/*
* pci_dn.c
*
* Copyright (C) 2001 Todd Inglett, IBM Corporation
*
* PCI manipulation via device_nodes.
*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/string.h>
#include <linux/init.h>
#include <asm/io.h>
#include <asm/prom.h>
#include <asm/pci-bridge.h>
#include <asm/ppc-pci.h>
#include <asm/firmware.h>
/*
* Traverse_func that inits the PCI fields of the device node.
* NOTE: this *must* be done before read/write config to the device.
*/
void * __devinit update_dn_pci_info(struct device_node *dn, void *data)
{
struct pci_controller *phb = data;
const int *type =
of_get_property(dn, "ibm,pci-config-space-type", NULL);
const u32 *regs;
struct pci_dn *pdn;
pdn = alloc_maybe_bootmem(sizeof(*pdn), GFP_KERNEL);
if (pdn == NULL)
return NULL;
memset(pdn, 0, sizeof(*pdn));
dn->data = pdn;
pdn->node = dn;
pdn->phb = phb;
regs = of_get_property(dn, "reg", NULL);
if (regs) {
/* First register entry is addr (00BBSS00) */
pdn->busno = (regs[0] >> 16) & 0xff;
pdn->devfn = (regs[0] >> 8) & 0xff;
}
pdn->pci_ext_config_space = (type && *type == 1);
return NULL;
}
/*
* Traverse a device tree stopping each PCI device in the tree.
* This is done depth first. As each node is processed, a "pre"
* function is called and the children are processed recursively.
*
* The "pre" func returns a value. If non-zero is returned from
* the "pre" func, the traversal stops and this value is returned.
* This return value is useful when using traverse as a method of
* finding a device.
*
* NOTE: we do not run the func for devices that do not appear to
* be PCI except for the start node which we assume (this is good
* because the start node is often a phb which may be missing PCI
* properties).
* We use the class-code as an indicator. If we run into
* one of these nodes we also assume its siblings are non-pci for
* performance.
*/
void *traverse_pci_devices(struct device_node *start, traverse_func pre,
void *data)
{
struct device_node *dn, *nextdn;
void *ret;
/* We started with a phb, iterate all childs */
for (dn = start->child; dn; dn = nextdn) {
const u32 *classp;
u32 class;
nextdn = NULL;
classp = of_get_property(dn, "class-code", NULL);
class = classp ? *classp : 0;
if (pre && ((ret = pre(dn, data)) != NULL))
return ret;
/* If we are a PCI bridge, go down */
if (dn->child && ((class >> 8) == PCI_CLASS_BRIDGE_PCI ||
(class >> 8) == PCI_CLASS_BRIDGE_CARDBUS))
/* Depth first...do children */
nextdn = dn->child;
else if (dn->sibling)
/* ok, try next sibling instead. */
nextdn = dn->sibling;
if (!nextdn) {
/* Walk up to next valid sibling. */
do {
dn = dn->parent;
if (dn == start)
return NULL;
} while (dn->sibling == NULL);
nextdn = dn->sibling;
}
}
return NULL;
}
/**
* pci_devs_phb_init_dynamic - setup pci devices under this PHB
* phb: pci-to-host bridge (top-level bridge connecting to cpu)
*
* This routine is called both during boot, (before the memory
* subsystem is set up, before kmalloc is valid) and during the
* dynamic lpar operation of adding a PHB to a running system.
*/
void __devinit pci_devs_phb_init_dynamic(struct pci_controller *phb)
{
struct device_node *dn = phb->dn;
struct pci_dn *pdn;
/* PHB nodes themselves must not match */
update_dn_pci_info(dn, phb);
pdn = dn->data;
if (pdn) {
pdn->devfn = pdn->busno = -1;
pdn->phb = phb;
}
/* Update dn->phb ptrs for new phb and children devices */
traverse_pci_devices(dn, update_dn_pci_info, phb);
}
/*
* Traversal func that looks for a <busno,devfcn> value.
* If found, the pci_dn is returned (thus terminating the traversal).
*/
static void *is_devfn_node(struct device_node *dn, void *data)
{
int busno = ((unsigned long)data >> 8) & 0xff;
int devfn = ((unsigned long)data) & 0xff;
struct pci_dn *pci = dn->data;
if (pci && (devfn == pci->devfn) && (busno == pci->busno))
return dn;
return NULL;
}
/*
* This is the "slow" path for looking up a device_node from a
* pci_dev. It will hunt for the device under its parent's
* phb and then update sysdata for a future fastpath.
*
* It may also do fixups on the actual device since this happens
* on the first read/write.
*
* Note that it also must deal with devices that don't exist.
* In this case it may probe for real hardware ("just in case")
* and add a device_node to the device tree if necessary.
*
*/
struct device_node *fetch_dev_dn(struct pci_dev *dev)
{
struct device_node *orig_dn = dev->sysdata;
struct device_node *dn;
unsigned long searchval = (dev->bus->number << 8) | dev->devfn;
dn = traverse_pci_devices(orig_dn, is_devfn_node, (void *)searchval);
if (dn)
dev->sysdata = dn;
return dn;
}
EXPORT_SYMBOL(fetch_dev_dn);
/**
* pci_devs_phb_init - Initialize phbs and pci devs under them.
*
* This routine walks over all phb's (pci-host bridges) on the
* system, and sets up assorted pci-related structures
* (including pci info in the device node structs) for each
* pci device found underneath. This routine runs once,
* early in the boot sequence.
*/
void __init pci_devs_phb_init(void)
{
struct pci_controller *phb, *tmp;
/* This must be done first so the device nodes have valid pci info! */
list_for_each_entry_safe(phb, tmp, &hose_list, list_node)
pci_devs_phb_init_dynamic(phb);
}
