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linux/arch/powerpc/platforms/pseries/pci_dlpar.c
Benjamin Herrenschmidt 3d5134ee83 [POWERPC] Rewrite IO allocation & mapping on powerpc64
This rewrites pretty much from scratch the handling of MMIO and PIO
space allocations on powerpc64.  The main goals are:

 - Get rid of imalloc and use more common code where possible
 - Simplify the current mess so that PIO space is allocated and
   mapped in a single place for PCI bridges
 - Handle allocation constraints of PIO for all bridges including
   hot plugged ones within the 2GB space reserved for IO ports,
   so that devices on hotplugged busses will now work with drivers
   that assume IO ports fit in an int.
 - Cleanup and separate tracking of the ISA space in the reserved
   low 64K of IO space. No ISA -> Nothing mapped there.

I booted a cell blade with IDE on PIO and MMIO and a dual G5 so
far, that's it :-)

With this patch, all allocations are done using the code in
mm/vmalloc.c, though we use the low level __get_vm_area with
explicit start/stop constraints in order to manage separate
areas for vmalloc/vmap, ioremap, and PCI IOs.

This greatly simplifies a lot of things, as you can see in the
diffstat of that patch :-)

A new pair of functions pcibios_map/unmap_io_space() now replace
all of the previous code that used to manipulate PCI IOs space.
The allocation is done at mapping time, which is now called from
scan_phb's, just before the devices are probed (instead of after,
which is by itself a bug fix). The only other caller is the PCI
hotplug code for hot adding PCI-PCI bridges (slots).

imalloc is gone, as is the "sub-allocation" thing, but I do beleive
that hotplug should still work in the sense that the space allocation
is always done by the PHB, but if you unmap a child bus of this PHB
(which seems to be possible), then the code should properly tear
down all the HPTE mappings for that area of the PHB allocated IO space.

I now always reserve the first 64K of IO space for the bridge with
the ISA bus on it. I have moved the code for tracking ISA in a separate
file which should also make it smarter if we ever are capable of
hot unplugging or re-plugging an ISA bridge.

This should have a side effect on platforms like powermac where VGA IOs
will no longer work. This is done on purpose though as they would have
worked semi-randomly before. The idea at this point is to isolate drivers
that might need to access those and fix them by providing a proper
function to obtain an offset to the legacy IOs of a given bus.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-06-14 22:29:56 +10:00

218 lines
5.6 KiB
C

/*
* PCI Dynamic LPAR, PCI Hot Plug and PCI EEH recovery code
* for RPA-compliant PPC64 platform.
* Copyright (C) 2003 Linda Xie <lxie@us.ibm.com>
* Copyright (C) 2005 International Business Machines
*
* Updates, 2005, John Rose <johnrose@austin.ibm.com>
* Updates, 2005, Linas Vepstas <linas@austin.ibm.com>
*
* All rights reserved.
*
* 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, GOOD TITLE or
* NON INFRINGEMENT. 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.
*/
#include <linux/pci.h>
#include <asm/pci-bridge.h>
#include <asm/ppc-pci.h>
#include <asm/firmware.h>
#include <asm/eeh.h>
static struct pci_bus *
find_bus_among_children(struct pci_bus *bus,
struct device_node *dn)
{
struct pci_bus *child = NULL;
struct list_head *tmp;
struct device_node *busdn;
busdn = pci_bus_to_OF_node(bus);
if (busdn == dn)
return bus;
list_for_each(tmp, &bus->children) {
child = find_bus_among_children(pci_bus_b(tmp), dn);
if (child)
break;
};
return child;
}
struct pci_bus *
pcibios_find_pci_bus(struct device_node *dn)
{
struct pci_dn *pdn = dn->data;
if (!pdn || !pdn->phb || !pdn->phb->bus)
return NULL;
return find_bus_among_children(pdn->phb->bus, dn);
}
EXPORT_SYMBOL_GPL(pcibios_find_pci_bus);
/**
* pcibios_remove_pci_devices - remove all devices under this bus
*
* Remove all of the PCI devices under this bus both from the
* linux pci device tree, and from the powerpc EEH address cache.
*/
void
pcibios_remove_pci_devices(struct pci_bus *bus)
{
struct pci_dev *dev, *tmp;
list_for_each_entry_safe(dev, tmp, &bus->devices, bus_list) {
eeh_remove_bus_device(dev);
pci_remove_bus_device(dev);
}
}
EXPORT_SYMBOL_GPL(pcibios_remove_pci_devices);
/* Must be called before pci_bus_add_devices */
void
pcibios_fixup_new_pci_devices(struct pci_bus *bus, int fix_bus)
{
struct pci_dev *dev;
list_for_each_entry(dev, &bus->devices, bus_list) {
/*
* Skip already-present devices (which are on the
* global device list.)
*/
if (list_empty(&dev->global_list)) {
int i;
/* Fill device archdata and setup iommu table */
pcibios_setup_new_device(dev);
if(fix_bus)
pcibios_fixup_device_resources(dev, bus);
pci_read_irq_line(dev);
for (i = 0; i < PCI_NUM_RESOURCES; i++) {
struct resource *r = &dev->resource[i];
if (r->parent || !r->start || !r->flags)
continue;
pci_claim_resource(dev, i);
}
}
}
}
EXPORT_SYMBOL_GPL(pcibios_fixup_new_pci_devices);
static int
pcibios_pci_config_bridge(struct pci_dev *dev)
{
u8 sec_busno;
struct pci_bus *child_bus;
/* Get busno of downstream bus */
pci_read_config_byte(dev, PCI_SECONDARY_BUS, &sec_busno);
/* Add to children of PCI bridge dev->bus */
child_bus = pci_add_new_bus(dev->bus, dev, sec_busno);
if (!child_bus) {
printk (KERN_ERR "%s: could not add second bus\n", __FUNCTION__);
return -EIO;
}
sprintf(child_bus->name, "PCI Bus #%02x", child_bus->number);
pci_scan_child_bus(child_bus);
/* Fixup new pci devices without touching bus struct */
pcibios_fixup_new_pci_devices(child_bus, 0);
/* Make the discovered devices available */
pci_bus_add_devices(child_bus);
eeh_add_device_tree_late(child_bus);
return 0;
}
/**
* pcibios_add_pci_devices - adds new pci devices to bus
*
* This routine will find and fixup new pci devices under
* the indicated bus. This routine presumes that there
* might already be some devices under this bridge, so
* it carefully tries to add only new devices. (And that
* is how this routine differs from other, similar pcibios
* routines.)
*/
void
pcibios_add_pci_devices(struct pci_bus * bus)
{
int slotno, num, mode;
struct pci_dev *dev;
struct device_node *dn = pci_bus_to_OF_node(bus);
eeh_add_device_tree_early(dn);
mode = PCI_PROBE_NORMAL;
if (ppc_md.pci_probe_mode)
mode = ppc_md.pci_probe_mode(bus);
if (mode == PCI_PROBE_DEVTREE) {
/* use ofdt-based probe */
of_scan_bus(dn, bus);
if (!list_empty(&bus->devices)) {
pcibios_fixup_new_pci_devices(bus, 0);
pci_bus_add_devices(bus);
eeh_add_device_tree_late(bus);
}
} else if (mode == PCI_PROBE_NORMAL) {
/* use legacy probe */
slotno = PCI_SLOT(PCI_DN(dn->child)->devfn);
num = pci_scan_slot(bus, PCI_DEVFN(slotno, 0));
if (num) {
pcibios_fixup_new_pci_devices(bus, 1);
pci_bus_add_devices(bus);
eeh_add_device_tree_late(bus);
}
list_for_each_entry(dev, &bus->devices, bus_list)
if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE)
pcibios_pci_config_bridge(dev);
}
}
EXPORT_SYMBOL_GPL(pcibios_add_pci_devices);
struct pci_controller * __devinit init_phb_dynamic(struct device_node *dn)
{
struct pci_controller *phb;
int primary;
primary = list_empty(&hose_list);
phb = pcibios_alloc_controller(dn);
if (!phb)
return NULL;
rtas_setup_phb(phb);
pci_process_bridge_OF_ranges(phb, dn, 0);
pci_devs_phb_init_dynamic(phb);
if (dn->child)
eeh_add_device_tree_early(dn);
scan_phb(phb);
pcibios_fixup_new_pci_devices(phb->bus, 0);
pci_bus_add_devices(phb->bus);
eeh_add_device_tree_late(phb->bus);
return phb;
}
EXPORT_SYMBOL_GPL(init_phb_dynamic);