1 files changed, 580 insertions, 0 deletions
diff --git a/drivers/pci/hotplug/pci_hotplug_core.c b/drivers/pci/hotplug/pci_hotplug_core.c
new file mode 100644
index 000000000..058d5937d
--- /dev/null
+++ b/drivers/pci/hotplug/pci_hotplug_core.c
@@ -0,0 +1,580 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * PCI HotPlug Controller Core
+ *
+ * Copyright (C) 2001-2002 Greg Kroah-Hartman (greg@kroah.com)
+ * Copyright (C) 2001-2002 IBM Corp.
+ *
+ * All rights reserved.
+ *
+ * Send feedback to <kristen.c.accardi@intel.com>
+ *
+ * Authors:
+ *   Greg Kroah-Hartman <greg@kroah.com>
+ *   Scott Murray <scottm@somanetworks.com>
+ */
+
+#include <linux/module.h>	/* try_module_get & module_put */
+#include <linux/moduleparam.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/list.h>
+#include <linux/kobject.h>
+#include <linux/sysfs.h>
+#include <linux/pagemap.h>
+#include <linux/init.h>
+#include <linux/mount.h>
+#include <linux/namei.h>
+#include <linux/mutex.h>
+#include <linux/pci.h>
+#include <linux/pci_hotplug.h>
+#include <linux/uaccess.h>
+#include "../pci.h"
+#include "cpci_hotplug.h"
+
+#define MY_NAME	"pci_hotplug"
+
+#define dbg(fmt, arg...) do { if (debug) printk(KERN_DEBUG "%s: %s: " fmt, MY_NAME, __func__, ## arg); } while (0)
+#define err(format, arg...) printk(KERN_ERR "%s: " format, MY_NAME, ## arg)
+#define info(format, arg...) printk(KERN_INFO "%s: " format, MY_NAME, ## arg)
+#define warn(format, arg...) printk(KERN_WARNING "%s: " format, MY_NAME, ## arg)
+
+/* local variables */
+static bool debug;
+
+static LIST_HEAD(pci_hotplug_slot_list);
+static DEFINE_MUTEX(pci_hp_mutex);
+
+/* Weee, fun with macros... */
+#define GET_STATUS(name, type)	\
+static int get_##name(struct hotplug_slot *slot, type *value)		\
+{									\
+	const struct hotplug_slot_ops *ops = slot->ops;			\
+	int retval = 0;							\
+	if (!try_module_get(slot->owner))				\
+		return -ENODEV;						\
+	if (ops->get_##name)						\
+		retval = ops->get_##name(slot, value);			\
+	module_put(slot->owner);					\
+	return retval;							\
+}
+
+GET_STATUS(power_status, u8)
+GET_STATUS(attention_status, u8)
+GET_STATUS(latch_status, u8)
+GET_STATUS(adapter_status, u8)
+
+static ssize_t power_read_file(struct pci_slot *pci_slot, char *buf)
+{
+	int retval;
+	u8 value;
+
+	retval = get_power_status(pci_slot->hotplug, &value);
+	if (retval)
+		return retval;
+
+	return sysfs_emit(buf, "%d\n", value);
+}
+
+static ssize_t power_write_file(struct pci_slot *pci_slot, const char *buf,
+				size_t count)
+{
+	struct hotplug_slot *slot = pci_slot->hotplug;
+	unsigned long lpower;
+	u8 power;
+	int retval = 0;
+
+	lpower = simple_strtoul(buf, NULL, 10);
+	power = (u8)(lpower & 0xff);
+	dbg("power = %d\n", power);
+
+	if (!try_module_get(slot->owner)) {
+		retval = -ENODEV;
+		goto exit;
+	}
+	switch (power) {
+	case 0:
+		if (slot->ops->disable_slot)
+			retval = slot->ops->disable_slot(slot);
+		break;
+
+	case 1:
+		if (slot->ops->enable_slot)
+			retval = slot->ops->enable_slot(slot);
+		break;
+
+	default:
+		err("Illegal value specified for power\n");
+		retval = -EINVAL;
+	}
+	module_put(slot->owner);
+
+exit:
+	if (retval)
+		return retval;
+	return count;
+}
+
+static struct pci_slot_attribute hotplug_slot_attr_power = {
+	.attr = {.name = "power", .mode = S_IFREG | S_IRUGO | S_IWUSR},
+	.show = power_read_file,
+	.store = power_write_file
+};
+
+static ssize_t attention_read_file(struct pci_slot *pci_slot, char *buf)
+{
+	int retval;
+	u8 value;
+
+	retval = get_attention_status(pci_slot->hotplug, &value);
+	if (retval)
+		return retval;
+
+	return sysfs_emit(buf, "%d\n", value);
+}
+
+static ssize_t attention_write_file(struct pci_slot *pci_slot, const char *buf,
+				    size_t count)
+{
+	struct hotplug_slot *slot = pci_slot->hotplug;
+	const struct hotplug_slot_ops *ops = slot->ops;
+	unsigned long lattention;
+	u8 attention;
+	int retval = 0;
+
+	lattention = simple_strtoul(buf, NULL, 10);
+	attention = (u8)(lattention & 0xff);
+	dbg(" - attention = %d\n", attention);
+
+	if (!try_module_get(slot->owner)) {
+		retval = -ENODEV;
+		goto exit;
+	}
+	if (ops->set_attention_status)
+		retval = ops->set_attention_status(slot, attention);
+	module_put(slot->owner);
+
+exit:
+	if (retval)
+		return retval;
+	return count;
+}
+
+static struct pci_slot_attribute hotplug_slot_attr_attention = {
+	.attr = {.name = "attention", .mode = S_IFREG | S_IRUGO | S_IWUSR},
+	.show = attention_read_file,
+	.store = attention_write_file
+};
+
+static ssize_t latch_read_file(struct pci_slot *pci_slot, char *buf)
+{
+	int retval;
+	u8 value;
+
+	retval = get_latch_status(pci_slot->hotplug, &value);
+	if (retval)
+		return retval;
+
+	return sysfs_emit(buf, "%d\n", value);
+}
+
+static struct pci_slot_attribute hotplug_slot_attr_latch = {
+	.attr = {.name = "latch", .mode = S_IFREG | S_IRUGO},
+	.show = latch_read_file,
+};
+
+static ssize_t presence_read_file(struct pci_slot *pci_slot, char *buf)
+{
+	int retval;
+	u8 value;
+
+	retval = get_adapter_status(pci_slot->hotplug, &value);
+	if (retval)
+		return retval;
+
+	return sysfs_emit(buf, "%d\n", value);
+}
+
+static struct pci_slot_attribute hotplug_slot_attr_presence = {
+	.attr = {.name = "adapter", .mode = S_IFREG | S_IRUGO},
+	.show = presence_read_file,
+};
+
+static ssize_t test_write_file(struct pci_slot *pci_slot, const char *buf,
+			       size_t count)
+{
+	struct hotplug_slot *slot = pci_slot->hotplug;
+	unsigned long ltest;
+	u32 test;
+	int retval = 0;
+
+	ltest = simple_strtoul(buf, NULL, 10);
+	test = (u32)(ltest & 0xffffffff);
+	dbg("test = %d\n", test);
+
+	if (!try_module_get(slot->owner)) {
+		retval = -ENODEV;
+		goto exit;
+	}
+	if (slot->ops->hardware_test)
+		retval = slot->ops->hardware_test(slot, test);
+	module_put(slot->owner);
+
+exit:
+	if (retval)
+		return retval;
+	return count;
+}
+
+static struct pci_slot_attribute hotplug_slot_attr_test = {
+	.attr = {.name = "test", .mode = S_IFREG | S_IRUGO | S_IWUSR},
+	.store = test_write_file
+};
+
+static bool has_power_file(struct pci_slot *pci_slot)
+{
+	struct hotplug_slot *slot = pci_slot->hotplug;
+
+	if ((!slot) || (!slot->ops))
+		return false;
+	if ((slot->ops->enable_slot) ||
+	    (slot->ops->disable_slot) ||
+	    (slot->ops->get_power_status))
+		return true;
+	return false;
+}
+
+static bool has_attention_file(struct pci_slot *pci_slot)
+{
+	struct hotplug_slot *slot = pci_slot->hotplug;
+
+	if ((!slot) || (!slot->ops))
+		return false;
+	if ((slot->ops->set_attention_status) ||
+	    (slot->ops->get_attention_status))
+		return true;
+	return false;
+}
+
+static bool has_latch_file(struct pci_slot *pci_slot)
+{
+	struct hotplug_slot *slot = pci_slot->hotplug;
+
+	if ((!slot) || (!slot->ops))
+		return false;
+	if (slot->ops->get_latch_status)
+		return true;
+	return false;
+}
+
+static bool has_adapter_file(struct pci_slot *pci_slot)
+{
+	struct hotplug_slot *slot = pci_slot->hotplug;
+
+	if ((!slot) || (!slot->ops))
+		return false;
+	if (slot->ops->get_adapter_status)
+		return true;
+	return false;
+}
+
+static bool has_test_file(struct pci_slot *pci_slot)
+{
+	struct hotplug_slot *slot = pci_slot->hotplug;
+
+	if ((!slot) || (!slot->ops))
+		return false;
+	if (slot->ops->hardware_test)
+		return true;
+	return false;
+}
+
+static int fs_add_slot(struct pci_slot *pci_slot)
+{
+	int retval = 0;
+
+	/* Create symbolic link to the hotplug driver module */
+	pci_hp_create_module_link(pci_slot);
+
+	if (has_power_file(pci_slot)) {
+		retval = sysfs_create_file(&pci_slot->kobj,
+					   &hotplug_slot_attr_power.attr);
+		if (retval)
+			goto exit_power;
+	}
+
+	if (has_attention_file(pci_slot)) {
+		retval = sysfs_create_file(&pci_slot->kobj,
+					   &hotplug_slot_attr_attention.attr);
+		if (retval)
+			goto exit_attention;
+	}
+
+	if (has_latch_file(pci_slot)) {
+		retval = sysfs_create_file(&pci_slot->kobj,
+					   &hotplug_slot_attr_latch.attr);
+		if (retval)
+			goto exit_latch;
+	}
+
+	if (has_adapter_file(pci_slot)) {
+		retval = sysfs_create_file(&pci_slot->kobj,
+					   &hotplug_slot_attr_presence.attr);
+		if (retval)
+			goto exit_adapter;
+	}
+
+	if (has_test_file(pci_slot)) {
+		retval = sysfs_create_file(&pci_slot->kobj,
+					   &hotplug_slot_attr_test.attr);
+		if (retval)
+			goto exit_test;
+	}
+
+	goto exit;
+
+exit_test:
+	if (has_adapter_file(pci_slot))
+		sysfs_remove_file(&pci_slot->kobj,
+				  &hotplug_slot_attr_presence.attr);
+exit_adapter:
+	if (has_latch_file(pci_slot))
+		sysfs_remove_file(&pci_slot->kobj, &hotplug_slot_attr_latch.attr);
+exit_latch:
+	if (has_attention_file(pci_slot))
+		sysfs_remove_file(&pci_slot->kobj,
+				  &hotplug_slot_attr_attention.attr);
+exit_attention:
+	if (has_power_file(pci_slot))
+		sysfs_remove_file(&pci_slot->kobj, &hotplug_slot_attr_power.attr);
+exit_power:
+	pci_hp_remove_module_link(pci_slot);
+exit:
+	return retval;
+}
+
+static void fs_remove_slot(struct pci_slot *pci_slot)
+{
+	if (has_power_file(pci_slot))
+		sysfs_remove_file(&pci_slot->kobj, &hotplug_slot_attr_power.attr);
+
+	if (has_attention_file(pci_slot))
+		sysfs_remove_file(&pci_slot->kobj,
+				  &hotplug_slot_attr_attention.attr);
+
+	if (has_latch_file(pci_slot))
+		sysfs_remove_file(&pci_slot->kobj, &hotplug_slot_attr_latch.attr);
+
+	if (has_adapter_file(pci_slot))
+		sysfs_remove_file(&pci_slot->kobj,
+				  &hotplug_slot_attr_presence.attr);
+
+	if (has_test_file(pci_slot))
+		sysfs_remove_file(&pci_slot->kobj, &hotplug_slot_attr_test.attr);
+
+	pci_hp_remove_module_link(pci_slot);
+}
+
+static struct hotplug_slot *get_slot_from_name(const char *name)
+{
+	struct hotplug_slot *slot;
+
+	list_for_each_entry(slot, &pci_hotplug_slot_list, slot_list) {
+		if (strcmp(hotplug_slot_name(slot), name) == 0)
+			return slot;
+	}
+	return NULL;
+}
+
+/**
+ * __pci_hp_register - register a hotplug_slot with the PCI hotplug subsystem
+ * @bus: bus this slot is on
+ * @slot: pointer to the &struct hotplug_slot to register
+ * @devnr: device number
+ * @name: name registered with kobject core
+ * @owner: caller module owner
+ * @mod_name: caller module name
+ *
+ * Prepares a hotplug slot for in-kernel use and immediately publishes it to
+ * user space in one go.  Drivers may alternatively carry out the two steps
+ * separately by invoking pci_hp_initialize() and pci_hp_add().
+ *
+ * Returns 0 if successful, anything else for an error.
+ */
+int __pci_hp_register(struct hotplug_slot *slot, struct pci_bus *bus,
+		      int devnr, const char *name,
+		      struct module *owner, const char *mod_name)
+{
+	int result;
+
+	result = __pci_hp_initialize(slot, bus, devnr, name, owner, mod_name);
+	if (result)
+		return result;
+
+	result = pci_hp_add(slot);
+	if (result)
+		pci_hp_destroy(slot);
+
+	return result;
+}
+EXPORT_SYMBOL_GPL(__pci_hp_register);
+
+/**
+ * __pci_hp_initialize - prepare hotplug slot for in-kernel use
+ * @slot: pointer to the &struct hotplug_slot to initialize
+ * @bus: bus this slot is on
+ * @devnr: slot number
+ * @name: name registered with kobject core
+ * @owner: caller module owner
+ * @mod_name: caller module name
+ *
+ * Allocate and fill in a PCI slot for use by a hotplug driver.  Once this has
+ * been called, the driver may invoke hotplug_slot_name() to get the slot's
+ * unique name.  The driver must be prepared to handle a ->reset_slot callback
+ * from this point on.
+ *
+ * Returns 0 on success or a negative int on error.
+ */
+int __pci_hp_initialize(struct hotplug_slot *slot, struct pci_bus *bus,
+			int devnr, const char *name, struct module *owner,
+			const char *mod_name)
+{
+	struct pci_slot *pci_slot;
+
+	if (slot == NULL)
+		return -ENODEV;
+	if (slot->ops == NULL)
+		return -EINVAL;
+
+	slot->owner = owner;
+	slot->mod_name = mod_name;
+
+	/*
+	 * No problems if we call this interface from both ACPI_PCI_SLOT
+	 * driver and call it here again. If we've already created the
+	 * pci_slot, the interface will simply bump the refcount.
+	 */
+	pci_slot = pci_create_slot(bus, devnr, name, slot);
+	if (IS_ERR(pci_slot))
+		return PTR_ERR(pci_slot);
+
+	slot->pci_slot = pci_slot;
+	pci_slot->hotplug = slot;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(__pci_hp_initialize);
+
+/**
+ * pci_hp_add - publish hotplug slot to user space
+ * @slot: pointer to the &struct hotplug_slot to publish
+ *
+ * Make a hotplug slot's sysfs interface available and inform user space of its
+ * addition by sending a uevent.  The hotplug driver must be prepared to handle
+ * all &struct hotplug_slot_ops callbacks from this point on.
+ *
+ * Returns 0 on success or a negative int on error.
+ */
+int pci_hp_add(struct hotplug_slot *slot)
+{
+	struct pci_slot *pci_slot = slot->pci_slot;
+	int result;
+
+	result = fs_add_slot(pci_slot);
+	if (result)
+		return result;
+
+	kobject_uevent(&pci_slot->kobj, KOBJ_ADD);
+	mutex_lock(&pci_hp_mutex);
+	list_add(&slot->slot_list, &pci_hotplug_slot_list);
+	mutex_unlock(&pci_hp_mutex);
+	dbg("Added slot %s to the list\n", hotplug_slot_name(slot));
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pci_hp_add);
+
+/**
+ * pci_hp_deregister - deregister a hotplug_slot with the PCI hotplug subsystem
+ * @slot: pointer to the &struct hotplug_slot to deregister
+ *
+ * The @slot must have been registered with the pci hotplug subsystem
+ * previously with a call to pci_hp_register().
+ *
+ * Returns 0 if successful, anything else for an error.
+ */
+void pci_hp_deregister(struct hotplug_slot *slot)
+{
+	pci_hp_del(slot);
+	pci_hp_destroy(slot);
+}
+EXPORT_SYMBOL_GPL(pci_hp_deregister);
+
+/**
+ * pci_hp_del - unpublish hotplug slot from user space
+ * @slot: pointer to the &struct hotplug_slot to unpublish
+ *
+ * Remove a hotplug slot's sysfs interface.
+ *
+ * Returns 0 on success or a negative int on error.
+ */
+void pci_hp_del(struct hotplug_slot *slot)
+{
+	struct hotplug_slot *temp;
+
+	if (WARN_ON(!slot))
+		return;
+
+	mutex_lock(&pci_hp_mutex);
+	temp = get_slot_from_name(hotplug_slot_name(slot));
+	if (WARN_ON(temp != slot)) {
+		mutex_unlock(&pci_hp_mutex);
+		return;
+	}
+
+	list_del(&slot->slot_list);
+	mutex_unlock(&pci_hp_mutex);
+	dbg("Removed slot %s from the list\n", hotplug_slot_name(slot));
+	fs_remove_slot(slot->pci_slot);
+}
+EXPORT_SYMBOL_GPL(pci_hp_del);
+
+/**
+ * pci_hp_destroy - remove hotplug slot from in-kernel use
+ * @slot: pointer to the &struct hotplug_slot to destroy
+ *
+ * Destroy a PCI slot used by a hotplug driver.  Once this has been called,
+ * the driver may no longer invoke hotplug_slot_name() to get the slot's
+ * unique name.  The driver no longer needs to handle a ->reset_slot callback
+ * from this point on.
+ *
+ * Returns 0 on success or a negative int on error.
+ */
+void pci_hp_destroy(struct hotplug_slot *slot)
+{
+	struct pci_slot *pci_slot = slot->pci_slot;
+
+	slot->pci_slot = NULL;
+	pci_slot->hotplug = NULL;
+	pci_destroy_slot(pci_slot);
+}
+EXPORT_SYMBOL_GPL(pci_hp_destroy);
+
+static int __init pci_hotplug_init(void)
+{
+	int result;
+
+	result = cpci_hotplug_init(debug);
+	if (result) {
+		err("cpci_hotplug_init with error %d\n", result);
+		return result;
+	}
+
+	return result;
+}
+device_initcall(pci_hotplug_init);
+
+/*
+ * not really modular, but the easiest way to keep compat with existing
+ * bootargs behaviour is to continue using module_param here.
+ */
+module_param(debug, bool, 0644);
+MODULE_PARM_DESC(debug, "Debugging mode enabled or not");