android_kernel_xiaomi_sm8350/drivers/pci/bus.c
Bjorn Helgaas 2fe2abf896 PCI: augment bus resource table with a list
Previously we used a table of size PCI_BUS_NUM_RESOURCES (16) for resources
forwarded to a bus by its upstream bridge.  We've increased this size
several times when the table overflowed.

But there's no good limit on the number of resources because host bridges
and subtractive decode bridges can forward any number of ranges to their
secondary buses.

This patch reduces the table to only PCI_BRIDGE_RESOURCE_NUM (4) entries,
which corresponds to the number of windows a PCI-to-PCI (3) or CardBus (4)
bridge can positively decode.  Any additional resources, e.g., PCI host
bridge windows or subtractively-decoded regions, are kept in a list.

I'd prefer a single list rather than this split table/list approach, but
that requires simultaneous changes to every architecture.  This approach
only requires immediate changes where we set up (a) host bridges with more
than four windows and (b) subtractive-decode P2P bridges, and we can
incrementally change other architectures to use the list.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-02-23 09:43:37 -08:00

304 lines
7.2 KiB
C

/*
* drivers/pci/bus.c
*
* From setup-res.c, by:
* Dave Rusling (david.rusling@reo.mts.dec.com)
* David Mosberger (davidm@cs.arizona.edu)
* David Miller (davem@redhat.com)
* Ivan Kokshaysky (ink@jurassic.park.msu.ru)
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/proc_fs.h>
#include <linux/init.h>
#include "pci.h"
void pci_bus_add_resource(struct pci_bus *bus, struct resource *res,
unsigned int flags)
{
struct pci_bus_resource *bus_res;
bus_res = kzalloc(sizeof(struct pci_bus_resource), GFP_KERNEL);
if (!bus_res) {
dev_err(&bus->dev, "can't add %pR resource\n", res);
return;
}
bus_res->res = res;
bus_res->flags = flags;
list_add_tail(&bus_res->list, &bus->resources);
}
struct resource *pci_bus_resource_n(const struct pci_bus *bus, int n)
{
struct pci_bus_resource *bus_res;
if (n < PCI_BRIDGE_RESOURCE_NUM)
return bus->resource[n];
n -= PCI_BRIDGE_RESOURCE_NUM;
list_for_each_entry(bus_res, &bus->resources, list) {
if (n-- == 0)
return bus_res->res;
}
return NULL;
}
EXPORT_SYMBOL_GPL(pci_bus_resource_n);
void pci_bus_remove_resources(struct pci_bus *bus)
{
struct pci_bus_resource *bus_res, *tmp;
int i;
for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++)
bus->resource[i] = 0;
list_for_each_entry_safe(bus_res, tmp, &bus->resources, list) {
list_del(&bus_res->list);
kfree(bus_res);
}
}
/**
* pci_bus_alloc_resource - allocate a resource from a parent bus
* @bus: PCI bus
* @res: resource to allocate
* @size: size of resource to allocate
* @align: alignment of resource to allocate
* @min: minimum /proc/iomem address to allocate
* @type_mask: IORESOURCE_* type flags
* @alignf: resource alignment function
* @alignf_data: data argument for resource alignment function
*
* Given the PCI bus a device resides on, the size, minimum address,
* alignment and type, try to find an acceptable resource allocation
* for a specific device resource.
*/
int
pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res,
resource_size_t size, resource_size_t align,
resource_size_t min, unsigned int type_mask,
resource_size_t (*alignf)(void *,
const struct resource *,
resource_size_t,
resource_size_t),
void *alignf_data)
{
int i, ret = -ENOMEM;
struct resource *r;
resource_size_t max = -1;
type_mask |= IORESOURCE_IO | IORESOURCE_MEM;
/* don't allocate too high if the pref mem doesn't support 64bit*/
if (!(res->flags & IORESOURCE_MEM_64))
max = PCIBIOS_MAX_MEM_32;
pci_bus_for_each_resource(bus, r, i) {
if (!r)
continue;
/* type_mask must match */
if ((res->flags ^ r->flags) & type_mask)
continue;
/* We cannot allocate a non-prefetching resource
from a pre-fetching area */
if ((r->flags & IORESOURCE_PREFETCH) &&
!(res->flags & IORESOURCE_PREFETCH))
continue;
/* Ok, try it out.. */
ret = allocate_resource(r, res, size,
r->start ? : min,
max, align,
alignf, alignf_data);
if (ret == 0)
break;
}
return ret;
}
/**
* pci_bus_add_device - add a single device
* @dev: device to add
*
* This adds a single pci device to the global
* device list and adds sysfs and procfs entries
*/
int pci_bus_add_device(struct pci_dev *dev)
{
int retval;
retval = device_add(&dev->dev);
if (retval)
return retval;
dev->is_added = 1;
pci_proc_attach_device(dev);
pci_create_sysfs_dev_files(dev);
return 0;
}
/**
* pci_bus_add_child - add a child bus
* @bus: bus to add
*
* This adds sysfs entries for a single bus
*/
int pci_bus_add_child(struct pci_bus *bus)
{
int retval;
if (bus->bridge)
bus->dev.parent = bus->bridge;
retval = device_register(&bus->dev);
if (retval)
return retval;
bus->is_added = 1;
retval = device_create_file(&bus->dev, &dev_attr_cpuaffinity);
if (retval)
return retval;
retval = device_create_file(&bus->dev, &dev_attr_cpulistaffinity);
/* Create legacy_io and legacy_mem files for this bus */
pci_create_legacy_files(bus);
return retval;
}
/**
* pci_bus_add_devices - insert newly discovered PCI devices
* @bus: bus to check for new devices
*
* Add newly discovered PCI devices (which are on the bus->devices
* list) to the global PCI device list, add the sysfs and procfs
* entries. Where a bridge is found, add the discovered bus to
* the parents list of child buses, and recurse (breadth-first
* to be compatible with 2.4)
*
* Call hotplug for each new devices.
*/
void pci_bus_add_devices(const struct pci_bus *bus)
{
struct pci_dev *dev;
struct pci_bus *child;
int retval;
list_for_each_entry(dev, &bus->devices, bus_list) {
/* Skip already-added devices */
if (dev->is_added)
continue;
retval = pci_bus_add_device(dev);
if (retval)
dev_err(&dev->dev, "Error adding device, continuing\n");
}
list_for_each_entry(dev, &bus->devices, bus_list) {
BUG_ON(!dev->is_added);
child = dev->subordinate;
/*
* If there is an unattached subordinate bus, attach
* it and then scan for unattached PCI devices.
*/
if (!child)
continue;
if (list_empty(&child->node)) {
down_write(&pci_bus_sem);
list_add_tail(&child->node, &dev->bus->children);
up_write(&pci_bus_sem);
}
pci_bus_add_devices(child);
/*
* register the bus with sysfs as the parent is now
* properly registered.
*/
if (child->is_added)
continue;
retval = pci_bus_add_child(child);
if (retval)
dev_err(&dev->dev, "Error adding bus, continuing\n");
}
}
void pci_enable_bridges(struct pci_bus *bus)
{
struct pci_dev *dev;
int retval;
list_for_each_entry(dev, &bus->devices, bus_list) {
if (dev->subordinate) {
if (!pci_is_enabled(dev)) {
retval = pci_enable_device(dev);
pci_set_master(dev);
}
pci_enable_bridges(dev->subordinate);
}
}
}
/** pci_walk_bus - walk devices on/under bus, calling callback.
* @top bus whose devices should be walked
* @cb callback to be called for each device found
* @userdata arbitrary pointer to be passed to callback.
*
* Walk the given bus, including any bridged devices
* on buses under this bus. Call the provided callback
* on each device found.
*
* We check the return of @cb each time. If it returns anything
* other than 0, we break out.
*
*/
void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *),
void *userdata)
{
struct pci_dev *dev;
struct pci_bus *bus;
struct list_head *next;
int retval;
bus = top;
down_read(&pci_bus_sem);
next = top->devices.next;
for (;;) {
if (next == &bus->devices) {
/* end of this bus, go up or finish */
if (bus == top)
break;
next = bus->self->bus_list.next;
bus = bus->self->bus;
continue;
}
dev = list_entry(next, struct pci_dev, bus_list);
if (dev->subordinate) {
/* this is a pci-pci bridge, do its devices next */
next = dev->subordinate->devices.next;
bus = dev->subordinate;
} else
next = dev->bus_list.next;
/* Run device routines with the device locked */
down(&dev->dev.sem);
retval = cb(dev, userdata);
up(&dev->dev.sem);
if (retval)
break;
}
up_read(&pci_bus_sem);
}
EXPORT_SYMBOL(pci_bus_alloc_resource);
EXPORT_SYMBOL_GPL(pci_bus_add_device);
EXPORT_SYMBOL(pci_bus_add_devices);
EXPORT_SYMBOL(pci_enable_bridges);