/* *	The PCI Library -- Portable interface to pread() and pwrite() * *	Copyright (c) 1997--2003 Martin Mares <mj@ucw.cz> * *	Can be freely distributed and used under the terms of the GNU GPL. *//* *  We'd like to use pread/pwrite for configuration space accesses, but *  unfortunately it isn't simple at all since all libc's until glibc 2.1 *  don't define it. */#if defined(__GLIBC__) && __GLIBC__ == 2 && __GLIBC_MINOR__ > 0/* glibc 2.1 or newer -> pread/pwrite supported automatically */#elif defined(i386) && defined(__GLIBC__)/* glibc 2.0 on i386 -> call syscalls directly */#include <asm/unistd.h>#include <syscall-list.h>#ifndef SYS_pread#define SYS_pread 180#endifstatic int pread(unsigned int fd, void *buf, size_t size, loff_t where){ return syscall(SYS_pread, fd, buf, size, where); }#ifndef SYS_pwrite#define SYS_pwrite 181#endifstatic int pwrite(unsigned int fd, void *buf, size_t size, loff_t where){ return syscall(SYS_pwrite, fd, buf, size, where); }#elif defined(i386)/* old libc on i386 -> call syscalls directly the old way */#include <asm/unistd.h>static _syscall5(int, pread, unsigned int, fd, void *, buf, size_t, size, u32, where_lo, u32, where_hi);static _syscall5(int, pwrite, unsigned int, fd, void *, buf, size_t, size, u32, where_lo, u32, where_hi);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); }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); }#define PCI_HAVE_DO_READ#else/* In all other cases we use lseek/read/write instead to be safe */#define make_rw_glue(op) \	static int do_##op(struct pci_dev *d, int fd, void *buf, size_t size, int where)	\	{											\	  struct pci_access *a = d->access;							\	  int r;										\	  if (a->fd_pos != where && lseek(fd, where, SEEK_SET) < 0)				\	    return -1;										\	  r = op(fd, buf, size);								\	  if (r < 0)										\	    a->fd_pos = -1;									\	  else											\	    a->fd_pos = where + r;								\	  return r;										\	}make_rw_glue(read)make_rw_glue(write)#define PCI_HAVE_DO_READ#endif#ifndef PCI_HAVE_DO_READ#define do_read(d,f,b,l,p) pread(f,b,l,p)#define do_write(d,f,b,l,p) pwrite(f,b,l,p)#endif