ACPI / driver core: Store an ACPI device pointer in struct acpi_dev_node

Modify struct acpi_dev_node to contain a pointer to struct acpi_device
associated with the given device object (that is, its ACPI companion
device) instead of an ACPI handle corresponding to it. Introduce two
new macros for manipulating that pointer in a CONFIG_ACPI-safe way,
ACPI_COMPANION() and ACPI_COMPANION_SET(), and rework the
ACPI_HANDLE() macro to take the above changes into account.
Drop the ACPI_HANDLE_SET() macro entirely and rework its users to
use ACPI_COMPANION_SET() instead. For some of them who used to
pass the result of acpi_get_child() directly to ACPI_HANDLE_SET()
introduce a helper routine acpi_preset_companion() doing an
equivalent thing.

The main motivation for doing this is that there are things
represented by struct acpi_device objects that don't have valid
ACPI handles (so called fixed ACPI hardware features, such as
power and sleep buttons) and we would like to create platform
device objects for them and "glue" them to their ACPI companions
in the usual way (which currently is impossible due to the
lack of valid ACPI handles). However, there are more reasons
why it may be useful.

First, struct acpi_device pointers allow of much better type checking
than void pointers which are ACPI handles, so it should be more
difficult to write buggy code using modified struct acpi_dev_node
and the new macros. Second, the change should help to reduce (over
time) the number of places in which the result of ACPI_HANDLE() is
passed to acpi_bus_get_device() in order to obtain a pointer to the
struct acpi_device associated with the given "physical" device,
because now that pointer is returned by ACPI_COMPANION() directly.
Finally, the change should make it easier to write generic code that
will build both for CONFIG_ACPI set and unset without adding explicit
compiler directives to it.

Signed-off-by: Rafael J. Wysocki <[e-mail]>
Acked-by: Greg Kroah-Hartman <[e-mail]>
Tested-by: Mika Westerberg <[e-mail]> # on Haswell
Reviewed-by: Mika Westerberg <[e-mail]>
Reviewed-by: Aaron Lu <[e-mail]> # for ATA and SDIO part

arch/ia64/hp/common/sba_iommu.c

···
 	if (PCI_CONTROLLER(bus)->iommu)
 		return;
 
-	handle = PCI_CONTROLLER(bus)->acpi_handle;
+	handle = acpi_device_handle(PCI_CONTROLLER(bus)->companion);
 	if (!handle)
 		return;
 

arch/ia64/include/asm/pci.h

···
 };
 
 struct pci_controller {
-	void *acpi_handle;
+	struct acpi_device *companion;
 	void *iommu;
 	int segment;
 	int node;		/* nearest node with memory or -1 for global allocation */

arch/ia64/pci/pci.c

···
 	if (!controller)
 		return NULL;
 
-	controller->acpi_handle = device->handle;
+	controller->companion = device;
 
-	pxm = acpi_get_pxm(controller->acpi_handle);
+	pxm = acpi_get_pxm(device->handle);
 #ifdef CONFIG_NUMA
 	if (pxm >= 0)
 		controller->node = pxm_to_node(pxm);
···
 {
 	struct pci_controller *controller = bridge->bus->sysdata;
 
-	ACPI_HANDLE_SET(&bridge->dev, controller->acpi_handle);
+	ACPI_COMPANION_SET(&bridge->dev, controller->companion);
 	return 0;
 }
 

arch/ia64/sn/kernel/io_acpi_init.c

···
 	struct acpi_resource_vendor_typed *vendor;
 
 
-	handle = PCI_CONTROLLER(bus)->acpi_handle;
+	handle = acpi_device_handle(PCI_CONTROLLER(bus)->companion);
 	status = acpi_get_vendor_resource(handle, METHOD_NAME__CRS,
 					  &sn_uuid, &buffer);
 	if (ACPI_FAILURE(status)) {
···
 	acpi_status status;
 	struct acpi_buffer name_buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 
-	rootbus_handle = PCI_CONTROLLER(dev)->acpi_handle;
+	rootbus_handle = acpi_device_handle(PCI_CONTROLLER(dev)->companion);
         status = acpi_evaluate_integer(rootbus_handle, METHOD_NAME__SEG, NULL,
                                        &segment);
         if (ACPI_SUCCESS(status)) {

arch/x86/include/asm/pci.h

···
 	int		domain;		/* PCI domain */
 	int		node;		/* NUMA node */
 #ifdef CONFIG_ACPI
-	void		*acpi;		/* ACPI-specific data */
+	struct acpi_device *companion;	/* ACPI companion device */
 #endif
 #ifdef CONFIG_X86_64
 	void		*iommu;		/* IOMMU private data */

arch/x86/pci/acpi.c

···
 	sd = &info->sd;
 	sd->domain = domain;
 	sd->node = node;
-	sd->acpi = device->handle;
+	sd->companion = device;
 	/*
 	 * Maybe the desired pci bus has been already scanned. In such case
 	 * it is unnecessary to scan the pci bus with the given domain,busnum.
···
 {
 	struct pci_sysdata *sd = bridge->bus->sysdata;
 
-	ACPI_HANDLE_SET(&bridge->dev, sd->acpi);
+	ACPI_COMPANION_SET(&bridge->dev, sd->companion);
 	return 0;
 }
 

drivers/acpi/acpi_platform.c

···
 	pdevinfo.id = -1;
 	pdevinfo.res = resources;
 	pdevinfo.num_res = count;
-	pdevinfo.acpi_node.handle = adev->handle;
+	pdevinfo.acpi_node.companion = adev;
 	pdev = platform_device_register_full(&pdevinfo);
 	if (IS_ERR(pdev)) {
 		dev_err(&adev->dev, "platform device creation failed: %ld\n",

drivers/acpi/device_pm.c

···
  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  */
 
-#include <linux/device.h>
+#include <linux/acpi.h>
 #include <linux/export.h>
 #include <linux/mutex.h>
 #include <linux/pm_qos.h>
 #include <linux/pm_runtime.h>
-
-#include <acpi/acpi.h>
-#include <acpi/acpi_bus.h>
-#include <acpi/acpi_drivers.h>
 
 #include "internal.h"
 

drivers/acpi/glue.c

···
 
 int acpi_bind_one(struct device *dev, acpi_handle handle)
 {
-	struct acpi_device *acpi_dev;
-	acpi_status status;
+	struct acpi_device *acpi_dev = NULL;
 	struct acpi_device_physical_node *physical_node, *pn;
 	char physical_node_name[PHYSICAL_NODE_NAME_SIZE];
 	struct list_head *physnode_list;
 	unsigned int node_id;
 	int retval = -EINVAL;
 
-	if (ACPI_HANDLE(dev)) {
+	if (ACPI_COMPANION(dev)) {
 		if (handle) {
-			dev_warn(dev, "ACPI handle is already set\n");
+			dev_warn(dev, "ACPI companion already set\n");
 			return -EINVAL;
 		} else {
-			handle = ACPI_HANDLE(dev);
+			acpi_dev = ACPI_COMPANION(dev);
 		}
+	} else {
+		acpi_bus_get_device(handle, &acpi_dev);
 	}
-	if (!handle)
+	if (!acpi_dev)
 		return -EINVAL;
 
 	get_device(dev);
-	status = acpi_bus_get_device(handle, &acpi_dev);
-	if (ACPI_FAILURE(status))
-		goto err;
-
 	physical_node = kzalloc(sizeof(*physical_node), GFP_KERNEL);
 	if (!physical_node) {
 		retval = -ENOMEM;
···
 
 			dev_warn(dev, "Already associated with ACPI node\n");
 			kfree(physical_node);
-			if (ACPI_HANDLE(dev) != handle)
+			if (ACPI_COMPANION(dev) != acpi_dev)
 				goto err;
 
 			put_device(dev);
···
 	list_add(&physical_node->node, physnode_list);
 	acpi_dev->physical_node_count++;
 
-	if (!ACPI_HANDLE(dev))
-		ACPI_HANDLE_SET(dev, acpi_dev->handle);
+	if (!ACPI_COMPANION(dev))
+		ACPI_COMPANION_SET(dev, acpi_dev);
 
 	acpi_physnode_link_name(physical_node_name, node_id);
 	retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
···
 	return 0;
 
  err:
-	ACPI_HANDLE_SET(dev, NULL);
+	ACPI_COMPANION_SET(dev, NULL);
 	put_device(dev);
 	return retval;
 }
···
 
 int acpi_unbind_one(struct device *dev)
 {
+	struct acpi_device *acpi_dev = ACPI_COMPANION(dev);
 	struct acpi_device_physical_node *entry;
-	struct acpi_device *acpi_dev;
-	acpi_status status;
 
-	if (!ACPI_HANDLE(dev))
+	if (!acpi_dev)
 		return 0;
-
-	status = acpi_bus_get_device(ACPI_HANDLE(dev), &acpi_dev);
-	if (ACPI_FAILURE(status)) {
-		dev_err(dev, "Oops, ACPI handle corrupt in %s()\n", __func__);
-		return -EINVAL;
-	}
 
 	mutex_lock(&acpi_dev->physical_node_lock);
 
···
 			acpi_physnode_link_name(physnode_name, entry->node_id);
 			sysfs_remove_link(&acpi_dev->dev.kobj, physnode_name);
 			sysfs_remove_link(&dev->kobj, "firmware_node");
-			ACPI_HANDLE_SET(dev, NULL);
+			ACPI_COMPANION_SET(dev, NULL);
 			/* acpi_bind_one() increase refcnt by one. */
 			put_device(dev);
 			kfree(entry);
···
 	return 0;
 }
 EXPORT_SYMBOL_GPL(acpi_unbind_one);
+
+void acpi_preset_companion(struct device *dev, acpi_handle parent, u64 addr)
+{
+	struct acpi_device *adev;
+
+	if (!acpi_bus_get_device(acpi_get_child(parent, addr), &adev))
+		ACPI_COMPANION_SET(dev, adev);
+}
+EXPORT_SYMBOL_GPL(acpi_preset_companion);
 
 static int acpi_platform_notify(struct device *dev)
 {

drivers/ata/libata-acpi.c

···
 	if (libata_noacpi || ap->flags & ATA_FLAG_ACPI_SATA || !host_handle)
 		return;
 
-	ACPI_HANDLE_SET(&ap->tdev, acpi_get_child(host_handle, ap->port_no));
+	acpi_preset_companion(&ap->tdev, host_handle, ap->port_no);
 
 	if (ata_acpi_gtm(ap, &ap->__acpi_init_gtm) == 0)
 		ap->pflags |= ATA_PFLAG_INIT_GTM_VALID;
···
 		parent_handle = port_handle;
 	}
 
-	ACPI_HANDLE_SET(&dev->tdev, acpi_get_child(parent_handle, adr));
+	acpi_preset_companion(&dev->tdev, parent_handle, adr);
 
 	register_hotplug_dock_device(ata_dev_acpi_handle(dev),
 				     &ata_acpi_dev_dock_ops, dev, NULL, NULL);

drivers/base/platform.c

···
 		goto err_alloc;
 
 	pdev->dev.parent = pdevinfo->parent;
-	ACPI_HANDLE_SET(&pdev->dev, pdevinfo->acpi_node.handle);
+	ACPI_COMPANION_SET(&pdev->dev, pdevinfo->acpi_node.companion);
 
 	if (pdevinfo->dma_mask) {
 		/*
···
 	ret = platform_device_add(pdev);
 	if (ret) {
 err:
-		ACPI_HANDLE_SET(&pdev->dev, NULL);
+		ACPI_COMPANION_SET(&pdev->dev, NULL);
 		kfree(pdev->dev.dma_mask);
 
 err_alloc:

drivers/gpio/gpiolib.c

···
 #include <linux/acpi_gpio.h>
 #include <linux/idr.h>
 #include <linux/slab.h>
+#include <linux/acpi.h>
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/gpio.h>

drivers/gpu/drm/radeon/radeon_atpx_handler.c

···
  */
 #include <linux/vga_switcheroo.h>
 #include <linux/slab.h>
-#include <acpi/acpi.h>
-#include <acpi/acpi_bus.h>
+#include <linux/acpi.h>
 #include <linux/pci.h>
 
 #include "radeon_acpi.h"

drivers/hid/i2c-hid/i2c-hid.c

···
 	hid->hid_get_raw_report = i2c_hid_get_raw_report;
 	hid->hid_output_raw_report = i2c_hid_output_raw_report;
 	hid->dev.parent = &client->dev;
-	ACPI_HANDLE_SET(&hid->dev, ACPI_HANDLE(&client->dev));
+	ACPI_COMPANION_SET(&hid->dev, ACPI_COMPANION(&client->dev));
 	hid->bus = BUS_I2C;
 	hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
 	hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);

drivers/i2c/i2c-core.c

···
 	client->dev.bus = &i2c_bus_type;
 	client->dev.type = &i2c_client_type;
 	client->dev.of_node = info->of_node;
-	ACPI_HANDLE_SET(&client->dev, info->acpi_node.handle);
+	ACPI_COMPANION_SET(&client->dev, info->acpi_node.companion);
 
 	/* For 10-bit clients, add an arbitrary offset to avoid collisions */
 	dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap),
···
 		return AE_OK;
 
 	memset(&info, 0, sizeof(info));
-	info.acpi_node.handle = handle;
+	info.acpi_node.companion = adev;
 	info.irq = -1;
 
 	INIT_LIST_HEAD(&resource_list);

drivers/ide/ide-acpi.c

···
  * Copyright (C) 2006 Hannes Reinecke
  */
 
+#include <linux/acpi.h>
 #include <linux/ata.h>
 #include <linux/delay.h>
 #include <linux/device.h>
···
 #include <linux/pci.h>
 #include <linux/dmi.h>
 #include <linux/module.h>
-
-#include <acpi/acpi_bus.h>
 
 #define REGS_PER_GTF		7
 

drivers/mmc/core/sdio_bus.c

···
 	struct mmc_host *host = func->card->host;
 	u64 addr = (host->slotno << 16) | func->num;
 
-	ACPI_HANDLE_SET(&func->dev,
-			acpi_get_child(ACPI_HANDLE(host->parent), addr));
+	acpi_preset_companion(&func->dev, ACPI_HANDLE(host->parent), addr);
 }
 #else
 static inline void sdio_acpi_set_handle(struct sdio_func *func) {}

drivers/pci/hotplug/sgi_hotplug.c

···
  * Work to add BIOS PROM support was completed by Mike Habeck.
  */
 
+#include <linux/acpi.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
···
 #include <asm/sn/sn_feature_sets.h>
 #include <asm/sn/sn_sal.h>
 #include <asm/sn/types.h>
-#include <linux/acpi.h>
 #include <asm/sn/acpi.h>
 
 #include "../pci.h"
···
 		acpi_handle rethandle;
 		acpi_status ret;
 
-		phandle = PCI_CONTROLLER(slot->pci_bus)->acpi_handle;
+		phandle = acpi_device_handle(PCI_CONTROLLER(slot->pci_bus)->companion);
 
 		if (acpi_bus_get_device(phandle, &pdevice)) {
 			dev_dbg(&slot->pci_bus->self->dev,
···
 
 	/* free the ACPI resources for the slot */
 	if (SN_ACPI_BASE_SUPPORT() &&
-            PCI_CONTROLLER(slot->pci_bus)->acpi_handle) {
+            PCI_CONTROLLER(slot->pci_bus)->companion) {
 		unsigned long long adr;
 		struct acpi_device *device;
 		acpi_handle phandle;
···
 		acpi_status ret;
 
 		/* Get the rootbus node pointer */
-		phandle = PCI_CONTROLLER(slot->pci_bus)->acpi_handle;
+		phandle = acpi_device_handle(PCI_CONTROLLER(slot->pci_bus)->companion);
 
 		acpi_scan_lock_acquire();
 		/*

drivers/spi/spi.c

···
 		return AE_NO_MEMORY;
 	}
 
-	ACPI_HANDLE_SET(&spi->dev, handle);
+	ACPI_COMPANION_SET(&spi->dev, adev);
 	spi->irq = -1;
 
 	INIT_LIST_HEAD(&resource_list);

include/acpi/acpi_bus.h

···
 {
 	return acpi_find_child(handle, addr, false);
 }
+void acpi_preset_companion(struct device *dev, acpi_handle parent, u64 addr);
 int acpi_is_root_bridge(acpi_handle);
 struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle);
-#define DEVICE_ACPI_HANDLE(dev) ((acpi_handle)ACPI_HANDLE(dev))
 
 int acpi_enable_wakeup_device_power(struct acpi_device *dev, int state);
 int acpi_disable_wakeup_device_power(struct acpi_device *dev);

include/linux/acpi.h

···
 #include <acpi/acpi_numa.h>
 #include <asm/acpi.h>
 
+static inline acpi_handle acpi_device_handle(struct acpi_device *adev)
+{
+	return adev ? adev->handle : NULL;
+}
+
+#define ACPI_COMPANION(dev)		((dev)->acpi_node.companion)
+#define ACPI_COMPANION_SET(dev, adev)	ACPI_COMPANION(dev) = (adev)
+#define ACPI_HANDLE(dev)		acpi_device_handle(ACPI_COMPANION(dev))
+
 enum acpi_irq_model_id {
 	ACPI_IRQ_MODEL_PIC = 0,
 	ACPI_IRQ_MODEL_IOAPIC,
···
 
 #define acpi_disabled 1
 
+#define ACPI_COMPANION(dev)		(NULL)
+#define ACPI_COMPANION_SET(dev, adev)	do { } while (0)
+#define ACPI_HANDLE(dev)		(NULL)
+
 static inline void acpi_early_init(void) { }
 
 static inline int early_acpi_boot_init(void)
···
 #define ACPI_PTR(_ptr)	(NULL)
 
 #endif	/* !CONFIG_ACPI */
+
+#define DEVICE_ACPI_HANDLE(dev)	ACPI_HANDLE(dev)
 
 #ifdef CONFIG_ACPI
 void acpi_os_set_prepare_sleep(int (*func)(u8 sleep_state,

include/linux/device.h

···
 	unsigned long segment_boundary_mask;
 };
 
+struct acpi_device;
+
 struct acpi_dev_node {
 #ifdef CONFIG_ACPI
-	void	*handle;
+	struct acpi_device *companion;
 #endif
 };
 
···
 {
 	return container_of(kobj, struct device, kobj);
 }
-
-#ifdef CONFIG_ACPI
-#define ACPI_HANDLE(dev)	((dev)->acpi_node.handle)
-#define ACPI_HANDLE_SET(dev, _handle_)	(dev)->acpi_node.handle = (_handle_)
-#else
-#define ACPI_HANDLE(dev)	(NULL)
-#define ACPI_HANDLE_SET(dev, _handle_)	do { } while (0)
-#endif
 
 /* Get the wakeup routines, which depend on struct device */
 #include <linux/pm_wakeup.h>