm/unistd.h>
                     36: static _syscall5(int, pread, unsigned int, fd, void *, buf, size_t, size, u32, where_lo, u32, where_hi);
                     37: static _syscall5(int, pwrite, unsigned int, fd, void *, buf, size_t, size, u32, where_lo, u32, where_hi);
                     38: static int do_read(struct pci_dev *d UNUSED, int fd, void *buf, size_t size, int where) { return pread(fd, buf, size, where, 0); }
                     39: static int do_write(struct pci_dev *d UNUSED, int fd, void *buf, size_t size, int where) { return pwrite(fd, buf, size, where, 0); }
                     40: #define PCI_HAVE_DO_READ
                     41: 
                     42: #else
                     43: /* In all other cases we use lseek/read/write instead to be safe */
                     44: #define make_rw_glue(op) \
                     45:        static int do_##op(struct pci_dev *d, int fd, void *buf, size_t size, int where)        \
                     46:        {                                                                                       \
                     47:          struct pci_access *a = d->access;                                                     \
                     48:          int r;                                                                                \
                     49:          if (a->fd_pos != where && lseek(fd, where, SEEK_SET) < 0)                             \
                     50:            return -1;                                                                          \
                     51:          r = op(fd, buf, size);                                                                \
                     52:          if (r < 0)                                                                            \
                     53:            a->fd_pos = -1;                                                                     \
                     54:          else                                                                                  \
                     55:            a->fd_pos = where + r;                                                              \
                     56:          return r;                                                                             \
                     57:        }
                     58: make_rw_glue(read)
                     59: make_rw_glue(write)
                     60: #define PCI_HAVE_DO_READ
                     61: #endif
                     62: 
                     63: #ifndef PCI_HAVE_DO_READ
                     64: #define do_read(d,f,b,l,p) pread(f,b,l,p)
                     65: #define do_write(d,f,b,l,p) pwrite(f,b,l,p)
                     66: #endif