Skip to content

Commit

Permalink
Browse files Browse the repository at this point in the history
[linux] Add support for accessing PCI configuration space via /proc/b…
…us/pci

Signed-off-by: Michael Brown <mcb30@ipxe.org>
  • Loading branch information
mcb30 committed Jul 13, 2013
1 parent 3dbcce5 commit d839285
Show file tree
Hide file tree
Showing 8 changed files with 332 additions and 0 deletions.
4 changes: 4 additions & 0 deletions src/arch/x86/core/linux/linux_api.c
Expand Up @@ -37,6 +37,10 @@ int linux_close ( int fd ) {
return linux_syscall ( __NR_close, fd );
}

off_t linux_lseek ( int fd, off_t offset, int whence ) {
return linux_syscall ( __NR_lseek, fd, offset, whence );
}

__kernel_ssize_t linux_read ( int fd, void *buf, __kernel_size_t count ) {
return linux_syscall ( __NR_read, fd, buf, count );
}
Expand Down
1 change: 1 addition & 0 deletions src/config/defaults/linux.h
Expand Up @@ -17,6 +17,7 @@
#define ENTROPY_LINUX
#define TIME_LINUX
#define REBOOT_NULL
#define PCIAPI_LINUX

#define DRIVERS_LINUX

Expand Down
1 change: 1 addition & 0 deletions src/include/ipxe/errfile.h
Expand Up @@ -275,6 +275,7 @@ FILE_LICENCE ( GPL2_OR_LATER );
#define ERRFILE_efi_init ( ERRFILE_OTHER | 0x00390000 )
#define ERRFILE_efi_timer ( ERRFILE_OTHER | 0x003a0000 )
#define ERRFILE_efi_umalloc ( ERRFILE_OTHER | 0x003b0000 )
#define ERRFILE_linux_pci ( ERRFILE_OTHER | 0x003c0000 )

/** @} */

Expand Down
8 changes: 8 additions & 0 deletions src/include/ipxe/linux.h
Expand Up @@ -30,6 +30,14 @@ FILE_LICENCE(GPL2_OR_LATER);
#include <ipxe/device.h>
#include <ipxe/settings.h>

/**
* Convert a Linux error number to an iPXE status code
*
* @v errno Linux error number
* @ret rc iPXE status code (before negation)
*/
#define ELINUX( errno ) EPLATFORM ( EINFO_EPLATFORM, errno )

/** A linux device */
struct linux_device {
/** Generic device */
Expand Down
130 changes: 130 additions & 0 deletions src/include/ipxe/linux/linux_pci.h
@@ -0,0 +1,130 @@
#ifndef _IPXE_LINUX_PCI_H
#define _IPXE_LINUX_PCI_H

/** @file
*
* iPXE PCI API for Linux
*
*/

FILE_LICENCE ( GPL2_OR_LATER );

#ifdef PCIAPI_LINUX
#define PCIAPI_PREFIX_linux
#else
#define PCIAPI_PREFIX_linux __linux_
#endif

struct pci_device;

extern int linux_pci_read ( struct pci_device *pci, unsigned long where,
unsigned long *value, size_t len );
extern int linux_pci_write ( struct pci_device *pci, unsigned long where,
unsigned long value, size_t len );

/**
* Read byte from PCI configuration space
*
* @v pci PCI device
* @v where Location within PCI configuration space
* @v value Value read
* @ret rc Return status code
*/
static inline __always_inline int
PCIAPI_INLINE ( linux, pci_read_config_byte ) ( struct pci_device *pci,
unsigned int where,
uint8_t *value ) {
int rc;
unsigned long tmp;

rc = linux_pci_read ( pci, where, &tmp, sizeof ( *value ) );
*value = tmp;
return rc;
}

/**
* Read word from PCI configuration space
*
* @v pci PCI device
* @v where Location within PCI configuration space
* @v value Value read
* @ret rc Return status code
*/
static inline __always_inline int
PCIAPI_INLINE ( linux, pci_read_config_word ) ( struct pci_device *pci,
unsigned int where,
uint16_t *value ) {
int rc;
unsigned long tmp;

rc = linux_pci_read ( pci, where, &tmp, sizeof ( *value ) );
*value = tmp;
return rc;
}

/**
* Read dword from PCI configuration space
*
* @v pci PCI device
* @v where Location within PCI configuration space
* @v value Value read
* @ret rc Return status code
*/
static inline __always_inline int
PCIAPI_INLINE ( linux, pci_read_config_dword ) ( struct pci_device *pci,
unsigned int where,
uint32_t *value ) {
int rc;
unsigned long tmp;

rc = linux_pci_read ( pci, where, &tmp, sizeof ( *value ) );
*value = tmp;
return rc;
}

/**
* Write byte to PCI configuration space
*
* @v pci PCI device
* @v where Location within PCI configuration space
* @v value Value to be written
* @ret rc Return status code
*/
static inline __always_inline int
PCIAPI_INLINE ( linux, pci_write_config_byte ) ( struct pci_device *pci,
unsigned int where,
uint8_t value ) {
return linux_pci_write ( pci, where, value, sizeof ( value ) );
}

/**
* Write word to PCI configuration space
*
* @v pci PCI device
* @v where Location within PCI configuration space
* @v value Value to be written
* @ret rc Return status code
*/
static inline __always_inline int
PCIAPI_INLINE ( linux, pci_write_config_word ) ( struct pci_device *pci,
unsigned int where,
uint16_t value ) {
return linux_pci_write ( pci, where, value, sizeof ( value ) );
}

/**
* Write dword to PCI configuration space
*
* @v pci PCI device
* @v where Location within PCI configuration space
* @v value Value to be written
* @ret rc Return status code
*/
static inline __always_inline int
PCIAPI_INLINE ( linux, pci_write_config_dword ) ( struct pci_device *pci,
unsigned int where,
uint32_t value ) {
return linux_pci_write ( pci, where, value, sizeof ( value ) );
}

#endif /* _IPXE_LINUX_PCI_H */
1 change: 1 addition & 0 deletions src/include/ipxe/pci_io.h
Expand Up @@ -44,6 +44,7 @@ FILE_LICENCE ( GPL2_OR_LATER );

/* Include all architecture-independent I/O API headers */
#include <ipxe/efi/efi_pci_api.h>
#include <ipxe/linux/linux_pci.h>

/* Include all architecture-dependent I/O API headers */
#include <bits/pci_io.h>
Expand Down
2 changes: 2 additions & 0 deletions src/include/linux_api.h
Expand Up @@ -47,11 +47,13 @@ typedef __kernel_loff_t loff_t;
typedef unsigned long nfds_t;
typedef uint32_t useconds_t;
#define MAP_FAILED ( ( void * ) -1 )
#define SEEK_SET 0

extern long linux_syscall ( int number, ... );

extern int linux_open ( const char *pathname, int flags );
extern int linux_close ( int fd );
extern off_t linux_lseek ( int fd, off_t offset, int whence );
extern __kernel_ssize_t linux_read ( int fd, void *buf, __kernel_size_t count );
extern __kernel_ssize_t linux_write ( int fd, const void *buf,
__kernel_size_t count );
Expand Down
185 changes: 185 additions & 0 deletions src/interface/linux/linux_pci.c
@@ -0,0 +1,185 @@
/*
* 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;
}

0 comments on commit d839285

Please sign in to comment.