IABSD.fr/xenocara/lib/libpciaccess/src/linux_devmem.c

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• Author : matthieu
  Date : 2009-04-14 20:14:23
  Hash : c1e1a926
  Message : Merge libpciaccess 0.10.5. No functionnal change on OpenBSD.

• lib/libpciaccess/src/linux_devmem.c

• /*
   * (C) Copyright IBM Corporation 2007
   * All Rights Reserved.
   *
   * Permission is hereby granted, free of charge, to any person obtaining a
   * copy of this software and associated documentation files (the "Software"),
   * to deal in the Software without restriction, including without limitation
   * on the rights to use, copy, modify, merge, publish, distribute, sub
   * license, and/or sell copies of the Software, and to permit persons to whom
   * the Software is furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice (including the next
   * paragraph) shall be included in all copies or substantial portions of the
   * Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.  IN NO EVENT SHALL
   * IBM AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
   * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
   * DEALINGS IN THE SOFTWARE.
   */
  
  /**
   * \file linux_devmem.c
   * Access PCI subsystem using Linux's the old /dev/mem interface.
   * 
   * \note
   * This is currently just a skeleton.  It only includes the /dev/mem based
   * function for reading the device ROM.
   *
   * \author Ian Romanick <idr@us.ibm.com>
   */
  
  #define _GNU_SOURCE
  
  #include <stdlib.h>
  #include <string.h>
  #include <stdio.h>
  #include <unistd.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <fcntl.h>
  #include <sys/mman.h>
  #include <dirent.h>
  #include <errno.h>
  
  #include "pciaccess.h"
  #include "pciaccess_private.h"
  #include "linux_devmem.h"
  
  /**
   * Read a device's expansion ROM using /dev/mem.
   * 
   * \note
   * This function could probably be used, as-is, on other platforms that have
   * a /dev/mem interface.
   * 
   * \bugs
   * Before using the VGA special case code, this function should check that
   * VGA access are routed to the device.  Right?
   */
  _pci_hidden int
  pci_device_linux_devmem_read_rom(struct pci_device *dev, void *buffer)
  {
      struct pci_device_private *priv = (struct pci_device_private *) dev;
      int fd;
      int err = 0;
      uint32_t rom_base_tmp;
      pciaddr_t rom_base;
      pciaddr_t rom_size;
      int PCI_ROM;
  
  
      /* Handle some special cases of legacy devices.
       */
      if (priv->base.rom_size == 0) {
  	/* VGA ROMs are supposed to be at 0xC0000.
  	 */
  	if ((priv->base.device_class & 0x00ffff00) == 0x000030000) {
  	    rom_base = 0x000C0000;
  	    rom_size = 0x00010000;
  	    PCI_ROM = 0;
  	}
  	else {
  	    /* "Function not implemented."
  	     */
  	    return ENOSYS;
  	}
      }
      else {
  	rom_base = priv->rom_base;
  	rom_size = priv->base.rom_size;
  	PCI_ROM = 1;
      }
      
  
  
      /* Enable the device's ROM.
       */
      if (PCI_ROM) {
  	err = pci_device_cfg_read_u32(& priv->base, & rom_base_tmp, 48);
  	if (err) {
  	    return err;
  	}
  
  	if ((rom_base_tmp & 0x000000001) == 0) {
  	    err = pci_device_cfg_write_u32(& priv->base, 
  					   rom_base_tmp | 1, 48);
  	    if (err) {
  		return err;
  	    }
  	}
      }
      
      
      /* Read the portion of /dev/mem that corresponds to the device's ROM.
       */
      fd = open("/dev/mem", O_RDONLY, 0);
      if (fd < 0) {
  	err = errno;
      }
      else {
  	size_t bytes;
  
  	for (bytes = 0; bytes < rom_size; /* empty */) {
  	    const ssize_t got = pread(fd, buffer, rom_size - bytes, 
  				      rom_base + bytes);
  	    if (got == -1) {
  		err = errno;
  		break;
  	    }
  
  	    bytes += got;
  	}
  
  	close(fd);
      }
  
      
      /* Disable the device's ROM.
       */
      if (PCI_ROM && ((rom_base_tmp & 0x000000001) == 0)) {
  	const int tmp_err = pci_device_cfg_write_u32(& priv->base,
  						     rom_base_tmp, 48);
  
  	/* Prefer to return the first error that occurred.
  	 */
  	if (err == 0) {
  	    err = tmp_err;
  	}
      }
  
      return err;
  }