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/*P:050 Lguest guests use a very simple bus for devices. It's a simple array
* of device descriptors contained just above the top of normal memory. The
* lguest bus is 80% tedious boilerplate code. :*/
#include <linux/init.h>
#include <linux/bootmem.h>
#include <linux/lguest_bus.h>
#include <asm/io.h>
static ssize_t type_show(struct device *_dev,
struct device_attribute *attr, char *buf)
{
struct lguest_device *dev = container_of(_dev,struct lguest_device,dev);
return sprintf(buf, "%hu", lguest_devices[dev->index].type);
}
static ssize_t features_show(struct device *_dev,
struct device_attribute *attr, char *buf)
{
struct lguest_device *dev = container_of(_dev,struct lguest_device,dev);
return sprintf(buf, "%hx", lguest_devices[dev->index].features);
}
static ssize_t pfn_show(struct device *_dev,
struct device_attribute *attr, char *buf)
{
struct lguest_device *dev = container_of(_dev,struct lguest_device,dev);
return sprintf(buf, "%u", lguest_devices[dev->index].pfn);
}
static ssize_t status_show(struct device *_dev,
struct device_attribute *attr, char *buf)
{
struct lguest_device *dev = container_of(_dev,struct lguest_device,dev);
return sprintf(buf, "%hx", lguest_devices[dev->index].status);
}
static ssize_t status_store(struct device *_dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct lguest_device *dev = container_of(_dev,struct lguest_device,dev);
if (sscanf(buf, "%hi", &lguest_devices[dev->index].status) != 1)
return -EINVAL;
return count;
}
static struct device_attribute lguest_dev_attrs[] = {
__ATTR_RO(type),
__ATTR_RO(features),
__ATTR_RO(pfn),
__ATTR(status, 0644, status_show, status_store),
__ATTR_NULL
};
static int lguest_dev_match(struct device *_dev, struct device_driver *_drv)
{
struct lguest_device *dev = container_of(_dev,struct lguest_device,dev);
struct lguest_driver *drv = container_of(_drv,struct lguest_driver,drv);
return (drv->device_type == lguest_devices[dev->index].type);
}
struct lguest_bus {
struct bus_type bus;
struct device dev;
};
static struct lguest_bus lguest_bus = {
.bus = {
.name = "lguest",
.match = lguest_dev_match,
.dev_attrs = lguest_dev_attrs,
},
.dev = {
.parent = NULL,
.bus_id = "lguest",
}
};
static int lguest_dev_probe(struct device *_dev)
{
int ret;
struct lguest_device *dev = container_of(_dev,struct lguest_device,dev);
struct lguest_driver *drv = container_of(dev->dev.driver,
struct lguest_driver, drv);
lguest_devices[dev->index].status |= LGUEST_DEVICE_S_DRIVER;
ret = drv->probe(dev);
if (ret == 0)
lguest_devices[dev->index].status |= LGUEST_DEVICE_S_DRIVER_OK;
return ret;
}
int register_lguest_driver(struct lguest_driver *drv)
{
if (!lguest_devices)
return 0;
drv->drv.bus = &lguest_bus.bus;
drv->drv.name = drv->name;
drv->drv.owner = drv->owner;
drv->drv.probe = lguest_dev_probe;
return driver_register(&drv->drv);
}
EXPORT_SYMBOL_GPL(register_lguest_driver);
static void add_lguest_device(unsigned int index)
{
struct lguest_device *new;
lguest_devices[index].status |= LGUEST_DEVICE_S_ACKNOWLEDGE;
new = kmalloc(sizeof(struct lguest_device), GFP_KERNEL);
if (!new) {
printk(KERN_EMERG "Cannot allocate lguest device %u\n", index);
lguest_devices[index].status |= LGUEST_DEVICE_S_FAILED;
return;
}
new->index = index;
new->private = NULL;
memset(&new->dev, 0, sizeof(new->dev));
new->dev.parent = &lguest_bus.dev;
new->dev.bus = &lguest_bus.bus;
sprintf(new->dev.bus_id, "%u", index);
if (device_register(&new->dev) != 0) {
printk(KERN_EMERG "Cannot register lguest device %u\n", index);
lguest_devices[index].status |= LGUEST_DEVICE_S_FAILED;
kfree(new);
}
}
static void scan_devices(void)
{
unsigned int i;
for (i = 0; i < LGUEST_MAX_DEVICES; i++)
if (lguest_devices[i].type)
add_lguest_device(i);
}
static int __init lguest_bus_init(void)
{
if (strcmp(paravirt_ops.name, "lguest") != 0)
return 0;
/* Devices are in page above top of "normal" mem. */
lguest_devices = lguest_map(max_pfn<<PAGE_SHIFT, 1);
if (bus_register(&lguest_bus.bus) != 0
|| device_register(&lguest_bus.dev) != 0)
panic("lguest bus registration failed");
scan_devices();
return 0;
}
postcore_initcall(lguest_bus_init);
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