platform.c(drivers\base)

/*
 * platform.c - platform 'pseudo' bus for legacy devices
 *
 * Copyright (c) 2002-3 Patrick Mochel
 * Copyright (c) 2002-3 Open Source Development Labs
 *
 * This file is released under the GPLv2
 *
 * Please see Documentation/driver-model/platform.txt for more
 * information.
 */


#include <linux/string.h>
#include <linux/platform_device.h>
#include <linux/of_device.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/dma-mapping.h>
#include <linux/bootmem.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/pm_runtime.h>
#include <linux/idr.h>
#include <linux/acpi.h>


#include "base.h"
#include "power/power.h"


/* For automatically allocated device IDs */
static DEFINE_IDA(platform_devid_ida);


#define to_platform_driver(drv) (container_of((drv), struct platform_driver, \
driver))


struct device platform_bus = {
.init_name = "platform",
};
EXPORT_SYMBOL_GPL(platform_bus);


/**
 * arch_setup_pdev_archdata - Allow manipulation of archdata before its used
 * @pdev: platform device
 *
 * This is called before platform_device_add() such that any pdev_archdata may
 * be setup before the platform_notifier is called.  So if a user needs to
 * manipulate any relevant information in the pdev_archdata they can do:
 *
 * platform_device_alloc()
 * ... manipulate ...
 * platform_device_add()
 *
 * And if they don't care they can just call platform_device_register() and
 * everything will just work out.
 */
void __weak arch_setup_pdev_archdata(struct platform_device *pdev)
{
}


/**
 * platform_get_resource - get a resource for a device
 * @dev: platform device
 * @type: resource type
 * @num: resource index
 */
struct resource *platform_get_resource(struct platform_device *dev,
       unsigned int type, unsigned int num)
{
int i;


for (i = 0; i < dev->num_resources; i++) {
struct resource *r = &dev->resource[i];


if (type == resource_type(r) && num-- == 0)
return r;
}
return NULL;
}
EXPORT_SYMBOL_GPL(platform_get_resource);


/**
 * platform_get_irq - get an IRQ for a device
 * @dev: platform device
 * @num: IRQ number index
 */
int platform_get_irq(struct platform_device *dev, unsigned int num)
{
#ifdef CONFIG_SPARC
/* sparc does not have irqs represented as IORESOURCE_IRQ resources */
if (!dev || num >= dev->archdata.num_irqs)
return -ENXIO;
return dev->archdata.irqs[num];
#else
struct resource *r = platform_get_resource(dev, IORESOURCE_IRQ, num);


return r ? r->start : -ENXIO;
#endif
}
EXPORT_SYMBOL_GPL(platform_get_irq);


/**
 * platform_get_resource_byname - get a resource for a device by name
 * @dev: platform device
 * @type: resource type
 * @name: resource name
 */
struct resource *platform_get_resource_byname(struct platform_device *dev,
      unsigned int type,
      const char *name)
{
int i;


for (i = 0; i < dev->num_resources; i++) {
struct resource *r = &dev->resource[i];


if (unlikely(!r->name))
continue;


if (type == resource_type(r) && !strcmp(r->name, name))
return r;
}
return NULL;
}
EXPORT_SYMBOL_GPL(platform_get_resource_byname);


/**
 * platform_get_irq_byname - get an IRQ for a device by name
 * @dev: platform device
 * @name: IRQ name
 */
int platform_get_irq_byname(struct platform_device *dev, const char *name)
{
struct resource *r = platform_get_resource_byname(dev, IORESOURCE_IRQ,
  name);


return r ? r->start : -ENXIO;
}
EXPORT_SYMBOL_GPL(platform_get_irq_byname);


/**
 * platform_add_devices - add a numbers of platform devices
 * @devs: array of platform devices to add
 * @num: number of platform devices in array
 */
int platform_add_devices(struct platform_device **devs, int num)
{
int i, ret = 0;


for (i = 0; i < num; i++) {
ret = platform_device_register(devs[i]);
if (ret) {
while (--i >= 0)
platform_device_unregister(devs[i]);
break;
}
}


return ret;
}
EXPORT_SYMBOL_GPL(platform_add_devices);


struct platform_object {
struct platform_device pdev;
char name[1];
};


/**
 * platform_device_put - destroy a platform device
 * @pdev: platform device to free
 *
 * Free all memory associated with a platform device.  This function must
 * _only_ be externally called in error cases.  All other usage is a bug.
 */
void platform_device_put(struct platform_device *pdev)
{
if (pdev)
put_device(&pdev->dev);
}
EXPORT_SYMBOL_GPL(platform_device_put);


static void platform_device_release(struct device *dev)
{
struct platform_object *pa = container_of(dev, struct platform_object,
  pdev.dev);


of_device_node_put(&pa->pdev.dev);
kfree(pa->pdev.dev.platform_data);
kfree(pa->pdev.mfd_cell);
kfree(pa->pdev.resource);
kfree(pa);
}


/**
 * platform_device_alloc - create a platform device
 * @name: base name of the device we're adding
 * @id: instance id
 *
 * Create a platform device object which can have other objects attached
 * to it, and which will have attached objects freed when it is released.
 */
struct platform_device *platform_device_alloc(const char *name, int id)
{
struct platform_object *pa;


pa = kzalloc(sizeof(struct platform_object) + strlen(name), GFP_KERNEL);
if (pa) {
strcpy(pa->name, name);
pa->pdev.name = pa->name;
pa->pdev.id = id;
device_initialize(&pa->pdev.dev);
pa->pdev.dev.release = platform_device_release;
arch_setup_pdev_archdata(&pa->pdev);
}


return pa ? &pa->pdev : NULL;
}
EXPORT_SYMBOL_GPL(platform_device_alloc);


/**
 * platform_device_add_resources - add resources to a platform device
 * @pdev: platform device allocated by platform_device_alloc to add resources to
 * @res: set of resources that needs to be allocated for the device
 * @num: number of resources
 *
 * Add a copy of the resources to the platform device.  The memory
 * associated with the resources will be freed when the platform device is
 * released.
 */
int platform_device_add_resources(struct platform_device *pdev,
  const struct resource *res, unsigned int num)
{
struct resource *r = NULL;


if (res) {
r = kmemdup(res, sizeof(struct resource) * num, GFP_KERNEL);
if (!r)
return -ENOMEM;
}


kfree(pdev->resource);
pdev->resource = r;
pdev->num_resources = num;
return 0;
}
EXPORT_SYMBOL_GPL(platform_device_add_resources);


/**
 * platform_device_add_data - add platform-specific data to a platform device
 * @pdev: platform device allocated by platform_device_alloc to add resources to
 * @data: platform specific data for this platform device
 * @size: size of platform specific data
 *
 * Add a copy of platform specific data to the platform device's
 * platform_data pointer.  The memory associated with the platform data
 * will be freed when the platform device is released.
 */
int platform_device_add_data(struct platform_device *pdev, const void *data,
     size_t size)
{
void *d = NULL;


if (data) {
d = kmemdup(data, size, GFP_KERNEL);
if (!d)
return -ENOMEM;
}


kfree(pdev->dev.platform_data);
pdev->dev.platform_data = d;
return 0;
}
EXPORT_SYMBOL_GPL(platform_device_add_data);


/**
 * platform_device_add - add a platform device to device hierarchy
 * @pdev: platform device we're adding
 *
 * This is part 2 of platform_device_register(), though may be called
 * separately _iff_ pdev was allocated by platform_device_alloc().
 */
int platform_device_add(struct platform_device *pdev)
{
int i, ret;


if (!pdev)
return -EINVAL;


if (!pdev->dev.parent)
pdev->dev.parent = &platform_bus;


pdev->dev.bus = &platform_bus_type;


switch (pdev->id) {
default:
dev_set_name(&pdev->dev, "%s.%d", pdev->name,  pdev->id);
break;
case PLATFORM_DEVID_NONE:
dev_set_name(&pdev->dev, "%s", pdev->name);
break;
case PLATFORM_DEVID_AUTO:
/*
* Automatically allocated device ID. We mark it as such so
* that we remember it must be freed, and we append a suffix
* to avoid namespace collision with explicit IDs.
*/
ret = ida_simple_get(&platform_devid_ida, 0, 0, GFP_KERNEL);
if (ret < 0)
goto err_out;
pdev->id = ret;
pdev->id_auto = true;
dev_set_name(&pdev->dev, "%s.%d.auto", pdev->name, pdev->id);
break;
}


for (i = 0; i < pdev->num_resources; i++) {
struct resource *p, *r = &pdev->resource[i];


if (r->name == NULL)
r->name = dev_name(&pdev->dev);


p = r->parent;
if (!p) {
if (resource_type(r) == IORESOURCE_MEM)
p = &iomem_resource;
else if (resource_type(r) == IORESOURCE_IO)
p = &ioport_resource;
}


if (p && insert_resource(p, r)) {
dev_err(&pdev->dev, "failed to claim resource %d\n", i);
ret = -EBUSY;
goto failed;
}
}


pr_debug("Registering platform device '%s'. Parent at %s\n",
dev_name(&pdev->dev), dev_name(pdev->dev.parent));


ret = device_add(&pdev->dev);
if (ret == 0)
return ret;


 failed:
if (pdev->id_auto) {
ida_simple_remove(&platform_devid_ida, pdev->id);
pdev->id = PLATFORM_DEVID_AUTO;
}


while (--i >= 0) {
struct resource *r = &pdev->resource[i];
unsigned long type = resource_type(r);


if (type == IORESOURCE_MEM || type == IORESOURCE_IO)
release_resource(r);
}


 err_out:
return ret;
}
EXPORT_SYMBOL_GPL(platform_device_add);


/**
 * platform_device_del - remove a platform-level device
 * @pdev: platform device we're removing
 *
 * Note that this function will also release all memory- and port-based
 * resources owned by the device (@dev->resource).  This function must
 * _only_ be externally called in error cases.  All other usage is a bug.
 */
void platform_device_del(struct platform_device *pdev)
{
int i;


if (pdev) {
device_del(&pdev->dev);


if (pdev->id_auto) {
ida_simple_remove(&platform_devid_ida, pdev->id);
pdev->id = PLATFORM_DEVID_AUTO;
}


for (i = 0; i < pdev->num_resources; i++) {
struct resource *r = &pdev->resource[i];
unsigned long type = resource_type(r);


if (type == IORESOURCE_MEM || type == IORESOURCE_IO)
release_resource(r);
}
}
}
EXPORT_SYMBOL_GPL(platform_device_del);


/**
 * platform_device_register - add a platform-level device
 * @pdev: platform device we're adding
 */
int platform_device_register(struct platform_device *pdev)
{
device_initialize(&pdev->dev);
arch_setup_pdev_archdata(pdev);
return platform_device_add(pdev);
}
EXPORT_SYMBOL_GPL(platform_device_register);


/**
 * platform_device_unregister - unregister a platform-level device
 * @pdev: platform device we're unregistering
 *
 * Unregistration is done in 2 steps. First we release all resources
 * and remove it from the subsystem, then we drop reference count by
 * calling platform_device_put().
 */
void platform_device_unregister(struct platform_device *pdev)
{
platform_device_del(pdev);
platform_device_put(pdev);
}
EXPORT_SYMBOL_GPL(platform_device_unregister);


/**
 * platform_device_register_full - add a platform-level device with
 * resources and platform-specific data
 *
 * @pdevinfo: data used to create device
 *
 * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
 */
struct platform_device *platform_device_register_full(
const struct platform_device_info *pdevinfo)
{
int ret = -ENOMEM;
struct platform_device *pdev;


pdev = platform_device_alloc(pdevinfo->name, pdevinfo->id);
if (!pdev)
goto err_alloc;


pdev->dev.parent = pdevinfo->parent;
ACPI_HANDLE_SET(&pdev->dev, pdevinfo->acpi_node.handle);


if (pdevinfo->dma_mask) {
/*
* This memory isn't freed when the device is put,
* I don't have a nice idea for that though.  Conceptually
* dma_mask in struct device should not be a pointer.
* See http://thread.gmane.org/gmane.linux.kernel.pci/9081
*/
pdev->dev.dma_mask =
kmalloc(sizeof(*pdev->dev.dma_mask), GFP_KERNEL);
if (!pdev->dev.dma_mask)
goto err;


*pdev->dev.dma_mask = pdevinfo->dma_mask;
pdev->dev.coherent_dma_mask = pdevinfo->dma_mask;
}


ret = platform_device_add_resources(pdev,
pdevinfo->res, pdevinfo->num_res);
if (ret)
goto err;


ret = platform_device_add_data(pdev,
pdevinfo->data, pdevinfo->size_data);
if (ret)
goto err;


ret = platform_device_add(pdev);
if (ret) {
err:
ACPI_HANDLE_SET(&pdev->dev, NULL);
kfree(pdev->dev.dma_mask);


err_alloc:
platform_device_put(pdev);
return ERR_PTR(ret);
}


return pdev;
}
EXPORT_SYMBOL_GPL(platform_device_register_full);


static int platform_drv_probe(struct device *_dev)
{
struct platform_driver *drv = to_platform_driver(_dev->driver);
struct platform_device *dev = to_platform_device(_dev);
int ret;


if (ACPI_HANDLE(_dev))
acpi_dev_pm_attach(_dev, true);


ret = drv->probe(dev);
if (ret && ACPI_HANDLE(_dev))
acpi_dev_pm_detach(_dev, true);


return ret;
}


static int platform_drv_probe_fail(struct device *_dev)
{
return -ENXIO;
}


static int platform_drv_remove(struct device *_dev)
{
struct platform_driver *drv = to_platform_driver(_dev->driver);
struct platform_device *dev = to_platform_device(_dev);
int ret;


ret = drv->remove(dev);
if (ACPI_HANDLE(_dev))
acpi_dev_pm_detach(_dev, true);


return ret;
}


static void platform_drv_shutdown(struct device *_dev)
{
struct platform_driver *drv = to_platform_driver(_dev->driver);
struct platform_device *dev = to_platform_device(_dev);


drv->shutdown(dev);
if (ACPI_HANDLE(_dev))
acpi_dev_pm_detach(_dev, true);
}


/**
 * platform_driver_register - register a driver for platform-level devices
 * @drv: platform driver structure
 */
int platform_driver_register(struct platform_driver *drv)
{
drv->driver.bus = &platform_bus_type;
if (drv->probe)
drv->driver.probe = platform_drv_probe;
if (drv->remove)
drv->driver.remove = platform_drv_remove;
if (drv->shutdown)
drv->driver.shutdown = platform_drv_shutdown;


return driver_register(&drv->driver);
}
EXPORT_SYMBOL_GPL(platform_driver_register);


/**
 * platform_driver_unregister - unregister a driver for platform-level devices
 * @drv: platform driver structure
 */
void platform_driver_unregister(struct platform_driver *drv)
{
driver_unregister(&drv->driver);
}
EXPORT_SYMBOL_GPL(platform_driver_unregister);


/**
 * platform_driver_probe - register driver for non-hotpluggable device
 * @drv: platform driver structure
 * @probe: the driver probe routine, probably from an __init section,
 *         must not return -EPROBE_DEFER.
 *
 * Use this instead of platform_driver_register() when you know the device
 * is not hotpluggable and has already been registered, and you want to
 * remove its run-once probe() infrastructure from memory after the driver
 * has bound to the device.
 *
 * One typical use for this would be with drivers for controllers integrated
 * into system-on-chip processors, where the controller devices have been
 * configured as part of board setup.
 *
 * This is incompatible with deferred probing so probe() must not
 * return -EPROBE_DEFER.
 *
 * Returns zero if the driver registered and bound to a device, else returns
 * a negative error code and with the driver not registered.
 */
int __init_or_module platform_driver_probe(struct platform_driver *drv,
int (*probe)(struct platform_device *))
{
int retval, code;


/* make sure driver won't have bind/unbind attributes */
drv->driver.suppress_bind_attrs = true;


/* temporary section violation during probe() */
drv->probe = probe;
retval = code = platform_driver_register(drv);


/*
* Fixup that section violation, being paranoid about code scanning
* the list of drivers in order to probe new devices.  Check to see
* if the probe was successful, and make sure any forced probes of
* new devices fail.
*/
spin_lock(&drv->driver.bus->p->klist_drivers.k_lock);
drv->probe = NULL;
if (code == 0 && list_empty(&drv->driver.p->klist_devices.k_list))
retval = -ENODEV;
drv->driver.probe = platform_drv_probe_fail;
spin_unlock(&drv->driver.bus->p->klist_drivers.k_lock);


if (code != retval)
platform_driver_unregister(drv);
return retval;
}
EXPORT_SYMBOL_GPL(platform_driver_probe);


/**
 * platform_create_bundle - register driver and create corresponding device
 * @driver: platform driver structure
 * @probe: the driver probe routine, probably from an __init section
 * @res: set of resources that needs to be allocated for the device
 * @n_res: number of resources
 * @data: platform specific data for this platform device
 * @size: size of platform specific data
 *
 * Use this in legacy-style modules that probe hardware directly and
 * register a single platform device and corresponding platform driver.
 *
 * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
 */
struct platform_device * __init_or_module platform_create_bundle(
struct platform_driver *driver,
int (*probe)(struct platform_device *),
struct resource *res, unsigned int n_res,
const void *data, size_t size)
{
struct platform_device *pdev;
int error;


pdev = platform_device_alloc(driver->driver.name, -1);
if (!pdev) {
error = -ENOMEM;
goto err_out;
}


error = platform_device_add_resources(pdev, res, n_res);
if (error)
goto err_pdev_put;


error = platform_device_add_data(pdev, data, size);
if (error)
goto err_pdev_put;


error = platform_device_add(pdev);
if (error)
goto err_pdev_put;


error = platform_driver_probe(driver, probe);
if (error)
goto err_pdev_del;


return pdev;


err_pdev_del:
platform_device_del(pdev);
err_pdev_put:
platform_device_put(pdev);
err_out:
return ERR_PTR(error);
}
EXPORT_SYMBOL_GPL(platform_create_bundle);


/* modalias support enables more hands-off userspace setup:
 * (a) environment variable lets new-style hotplug events work once system is
 *     fully running:  "modprobe $MODALIAS"
 * (b) sysfs attribute lets new-style coldplug recover from hotplug events
 *     mishandled before system is fully running:  "modprobe $(cat modalias)"
 */
static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
     char *buf)
{
struct platform_device *pdev = to_platform_device(dev);
int len = snprintf(buf, PAGE_SIZE, "platform:%s\n", pdev->name);


return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
}


static struct device_attribute platform_dev_attrs[] = {
__ATTR_RO(modalias),
__ATTR_NULL,
};


static int platform_uevent(struct device *dev, struct kobj_uevent_env *env)
{
struct platform_device *pdev = to_platform_device(dev);
int rc;


/* Some devices have extra OF data and an OF-style MODALIAS */
rc = of_device_uevent_modalias(dev, env);
if (rc != -ENODEV)
return rc;


add_uevent_var(env, "MODALIAS=%s%s", PLATFORM_MODULE_PREFIX,
pdev->name);
return 0;
}


static const struct platform_device_id *platform_match_id(
const struct platform_device_id *id,
struct platform_device *pdev)
{
while (id->name[0]) {
if (strcmp(pdev->name, id->name) == 0) {
pdev->id_entry = id;
return id;
}
id++;
}
return NULL;
}


/**
 * platform_match - bind platform device to platform driver.
 * @ dev: device.
 * @ drv: driver.
 *
 * Platform device IDs are assumed to be encoded like this:
 * "<name><instance>", where <name> is a short description of the type of
 * device, like "pci" or "floppy", and <instance> is the enumerated
 * instance of the device, like '0' or '42'.  Driver IDs are simply
 * "<name>".  So, extract the <name> from the platform_device structure,
 * and compare it against the name of the driver. Return whether they match
 * or not.
 */
static int platform_match(struct device *dev, struct device_driver *drv)
{
struct platform_device *pdev = to_platform_device(dev);
struct platform_driver *pdrv = to_platform_driver(drv);


/* Attempt an OF style match first */
if ( of_driver_match_device(dev, drv))
return 1;


/* Then try ACPI style match */
if (acpi_driver_match_device(dev, drv))
return 1;


/* Then try to match against the id table */
if (pdrv->id_table)
return platform_match_id(pdrv->id_table, pdev) != NULL;


/* fall-back to driver name match */
return (strcmp(pdev->name, drv->name) == 0);
}


#ifdef CONFIG_PM_SLEEP


static int platform_legacy_suspend(struct device *dev, pm_message_t mesg)
{
struct platform_driver *pdrv = to_platform_driver(dev->driver);
struct platform_device *pdev = to_platform_device(dev);
int ret = 0;


if (dev->driver && pdrv->suspend)
ret = pdrv->suspend(pdev, mesg);


return ret;
}


static int platform_legacy_resume(struct device *dev)
{
struct platform_driver *pdrv = to_platform_driver(dev->driver);
struct platform_device *pdev = to_platform_device(dev);
int ret = 0;


if (dev->driver && pdrv->resume)
ret = pdrv->resume(pdev);


return ret;
}


#endif /* CONFIG_PM_SLEEP */


#ifdef CONFIG_SUSPEND


int platform_pm_suspend(struct device *dev)
{
struct device_driver *drv = dev->driver;
int ret = 0;


if (!drv)
return 0;


if (drv->pm) {
if (drv->pm->suspend)
ret = drv->pm->suspend(dev);
} else {
ret = platform_legacy_suspend(dev, PMSG_SUSPEND);
}


return ret;
}


int platform_pm_resume(struct device *dev)
{
struct device_driver *drv = dev->driver;
int ret = 0;


if (!drv)
return 0;


if (drv->pm) {
if (drv->pm->resume)
ret = drv->pm->resume(dev);
} else {
ret = platform_legacy_resume(dev);
}


return ret;
}


#endif /* CONFIG_SUSPEND */


#ifdef CONFIG_HIBERNATE_CALLBACKS


int platform_pm_freeze(struct device *dev)
{
struct device_driver *drv = dev->driver;
int ret = 0;


if (!drv)
return 0;


if (drv->pm) {
if (drv->pm->freeze)
ret = drv->pm->freeze(dev);
} else {
ret = platform_legacy_suspend(dev, PMSG_FREEZE);
}


return ret;
}


int platform_pm_thaw(struct device *dev)
{
struct device_driver *drv = dev->driver;
int ret = 0;


if (!drv)
return 0;


if (drv->pm) {
if (drv->pm->thaw)
ret = drv->pm->thaw(dev);
} else {
ret = platform_legacy_resume(dev);
}


return ret;
}


int platform_pm_poweroff(struct device *dev)
{
struct device_driver *drv = dev->driver;
int ret = 0;


if (!drv)
return 0;


if (drv->pm) {
if (drv->pm->poweroff)
ret = drv->pm->poweroff(dev);
} else {
ret = platform_legacy_suspend(dev, PMSG_HIBERNATE);
}


return ret;
}


int platform_pm_restore(struct device *dev)
{
struct device_driver *drv = dev->driver;
int ret = 0;


if (!drv)
return 0;


if (drv->pm) {
if (drv->pm->restore)
ret = drv->pm->restore(dev);
} else {
ret = platform_legacy_resume(dev);
}


return ret;
}


#endif /* CONFIG_HIBERNATE_CALLBACKS */


static const struct dev_pm_ops platform_dev_pm_ops = {
.runtime_suspend = pm_generic_runtime_suspend,
.runtime_resume = pm_generic_runtime_resume,
.runtime_idle = pm_generic_runtime_idle,
USE_PLATFORM_PM_SLEEP_OPS
};


struct bus_type platform_bus_type = {
.name = "platform",
.dev_attrs = platform_dev_attrs,
.match = platform_match,
.uevent = platform_uevent,
.pm = &platform_dev_pm_ops,
};
EXPORT_SYMBOL_GPL(platform_bus_type);


int __init platform_bus_init(void)
{
int error;


early_platform_cleanup();


error = device_register(&platform_bus);
if (error)
return error;
error =  bus_register(&platform_bus_type);
if (error)
device_unregister(&platform_bus);
return error;
}


#ifndef ARCH_HAS_DMA_GET_REQUIRED_MASK
u64 dma_get_required_mask(struct device *dev)
{
u32 low_totalram = ((max_pfn - 1) << PAGE_SHIFT);
u32 high_totalram = ((max_pfn - 1) >> (32 - PAGE_SHIFT));
u64 mask;


if (!high_totalram) {
/* convert to mask just covering totalram */
low_totalram = (1 << (fls(low_totalram) - 1));
low_totalram += low_totalram - 1;
mask = low_totalram;
} else {
high_totalram = (1 << (fls(high_totalram) - 1));
high_totalram += high_totalram - 1;
mask = (((u64)high_totalram) << 32) + 0xffffffff;
}
return mask;
}
EXPORT_SYMBOL_GPL(dma_get_required_mask);
#endif


static __initdata LIST_HEAD(early_platform_driver_list);
static __initdata LIST_HEAD(early_platform_device_list);


/**
 * early_platform_driver_register - register early platform driver
 * @epdrv: early_platform driver structure
 * @buf: string passed from early_param()
 *
 * Helper function for early_platform_init() / early_platform_init_buffer()
 */
int __init early_platform_driver_register(struct early_platform_driver *epdrv,
  char *buf)
{
char *tmp;
int n;


/* Simply add the driver to the end of the global list.
* Drivers will by default be put on the list in compiled-in order.
*/
if (!epdrv->list.next) {
INIT_LIST_HEAD(&epdrv->list);
list_add_tail(&epdrv->list, &early_platform_driver_list);
}


/* If the user has specified device then make sure the driver
* gets prioritized. The driver of the last device specified on
* command line will be put first on the list.
*/
n = strlen(epdrv->pdrv->driver.name);
if (buf && !strncmp(buf, epdrv->pdrv->driver.name, n)) {
list_move(&epdrv->list, &early_platform_driver_list);


/* Allow passing parameters after device name */
if (buf[n] == '\0' || buf[n] == ',')
epdrv->requested_id = -1;
else {
epdrv->requested_id = simple_strtoul(&buf[n + 1],
     &tmp, 10);


if (buf[n] != '.' || (tmp == &buf[n + 1])) {
epdrv->requested_id = EARLY_PLATFORM_ID_ERROR;
n = 0;
} else
n += strcspn(&buf[n + 1], ",") + 1;
}


if (buf[n] == ',')
n++;


if (epdrv->bufsize) {
memcpy(epdrv->buffer, &buf[n],
       min_t(int, epdrv->bufsize, strlen(&buf[n]) + 1));
epdrv->buffer[epdrv->bufsize - 1] = '\0';
}
}


return 0;
}


/**
 * early_platform_add_devices - adds a number of early platform devices
 * @devs: array of early platform devices to add
 * @num: number of early platform devices in array
 *
 * Used by early architecture code to register early platform devices and
 * their platform data.
 */
void __init early_platform_add_devices(struct platform_device **devs, int num)
{
struct device *dev;
int i;


/* simply add the devices to list */
for (i = 0; i < num; i++) {
dev = &devs[i]->dev;


if (!dev->devres_head.next) {
pm_runtime_early_init(dev);
INIT_LIST_HEAD(&dev->devres_head);
list_add_tail(&dev->devres_head,
      &early_platform_device_list);
}
}
}


/**
 * early_platform_driver_register_all - register early platform drivers
 * @class_str: string to identify early platform driver class
 *
 * Used by architecture code to register all early platform drivers
 * for a certain class. If omitted then only early platform drivers
 * with matching kernel command line class parameters will be registered.
 */
void __init early_platform_driver_register_all(char *class_str)
{
/* The "class_str" parameter may or may not be present on the kernel
* command line. If it is present then there may be more than one
* matching parameter.
*
* Since we register our early platform drivers using early_param()
* we need to make sure that they also get registered in the case
* when the parameter is missing from the kernel command line.
*
* We use parse_early_options() to make sure the early_param() gets
* called at least once. The early_param() may be called more than
* once since the name of the preferred device may be specified on
* the kernel command line. early_platform_driver_register() handles
* this case for us.
*/
parse_early_options(class_str);
}


/**
 * early_platform_match - find early platform device matching driver
 * @epdrv: early platform driver structure
 * @id: id to match against
 */
static  __init struct platform_device *
early_platform_match(struct early_platform_driver *epdrv, int id)
{
struct platform_device *pd;


list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
if (platform_match(&pd->dev, &epdrv->pdrv->driver))
if (pd->id == id)
return pd;


return NULL;
}


/**
 * early_platform_left - check if early platform driver has matching devices
 * @epdrv: early platform driver structure
 * @id: return true if id or above exists
 */
static  __init int early_platform_left(struct early_platform_driver *epdrv,
       int id)
{
struct platform_device *pd;


list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
if (platform_match(&pd->dev, &epdrv->pdrv->driver))
if (pd->id >= id)
return 1;


return 0;
}


/**
 * early_platform_driver_probe_id - probe drivers matching class_str and id
 * @class_str: string to identify early platform driver class
 * @id: id to match against
 * @nr_probe: number of platform devices to successfully probe before exiting
 */
static int __init early_platform_driver_probe_id(char *class_str,
int id,
int nr_probe)
{
struct early_platform_driver *epdrv;
struct platform_device *match;
int match_id;
int n = 0;
int left = 0;


list_for_each_entry(epdrv, &early_platform_driver_list, list) {
/* only use drivers matching our class_str */
if (strcmp(class_str, epdrv->class_str))
continue;


if (id == -2) {
match_id = epdrv->requested_id;
left = 1;


} else {
match_id = id;
left += early_platform_left(epdrv, id);


/* skip requested id */
switch (epdrv->requested_id) {
case EARLY_PLATFORM_ID_ERROR:
case EARLY_PLATFORM_ID_UNSET:
break;
default:
if (epdrv->requested_id == id)
match_id = EARLY_PLATFORM_ID_UNSET;
}
}


switch (match_id) {
case EARLY_PLATFORM_ID_ERROR:
pr_warn("%s: unable to parse %s parameter\n",
class_str, epdrv->pdrv->driver.name);
/* fall-through */
case EARLY_PLATFORM_ID_UNSET:
match = NULL;
break;
default:
match = early_platform_match(epdrv, match_id);
}


if (match) {
/*
* Set up a sensible init_name to enable
* dev_name() and others to be used before the
* rest of the driver core is initialized.
*/
if (!match->dev.init_name && slab_is_available()) {
if (match->id != -1)
match->dev.init_name =
kasprintf(GFP_KERNEL, "%s.%d",
  match->name,
  match->id);
else
match->dev.init_name =
kasprintf(GFP_KERNEL, "%s",
  match->name);


if (!match->dev.init_name)
return -ENOMEM;
}


if (epdrv->pdrv->probe(match))
pr_warn("%s: unable to probe %s early.\n",
class_str, match->name);
else
n++;
}


if (n >= nr_probe)
break;
}


if (left)
return n;
else
return -ENODEV;
}


/**
 * early_platform_driver_probe - probe a class of registered drivers
 * @class_str: string to identify early platform driver class
 * @nr_probe: number of platform devices to successfully probe before exiting
 * @user_only: only probe user specified early platform devices
 *
 * Used by architecture code to probe registered early platform drivers
 * within a certain class. For probe to happen a registered early platform
 * device matching a registered early platform driver is needed.
 */
int __init early_platform_driver_probe(char *class_str,
       int nr_probe,
       int user_only)
{
int k, n, i;


n = 0;
for (i = -2; n < nr_probe; i++) {
k = early_platform_driver_probe_id(class_str, i, nr_probe - n);


if (k < 0)
break;


n += k;


if (user_only)
break;
}


return n;
}


/**
 * early_platform_cleanup - clean up early platform code
 */
void __init early_platform_cleanup(void)
{
struct platform_device *pd, *pd2;


/* clean up the devres list used to chain devices */
list_for_each_entry_safe(pd, pd2, &early_platform_device_list,
dev.devres_head) {
list_del(&pd->dev.devres_head);
memset(&pd->dev.devres_head, 0, sizeof(pd->dev.devres_head));
}
}