[PATCH v7 50/50] PCI/hotplug: PowerPC PowerNV PCI hotplug driver

[Gavin Shan <gwshan@linux.vnet.ibm.com>]

This adds standalone driver to support PCI hotplug for PowerPC PowerNV
platform that runs on top of skiboot firmware. The firmware identifies
hotpluggable slots and marked their device tree node with proper
"ibm,slot-pluggable" and "ibm,reset-by-firmware". The driver scans device
tree nodes to create/register PCI hotplug slot accordingly.

If the skiboot firmware doesn't support slot status retrieval, the PCI
slot device node shouldn't have property "ibm,reset-by-firmware". In
that case, none of valid PCI slots will be detected from device tree.
The skiboot firmware doesn't export the capability to access attention
LEDs yet and it's something for TBD.

Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
---
 MAINTAINERS                   |   6 +
 drivers/pci/hotplug/Kconfig   |  12 +
 drivers/pci/hotplug/Makefile  |   3 +
 drivers/pci/hotplug/pnv_php.c | 866 ++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 887 insertions(+)
 create mode 100644 drivers/pci/hotplug/pnv_php.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 9f6685f..10088f1 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7931,6 +7931,12 @@ L:	linux-pci@vger.kernel.org
 S:	Supported
 F:	Documentation/PCI/pci-error-recovery.txt
 
+PCI HOTPLUG DRIVER FOR POWERNV PLATFORM
+M:	Gavin Shan <gwshan@linux.vnet.ibm.com>
+L:	linux-pci@vger.kernel.org
+S:	Supported
+F:	drivers/pci/hotplug/pnv_php.c
+
 PCI SUBSYSTEM
 M:	Bjorn Helgaas <bhelgaas@google.com>
 L:	linux-pci@vger.kernel.org
diff --git a/drivers/pci/hotplug/Kconfig b/drivers/pci/hotplug/Kconfig
index df8caec..167c8ce 100644
--- a/drivers/pci/hotplug/Kconfig
+++ b/drivers/pci/hotplug/Kconfig
@@ -113,6 +113,18 @@ config HOTPLUG_PCI_SHPC
 
 	  When in doubt, say N.
 
+config HOTPLUG_PCI_POWERNV
+	tristate "PowerPC PowerNV PCI Hotplug driver"
+	depends on PPC_POWERNV && EEH
+	help
+	  Say Y here if you run PowerPC PowerNV platform that supports
+	  PCI Hotplug
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called pnv-php.
+
+	  When in doubt, say N.
+
 config HOTPLUG_PCI_RPA
 	tristate "RPA PCI Hotplug driver"
 	depends on PPC_PSERIES && EEH
diff --git a/drivers/pci/hotplug/Makefile b/drivers/pci/hotplug/Makefile
index b616e75..e33cdda 100644
--- a/drivers/pci/hotplug/Makefile
+++ b/drivers/pci/hotplug/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_HOTPLUG_PCI_PCIE)		+= pciehp.o
 obj-$(CONFIG_HOTPLUG_PCI_CPCI_ZT5550)	+= cpcihp_zt5550.o
 obj-$(CONFIG_HOTPLUG_PCI_CPCI_GENERIC)	+= cpcihp_generic.o
 obj-$(CONFIG_HOTPLUG_PCI_SHPC)		+= shpchp.o
+obj-$(CONFIG_HOTPLUG_PCI_POWERNV)	+= pnv-php.o
 obj-$(CONFIG_HOTPLUG_PCI_RPA)		+= rpaphp.o
 obj-$(CONFIG_HOTPLUG_PCI_RPA_DLPAR)	+= rpadlpar_io.o
 obj-$(CONFIG_HOTPLUG_PCI_SGI)		+= sgi_hotplug.o
@@ -50,6 +51,8 @@ ibmphp-objs		:=	ibmphp_core.o	\
 acpiphp-objs		:=	acpiphp_core.o	\
 				acpiphp_glue.o
 
+pnv-php-objs		:=	pnv_php.o
+
 rpaphp-objs		:=	rpaphp_core.o	\
 				rpaphp_pci.o	\
 				rpaphp_slot.o
diff --git a/drivers/pci/hotplug/pnv_php.c b/drivers/pci/hotplug/pnv_php.c
new file mode 100644
index 0000000..415e9b9
--- /dev/null
+++ b/drivers/pci/hotplug/pnv_php.c
@@ -0,0 +1,866 @@
+/*
+ * PCI Hotplug Driver for PowerPC PowerNV platform.
+ *
+ * Copyright Gavin Shan, IBM Corporation 2015.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/pci.h>
+#include <linux/pci_hotplug.h>
+#include <linux/module.h>
+
+#include <asm/opal.h>
+#include <asm/pnv-pci.h>
+#include <asm/ppc-pci.h>
+
+#define DRIVER_VERSION	"0.1"
+#define DRIVER_AUTHOR	"Gavin Shan, IBM Corporation"
+#define DRIVER_DESC	"PowerPC PowerNV PCI Hotplug Driver"
+
+struct pnv_php_slot {
+	struct hotplug_slot		php_slot;
+	struct hotplug_slot_info	php_slot_info;
+	uint64_t			id;
+	char				*name;
+	int				slot_no;
+	struct kref			kref;
+	int				state;
+#define PNV_PHP_STATE_INIT		0
+#define PNV_PHP_STATE_REGISTER		1
+#define PNV_PHP_STATE_POPULATED		2
+	struct device_node		*dn;
+	struct pci_dev			*pdev;
+	struct pci_bus			*bus;
+	bool				power_state_check;
+	int				power_state_confirmed;
+#define PNV_PHP_POWER_CONFIRMED_INVALID	0
+#define PNV_PHP_POWER_CONFIRMED_SUCCESS	1
+#define PNV_PHP_POWER_CONFIRMED_FAIL	2
+	struct opal_msg			*msg;
+	void				*fdt;
+	void				*dt;
+	struct of_changeset		ocs;
+	struct work_struct		work;
+	wait_queue_head_t		queue;
+	struct pnv_php_slot		*parent;
+	struct list_head		children;
+	struct list_head		link;
+};
+
+static LIST_HEAD(pnv_php_slot_list);
+static DEFINE_SPINLOCK(pnv_php_lock);
+
+static void pnv_php_register(struct device_node *dn);
+static void pnv_php_unregister_one(struct device_node *dn);
+static void pnv_php_unregister(struct device_node *dn);
+
+static inline struct pnv_php_slot *pnv_php_get_slot(struct pnv_php_slot *slot)
+{
+	if (slot) {
+		kref_get(&slot->kref);
+		return slot;
+	}
+
+	return NULL;
+}
+
+static void pnv_php_free_slot(struct kref *kref)
+{
+	struct pnv_php_slot *slot = container_of(kref,
+						 struct pnv_php_slot,
+						 kref);
+
+	WARN_ON(!list_empty(&slot->children));
+	kfree(slot->name);
+	kfree(slot);
+}
+
+static inline void pnv_php_put_slot(struct pnv_php_slot *slot)
+{
+	if (!slot)
+		return;
+
+	kref_put(&slot->kref, pnv_php_free_slot);
+}
+
+static struct pnv_php_slot *pnv_php_match(struct device_node *dn,
+					  struct pnv_php_slot *slot)
+{
+	struct pnv_php_slot *target, *tmp;
+
+	if (slot->dn == dn)
+		return pnv_php_get_slot(slot);
+
+	list_for_each_entry(tmp, &slot->children, link) {
+		target = pnv_php_match(dn, tmp);
+		if (target)
+			return target;
+	}
+
+	return NULL;
+}
+
+static struct pnv_php_slot *pnv_php_find_slot(struct device_node *dn)
+{
+	struct pnv_php_slot *slot, *tmp;
+	unsigned long flags;
+
+	spin_lock_irqsave(&pnv_php_lock, flags);
+	list_for_each_entry(tmp, &pnv_php_slot_list, link) {
+		slot = pnv_php_match(dn, tmp);
+		if (slot) {
+			spin_unlock_irqrestore(&pnv_php_lock, flags);
+			return slot;
+		}
+	}
+	spin_unlock_irqrestore(&pnv_php_lock, flags);
+
+	return NULL;
+}
+
+/*
+ * Remove pdn for all children of the indicated device node.
+ * The function should remove pdn in a depth-first manner.
+ */
+static void pnv_php_rmv_pdns(struct device_node *dn)
+{
+	struct device_node *child;
+
+	for_each_child_of_node(dn, child) {
+		pnv_php_rmv_pdns(child);
+
+		pci_remove_device_node_info(child);
+	}
+}
+
+/*
+ * Remove all child nodes of the indicated device nodes. The
+ * function should remove device nodes in depth-first manner.
+ */
+static int pnv_php_rmv_device_nodes(struct device_node *parent)
+{
+	struct device_node *dn, *child;
+	int ret = 0;
+
+	for_each_child_of_node(parent, dn) {
+		ret = pnv_php_rmv_device_nodes(dn);
+		if (ret)
+			return ret;
+
+		child = of_get_next_child(dn, NULL);
+		if (child) {
+			of_node_put(child);
+			of_node_put(dn);
+			pr_err("%s: Alive children of node <%s>\n",
+			       __func__, of_node_full_name(dn));
+			return -EBUSY;
+		}
+
+		of_detach_node(dn);
+		of_node_put(dn);
+	}
+
+	return 0;
+}
+
+/*
+ * The function processes the message sent by firmware
+ * to remove all device tree nodes beneath the slot's
+ * nodes and the associated auxiliary data.
+ */
+static void pnv_php_handle_poweroff(struct pnv_php_slot *slot)
+{
+	int ret;
+
+	pnv_php_rmv_pdns(slot->dn);
+
+	/*
+	 * If the device sub-tree was created from OF changeset, simply
+	 * to revert that. Otherwise, the device nodes in the sub-tree
+	 * need to be iterated and detached.
+	 */
+	if (slot->fdt) {
+		of_changeset_destroy(&slot->ocs);
+		kfree(slot->dt);
+		kfree(slot->fdt);
+		slot->dt = NULL;
+		slot->dn->child = NULL;
+		slot->fdt = NULL;
+		slot->power_state_confirmed = PNV_PHP_POWER_CONFIRMED_SUCCESS;
+		goto confirm;
+	}
+
+	ret = pnv_php_rmv_device_nodes(slot->dn);
+	if (!ret) {
+		slot->power_state_confirmed = PNV_PHP_POWER_CONFIRMED_SUCCESS;
+	} else {
+		slot->power_state_confirmed = PNV_PHP_POWER_CONFIRMED_FAIL;
+		dev_warn(&slot->pdev->dev, "Error %d freeing nodes\n",
+			 ret);
+	}
+
+confirm:
+	wake_up_interruptible(&slot->queue);
+}
+
+static int pnv_php_populate_changeset(struct of_changeset *ocs,
+				      struct device_node *dn)
+{
+	struct device_node *child;
+	int ret = 0;
+
+	for_each_child_of_node(dn, child) {
+		ret = of_changeset_attach_node(ocs, child);
+		if (ret)
+			return ret;
+
+		ret = pnv_php_populate_changeset(ocs, child);
+	}
+
+	return ret;
+}
+
+static void *pnv_php_add_one_pdn(struct device_node *dn, void *data)
+{
+	struct pci_controller *hose = (struct pci_controller *)data;
+	struct pci_dn *pdn;
+
+	pdn = pci_add_device_node_info(hose, dn);
+	if (!pdn)
+		return ERR_PTR(-ENOMEM);
+
+	return NULL;
+}
+
+static void pnv_php_add_pdns(struct pnv_php_slot *slot)
+{
+	struct pci_controller *hose = pci_bus_to_host(slot->bus);
+
+	pci_traverse_device_nodes(slot->dn, pnv_php_add_one_pdn, hose);
+}
+
+static void pnv_php_handle_poweron(struct pnv_php_slot *slot)
+{
+	void *fdt, *dt;
+	uint64_t len;
+	int confirm = PNV_PHP_POWER_CONFIRMED_SUCCESS;
+	int ret;
+
+	/* We don't know the FDT blob size. It tries with incremental
+	 * sized memory chunk.
+	 */
+	for (len = 0x2000; len <= 0x10000; len += 0x2000) {
+		fdt = kzalloc(len, GFP_KERNEL);
+		if (!fdt)
+			break;
+
+		ret = pnv_pci_get_device_tree(slot->dn->phandle, fdt, len);
+		if (!ret)
+			break;
+
+		kfree(fdt);
+	}
+
+	if (len > 0x10000) {
+		dev_warn(&slot->pdev->dev, "Cannot alloc FDT blob\n");
+		goto out;
+	}
+
+	/* Unflatten device tree blob */
+	dt = of_fdt_unflatten_tree(fdt, slot->dn, NULL);
+	if (!dt) {
+		dev_warn(&slot->pdev->dev, "Cannot unflatten FDT\n");
+		goto free_fdt;
+	}
+
+	/* Initialize and apply the changeset */
+	of_changeset_init(&slot->ocs);
+	ret = pnv_php_populate_changeset(&slot->ocs, slot->dn);
+	if (ret) {
+		dev_warn(&slot->pdev->dev, "Error %d populating changeset\n",
+			 ret);
+		goto free_dt;
+	}
+
+	slot->dn->child = NULL;
+	ret = of_changeset_apply(&slot->ocs);
+	if (ret) {
+		dev_warn(&slot->pdev->dev, "Error %d applying changeset\n",
+			 ret);
+		goto destroy_changeset;
+	}
+
+	/* Add device node firmware data */
+	pnv_php_add_pdns(slot);
+	slot->fdt = fdt;
+	slot->dt = dt;
+	goto out;
+
+destroy_changeset:
+	of_changeset_destroy(&slot->ocs);
+free_dt:
+	kfree(dt);
+	slot->dn->child = NULL;
+free_fdt:
+	kfree(fdt);
+	confirm = PNV_PHP_POWER_CONFIRMED_FAIL;
+out:
+	/* Confirm status change */
+	slot->power_state_confirmed = confirm;
+	wake_up_interruptible(&slot->queue);
+}
+
+static void pnv_php_work(struct work_struct *data)
+{
+	struct pnv_php_slot *slot = container_of(data,
+						 struct pnv_php_slot, work);
+	uint64_t event = be64_to_cpu(slot->msg->params[0]);
+
+	if (event == OPAL_PCI_SLOT_POWER_OFF)
+		pnv_php_handle_poweroff(slot);
+	else
+		pnv_php_handle_poweron(slot);
+
+	pnv_php_put_slot(slot);
+}
+
+static int pnv_php_handle_msg(struct notifier_block *nb,
+			      unsigned long type,
+			      void *message)
+{
+	phandle h;
+	struct device_node *dn;
+	struct pnv_php_slot *slot;
+	struct opal_msg *msg = message;
+
+	if (type != OPAL_MSG_PCI_HOTPLUG) {
+		pr_warn("%s: Invalid message %ld received!\n",
+			__func__, type);
+		return NOTIFY_DONE;
+	}
+
+	h = (phandle)be64_to_cpu(msg->params[1]);
+	dn = of_find_node_by_phandle(h);
+	if (!dn) {
+		pr_warn("%s: No device node for phandle 0x%x\n",
+			__func__, h);
+		return NOTIFY_DONE;
+	}
+
+	slot = pnv_php_find_slot(dn);
+	of_node_put(dn);
+	if (!slot) {
+		pr_warn("%s: No slot found for node <%s>\n",
+			__func__, of_node_full_name(dn));
+		of_node_put(dn);
+		return NOTIFY_DONE;
+	}
+
+	slot->msg = msg;
+	schedule_work(&slot->work);
+	return NOTIFY_OK;
+}
+
+static int pnv_php_set_power_state(struct hotplug_slot *php_slot, u8 state)
+{
+	struct pnv_php_slot *slot = php_slot->private;
+	int ret;
+
+	slot->power_state_confirmed = PNV_PHP_POWER_CONFIRMED_INVALID;
+	ret = pnv_pci_set_power_state(slot->id, state);
+	if (ret) {
+		dev_warn(&slot->pdev->dev, "Error %d powering %s slot\n",
+			 ret, state ? "on" : "off");
+		return ret;
+	}
+
+	/* Continue to PCI probing after finalized device-tree. The
+	 * device-tree might have been updated completely at this
+	 * point. Thus we don't have to always waiting for that.
+	 */
+	if (slot->power_state_confirmed == PNV_PHP_POWER_CONFIRMED_SUCCESS)
+		return 0;
+	else if (slot->power_state_confirmed == PNV_PHP_POWER_CONFIRMED_FAIL)
+		return -EBUSY;
+
+	ret = wait_event_timeout(slot->queue,
+				 slot->power_state_confirmed, 10 * HZ);
+	if (!ret) {
+		dev_warn(&slot->pdev->dev, "Error %d waiting for power-%s\n",
+			 ret, state ? "on" : "off");
+		return -EBUSY;
+	}
+
+	if (slot->power_state_confirmed == PNV_PHP_POWER_CONFIRMED_SUCCESS)
+		return 0;
+
+	dev_warn(&slot->pdev->dev, "Error status %d for power-%s\n",
+		 slot->power_state_confirmed, state ? "on" : "off");
+	return -EBUSY;
+}
+
+static int pnv_php_get_power_state(struct hotplug_slot *php_slot, u8 *state)
+{
+	struct pnv_php_slot *slot = php_slot->private;
+	uint8_t power_state;
+	int ret;
+
+	/*
+	 * Retrieve power status from firmware. If we fail
+	 * getting that, the power status fails back to
+	 * be on.
+	 */
+	ret = pnv_pci_get_power_state(slot->id, &power_state);
+	if (ret) {
+		*state = OPAL_PCI_SLOT_POWER_ON;
+		dev_warn(&slot->pdev->dev, "Error %d getting power status\n",
+			 ret);
+	} else {
+		*state = power_state;
+		php_slot->info->power_status = power_state;
+	}
+
+	return 0;
+}
+
+static int pnv_php_get_adapter_state(struct hotplug_slot *php_slot, u8 *state)
+{
+	struct pnv_php_slot *slot = php_slot->private;
+	uint8_t presence;
+	int ret;
+
+	/*
+	 * Retrieve presence status from firmware. If we can't
+	 * get that, it will fail back to be empty.
+	 */
+	ret = pnv_pci_get_presence_state(slot->id, &presence);
+	if (ret >= 0) {
+		*state = presence;
+		php_slot->info->adapter_status = presence;
+		ret = 0;
+	} else {
+		*state = OPAL_PCI_SLOT_EMPTY;
+		dev_warn(&slot->pdev->dev, "Error %d getting presence\n",
+			 ret);
+	}
+
+	return ret;
+}
+
+static int pnv_php_set_attention_state(struct hotplug_slot *php_slot, u8 state)
+{
+	/* FIXME: Make it real once firmware supports it */
+	php_slot->info->attention_status = state;
+
+	return 0;
+}
+
+static int pnv_php_enable(struct pnv_php_slot *slot, bool rescan)
+{
+	struct hotplug_slot *php_slot = &slot->php_slot;
+	uint8_t presence, power_status;
+	int ret;
+
+	/* Check if the slot has been configured */
+	if (slot->state != PNV_PHP_STATE_REGISTER)
+		return 0;
+
+	/* Retrieve slot presence status */
+	ret = php_slot->ops->get_adapter_status(php_slot, &presence);
+	if (ret)
+		return ret;
+
+	/* Proceed if there have nothing behind the slot */
+	if (presence == OPAL_PCI_SLOT_EMPTY)
+		goto scan;
+
+	/*
+	 * If we don't detect something behind the slot, we need
+	 * make sure the power suply to the slot is on. Otherwise,
+	 * the slot downstream PCIe linkturn should be down.
+	 *
+	 * On the first time, we don't change the power status to
+	 * boost system boot with assumption that the firmware
+	 * supplies consistent slot power status: empty slot always
+	 * has its power off and non-empty slot has its power on.
+	 */
+	if (!slot->power_state_check) {
+		slot->power_state_check = true;
+		goto scan;
+	}
+
+	/* Check the power status. Scan the slot if that's already on */
+	ret = php_slot->ops->get_power_status(php_slot, &power_status);
+	if (ret)
+		return ret;
+
+	if (power_status == OPAL_PCI_SLOT_POWER_ON)
+		goto scan;
+
+	/* Power is off, turn it on and then scan the slot */
+	ret = pnv_php_set_power_state(php_slot, OPAL_PCI_SLOT_POWER_ON);
+	if (ret)
+		return ret;
+
+scan:
+	if (presence == OPAL_PCI_SLOT_PRESENT) {
+		if (rescan) {
+			pci_lock_rescan_remove();
+			pci_add_pci_devices(slot->bus);
+			pci_unlock_rescan_remove();
+		}
+
+		/* Rescan for child hotpluggable slots */
+		slot->state = PNV_PHP_STATE_POPULATED;
+		if (rescan)
+			pnv_php_register(slot->dn);
+	} else {
+		slot->state = PNV_PHP_STATE_POPULATED;
+	}
+
+	return 0;
+}
+
+static int pnv_php_enable_slot(struct hotplug_slot *php_slot)
+{
+	struct pnv_php_slot *slot = container_of(php_slot,
+						 struct pnv_php_slot,
+						 php_slot);
+
+	return pnv_php_enable(slot, true);
+}
+
+static int pnv_php_disable_slot(struct hotplug_slot *php_slot)
+{
+	struct pnv_php_slot *slot = php_slot->private;
+	uint8_t power_state;
+	int ret;
+
+	if (slot->state != PNV_PHP_STATE_POPULATED)
+		return 0;
+
+	/* Remove all devices behind the slot */
+	pci_lock_rescan_remove();
+	pci_remove_pci_devices(slot->bus);
+	pci_unlock_rescan_remove();
+
+	/* Detach the child hotpluggable slots */
+	pnv_php_unregister(slot->dn);
+
+	/*
+	 * Check the power status and turn it off if necessary. If we
+	 * fail to get the power status, the power will be forced to
+	 * be off.
+	 */
+	ret = php_slot->ops->get_power_status(php_slot, &power_state);
+	if (ret || power_state == OPAL_PCI_SLOT_POWER_ON) {
+		ret = pnv_php_set_power_state(php_slot,
+					      OPAL_PCI_SLOT_POWER_OFF);
+		if (ret)
+			dev_warn(&slot->pdev->dev, "Error %d powering off\n",
+				 ret);
+	}
+
+	/* Update slot state */
+	slot->state = PNV_PHP_STATE_REGISTER;
+	return 0;
+}
+
+static struct hotplug_slot_ops php_slot_ops = {
+	.get_power_status	= pnv_php_get_power_state,
+	.get_adapter_status	= pnv_php_get_adapter_state,
+	.set_attention_status	= pnv_php_set_attention_state,
+	.enable_slot		= pnv_php_enable_slot,
+	.disable_slot		= pnv_php_disable_slot,
+};
+
+static void pnv_php_release(struct hotplug_slot *hp_slot)
+{
+	struct pnv_php_slot *slot = hp_slot->private;
+	unsigned long flags;
+
+	/* Remove from global or child list */
+	spin_lock_irqsave(&pnv_php_lock, flags);
+	list_del(&slot->link);
+	spin_unlock_irqrestore(&pnv_php_lock, flags);
+
+	/* Detach from parent */
+	pnv_php_put_slot(slot);
+	pnv_php_put_slot(slot->parent);
+}
+
+static int pnv_php_get_slot_id(struct device_node *dn, uint64_t *id)
+{
+	struct device_node *parent = dn;
+	const __be64 *prop64;
+	const __be32 *prop32;
+
+	/*
+	 * The hotpluggable slot always has a compound Id, which
+	 * consists of 16-bits PHB Id, 16 bits bus/slot/function
+	 * number, and compound indicator
+	 */
+	*id = (0x1ul << 63);
+
+	/* Bus/Slot/Function number */
+	prop32 = of_get_property(dn, "reg", NULL);
+	if (!prop32)
+		return -ENXIO;
+	*id |= ((of_read_number(prop32, 1) & 0x00ffff00) << 8);
+
+	/* PHB Id */
+	while ((parent = of_get_parent(parent))) {
+		if (!PCI_DN(parent)) {
+			of_node_put(parent);
+			break;
+		}
+
+		if (!of_device_is_compatible(parent, "ibm,ioda2-phb") &&
+		    !of_device_is_compatible(parent, "ibm,ioda-phb")) {
+			of_node_put(parent);
+			continue;
+		}
+
+		prop64 = of_get_property(parent, "ibm,opal-phbid", NULL);
+		if (!prop64) {
+			of_node_put(parent);
+			return -ENXIO;
+		}
+
+		*id |= be64_to_cpup(prop64);
+		of_node_put(parent);
+		return 0;
+	}
+
+	return -ENODEV;
+}
+
+static struct pnv_php_slot *pnv_php_alloc_slot(struct device_node *dn)
+{
+	struct pnv_php_slot *slot;
+	struct pci_bus *bus;
+	const char *label;
+	uint64_t id;
+
+	label = of_get_property(dn, "ibm,slot-label", NULL);
+	if (!label)
+		return NULL;
+
+	if (pnv_php_get_slot_id(dn, &id))
+		return NULL;
+
+	bus = pci_find_bus_by_node(dn);
+	if (!bus)
+		return NULL;
+
+	slot = kzalloc(sizeof(*slot), GFP_KERNEL);
+	if (!slot)
+		return NULL;
+
+	slot->name = kstrdup(label, GFP_KERNEL);
+	if (!slot->name) {
+		kfree(slot);
+		return NULL;
+	}
+
+	if (dn->child && PCI_DN(dn->child))
+		slot->slot_no = PCI_SLOT(PCI_DN(dn->child)->devfn);
+	else
+		slot->slot_no = -1;   /* Placeholder slot */
+
+	kref_init(&slot->kref);
+	slot->state	            = PNV_PHP_STATE_INIT;
+	slot->dn	            = dn;
+	slot->pdev	            = bus->self;
+	slot->bus	            = bus;
+	slot->id	            = id;
+	slot->power_state_check     = false;
+	slot->power_state_confirmed = PNV_PHP_POWER_CONFIRMED_INVALID;
+	slot->php_slot.ops          = &php_slot_ops;
+	slot->php_slot.info         = &slot->php_slot_info;
+	slot->php_slot.release      = pnv_php_release;
+	slot->php_slot.private      = slot;
+
+	INIT_WORK(&slot->work, pnv_php_work);
+	init_waitqueue_head(&slot->queue);
+	INIT_LIST_HEAD(&slot->children);
+	INIT_LIST_HEAD(&slot->link);
+
+	return slot;
+}
+
+static int pnv_php_register_slot(struct pnv_php_slot *slot)
+{
+	struct pnv_php_slot *parent;
+	struct device_node *dn = slot->dn;
+	unsigned long flags;
+	int ret;
+
+	/* Check if the slot exists or not */
+	parent = pnv_php_find_slot(slot->dn);
+	if (parent) {
+		pnv_php_put_slot(parent);
+		return -EEXIST;
+	}
+
+	/* Register PCI slot */
+	ret = pci_hp_register(&slot->php_slot, slot->bus,
+			      slot->slot_no, slot->name);
+	if (ret) {
+		dev_warn(&slot->pdev->dev, "Error %d registering slot\n",
+			 ret);
+		return ret;
+	}
+
+	/* Attach to the parent's child list or global list */
+	while ((dn = of_get_parent(dn))) {
+		if (!PCI_DN(dn)) {
+			of_node_put(dn);
+			break;
+		}
+
+		parent = pnv_php_find_slot(dn);
+		if (parent) {
+			of_node_put(dn);
+			break;
+		}
+	}
+
+	spin_lock_irqsave(&pnv_php_lock, flags);
+	slot->parent = parent;
+	if (parent)
+		list_add_tail(&slot->link, &parent->children);
+	else
+		list_add_tail(&slot->link, &pnv_php_slot_list);
+	spin_unlock_irqrestore(&pnv_php_lock, flags);
+
+	slot->state = PNV_PHP_STATE_REGISTER;
+	return 0;
+}
+
+static int pnv_php_register_one(struct device_node *dn)
+{
+	struct pnv_php_slot *slot;
+	const __be32 *prop32;
+	int ret;
+
+	/* Check if it's hotpluggable slot */
+	prop32 = of_get_property(dn, "ibm,slot-pluggable", NULL);
+	if (!prop32 || !of_read_number(prop32, 1))
+		return -ENXIO;
+
+	prop32 = of_get_property(dn, "ibm,reset-by-firmware", NULL);
+	if (!prop32 || !of_read_number(prop32, 1))
+		return -ENXIO;
+
+	slot = pnv_php_alloc_slot(dn);
+	if (!slot)
+		return -ENODEV;
+
+	ret = pnv_php_register_slot(slot);
+	if (ret)
+		goto free_slot;
+
+	ret = pnv_php_enable(slot, false);
+	if (ret)
+		goto unregister_slot;
+
+	return 0;
+
+unregister_slot:
+	pnv_php_unregister_one(slot->dn);
+free_slot:
+	pnv_php_put_slot(slot);
+	return ret;
+}
+
+static void pnv_php_register(struct device_node *dn)
+{
+	struct device_node *child;
+
+	/*
+	 * The parent slots should be registered before their
+	 * child slots.
+	 */
+	for_each_child_of_node(dn, child) {
+		pnv_php_register_one(child);
+		pnv_php_register(child);
+	}
+}
+
+static void pnv_php_unregister_one(struct device_node *dn)
+{
+	struct pnv_php_slot *slot;
+
+	slot = pnv_php_find_slot(dn);
+	if (!slot)
+		return;
+
+	pnv_php_put_slot(slot);
+	pci_hp_deregister(&slot->php_slot);
+}
+
+static void pnv_php_unregister(struct device_node *dn)
+{
+	struct device_node *child;
+
+	/* The child slots should go before their parent slots */
+	for_each_child_of_node(dn, child) {
+		pnv_php_unregister(child);
+		pnv_php_unregister_one(child);
+	}
+}
+
+static struct notifier_block php_msg_nb = {
+	.notifier_call	= pnv_php_handle_msg,
+	.next		= NULL,
+	.priority	= 0,
+};
+
+static int __init pnv_php_init(void)
+{
+	struct device_node *dn;
+	int ret;
+
+	pr_info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
+
+	/* Register hotplug message handler */
+	ret = pnv_pci_hotplug_notifier_register(&php_msg_nb);
+	if (ret) {
+		pr_warn("%s: Error %d registering hotplug notifier\n",
+			__func__, ret);
+		return ret;
+	}
+
+	/* Scan PHB nodes and their children */
+	for_each_compatible_node(dn, NULL, "ibm,ioda-phb")
+		pnv_php_register(dn);
+	for_each_compatible_node(dn, NULL, "ibm,ioda2-phb")
+		pnv_php_register(dn);
+
+	return 0;
+}
+
+static void __exit pnv_php_exit(void)
+{
+	struct device_node *dn;
+
+	for_each_compatible_node(dn, NULL, "ibm,ioda-phb")
+		pnv_php_unregister(dn);
+	for_each_compatible_node(dn, NULL, "ibm,ioda2-phb")
+		pnv_php_unregister(dn);
+
+	pnv_pci_hotplug_notifier_unregister(&php_msg_nb);
+}
+
+module_init(pnv_php_init);
+module_exit(pnv_php_exit);
+
+MODULE_VERSION(DRIVER_VERSION);
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
-- 
2.1.0