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linux/drivers/pnp/manager.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

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/*
* manager.c - Resource Management, Conflict Resolution, Activation and Disabling of Devices
*
* based on isapnp.c resource management (c) Jaroslav Kysela <perex@perex.cz>
* Copyright 2003 Adam Belay <ambx1@neo.rr.com>
* Copyright (C) 2008 Hewlett-Packard Development Company, L.P.
* Bjorn Helgaas <bjorn.helgaas@hp.com>
*/
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/pnp.h>
#include <linux/slab.h>
#include <linux/bitmap.h>
#include <linux/mutex.h>
#include "base.h"
DEFINE_MUTEX(pnp_res_mutex);
static int pnp_assign_port(struct pnp_dev *dev, struct pnp_port *rule, int idx)
{
struct resource *res, local_res;
res = pnp_get_resource(dev, IORESOURCE_IO, idx);
if (res) {
dev_dbg(&dev->dev, " io %d already set to %#llx-%#llx "
"flags %#lx\n", idx, (unsigned long long) res->start,
(unsigned long long) res->end, res->flags);
return 0;
}
res = &local_res;
res->flags = rule->flags | IORESOURCE_AUTO;
res->start = 0;
res->end = 0;
if (!rule->size) {
res->flags |= IORESOURCE_DISABLED;
dev_dbg(&dev->dev, " io %d disabled\n", idx);
goto __add;
}
res->start = rule->min;
res->end = res->start + rule->size - 1;
while (!pnp_check_port(dev, res)) {
res->start += rule->align;
res->end = res->start + rule->size - 1;
if (res->start > rule->max || !rule->align) {
dev_dbg(&dev->dev, " couldn't assign io %d "
"(min %#llx max %#llx)\n", idx,
(unsigned long long) rule->min,
(unsigned long long) rule->max);
return -EBUSY;
}
}
__add:
pnp_add_io_resource(dev, res->start, res->end, res->flags);
return 0;
}
static int pnp_assign_mem(struct pnp_dev *dev, struct pnp_mem *rule, int idx)
{
struct resource *res, local_res;
res = pnp_get_resource(dev, IORESOURCE_MEM, idx);
if (res) {
dev_dbg(&dev->dev, " mem %d already set to %#llx-%#llx "
"flags %#lx\n", idx, (unsigned long long) res->start,
(unsigned long long) res->end, res->flags);
return 0;
}
res = &local_res;
res->flags = rule->flags | IORESOURCE_AUTO;
res->start = 0;
res->end = 0;
if (!(rule->flags & IORESOURCE_MEM_WRITEABLE))
res->flags |= IORESOURCE_READONLY;
if (rule->flags & IORESOURCE_MEM_CACHEABLE)
res->flags |= IORESOURCE_CACHEABLE;
if (rule->flags & IORESOURCE_MEM_RANGELENGTH)
res->flags |= IORESOURCE_RANGELENGTH;
if (rule->flags & IORESOURCE_MEM_SHADOWABLE)
res->flags |= IORESOURCE_SHADOWABLE;
if (!rule->size) {
res->flags |= IORESOURCE_DISABLED;
dev_dbg(&dev->dev, " mem %d disabled\n", idx);
goto __add;
}
res->start = rule->min;
res->end = res->start + rule->size - 1;
while (!pnp_check_mem(dev, res)) {
res->start += rule->align;
res->end = res->start + rule->size - 1;
if (res->start > rule->max || !rule->align) {
dev_dbg(&dev->dev, " couldn't assign mem %d "
"(min %#llx max %#llx)\n", idx,
(unsigned long long) rule->min,
(unsigned long long) rule->max);
return -EBUSY;
}
}
__add:
pnp_add_mem_resource(dev, res->start, res->end, res->flags);
return 0;
}
static int pnp_assign_irq(struct pnp_dev *dev, struct pnp_irq *rule, int idx)
{
struct resource *res, local_res;
int i;
/* IRQ priority: this table is good for i386 */
static unsigned short xtab[16] = {
5, 10, 11, 12, 9, 14, 15, 7, 3, 4, 13, 0, 1, 6, 8, 2
};
res = pnp_get_resource(dev, IORESOURCE_IRQ, idx);
if (res) {
dev_dbg(&dev->dev, " irq %d already set to %d flags %#lx\n",
idx, (int) res->start, res->flags);
return 0;
}
res = &local_res;
res->flags = rule->flags | IORESOURCE_AUTO;
res->start = -1;
res->end = -1;
if (bitmap_empty(rule->map.bits, PNP_IRQ_NR)) {
res->flags |= IORESOURCE_DISABLED;
dev_dbg(&dev->dev, " irq %d disabled\n", idx);
goto __add;
}
/* TBD: need check for >16 IRQ */
res->start = find_next_bit(rule->map.bits, PNP_IRQ_NR, 16);
if (res->start < PNP_IRQ_NR) {
res->end = res->start;
goto __add;
}
for (i = 0; i < 16; i++) {
if (test_bit(xtab[i], rule->map.bits)) {
res->start = res->end = xtab[i];
if (pnp_check_irq(dev, res))
goto __add;
}
}
if (rule->flags & IORESOURCE_IRQ_OPTIONAL) {
res->start = -1;
res->end = -1;
res->flags |= IORESOURCE_DISABLED;
dev_dbg(&dev->dev, " irq %d disabled (optional)\n", idx);
goto __add;
}
dev_dbg(&dev->dev, " couldn't assign irq %d\n", idx);
return -EBUSY;
__add:
pnp_add_irq_resource(dev, res->start, res->flags);
return 0;
}
static int pnp_assign_dma(struct pnp_dev *dev, struct pnp_dma *rule, int idx)
{
struct resource *res, local_res;
int i;
/* DMA priority: this table is good for i386 */
static unsigned short xtab[8] = {
1, 3, 5, 6, 7, 0, 2, 4
};
res = pnp_get_resource(dev, IORESOURCE_DMA, idx);
if (res) {
dev_dbg(&dev->dev, " dma %d already set to %d flags %#lx\n",
idx, (int) res->start, res->flags);
return 0;
}
res = &local_res;
res->flags = rule->flags | IORESOURCE_AUTO;
res->start = -1;
res->end = -1;
for (i = 0; i < 8; i++) {
if (rule->map & (1 << xtab[i])) {
res->start = res->end = xtab[i];
if (pnp_check_dma(dev, res))
goto __add;
}
}
#ifdef MAX_DMA_CHANNELS
res->start = res->end = MAX_DMA_CHANNELS;
#endif
res->flags |= IORESOURCE_DISABLED;
dev_dbg(&dev->dev, " disable dma %d\n", idx);
__add:
pnp_add_dma_resource(dev, res->start, res->flags);
return 0;
}
void pnp_init_resources(struct pnp_dev *dev)
{
pnp_free_resources(dev);
}
static void pnp_clean_resource_table(struct pnp_dev *dev)
{
struct pnp_resource *pnp_res, *tmp;
list_for_each_entry_safe(pnp_res, tmp, &dev->resources, list) {
if (pnp_res->res.flags & IORESOURCE_AUTO)
pnp_free_resource(pnp_res);
}
}
/**
* pnp_assign_resources - assigns resources to the device based on the specified dependent number
* @dev: pointer to the desired device
* @set: the dependent function number
*/
static int pnp_assign_resources(struct pnp_dev *dev, int set)
{
struct pnp_option *option;
int nport = 0, nmem = 0, nirq = 0, ndma = 0;
int ret = 0;
dev_dbg(&dev->dev, "pnp_assign_resources, try dependent set %d\n", set);
mutex_lock(&pnp_res_mutex);
pnp_clean_resource_table(dev);
list_for_each_entry(option, &dev->options, list) {
if (pnp_option_is_dependent(option) &&
pnp_option_set(option) != set)
continue;
switch (option->type) {
case IORESOURCE_IO:
ret = pnp_assign_port(dev, &option->u.port, nport++);
break;
case IORESOURCE_MEM:
ret = pnp_assign_mem(dev, &option->u.mem, nmem++);
break;
case IORESOURCE_IRQ:
ret = pnp_assign_irq(dev, &option->u.irq, nirq++);
break;
case IORESOURCE_DMA:
ret = pnp_assign_dma(dev, &option->u.dma, ndma++);
break;
default:
ret = -EINVAL;
break;
}
if (ret < 0)
break;
}
mutex_unlock(&pnp_res_mutex);
if (ret < 0) {
dev_dbg(&dev->dev, "pnp_assign_resources failed (%d)\n", ret);
pnp_clean_resource_table(dev);
} else
dbg_pnp_show_resources(dev, "pnp_assign_resources succeeded");
return ret;
}
/**
* pnp_auto_config_dev - automatically assigns resources to a device
* @dev: pointer to the desired device
*/
int pnp_auto_config_dev(struct pnp_dev *dev)
{
int i, ret;
if (!pnp_can_configure(dev)) {
dev_dbg(&dev->dev, "configuration not supported\n");
return -ENODEV;
}
ret = pnp_assign_resources(dev, 0);
if (ret == 0)
return 0;
for (i = 1; i < dev->num_dependent_sets; i++) {
ret = pnp_assign_resources(dev, i);
if (ret == 0)
return 0;
}
dev_err(&dev->dev, "unable to assign resources\n");
return ret;
}
/**
* pnp_start_dev - low-level start of the PnP device
* @dev: pointer to the desired device
*
* assumes that resources have already been allocated
*/
int pnp_start_dev(struct pnp_dev *dev)
{
if (!pnp_can_write(dev)) {
dev_dbg(&dev->dev, "activation not supported\n");
return -EINVAL;
}
dbg_pnp_show_resources(dev, "pnp_start_dev");
if (dev->protocol->set(dev) < 0) {
dev_err(&dev->dev, "activation failed\n");
return -EIO;
}
dev_info(&dev->dev, "activated\n");
return 0;
}
/**
* pnp_stop_dev - low-level disable of the PnP device
* @dev: pointer to the desired device
*
* does not free resources
*/
int pnp_stop_dev(struct pnp_dev *dev)
{
if (!pnp_can_disable(dev)) {
dev_dbg(&dev->dev, "disabling not supported\n");
return -EINVAL;
}
if (dev->protocol->disable(dev) < 0) {
dev_err(&dev->dev, "disable failed\n");
return -EIO;
}
dev_info(&dev->dev, "disabled\n");
return 0;
}
/**
* pnp_activate_dev - activates a PnP device for use
* @dev: pointer to the desired device
*
* does not validate or set resources so be careful.
*/
int pnp_activate_dev(struct pnp_dev *dev)
{
int error;
if (dev->active)
return 0;
/* ensure resources are allocated */
if (pnp_auto_config_dev(dev))
return -EBUSY;
error = pnp_start_dev(dev);
if (error)
return error;
dev->active = 1;
return 0;
}
/**
* pnp_disable_dev - disables device
* @dev: pointer to the desired device
*
* inform the correct pnp protocol so that resources can be used by other devices
*/
int pnp_disable_dev(struct pnp_dev *dev)
{
int error;
if (!dev->active)
return 0;
error = pnp_stop_dev(dev);
if (error)
return error;
dev->active = 0;
/* release the resources so that other devices can use them */
mutex_lock(&pnp_res_mutex);
pnp_clean_resource_table(dev);
mutex_unlock(&pnp_res_mutex);
return 0;
}
EXPORT_SYMBOL(pnp_start_dev);
EXPORT_SYMBOL(pnp_stop_dev);
EXPORT_SYMBOL(pnp_activate_dev);
EXPORT_SYMBOL(pnp_disable_dev);
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