/*
* Copyright (C) 2006 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 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.
*
* You can also choose to distribute this program under the terms of
* the Unmodified Binary Distribution Licence (as given in the file
* COPYING.UBDL), provided that you have satisfied its requirements.
*/
FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
#include <stdint.h>
#include <ipxe/pci.h>
#include <realmode.h>
/** @file
*
* PCI configuration space access via PCI BIOS
*
*/
/**
* Determine number of PCI buses within system
*
* @ret num_bus Number of buses
*/
static int pcibios_num_bus ( void ) {
int discard_a, discard_D;
uint8_t max_bus;
/* We issue this call using flat real mode, to work around a
* bug in some HP BIOSes.
*/
__asm__ __volatile__ ( REAL_CODE ( "call flatten_real_mode\n\t"
"stc\n\t"
"int $0x1a\n\t"
"jnc 1f\n\t"
"xorw %%cx, %%cx\n\t"
"\n1:\n\t" )
: "=c" ( max_bus ), "=a" ( discard_a ),
"=D" ( discard_D )
: "a" ( PCIBIOS_INSTALLATION_CHECK >> 16 ),
"D" ( 0 )
: "ebx", "edx" );
return ( max_bus + 1 );
}
/**
* Read configuration space via PCI BIOS
*
* @v pci PCI device
* @v command PCI BIOS command
* @v value Value read
* @ret rc Return status code
*/
int pcibios_read ( struct pci_device *pci, uint32_t command, uint32_t *value ){
int discard_b, discard_D;
uint16_t status;
__asm__ __volatile__ ( REAL_CODE ( "stc\n\t"
"int $0x1a\n\t"
"jnc 1f\n\t"
"xorl %%eax, %%eax\n\t"
"decl %%eax\n\t"
"movl %%eax, %%ecx\n\t"
"\n1:\n\t" )
: "=a" ( status ), "=b" ( discard_b ),
"=c" ( *value ), "=D" ( discard_D )
: "a" ( command >> 16 ), "D" ( command ),
"b" ( pci->busdevfn )
: "edx" );
return ( status >> 8 );
}
/**
* Write configuration space via PCI BIOS
*
* @v pci PCI device
* @v command PCI BIOS command
* @v value Value to be written
* @ret rc Return status code
*/
int pcibios_write ( struct pci_device *pci, uint32_t command, uint32_t value ){
int discard_b, discard_c, discard_D;
uint16_t status;
__asm__ __volatile__ ( REAL_CODE ( "stc\n\t"
"int $0x1a\n\t"
"jnc 1f\n\t"
"movb $0xff, %%ah\n\t"
"\n1:\n\t" )
: "=a" ( status ), "=b" ( discard_b ),
"=c" ( discard_c ), "=D" ( discard_D )
: "a" ( command >> 16 ), "D" ( command ),
"b" ( pci->busdevfn ), "c" ( value )
: "edx" );
return ( status >> 8 );
}
PROVIDE_PCIAPI ( pcbios, pci_num_bus, pcibios_num_bus );
PROVIDE_PCIAPI_INLINE ( pcbios, pci_read_config_byte );
PROVIDE_PCIAPI_INLINE ( pcbios, pci_read_config_word );
PROVIDE_PCIAPI_INLINE ( pcbios, pci_read_config_dword );
PROVIDE_PCIAPI_INLINE ( pcbios, pci_write_config_byte );
PROVIDE_PCIAPI_INLINE ( pcbios, pci_write_config_word );
PROVIDE_PCIAPI_INLINE ( pcbios, pci_write_config_dword );
