linux/drivers/acpi/acpi_platform.c
Andy Shevchenko cb0701acfa ACPI: platform: Unregister stale platform devices
When commit 68bdb67732 ("ACPI: add support for ACPI reconfiguration
notifiers") introduced reconfiguration notifiers, it missed the point
that the ACPI table, which might be loaded and then unloaded via
ConfigFS, could contain devices that were not enumerated by their
parents.

In such cases, the stale platform device is dangling in the system
while the rest of the devices from the same table are already gone.

Introduce acpi_platform_device_remove_notify() notifier that, in
similar way to I²C or SPI buses, unregisters the platform devices
on table removal event.

Fixes: 68bdb67732 ("ACPI: add support for ACPI reconfiguration notifiers")
Depends-on: 00500147cb ("drivers: Introduce device lookup variants by ACPI_COMPANION device")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
[ rjw: Changelog & function rename ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-10-17 23:48:39 +02:00

176 lines
4.8 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* ACPI support for platform bus type.
*
* Copyright (C) 2012, Intel Corporation
* Authors: Mika Westerberg <mika.westerberg@linux.intel.com>
* Mathias Nyman <mathias.nyman@linux.intel.com>
* Rafael J. Wysocki <rafael.j.wysocki@intel.com>
*/
#include <linux/acpi.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/dma-mapping.h>
#include <linux/pci.h>
#include <linux/platform_device.h>
#include "internal.h"
ACPI_MODULE_NAME("platform");
static const struct acpi_device_id forbidden_id_list[] = {
{"PNP0000", 0}, /* PIC */
{"PNP0100", 0}, /* Timer */
{"PNP0200", 0}, /* AT DMA Controller */
{"ACPI0009", 0}, /* IOxAPIC */
{"ACPI000A", 0}, /* IOAPIC */
{"SMB0001", 0}, /* ACPI SMBUS virtual device */
{"", 0},
};
static struct platform_device *acpi_platform_device_find_by_companion(struct acpi_device *adev)
{
struct device *dev;
dev = bus_find_device_by_acpi_dev(&platform_bus_type, adev);
return dev ? to_platform_device(dev) : NULL;
}
static int acpi_platform_device_remove_notify(struct notifier_block *nb,
unsigned long value, void *arg)
{
struct acpi_device *adev = arg;
struct platform_device *pdev;
switch (value) {
case ACPI_RECONFIG_DEVICE_ADD:
/* Nothing to do here */
break;
case ACPI_RECONFIG_DEVICE_REMOVE:
if (!acpi_device_enumerated(adev))
break;
pdev = acpi_platform_device_find_by_companion(adev);
if (!pdev)
break;
platform_device_unregister(pdev);
put_device(&pdev->dev);
break;
}
return NOTIFY_OK;
}
static struct notifier_block acpi_platform_notifier = {
.notifier_call = acpi_platform_device_remove_notify,
};
static void acpi_platform_fill_resource(struct acpi_device *adev,
const struct resource *src, struct resource *dest)
{
struct device *parent;
*dest = *src;
/*
* If the device has parent we need to take its resources into
* account as well because this device might consume part of those.
*/
parent = acpi_get_first_physical_node(adev->parent);
if (parent && dev_is_pci(parent))
dest->parent = pci_find_resource(to_pci_dev(parent), dest);
}
/**
* acpi_create_platform_device - Create platform device for ACPI device node
* @adev: ACPI device node to create a platform device for.
* @properties: Optional collection of build-in properties.
*
* Check if the given @adev can be represented as a platform device and, if
* that's the case, create and register a platform device, populate its common
* resources and returns a pointer to it. Otherwise, return %NULL.
*
* Name of the platform device will be the same as @adev's.
*/
struct platform_device *acpi_create_platform_device(struct acpi_device *adev,
struct property_entry *properties)
{
struct platform_device *pdev = NULL;
struct platform_device_info pdevinfo;
struct resource_entry *rentry;
struct list_head resource_list;
struct resource *resources = NULL;
int count;
/* If the ACPI node already has a physical device attached, skip it. */
if (adev->physical_node_count)
return NULL;
if (!acpi_match_device_ids(adev, forbidden_id_list))
return ERR_PTR(-EINVAL);
INIT_LIST_HEAD(&resource_list);
count = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
if (count < 0) {
return NULL;
} else if (count > 0) {
resources = kcalloc(count, sizeof(struct resource),
GFP_KERNEL);
if (!resources) {
dev_err(&adev->dev, "No memory for resources\n");
acpi_dev_free_resource_list(&resource_list);
return ERR_PTR(-ENOMEM);
}
count = 0;
list_for_each_entry(rentry, &resource_list, node)
acpi_platform_fill_resource(adev, rentry->res,
&resources[count++]);
acpi_dev_free_resource_list(&resource_list);
}
memset(&pdevinfo, 0, sizeof(pdevinfo));
/*
* If the ACPI node has a parent and that parent has a physical device
* attached to it, that physical device should be the parent of the
* platform device we are about to create.
*/
pdevinfo.parent = adev->parent ?
acpi_get_first_physical_node(adev->parent) : NULL;
pdevinfo.name = dev_name(&adev->dev);
pdevinfo.id = -1;
pdevinfo.res = resources;
pdevinfo.num_res = count;
pdevinfo.fwnode = acpi_fwnode_handle(adev);
pdevinfo.properties = properties;
if (acpi_dma_supported(adev))
pdevinfo.dma_mask = DMA_BIT_MASK(32);
else
pdevinfo.dma_mask = 0;
pdev = platform_device_register_full(&pdevinfo);
if (IS_ERR(pdev))
dev_err(&adev->dev, "platform device creation failed: %ld\n",
PTR_ERR(pdev));
else {
set_dev_node(&pdev->dev, acpi_get_node(adev->handle));
dev_dbg(&adev->dev, "created platform device %s\n",
dev_name(&pdev->dev));
}
kfree(resources);
return pdev;
}
EXPORT_SYMBOL_GPL(acpi_create_platform_device);
void __init acpi_platform_init(void)
{
acpi_reconfig_notifier_register(&acpi_platform_notifier);
}