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/*
* Copyright (C) 2013 Michael Brown <mbrown@fensystems.co.uk>.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*/
FILE_LICENCE ( GPL2_OR_LATER );
#include <stdio.h>
#include <errno.h>
#include <byteswap.h>
#include <linux_api.h>
#include <ipxe/linux.h>
#include <ipxe/pci.h>
/** @file
*
* iPXE PCI API for Linux
*
*/
/**
* Open PCI configuration space
*
* @v pci PCI device
* @v flags Access mode flags
* @v where Address within configuration space
* @ret fd File handle, or negative error
*/
static int linux_pci_open ( struct pci_device *pci, int flags,
unsigned long where ) {
char filename[ 22 /* "/proc/bus/pci/xx/xx.x" + NUL */ ];
int fd;
int rc;
/* Construct filename */
snprintf ( filename, sizeof ( filename ), "/proc/bus/pci/%02x/%02x.%x",
PCI_BUS ( pci->busdevfn ), PCI_SLOT ( pci->busdevfn ),
PCI_FUNC ( pci->busdevfn ) );
/* Open file */
fd = linux_open ( filename, flags );
if ( fd < 0 ) {
DBGC ( pci, "PCI could not open %s: %s\n", filename,
linux_strerror ( linux_errno ) );
rc = -ELINUX ( linux_errno );
goto err_open;
}
/* Seek to location */
if ( linux_lseek ( fd, where, SEEK_SET ) < 0 ) {
DBGC ( pci, "PCI could not seek to %s offset %#02lx: %s\n",
filename, where, linux_strerror ( linux_errno ) );
rc = -ELINUX ( linux_errno );
goto err_seek;
}
return fd;
err_seek:
linux_close ( fd );
err_open:
return rc;
}
/**
* Read from PCI configuration space
*
* @v pci PCI device
* @v where Address within configuration space
* @v value Data buffer
* @v len Length to read
* @ret rc Return status code
*/
int linux_pci_read ( struct pci_device *pci, unsigned long where,
unsigned long *value, size_t len ) {
uint32_t tmp = 0;
int fd;
int check_len;
int rc;
/* Return "missing device" in case of error */
*value = -1UL;
/* Open configuration space */
fd = linux_pci_open ( pci, O_RDONLY, where );
if ( fd < 0 ) {
rc = fd;
goto err_open;
}
/* Read value */
check_len = linux_read ( fd, &tmp, len );
if ( check_len < 0 ) {
DBGC ( pci, "PCI could not read from " PCI_FMT " %#02lx+%#zx: "
"%s\n", PCI_ARGS ( pci ), where, len,
linux_strerror ( linux_errno ) );
rc = -ELINUX ( linux_errno );
goto err_read;
}
if ( ( size_t ) check_len != len ) {
DBGC ( pci, "PCI read only %#x bytes from " PCI_FMT
" %#02lx+%#zx\n", check_len, PCI_ARGS ( pci ),
where, len );
rc = -EIO;
goto err_read;
}
/* Return value */
*value = le32_to_cpu ( tmp );
/* Success */
rc = 0;
err_read:
linux_close ( fd );
err_open:
return rc;
}
/**
* Write to PCI configuration space
*
* @v pci PCI device
* @v where Address within configuration space
* @v value Value to write
* @v len Length of value
* @ret rc Return status code
*/
int linux_pci_write ( struct pci_device *pci, unsigned long where,
unsigned long value, size_t len ) {
uint32_t tmp;
int fd;
int check_len;
int rc;
/* Open configuration space */
fd = linux_pci_open ( pci, O_WRONLY, where );
if ( fd < 0 ) {
rc = fd;
goto err_open;
}
/* Prepare value for writing */
tmp = cpu_to_le32 ( value );
assert ( len <= sizeof ( tmp ) );
/* Write value */
check_len = linux_write ( fd, &tmp, len );
if ( check_len < 0 ) {
DBGC ( pci, "PCI could not write to " PCI_FMT " %#02lx+%#zx: "
"%s\n", PCI_ARGS ( pci ), where, len,
linux_strerror ( linux_errno ) );
rc = -ELINUX ( linux_errno );
goto err_write;
}
if ( ( size_t ) check_len != len ) {
DBGC ( pci, "PCI wrote only %#x bytes to " PCI_FMT
" %#02lx+%#zx\n", check_len, PCI_ARGS ( pci ),
where, len );
rc = -EIO;
goto err_write;
}
/* Success */
rc = 0;
err_write:
linux_close ( fd );
err_open:
return rc;
}
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