linux/drivers/pnp/manager.c
Bjorn Helgaas b173491339 PNP: remove null pointer checks
Remove some null pointer checks.  Null pointers in these areas indicate
programming errors, and I think it's better to oops immediately rather
than return an error that is easily ignored.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Acked-by: Adam Belay <abelay@novell.com>
Signed-off-by: Len Brown <len.brown@intel.com>
2007-08-24 01:27:24 -04:00

589 lines
14 KiB
C

/*
* manager.c - Resource Management, Conflict Resolution, Activation and Disabling of Devices
*
* based on isapnp.c resource management (c) Jaroslav Kysela <perex@suse.cz>
* Copyright 2003 Adam Belay <ambx1@neo.rr.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 "base.h"
DECLARE_MUTEX(pnp_res_mutex);
static int pnp_assign_port(struct pnp_dev *dev, struct pnp_port *rule, int idx)
{
resource_size_t *start, *end;
unsigned long *flags;
if (idx >= PNP_MAX_PORT) {
pnp_err
("More than 4 ports is incompatible with pnp specifications.");
/* pretend we were successful so at least the manager won't try again */
return 1;
}
/* check if this resource has been manually set, if so skip */
if (!(dev->res.port_resource[idx].flags & IORESOURCE_AUTO))
return 1;
start = &dev->res.port_resource[idx].start;
end = &dev->res.port_resource[idx].end;
flags = &dev->res.port_resource[idx].flags;
/* set the initial values */
*flags |= rule->flags | IORESOURCE_IO;
*flags &= ~IORESOURCE_UNSET;
if (!rule->size) {
*flags |= IORESOURCE_DISABLED;
return 1; /* skip disabled resource requests */
}
*start = rule->min;
*end = *start + rule->size - 1;
/* run through until pnp_check_port is happy */
while (!pnp_check_port(dev, idx)) {
*start += rule->align;
*end = *start + rule->size - 1;
if (*start > rule->max || !rule->align)
return 0;
}
return 1;
}
static int pnp_assign_mem(struct pnp_dev *dev, struct pnp_mem *rule, int idx)
{
resource_size_t *start, *end;
unsigned long *flags;
if (idx >= PNP_MAX_MEM) {
pnp_err
("More than 8 mems is incompatible with pnp specifications.");
/* pretend we were successful so at least the manager won't try again */
return 1;
}
/* check if this resource has been manually set, if so skip */
if (!(dev->res.mem_resource[idx].flags & IORESOURCE_AUTO))
return 1;
start = &dev->res.mem_resource[idx].start;
end = &dev->res.mem_resource[idx].end;
flags = &dev->res.mem_resource[idx].flags;
/* set the initial values */
*flags |= rule->flags | IORESOURCE_MEM;
*flags &= ~IORESOURCE_UNSET;
/* convert pnp flags to standard Linux flags */
if (!(rule->flags & IORESOURCE_MEM_WRITEABLE))
*flags |= IORESOURCE_READONLY;
if (rule->flags & IORESOURCE_MEM_CACHEABLE)
*flags |= IORESOURCE_CACHEABLE;
if (rule->flags & IORESOURCE_MEM_RANGELENGTH)
*flags |= IORESOURCE_RANGELENGTH;
if (rule->flags & IORESOURCE_MEM_SHADOWABLE)
*flags |= IORESOURCE_SHADOWABLE;
if (!rule->size) {
*flags |= IORESOURCE_DISABLED;
return 1; /* skip disabled resource requests */
}
*start = rule->min;
*end = *start + rule->size - 1;
/* run through until pnp_check_mem is happy */
while (!pnp_check_mem(dev, idx)) {
*start += rule->align;
*end = *start + rule->size - 1;
if (*start > rule->max || !rule->align)
return 0;
}
return 1;
}
static int pnp_assign_irq(struct pnp_dev *dev, struct pnp_irq *rule, int idx)
{
resource_size_t *start, *end;
unsigned long *flags;
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
};
if (idx >= PNP_MAX_IRQ) {
pnp_err
("More than 2 irqs is incompatible with pnp specifications.");
/* pretend we were successful so at least the manager won't try again */
return 1;
}
/* check if this resource has been manually set, if so skip */
if (!(dev->res.irq_resource[idx].flags & IORESOURCE_AUTO))
return 1;
start = &dev->res.irq_resource[idx].start;
end = &dev->res.irq_resource[idx].end;
flags = &dev->res.irq_resource[idx].flags;
/* set the initial values */
*flags |= rule->flags | IORESOURCE_IRQ;
*flags &= ~IORESOURCE_UNSET;
if (bitmap_empty(rule->map, PNP_IRQ_NR)) {
*flags |= IORESOURCE_DISABLED;
return 1; /* skip disabled resource requests */
}
/* TBD: need check for >16 IRQ */
*start = find_next_bit(rule->map, PNP_IRQ_NR, 16);
if (*start < PNP_IRQ_NR) {
*end = *start;
return 1;
}
for (i = 0; i < 16; i++) {
if (test_bit(xtab[i], rule->map)) {
*start = *end = xtab[i];
if (pnp_check_irq(dev, idx))
return 1;
}
}
return 0;
}
static int pnp_assign_dma(struct pnp_dev *dev, struct pnp_dma *rule, int idx)
{
resource_size_t *start, *end;
unsigned long *flags;
int i;
/* DMA priority: this table is good for i386 */
static unsigned short xtab[8] = {
1, 3, 5, 6, 7, 0, 2, 4
};
if (idx >= PNP_MAX_DMA) {
pnp_err
("More than 2 dmas is incompatible with pnp specifications.");
/* pretend we were successful so at least the manager won't try again */
return 1;
}
/* check if this resource has been manually set, if so skip */
if (!(dev->res.dma_resource[idx].flags & IORESOURCE_AUTO))
return 1;
start = &dev->res.dma_resource[idx].start;
end = &dev->res.dma_resource[idx].end;
flags = &dev->res.dma_resource[idx].flags;
/* set the initial values */
*flags |= rule->flags | IORESOURCE_DMA;
*flags &= ~IORESOURCE_UNSET;
if (!rule->map) {
*flags |= IORESOURCE_DISABLED;
return 1; /* skip disabled resource requests */
}
for (i = 0; i < 8; i++) {
if (rule->map & (1 << xtab[i])) {
*start = *end = xtab[i];
if (pnp_check_dma(dev, idx))
return 1;
}
}
return 0;
}
/**
* pnp_init_resources - Resets a resource table to default values.
* @table: pointer to the desired resource table
*/
void pnp_init_resource_table(struct pnp_resource_table *table)
{
int idx;
for (idx = 0; idx < PNP_MAX_IRQ; idx++) {
table->irq_resource[idx].name = NULL;
table->irq_resource[idx].start = -1;
table->irq_resource[idx].end = -1;
table->irq_resource[idx].flags =
IORESOURCE_IRQ | IORESOURCE_AUTO | IORESOURCE_UNSET;
}
for (idx = 0; idx < PNP_MAX_DMA; idx++) {
table->dma_resource[idx].name = NULL;
table->dma_resource[idx].start = -1;
table->dma_resource[idx].end = -1;
table->dma_resource[idx].flags =
IORESOURCE_DMA | IORESOURCE_AUTO | IORESOURCE_UNSET;
}
for (idx = 0; idx < PNP_MAX_PORT; idx++) {
table->port_resource[idx].name = NULL;
table->port_resource[idx].start = 0;
table->port_resource[idx].end = 0;
table->port_resource[idx].flags =
IORESOURCE_IO | IORESOURCE_AUTO | IORESOURCE_UNSET;
}
for (idx = 0; idx < PNP_MAX_MEM; idx++) {
table->mem_resource[idx].name = NULL;
table->mem_resource[idx].start = 0;
table->mem_resource[idx].end = 0;
table->mem_resource[idx].flags =
IORESOURCE_MEM | IORESOURCE_AUTO | IORESOURCE_UNSET;
}
}
/**
* pnp_clean_resources - clears resources that were not manually set
* @res: the resources to clean
*/
static void pnp_clean_resource_table(struct pnp_resource_table *res)
{
int idx;
for (idx = 0; idx < PNP_MAX_IRQ; idx++) {
if (!(res->irq_resource[idx].flags & IORESOURCE_AUTO))
continue;
res->irq_resource[idx].start = -1;
res->irq_resource[idx].end = -1;
res->irq_resource[idx].flags =
IORESOURCE_IRQ | IORESOURCE_AUTO | IORESOURCE_UNSET;
}
for (idx = 0; idx < PNP_MAX_DMA; idx++) {
if (!(res->dma_resource[idx].flags & IORESOURCE_AUTO))
continue;
res->dma_resource[idx].start = -1;
res->dma_resource[idx].end = -1;
res->dma_resource[idx].flags =
IORESOURCE_DMA | IORESOURCE_AUTO | IORESOURCE_UNSET;
}
for (idx = 0; idx < PNP_MAX_PORT; idx++) {
if (!(res->port_resource[idx].flags & IORESOURCE_AUTO))
continue;
res->port_resource[idx].start = 0;
res->port_resource[idx].end = 0;
res->port_resource[idx].flags =
IORESOURCE_IO | IORESOURCE_AUTO | IORESOURCE_UNSET;
}
for (idx = 0; idx < PNP_MAX_MEM; idx++) {
if (!(res->mem_resource[idx].flags & IORESOURCE_AUTO))
continue;
res->mem_resource[idx].start = 0;
res->mem_resource[idx].end = 0;
res->mem_resource[idx].flags =
IORESOURCE_MEM | IORESOURCE_AUTO | IORESOURCE_UNSET;
}
}
/**
* pnp_assign_resources - assigns resources to the device based on the specified dependent number
* @dev: pointer to the desired device
* @depnum: the dependent function number
*
* Only set depnum to 0 if the device does not have dependent options.
*/
static int pnp_assign_resources(struct pnp_dev *dev, int depnum)
{
struct pnp_port *port;
struct pnp_mem *mem;
struct pnp_irq *irq;
struct pnp_dma *dma;
int nport = 0, nmem = 0, nirq = 0, ndma = 0;
if (!pnp_can_configure(dev))
return -ENODEV;
down(&pnp_res_mutex);
pnp_clean_resource_table(&dev->res); /* start with a fresh slate */
if (dev->independent) {
port = dev->independent->port;
mem = dev->independent->mem;
irq = dev->independent->irq;
dma = dev->independent->dma;
while (port) {
if (!pnp_assign_port(dev, port, nport))
goto fail;
nport++;
port = port->next;
}
while (mem) {
if (!pnp_assign_mem(dev, mem, nmem))
goto fail;
nmem++;
mem = mem->next;
}
while (irq) {
if (!pnp_assign_irq(dev, irq, nirq))
goto fail;
nirq++;
irq = irq->next;
}
while (dma) {
if (!pnp_assign_dma(dev, dma, ndma))
goto fail;
ndma++;
dma = dma->next;
}
}
if (depnum) {
struct pnp_option *dep;
int i;
for (i = 1, dep = dev->dependent; i < depnum;
i++, dep = dep->next)
if (!dep)
goto fail;
port = dep->port;
mem = dep->mem;
irq = dep->irq;
dma = dep->dma;
while (port) {
if (!pnp_assign_port(dev, port, nport))
goto fail;
nport++;
port = port->next;
}
while (mem) {
if (!pnp_assign_mem(dev, mem, nmem))
goto fail;
nmem++;
mem = mem->next;
}
while (irq) {
if (!pnp_assign_irq(dev, irq, nirq))
goto fail;
nirq++;
irq = irq->next;
}
while (dma) {
if (!pnp_assign_dma(dev, dma, ndma))
goto fail;
ndma++;
dma = dma->next;
}
} else if (dev->dependent)
goto fail;
up(&pnp_res_mutex);
return 1;
fail:
pnp_clean_resource_table(&dev->res);
up(&pnp_res_mutex);
return 0;
}
/**
* pnp_manual_config_dev - Disables Auto Config and Manually sets the resource table
* @dev: pointer to the desired device
* @res: pointer to the new resource config
* @mode: 0 or PNP_CONFIG_FORCE
*
* This function can be used by drivers that want to manually set thier resources.
*/
int pnp_manual_config_dev(struct pnp_dev *dev, struct pnp_resource_table *res,
int mode)
{
int i;
struct pnp_resource_table *bak;
if (!pnp_can_configure(dev))
return -ENODEV;
bak = pnp_alloc(sizeof(struct pnp_resource_table));
if (!bak)
return -ENOMEM;
*bak = dev->res;
down(&pnp_res_mutex);
dev->res = *res;
if (!(mode & PNP_CONFIG_FORCE)) {
for (i = 0; i < PNP_MAX_PORT; i++) {
if (!pnp_check_port(dev, i))
goto fail;
}
for (i = 0; i < PNP_MAX_MEM; i++) {
if (!pnp_check_mem(dev, i))
goto fail;
}
for (i = 0; i < PNP_MAX_IRQ; i++) {
if (!pnp_check_irq(dev, i))
goto fail;
}
for (i = 0; i < PNP_MAX_DMA; i++) {
if (!pnp_check_dma(dev, i))
goto fail;
}
}
up(&pnp_res_mutex);
kfree(bak);
return 0;
fail:
dev->res = *bak;
up(&pnp_res_mutex);
kfree(bak);
return -EINVAL;
}
/**
* 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)
{
struct pnp_option *dep;
int i = 1;
if (!pnp_can_configure(dev)) {
pnp_dbg("Device %s does not support resource configuration.",
dev->dev.bus_id);
return -ENODEV;
}
if (!dev->dependent) {
if (pnp_assign_resources(dev, 0))
return 0;
} else {
dep = dev->dependent;
do {
if (pnp_assign_resources(dev, i))
return 0;
dep = dep->next;
i++;
} while (dep);
}
pnp_err("Unable to assign resources to device %s.", dev->dev.bus_id);
return -EBUSY;
}
/**
* 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)) {
pnp_dbg("Device %s does not support activation.",
dev->dev.bus_id);
return -EINVAL;
}
if (dev->protocol->set(dev, &dev->res) < 0) {
pnp_err("Failed to activate device %s.", dev->dev.bus_id);
return -EIO;
}
pnp_info("Device %s activated.", dev->dev.bus_id);
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)) {
pnp_dbg("Device %s does not support disabling.",
dev->dev.bus_id);
return -EINVAL;
}
if (dev->protocol->disable(dev) < 0) {
pnp_err("Failed to disable device %s.", dev->dev.bus_id);
return -EIO;
}
pnp_info("Device %s disabled.", dev->dev.bus_id);
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; /* the device is already active */
/* 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 1;
}
/**
* 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; /* the device is already disabled */
error = pnp_stop_dev(dev);
if (error)
return error;
dev->active = 0;
/* release the resources so that other devices can use them */
down(&pnp_res_mutex);
pnp_clean_resource_table(&dev->res);
up(&pnp_res_mutex);
return 1;
}
/**
* pnp_resource_change - change one resource
* @resource: pointer to resource to be changed
* @start: start of region
* @size: size of region
*/
void pnp_resource_change(struct resource *resource, resource_size_t start,
resource_size_t size)
{
resource->flags &= ~(IORESOURCE_AUTO | IORESOURCE_UNSET);
resource->start = start;
resource->end = start + size - 1;
}
EXPORT_SYMBOL(pnp_manual_config_dev);
EXPORT_SYMBOL(pnp_start_dev);
EXPORT_SYMBOL(pnp_stop_dev);
EXPORT_SYMBOL(pnp_activate_dev);
EXPORT_SYMBOL(pnp_disable_dev);
EXPORT_SYMBOL(pnp_resource_change);
EXPORT_SYMBOL(pnp_init_resource_table);