/*
* Copyright (C) 2016 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.
*
* 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 <errno.h>
#include <ipxe/pci.h>
#include <ipxe/pciea.h>
/** @file
*
* PCI Enhanced Allocation
*
*/
/**
* Locate PCI Enhanced Allocation BAR equivalent entry
*
* @v pci PCI device
* @v bei BAR equivalent indicator
* @ret offset PCI Enhanced Allocation entry offset, or negative error
*/
static int pciea_offset ( struct pci_device *pci, unsigned int bei ) {
uint8_t entries;
uint32_t desc;
unsigned int i;
int offset;
/* Locate Enhanced Allocation capability */
offset = pci_find_capability ( pci, PCI_CAP_ID_EA );
if ( offset < 0 )
return offset;
/* Get number of entries */
pci_read_config_byte ( pci, ( offset + PCIEA_ENTRIES ), &entries );
entries &= PCIEA_ENTRIES_MASK;
/* Locate first entry */
offset += PCIEA_FIRST;
/* Search for a matching entry */
for ( i = 0 ; i < entries ; i++ ) {
/* Read entry descriptor */
pci_read_config_dword ( pci, offset, &desc );
/* Check for a matching entry */
if ( ( desc & PCIEA_DESC_ENABLED ) &&
( bei == PCIEA_DESC_BEI ( desc ) ) )
return offset;
/* Move to next entry */
offset += ( ( PCIEA_DESC_SIZE ( desc ) + 1 ) << 2 );
}
return -ENOENT;
}
/**
* Read PCI Enhanced Allocation BAR equivalent value
*
* @v pci PCI device
* @v bei BAR equivalent indicator
* @v low_offset Offset to low dword of value
* @ret value BAR equivalent value
*/
static unsigned long pciea_bar_value ( struct pci_device *pci, unsigned int bei,
unsigned int low_offset ) {
uint32_t low;
uint32_t high;
int offset;
/* Locate Enhanced Allocation offset for this BEI */
offset = pciea_offset ( pci, bei );
if ( offset < 0 )
return 0;
/* Read BAR equivalent */
offset += low_offset;
pci_read_config_dword ( pci, offset, &low );
if ( low & PCIEA_LOW_ATTR_64BIT ) {
offset += PCIEA_LOW_HIGH;
pci_read_config_dword ( pci, offset, &high );
if ( high ) {
if ( sizeof ( unsigned long ) > sizeof ( uint32_t ) ) {
return ( ( ( uint64_t ) high << 32 ) | low );
} else {
DBGC ( pci, PCI_FMT " unhandled 64-bit EA BAR "
"%08x%08x\n",
PCI_ARGS ( pci ), high, low );
return 0;
}
}
}
return low;
}
/**
* Find the start of a PCI Enhanced Allocation BAR equivalent
*
* @v pci PCI device
* @v bei BAR equivalent indicator
* @ret start BAR start address
*
* If the address exceeds the size of an unsigned long (i.e. if a
* 64-bit BAR has a non-zero high dword on a 32-bit machine), the
* return value will be zero.
*/
unsigned long pciea_bar_start ( struct pci_device *pci, unsigned int bei ) {
unsigned long base;
base = pciea_bar_value ( pci, bei, PCIEA_LOW_BASE );
return ( base & ~PCIEA_LOW_ATTR_MASK );
}
/**
* Find the size of a PCI Enhanced Allocation BAR equivalent
*
* @v pci PCI device
* @v bei BAR equivalent indicator
* @ret size BAR size
*/
unsigned long pciea_bar_size ( struct pci_device *pci, unsigned int bei ) {
unsigned long limit;
limit = pciea_bar_value ( pci, bei, PCIEA_LOW_LIMIT );
return ( limit ? ( ( limit | PCIEA_LOW_ATTR_MASK ) + 1 ) : 0 );
}
