linux/drivers/pnp/core.c
Bjorn Helgaas 1f32ca31e7 PNP: convert resource options to single linked list
ISAPNP, PNPBIOS, and ACPI describe the "possible resource settings" of
a device, i.e., the possibilities an OS bus driver has when it assigns
I/O port, MMIO, and other resources to the device.

PNP used to maintain this "possible resource setting" information in
one independent option structure and a list of dependent option
structures for each device.  Each of these option structures had lists
of I/O, memory, IRQ, and DMA resources, for example:

  dev
    independent options
      ind-io0  -> ind-io1  ...
      ind-mem0 -> ind-mem1 ...
      ...
    dependent option set 0
      dep0-io0  -> dep0-io1  ...
      dep0-mem0 -> dep0-mem1 ...
      ...
    dependent option set 1
      dep1-io0  -> dep1-io1  ...
      dep1-mem0 -> dep1-mem1 ...
      ...
    ...

This data structure was designed for ISAPNP, where the OS configures
device resource settings by writing directly to configuration
registers.  The OS can write the registers in arbitrary order much
like it writes PCI BARs.

However, for PNPBIOS and ACPI devices, the OS uses firmware interfaces
that perform device configuration, and it is important to pass the
desired settings to those interfaces in the correct order.  The OS
learns the correct order by using firmware interfaces that return the
"current resource settings" and "possible resource settings," but the
option structures above doesn't store the ordering information.

This patch replaces the independent and dependent lists with a single
list of options.  For example, a device might have possible resource
settings like this:

  dev
    options
      ind-io0 -> dep0-io0 -> dep1->io0 -> ind-io1 ...

All the possible settings are in the same list, in the order they
come from the firmware "possible resource settings" list.  Each entry
is tagged with an independent/dependent flag.  Dependent entries also
have a "set number" and an optional priority value.  All dependent
entries must be assigned from the same set.  For example, the OS can
use all the entries from dependent set 0, or all the entries from
dependent set 1, but it cannot mix entries from set 0 with entries
from set 1.

Prior to this patch PNP didn't keep track of the order of this list,
and it assigned all independent options first, then all dependent
ones.  Using the example above, that resulted in a "desired
configuration" list like this:

  ind->io0 -> ind->io1 -> depN-io0 ...

instead of the list the firmware expects, which looks like this:

  ind->io0 -> depN-io0 -> ind-io1 ...

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Rene Herman <rene.herman@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>
2008-07-16 23:27:07 +02:00

225 lines
4.6 KiB
C

/*
* core.c - contains all core device and protocol registration functions
*
* Copyright 2002 Adam Belay <ambx1@neo.rr.com>
*/
#include <linux/pnp.h>
#include <linux/types.h>
#include <linux/list.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/dma-mapping.h>
#include "base.h"
static LIST_HEAD(pnp_protocols);
LIST_HEAD(pnp_global);
DEFINE_SPINLOCK(pnp_lock);
/*
* ACPI or PNPBIOS should tell us about all platform devices, so we can
* skip some blind probes. ISAPNP typically enumerates only plug-in ISA
* devices, not built-in things like COM ports.
*/
int pnp_platform_devices;
EXPORT_SYMBOL(pnp_platform_devices);
void *pnp_alloc(long size)
{
void *result;
result = kzalloc(size, GFP_KERNEL);
if (!result) {
printk(KERN_ERR "pnp: Out of Memory\n");
return NULL;
}
return result;
}
/**
* pnp_protocol_register - adds a pnp protocol to the pnp layer
* @protocol: pointer to the corresponding pnp_protocol structure
*
* Ex protocols: ISAPNP, PNPBIOS, etc
*/
int pnp_register_protocol(struct pnp_protocol *protocol)
{
int nodenum;
struct list_head *pos;
INIT_LIST_HEAD(&protocol->devices);
INIT_LIST_HEAD(&protocol->cards);
nodenum = 0;
spin_lock(&pnp_lock);
/* assign the lowest unused number */
list_for_each(pos, &pnp_protocols) {
struct pnp_protocol *cur = to_pnp_protocol(pos);
if (cur->number == nodenum) {
pos = &pnp_protocols;
nodenum++;
}
}
list_add_tail(&protocol->protocol_list, &pnp_protocols);
spin_unlock(&pnp_lock);
protocol->number = nodenum;
sprintf(protocol->dev.bus_id, "pnp%d", nodenum);
return device_register(&protocol->dev);
}
/**
* pnp_protocol_unregister - removes a pnp protocol from the pnp layer
* @protocol: pointer to the corresponding pnp_protocol structure
*/
void pnp_unregister_protocol(struct pnp_protocol *protocol)
{
spin_lock(&pnp_lock);
list_del(&protocol->protocol_list);
spin_unlock(&pnp_lock);
device_unregister(&protocol->dev);
}
static void pnp_free_ids(struct pnp_dev *dev)
{
struct pnp_id *id;
struct pnp_id *next;
id = dev->id;
while (id) {
next = id->next;
kfree(id);
id = next;
}
}
void pnp_free_resource(struct pnp_resource *pnp_res)
{
list_del(&pnp_res->list);
kfree(pnp_res);
}
void pnp_free_resources(struct pnp_dev *dev)
{
struct pnp_resource *pnp_res, *tmp;
list_for_each_entry_safe(pnp_res, tmp, &dev->resources, list) {
pnp_free_resource(pnp_res);
}
}
static void pnp_release_device(struct device *dmdev)
{
struct pnp_dev *dev = to_pnp_dev(dmdev);
pnp_free_ids(dev);
pnp_free_resources(dev);
pnp_free_options(dev);
kfree(dev);
}
struct pnp_dev *pnp_alloc_dev(struct pnp_protocol *protocol, int id, char *pnpid)
{
struct pnp_dev *dev;
struct pnp_id *dev_id;
dev = kzalloc(sizeof(struct pnp_dev), GFP_KERNEL);
if (!dev)
return NULL;
INIT_LIST_HEAD(&dev->resources);
INIT_LIST_HEAD(&dev->options);
dev->protocol = protocol;
dev->number = id;
dev->dma_mask = DMA_24BIT_MASK;
dev->dev.parent = &dev->protocol->dev;
dev->dev.bus = &pnp_bus_type;
dev->dev.dma_mask = &dev->dma_mask;
dev->dev.coherent_dma_mask = dev->dma_mask;
dev->dev.release = &pnp_release_device;
sprintf(dev->dev.bus_id, "%02x:%02x", dev->protocol->number,
dev->number);
dev_id = pnp_add_id(dev, pnpid);
if (!dev_id) {
kfree(dev);
return NULL;
}
return dev;
}
int __pnp_add_device(struct pnp_dev *dev)
{
int ret;
pnp_fixup_device(dev);
dev->status = PNP_READY;
spin_lock(&pnp_lock);
list_add_tail(&dev->global_list, &pnp_global);
list_add_tail(&dev->protocol_list, &dev->protocol->devices);
spin_unlock(&pnp_lock);
ret = device_register(&dev->dev);
if (ret)
return ret;
pnp_interface_attach_device(dev);
return 0;
}
/*
* pnp_add_device - adds a pnp device to the pnp layer
* @dev: pointer to dev to add
*
* adds to driver model, name database, fixups, interface, etc.
*/
int pnp_add_device(struct pnp_dev *dev)
{
int ret;
if (dev->card)
return -EINVAL;
ret = __pnp_add_device(dev);
if (ret)
return ret;
#ifdef CONFIG_PNP_DEBUG
{
struct pnp_id *id;
dev_printk(KERN_DEBUG, &dev->dev, "%s device, IDs",
dev->protocol->name);
for (id = dev->id; id; id = id->next)
printk(" %s", id->id);
printk(" (%s)\n", dev->active ? "active" : "disabled");
}
#endif
return 0;
}
void __pnp_remove_device(struct pnp_dev *dev)
{
spin_lock(&pnp_lock);
list_del(&dev->global_list);
list_del(&dev->protocol_list);
spin_unlock(&pnp_lock);
device_unregister(&dev->dev);
}
static int __init pnp_init(void)
{
printk(KERN_INFO "Linux Plug and Play Support v0.97 (c) Adam Belay\n");
return bus_register(&pnp_bus_type);
}
subsys_initcall(pnp_init);