[PATCH v2 0/5] PCI Hotplug Driver for PowerPC PowerNV

@@ -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 powernv-php.
+
+	  When in doubt, say N.
+
 config HOTPLUG_PCI_RPA
 	tristate "RPA PCI Hotplug driver"
 	depends on PPC_PSERIES && EEH

@@ -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-$(CONFIG_HOTPLUG_PCI_POWERNV)	+= powernv-php.o
 obj-$(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 +51,9 @@ ibmphp-objs		:=	ibmphp_core.o	\
 acpiphp-objs		:=	acpiphp_core.o	\
 				acpiphp_glue.o
 
+powernv-php-objs	:=	powernv_php.o	\
+				powernv_php_slot.o
+
 rpaphp-objs		:=	rpaphp_core.o	\
 				rpaphp_pci.o	\
 				rpaphp_slot.o

@@ -0,0 +1,126 @@
+/*
+ * 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/kernel.h>
+#include <linux/module.h>
+#include <linux/sysfs.h>
+#include <linux/pci.h>
+#include <linux/pci_hotplug.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <asm/opal.h>
+#include <asm/pnv-pci.h>
+
+#include "powernv_php.h"
+
+#define DRIVER_VERSION	"0.1"
+#define DRIVER_AUTHOR	"Gavin Shan, IBM Corporation"
+#define DRIVER_DESC	"PowerPC PowerNV PCI Hotplug Driver"
+
+static int powernv_php_register_one(struct device_node *dn)
+{
+	struct powernv_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 0;
+
+	prop32 = of_get_property(dn, "ibm,reset-by-firmware", NULL);
+	if (!prop32 || !of_read_number(prop32, 1))
+		return 0;
+
+	/* Allocate slot */
+	slot = powernv_php_slot_alloc(dn);
+	if (!slot)
+		return -ENODEV;
+
+	/* Register it */
+	ret = powernv_php_slot_register(slot);
+	if (ret) {
+		powernv_php_slot_put(slot);
+		return ret;
+	}
+
+	return powernv_php_slot_enable(slot->php_slot, false);
+}
+
+int powernv_php_register(struct device_node *dn)
+{
+	struct device_node *child;
+	int ret = 0;
+
+	for_each_child_of_node(dn, child) {
+		ret = powernv_php_register_one(child);
+		if (ret)
+			break;
+
+		powernv_php_register(child);
+	}
+
+	return ret;
+}
+
+static void powernv_php_unregister_one(struct device_node *dn)
+{
+	struct powernv_php_slot *slot;
+
+	slot = powernv_php_slot_find(dn);
+	if (!slot)
+		return;
+
+	pci_hp_deregister(slot->php_slot);
+}
+
+void powernv_php_unregister(struct device_node *dn)
+{
+	struct device_node *child;
+
+	for_each_child_of_node(dn, child) {
+		powernv_php_unregister_one(child);
+		powernv_php_unregister(child);
+	}
+}
+
+static int __init powernv_php_init(void)
+{
+	struct device_node *dn;
+
+	pr_info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
+
+	/* Scan PHB nodes and their children */
+	for_each_compatible_node(dn, NULL, "ibm,ioda-phb")
+		powernv_php_register(dn);
+	for_each_compatible_node(dn, NULL, "ibm,ioda2-phb")
+		powernv_php_register(dn);
+
+	return 0;
+}
+
+static void __exit powernv_php_exit(void)
+{
+	struct device_node *dn;
+
+	for_each_compatible_node(dn, NULL, "ibm,ioda-phb")
+		powernv_php_unregister(dn);
+	for_each_compatible_node(dn, NULL, "ibm,ioda2-phb")
+		powernv_php_unregister(dn);
+}
+
+module_init(powernv_php_init);
+module_exit(powernv_php_exit);
+
+MODULE_VERSION(DRIVER_VERSION);
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);

@@ -0,0 +1,70 @@
+/*
+ * 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.
+ */
+
+#ifndef _POWERNV_PHP_H
+#define _POWERNV_PHP_H
+
+/* Slot power status */
+#define POWERNV_PHP_SLOT_POWER_OFF	0
+#define POWERNV_PHP_SLOT_POWER_ON	1
+
+/* Slot presence status */
+#define POWERNV_PHP_SLOT_EMPTY		0
+#define POWERNV_PHP_SLOT_PRESENT	1
+
+/* Slot attention status */
+#define POWERNV_PHP_SLOT_ATTEN_OFF	0
+#define POWERNV_PHP_SLOT_ATTEN_ON	1
+#define POWERNV_PHP_SLOT_ATTEN_IND	2
+#define POWERNV_PHP_SLOT_ATTEN_ACT	3
+
+struct powernv_php_slot {
+	struct kref		kref;
+	int			state;
+#define POWERNV_PHP_SLOT_STATE_INIT		0x0
+#define POWERNV_PHP_SLOT_STATE_REGISTER		0x1
+#define POWERNV_PHP_SLOT_STATE_POPULATED	0x2
+	char			*name;
+	struct device_node	*dn;
+	struct pci_bus		*bus;
+	uint64_t		id;
+	int			slot_no;
+	struct hotplug_slot	*php_slot;
+	struct powernv_php_slot	*parent;
+	void (*release)(struct kref *kref);
+	struct list_head	children;
+	struct list_head	link;
+};
+
+#define to_powernv_php_slot(kref) container_of(kref, struct powernv_php_slot, kref)
+
+static inline void powernv_php_slot_get(struct powernv_php_slot *slot)
+{
+	if (slot)
+		kref_get(&slot->kref);
+}
+
+static inline int powernv_php_slot_put(struct powernv_php_slot *slot)
+{
+	if (slot)
+		return kref_put(&slot->kref, slot->release);
+
+	return 0;
+}
+
+struct powernv_php_slot *powernv_php_slot_find(struct device_node *dn);
+struct powernv_php_slot *powernv_php_slot_alloc(struct device_node *dn);
+int powernv_php_slot_register(struct powernv_php_slot *slot);
+int powernv_php_slot_enable(struct hotplug_slot *php_slot, bool rescan);
+int powernv_php_register(struct device_node *dn);
+void powernv_php_unregister(struct device_node *dn);
+
+#endif /* !_POWERNV_PHP_H */

@@ -0,0 +1,382 @@
+/*
+ * 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/kernel.h>
+#include <linux/module.h>
+#include <linux/sysfs.h>
+#include <linux/pci.h>
+#include <linux/pci_hotplug.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+
+#include <asm/opal.h>
+#include <asm/pnv-pci.h>
+
+#include "powernv_php.h"
+
+static LIST_HEAD(php_slot_list);
+static DEFINE_MUTEX(php_slot_mutex);
+
+static int get_power_status(struct hotplug_slot *php_slot, u8 *val)
+{
+	struct powernv_php_slot *slot = php_slot->private;
+	uint8_t state;
+	int ret;
+
+	/* By default, the power is on */
+	*val = POWERNV_PHP_SLOT_POWER_ON;
+
+	/* Retrieve power status from firmware */
+	ret = pnv_pci_get_power_status(slot->id, &state);
+	if (!ret) {
+		*val = state ? POWERNV_PHP_SLOT_POWER_ON :
+			       POWERNV_PHP_SLOT_POWER_OFF;
+		php_slot->info->power_status = *val;
+	}
+
+	return 0;
+}
+
+static int get_adapter_status(struct hotplug_slot *php_slot, u8 *val)
+{
+	struct powernv_php_slot *slot = php_slot->private;
+	uint8_t state;
+	int ret;
+
+	/* By default, the slot is empty */
+	*val = 0;
+
+	/* Retrieve presence status from firmware */
+	ret = pnv_pci_get_presence_status(slot->id, &state);
+	if (ret >= 0) {
+		*val = state ? POWERNV_PHP_SLOT_PRESENT :
+			       POWERNV_PHP_SLOT_EMPTY;
+		php_slot->info->adapter_status = *val;
+	}
+
+	return 0;
+}
+
+static int set_attention_status(struct hotplug_slot *php_slot, u8 val)
+{
+	/*
+	 * The default operation would to turn on
+	 * the attention
+	*/
+	switch (val) {
+	case POWERNV_PHP_SLOT_ATTEN_OFF:
+	case POWERNV_PHP_SLOT_ATTEN_ON:
+	case POWERNV_PHP_SLOT_ATTEN_IND:
+	case POWERNV_PHP_SLOT_ATTEN_ACT:
+		break;
+	default:
+		val = POWERNV_PHP_SLOT_ATTEN_ON;
+	}
+
+	/* FIXME: Make it real once firmware supports it */
+	php_slot->info->attention_status = val;
+
+	return 0;
+}
+
+int powernv_php_slot_enable(struct hotplug_slot *php_slot, bool rescan)
+{
+	struct powernv_php_slot *slot = php_slot->private;
+	uint8_t presence;
+	int ret;
+
+	/* Check if the slot has been configured */
+	if (slot->state != POWERNV_PHP_SLOT_STATE_REGISTER)
+		return 0;
+
+	/* Retrieve slot presence status */
+	ret = php_slot->ops->get_adapter_status(php_slot, &presence);
+	if (ret)
+		return ret;
+
+	switch (presence) {
+	case POWERNV_PHP_SLOT_PRESENT:
+		pci_lock_rescan_remove();
+		pcibios_add_pci_devices(slot->bus);
+		pci_unlock_rescan_remove();
+		slot->state = POWERNV_PHP_SLOT_STATE_POPULATED;
+
+		/* Rescan for child hotpluggable slots */
+		if (rescan)
+			powernv_php_register(slot->dn);
+		break;
+	case POWERNV_PHP_SLOT_EMPTY:
+		break;
+	default:
+		pr_warn("%s: Invalid presence status %d on slot %s\n",
+			__func__, presence, slot->name);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int enable_slot(struct hotplug_slot *php_slot)
+{
+	return powernv_php_slot_enable(php_slot, true);
+}
+
+static int disable_slot(struct hotplug_slot *php_slot)
+{
+	struct powernv_php_slot *slot = php_slot->private;
+
+	if (slot->state != POWERNV_PHP_SLOT_STATE_POPULATED)
+		return 0;
+
+	pci_lock_rescan_remove();
+	pcibios_remove_pci_devices(slot->bus);
+	pci_unlock_rescan_remove();
+	vm_unmap_aliases();
+
+	/* Detach the child hotpluggable slots */
+	powernv_php_unregister(slot->dn);
+
+	/* Update slot state */
+	slot->state = POWERNV_PHP_SLOT_STATE_REGISTER;
+	return 0;
+}
+
+static struct hotplug_slot_ops php_slot_ops = {
+	.get_power_status	= get_power_status,
+	.get_adapter_status	= get_adapter_status,
+	.set_attention_status	= set_attention_status,
+	.enable_slot		= enable_slot,
+	.disable_slot		= disable_slot,
+};
+
+static struct powernv_php_slot *php_slot_match(struct device_node *dn,
+					       struct powernv_php_slot *slot)
+{
+	struct powernv_php_slot *target, *tmp;
+
+	if (slot->dn == dn)
+		return slot;
+
+	list_for_each_entry(tmp, &slot->children, link) {
+		target = php_slot_match(dn, tmp);
+		if (target)
+			return target;
+	}
+
+	return NULL;
+}
+
+struct powernv_php_slot *powernv_php_slot_find(struct device_node *dn)
+{
+	struct powernv_php_slot *slot, *tmp;
+
+	mutex_lock(&php_slot_mutex);
+	list_for_each_entry(tmp, &php_slot_list, link) {
+		slot = php_slot_match(dn, tmp);
+		if (slot) {
+			mutex_unlock(&php_slot_mutex);
+			return slot;
+		}
+	}
+	mutex_unlock(&php_slot_mutex);
+
+	return NULL;
+}
+
+static void php_slot_free(struct kref *kref)
+{
+	struct powernv_php_slot *slot = to_powernv_php_slot(kref);
+
+	WARN_ON(!list_empty(&slot->children));
+	kfree(slot->name);
+	kfree(slot);
+}
+
+static void php_slot_release(struct hotplug_slot *hp_slot)
+{
+	struct powernv_php_slot *slot = hp_slot->private;
+
+	/* Remove from global or child list */
+	mutex_lock(&php_slot_mutex);
+	list_del(&slot->link);
+	mutex_unlock(&php_slot_mutex);
+
+	/* Detach from parent */
+	powernv_php_slot_put(slot);
+	powernv_php_slot_put(slot->parent);
+}
+
+static bool php_slot_get_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 false;
+	*id |= ((of_read_number(prop32, 1) & 0x00ffff00) << 16);
+
+	/* 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 false;
+		}
+
+		*id |= be64_to_cpup(prop64);
+		of_node_put(parent);
+		return true;
+	}
+
+        return false;
+}
+
+struct powernv_php_slot *powernv_php_slot_alloc(struct device_node *dn)
+{
+	struct pci_bus *bus;
+	struct powernv_php_slot *slot;
+	const char *label;
+	uint64_t id;
+	int slot_no;
+	size_t size;
+	void *pmem;
+
+	/* Slot name */
+	label = of_get_property(dn, "ibm,slot-label", NULL);
+	if (!label)
+		return NULL;
+
+	/* Slot indentifier */
+	if (!php_slot_get_id(dn, &id))
+		return NULL;
+
+	/* PCI bus */
+	bus = pcibios_find_pci_bus(dn);
+	if (!bus)
+		return NULL;
+
+	/* Slot number */
+	if (dn->child && PCI_DN(dn->child))
+		slot_no = PCI_SLOT(PCI_DN(dn->child)->devfn);
+	else
+		slot_no = -1;
+
+	/* Allocate slot */
+	size = sizeof(struct powernv_php_slot) +
+	       sizeof(struct hotplug_slot) +
+	       sizeof(struct hotplug_slot_info);
+	pmem = kzalloc(size, GFP_KERNEL);
+	if (!pmem) {
+		pr_warn("%s: Cannot allocate slot for node %s\n",
+			__func__, dn->full_name);
+		return NULL;
+	}
+
+	/* Assign memory blocks */
+	slot = pmem;
+	slot->php_slot = pmem + sizeof(struct powernv_php_slot);
+	slot->php_slot->info = pmem + sizeof(struct powernv_php_slot) +
+			      sizeof(struct hotplug_slot);
+	slot->name = kstrdup(label, GFP_KERNEL);
+	if (!slot->name) {
+		pr_warn("%s: Cannot populate name for node %s\n",
+			__func__, dn->full_name);
+		kfree(pmem);
+		return NULL;
+	}
+
+	/* Initialize slot */
+	kref_init(&slot->kref);
+	slot->state = POWERNV_PHP_SLOT_STATE_INIT;
+	slot->dn = dn;
+	slot->bus = bus;
+	slot->id = id;
+	slot->slot_no = slot_no;
+	slot->release = php_slot_free;
+	slot->php_slot->ops = &php_slot_ops;
+	slot->php_slot->release = php_slot_release;
+	slot->php_slot->private = slot;
+	INIT_LIST_HEAD(&slot->children);
+	INIT_LIST_HEAD(&slot->link);
+
+	return slot;
+}
+
+int powernv_php_slot_register(struct powernv_php_slot *slot)
+{
+	struct powernv_php_slot *parent;
+	struct device_node *dn = slot->dn;
+	int ret;
+
+	/* Avoid register same slot for twice */
+	if (powernv_php_slot_find(slot->dn))
+		return -EEXIST;
+
+	/* Register slot */
+	ret = pci_hp_register(slot->php_slot, slot->bus,
+			      slot->slot_no, slot->name);
+	if (ret) {
+		pr_warn("%s: Cannot register slot %s (%d)\n",
+			__func__, slot->name, ret);
+		return ret;
+	}
+
+	/* Put into global or parent list */
+	while ((dn = of_get_parent(dn))) {
+		if (!PCI_DN(dn)) {
+			of_node_put(dn);
+			break;
+		}
+
+		parent = powernv_php_slot_find(dn);
+		if (parent) {
+			of_node_put(dn);
+			break;
+		}
+	}
+
+	mutex_lock(&php_slot_mutex);
+	if (parent) {
+		powernv_php_slot_get(parent);
+		slot->parent = parent;
+		list_add_tail(&slot->link, &parent->children);
+	} else {
+		list_add_tail(&slot->link, &php_slot_list);
+	}
+	mutex_unlock(&php_slot_mutex);
+
+	/* Update slot state */
+	slot->state = POWERNV_PHP_SLOT_STATE_REGISTER;
+	return 0;
+}

@@ -21,6 +21,42 @@
 #include <asm/firmware.h>
 #include <asm/eeh.h>
 
+static struct pci_bus *find_pci_bus(struct pci_bus *bus,
+				    struct device_node *dn)
+{
+	struct pci_bus *tmp, *child = NULL;
+	struct device_node *busdn;
+
+	busdn = pci_bus_to_OF_node(bus);
+	if (busdn == dn)
+		return bus;
+
+	list_for_each_entry(tmp, &bus->children, node) {
+		child = find_pci_bus(tmp, dn);
+		if (child)
+			break;
+	}
+
+	return child;
+}
+
+/**
+ * pcibios_find_pci_bus - find PCI bus according to the given device node
+ * @dn: Device node
+ *
+ * Find the corresponding PCI bus according to the given device node.
+ */
+struct pci_bus *pcibios_find_pci_bus(struct device_node *dn)
+{
+	struct pci_dn *pdn = PCI_DN(dn);
+
+	if (!pdn  || !pdn->phb || !pdn->phb->bus)
+		return NULL;
+
+	return find_pci_bus(pdn->phb->bus, dn);
+}
+EXPORT_SYMBOL_GPL(pcibios_find_pci_bus);
+
 /**
  * pcibios_release_device - release PCI device
  * @dev: PCI device

@@ -32,38 +32,6 @@
 #include <asm/firmware.h>
 #include <asm/eeh.h>
 
-static struct pci_bus *
-find_bus_among_children(struct pci_bus *bus,
-                        struct device_node *dn)
-{
-	struct pci_bus *child = NULL;
-	struct pci_bus *tmp;
-	struct device_node *busdn;
-
-	busdn = pci_bus_to_OF_node(bus);
-	if (busdn == dn)
-		return bus;
-
-	list_for_each_entry(tmp, &bus->children, node) {
-		child = find_bus_among_children(tmp, dn);
-		if (child)
-			break;
-	};
-	return child;
-}
-
-struct pci_bus *
-pcibios_find_pci_bus(struct device_node *dn)
-{
-	struct pci_dn *pdn = dn->data;
-
-	if (!pdn  || !pdn->phb || !pdn->phb->bus)
-		return NULL;
-
-	return find_bus_among_children(pdn->phb->bus, dn);
-}
-EXPORT_SYMBOL_GPL(pcibios_find_pci_bus);
-
 struct pci_controller *init_phb_dynamic(struct device_node *dn)
 {
 	struct pci_controller *phb;

@@ -490,24 +490,6 @@ static int ioda_eeh_get_state(struct eeh_pe *pe)
 	return ioda_eeh_get_pe_state(pe);
 }
 
-static s64 ioda_eeh_poll(uint64_t id)
-{
-	s64 rc = OPAL_HARDWARE;
-
-	while (1) {
-		rc = opal_pci_poll(id, NULL);
-		if (rc <= 0)
-			break;
-
-		if (system_state < SYSTEM_RUNNING)
-			udelay(1000 * rc);
-		else
-			msleep(rc);
-	}
-
-	return rc;
-}
-
 int ioda_eeh_phb_reset(struct pci_controller *hose, int option)
 {
 	struct pnv_phb *phb = hose->private_data;

@@ -536,10 +518,7 @@ int ioda_eeh_phb_reset(struct pci_controller *hose, int option)
 
 	/* Issue reset and poll until it's completed */
 	rc = opal_pci_reset(phb->opal_id, scope, OPAL_ASSERT_RESET);
-	if (rc > 0)
-		rc = ioda_eeh_poll(phb->opal_id);
-
-	return (rc == OPAL_SUCCESS) ? 0 : -EIO;
+	return pnv_pci_poll(phb->opal_id, rc, NULL);
 }
 
 static int __ioda_eeh_bridge_reset(struct pci_dev *dev, int option)

@@ -630,10 +609,7 @@ static int ioda_eeh_bridge_reset(struct pci_dev *dev, int option)
 	phb = hose->private_data;
 	id |= (dev->bus->number << 24) | (dev->devfn << 16) | phb->opal_id;
 	rc = opal_pci_reset(id, scope, OPAL_ASSERT_RESET);
-	if (rc > 0)
-		ioda_eeh_poll(id);
-
-	return (rc == OPAL_SUCCESS) ? 0 : -EIO;
+	return pnv_pci_poll(id, rc, NULL);
 }
 
 static int pnv_pci_dev_reset_type(struct pci_dev *pdev, void *data)

@@ -45,6 +45,25 @@
 #define cfg_dbg(fmt...)	do { } while(0)
 //#define cfg_dbg(fmt...)	printk(fmt)
 
+int pnv_pci_poll(uint64_t id, int64_t rval, uint8_t *pval)
+{
+	while (rval > 0) {
+		rval = opal_pci_poll(id, pval);
+		if (rval == OPAL_SUCCESS && pval)
+			rval = opal_pci_poll(id, pval);
+
+		if (rval <= 0)
+			break;
+
+		if (system_state < SYSTEM_RUNNING)
+			udelay(1000 * rval);
+		else
+			msleep(rval);
+	}
+
+	return rval ? -EIO : 0;
+}
+
 #ifdef CONFIG_PCI_MSI
 static int pnv_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
 {

@@ -217,6 +217,7 @@ extern struct pci_ops pnv_pci_ops;
 extern struct pnv_eeh_ops ioda_eeh_ops;
 #endif
 
+int pnv_pci_poll(uint64_t id, int64_t rval, uint8_t *pval);
 void pnv_pci_dump_phb_diag_data(struct pci_controller *hose,
 				unsigned char *log_buff);
 int pnv_pci_cfg_read(struct device_node *dn,

@@ -120,7 +120,8 @@ void pcibios_add_pci_devices(struct pci_bus * bus)
 	if (mode == PCI_PROBE_DEVTREE) {
 		/* use ofdt-based probe */
 		of_rescan_bus(dn, bus);
-	} else if (mode == PCI_PROBE_NORMAL) {
+	} else if (mode == PCI_PROBE_NORMAL &&
+		   dn->child && PCI_DN(dn->child)) {
 		/*
 		 * Use legacy probe. In the partial hotplug case, we
 		 * probably have grandchildren devices unplugged. So

@@ -154,6 +154,8 @@ struct opal_sg_list {
 #define OPAL_HANDLE_HMI				98
 #define OPAL_REGISTER_DUMP_REGION		101
 #define OPAL_UNREGISTER_DUMP_REGION		102
+#define OPAL_PCI_GET_POWER_STATUS		110
+#define OPAL_PCI_GET_PRESENCE_STATUS		111
 
 #ifndef __ASSEMBLY__
 

@@ -958,6 +960,8 @@ int64_t opal_handle_hmi(void);
 int64_t opal_register_dump_region(uint32_t id, uint64_t start, uint64_t end);
 int64_t opal_unregister_dump_region(uint32_t id);
 int64_t opal_pci_set_phb_cxl_mode(uint64_t phb_id, uint64_t mode, uint64_t pe_number);
+int64_t opal_pci_get_power_status(uint64_t id, uint8_t *status);
+int64_t opal_pci_get_presence_status(uint64_t id, uint8_t *status);
 
 /* Internal functions */
 extern int early_init_dt_scan_opal(unsigned long node, const char *uname,

@@ -13,6 +13,9 @@
 #include <linux/pci.h>
 #include <misc/cxl.h>
 
+extern int pnv_pci_get_power_status(uint64_t id, uint8_t *status);
+extern int pnv_pci_get_presence_status(uint64_t id, uint8_t *status);
+
 int pnv_phb_to_cxl(struct pci_dev *dev);
 int pnv_cxl_ioda_msi_setup(struct pci_dev *dev, unsigned int hwirq,
 			   unsigned int virq);

@@ -250,3 +250,5 @@ OPAL_CALL(opal_handle_hmi,			OPAL_HANDLE_HMI);
 OPAL_CALL(opal_register_dump_region,		OPAL_REGISTER_DUMP_REGION);
 OPAL_CALL(opal_unregister_dump_region,		OPAL_UNREGISTER_DUMP_REGION);
 OPAL_CALL(opal_pci_set_phb_cxl_mode,		OPAL_PCI_SET_PHB_CXL_MODE);
+OPAL_CALL(opal_pci_get_power_status,		OPAL_PCI_GET_POWER_STATUS);
+OPAL_CALL(opal_pci_get_presence_status,		OPAL_PCI_GET_PRESENCE_STATUS);

@@ -64,6 +64,30 @@ int pnv_pci_poll(uint64_t id, int64_t rval, uint8_t *pval)
 	return rval ? -EIO : 0;
 }
 
+int pnv_pci_get_power_status(uint64_t id, uint8_t *status)
+{
+	long rc;
+
+	if (!opal_check_token(OPAL_PCI_GET_POWER_STATUS))
+		return -ENXIO;
+
+	rc = opal_pci_get_power_status(id, status);
+	return pnv_pci_poll(id, rc, status);
+}
+EXPORT_SYMBOL_GPL(pnv_pci_get_power_status);
+
+int pnv_pci_get_presence_status(uint64_t id, uint8_t *status)
+{
+	long rc;
+
+	if (!opal_check_token(OPAL_PCI_GET_PRESENCE_STATUS))
+		return -ENXIO;
+
+	rc = opal_pci_get_presence_status(id, status);
+	return pnv_pci_poll(id, rc, status);
+}
+EXPORT_SYMBOL_GPL(pnv_pci_get_presence_status);
+
 #ifdef CONFIG_PCI_MSI
 static int pnv_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
 {