/*
* Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
*
* Based in part on pci.c from Etherboot 5.4, by Ken Yap and David
* Munro, in turn based on the Linux kernel's PCI implementation.
*
* 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
FILE_LICENCE ( GPL2_OR_LATER );
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <gpxe/tables.h>
#include <gpxe/device.h>
#include <gpxe/pci.h>
/** @file
*
* PCI bus
*
*/
static void pcibus_remove ( struct root_device *rootdev );
/**
* Read PCI BAR
*
* @v pci PCI device
* @v reg PCI register number
* @ret bar Base address register
*
* Reads the specified PCI base address register, including the flags
* portion. 64-bit BARs will be handled automatically. If the value
* of the 64-bit BAR exceeds the size of an unsigned long (i.e. if the
* high dword is non-zero on a 32-bit platform), then the value
* returned will be zero plus the flags for a 64-bit BAR. Unreachable
* 64-bit BARs are therefore returned as uninitialised 64-bit BARs.
*/
static unsigned long pci_bar ( struct pci_device *pci, unsigned int reg ) {
uint32_t low;
uint32_t high;
pci_read_config_dword ( pci, reg, &low );
if ( ( low & (PCI_BASE_ADDRESS_SPACE|PCI_BASE_ADDRESS_MEM_TYPE_MASK) )
== (PCI_BASE_ADDRESS_SPACE_MEMORY|PCI_BASE_ADDRESS_MEM_TYPE_64) ){
pci_read_config_dword ( pci, reg + 4, &high );
if ( high ) {
if ( sizeof ( unsigned long ) > sizeof ( uint32_t ) ) {
return ( ( ( uint64_t ) high << 32 ) | low );
} else {
DBG ( "Unhandled 64-bit BAR %08x%08x\n",
high, low );
return PCI_BASE_ADDRESS_MEM_TYPE_64;
}
}
}
return low;
}
/**
* Find the start of a PCI BAR
*
* @v pci PCI device
* @v reg PCI register number
* @ret start BAR start address
*
* Reads the specified PCI base address register, and returns the
* address portion of the BAR (i.e. without the flags).
*
* 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 pci_bar_start ( struct pci_device *pci, unsigned int reg ) {
unsigned long bar;
bar = pci_bar ( pci, reg );
if ( (bar & PCI_BASE_ADDRESS_SPACE) == PCI_BASE_ADDRESS_SPACE_MEMORY ){
return ( bar & PCI_BASE_ADDRESS_MEM_MASK );
} else {
return ( bar & PCI_BASE_ADDRESS_IO_MASK );
}
}
/**
* Read membase and ioaddr for a PCI device
*
* @v pci PCI device
*
* This scans through all PCI BARs on the specified device. The first
* valid memory BAR is recorded as pci_device::membase, and the first
* valid IO BAR is recorded as pci_device::ioaddr.
*
* 64-bit BARs are handled automatically. On a 32-bit platform, if a
* 64-bit BAR has a non-zero high dword, it will be regarded as
* invalid.
*/
static void pci_read_bases ( struct pci_device *pci ) {
unsigned long bar;
int reg;
for ( reg = PCI_BASE_ADDRESS_0; reg <= PCI_BASE_ADDRESS_5; reg += 4 ) {
bar = pci_bar ( pci, reg );
if ( bar & PCI_BASE_ADDRESS_SPACE_IO ) {
if ( ! pci->ioaddr )
pci->ioaddr =
( bar & PCI_BASE_ADDRESS_IO_MASK );
} else {
if ( ! pci->membase )
pci->membase =
( bar & PCI_BASE_ADDRESS_MEM_MASK );
/* Skip next BAR if 64-bit */
if ( bar & PCI_BASE_ADDRESS_MEM_TYPE_64 )
reg += 4;
}
}
}
/**
* Enable PCI device
*
* @v pci PCI device
*
* Set device to be a busmaster in case BIOS neglected to do so. Also
* adjust PCI latency timer to a reasonable value, 32.
*/
void adjust_pci_device ( struct pci_device *pci ) {
unsigned short new_command, pci_command;
unsigned char pci_latency;
pci_read_config_word ( pci, PCI_COMMAND, &pci_command );
new_command = ( pci_command | PCI_COMMAND_MASTER |
PCI_COMMAND_MEM | PCI_COMMAND_IO );
if ( pci_command != new_command ) {
DBG ( "PCI BIOS has not enabled device %02x:%02x.%x! "
"Updating PCI command %04x->%04x\n", pci->bus,
PCI_SLOT ( pci->devfn ), PCI_FUNC ( pci->devfn ),
pci_command, new_command );
pci_write_config_word ( pci, PCI_COMMAND, new_command );
}
pci_read_config_byte ( pci, PCI_LATENCY_TIMER, &pci_latency);
if ( pci_latency < 32 ) {
DBG ( "PCI device %02x:%02x.%x latency timer is unreasonably "
"low at %d. Setting to 32.\n", pci->bus,
PCI_SLOT ( pci->devfn ), PCI_FUNC ( pci->devfn ),
pci_latency );
pci_write_config_byte ( pci, PCI_LATENCY_TIMER, 32);
}
}
/**
* Probe a PCI device
*
* @v pci PCI device
* @ret rc Return status code
*
* Searches for a driver for the PCI device. If a driver is found,
* its probe() routine is called.
*/
static int pci_probe ( struct pci_device *pci ) {
struct pci_driver *driver;
struct pci_device_id *id;
unsigned int i;
int rc;
DBG ( "Adding PCI device %02x:%02x.%x (%04x:%04x mem %lx io %lx "
"irq %d)\n", pci->bus, PCI_SLOT ( pci->devfn ),
PCI_FUNC ( pci->devfn ), pci->vendor, pci->device,
pci->membase, pci->ioaddr, pci->irq );
for_each_table_entry ( driver, PCI_DRIVERS ) {
for ( i = 0 ; i < driver->id_count ; i++ ) {
id = &driver->ids[i];
if ( ( id->vendor != PCI_ANY_ID ) &&
( id->vendor != pci->vendor ) )
continue;
if ( ( id->device != PCI_ANY_ID ) &&
( id->device != pci->device ) )
continue;
pci->driver = driver;
pci->driver_name = id->name;
DBG ( "...using driver %s\n", pci->driver_name );
if ( ( rc = driver->probe ( pci, id ) ) != 0 ) {
DBG ( "......probe failed\n" );
continue;
}
return 0;
}
}
DBG ( "...no driver found\n" );
return -ENOTTY;
}
/**
* Remove a PCI device
*
* @v pci PCI device
*/
static void pci_remove ( struct pci_device *pci ) {
pci->driver->remove ( pci );
DBG ( "Removed PCI device %02x:%02x.%x\n", pci->bus,
PCI_SLOT ( pci->devfn ), PCI_FUNC ( pci->devfn ) );
}
/**
* Probe PCI root bus
*
* @v rootdev PCI bus root device
*
* Scans the PCI bus for devices and registers all devices it can
* find.
*/
static int pcibus_probe ( struct root_device *rootdev ) {
struct pci_device *pci = NULL;
unsigned int max_bus;
unsigned int bus;
unsigned int devfn;
uint8_t hdrtype = 0;
uint32_t tmp;
int rc;
max_bus = pci_max_bus();
for ( bus = 0 ; bus <= max_bus ; bus++ ) {
for ( devfn = 0 ; devfn <= 0xff ; devfn++ ) {
/* Allocate struct pci_device */
if ( ! pci )
pci = malloc ( sizeof ( *pci ) );
if ( ! pci ) {
rc = -ENOMEM;
goto err;
}
memset ( pci, 0, sizeof ( *pci ) );
pci->bus = bus;
pci->devfn = devfn;
/* Skip all but the first function on
* non-multifunction cards
*/
if ( PCI_FUNC ( devfn ) == 0 ) {
pci_read_config_byte ( pci, PCI_HEADER_TYPE,
&hdrtype );
} else if ( ! ( hdrtype & 0x80 ) ) {
continue;
}
/* Check for physical device presence */
pci_read_config_dword ( pci, PCI_VENDOR_ID, &tmp );
if ( ( tmp == 0xffffffff ) || ( tmp == 0 ) )
continue;
/* Populate struct pci_device */
pci->vendor = ( tmp & 0xffff );
pci->device = ( tmp >> 16 );
pci_read_config_dword ( pci, PCI_REVISION, &tmp );
pci->class = ( tmp >> 8 );
pci_read_config_byte ( pci, PCI_INTERRUPT_LINE,
&pci->irq );
pci_read_bases ( pci );
/* Add to device hierarchy */
snprintf ( pci->dev.name, sizeof ( pci->dev.name ),
"PCI%02x:%02x.%x", bus,
PCI_SLOT ( devfn ), PCI_FUNC ( devfn ) );
pci->dev.desc.bus_type = BUS_TYPE_PCI;
pci->dev.desc.location = PCI_BUSDEVFN (bus, devfn);
pci->dev.desc.vendor = pci->vendor;
pci->dev.desc.device = pci->device;
pci->dev.desc.class = pci->class;
pci->dev.desc.ioaddr = pci->ioaddr;
pci->dev.desc.irq = pci->irq;
pci->dev.parent = &rootdev->dev;
list_add ( &pci->dev.siblings, &rootdev->dev.children);
INIT_LIST_HEAD ( &pci->dev.children );
/* Look for a driver */
if ( pci_probe ( pci ) == 0 ) {
/* pcidev registered, we can drop our ref */
pci = NULL;
} else {
/* Not registered; re-use struct pci_device */
list_del ( &pci->dev.siblings );
}
}
}
free ( pci );
return 0;
err:
free ( pci );
pcibus_remove ( rootdev );
return rc;
}
/**
* Remove PCI root bus
*
* @v rootdev PCI bus root device
*/
static void pcibus_remove ( struct root_device *rootdev ) {
struct pci_device *pci;
struct pci_device *tmp;
list_for_each_entry_safe ( pci, tmp, &rootdev->dev.children,
dev.siblings ) {
pci_remove ( pci );
list_del ( &pci->dev.siblings );
free ( pci );
}
}
/** PCI bus root device driver */
static struct root_driver pci_root_driver = {
.probe = pcibus_probe,
.remove = pcibus_remove,
};
/** PCI bus root device */
struct root_device pci_root_device __root_device = {
.dev = { .name = "PCI" },
.driver = &pci_root_driver,
};
