blob: e6245b03f0a1cf8312116b8bcb7395f02bef0432 [file] [log] [blame]
/*
* PCI Hotplug Driver for PowerPC PowerNV platform.
*
* Copyright Gavin Shan, IBM Corporation 2016.
*
* 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/libfdt.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/pci_hotplug.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"
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 void pnv_php_free_slot(struct kref *kref)
{
struct pnv_php_slot *php_slot = container_of(kref,
struct pnv_php_slot, kref);
WARN_ON(!list_empty(&php_slot->children));
kfree(php_slot->name);
kfree(php_slot);
}
static inline void pnv_php_put_slot(struct pnv_php_slot *php_slot)
{
if (WARN_ON(!php_slot))
return;
kref_put(&php_slot->kref, pnv_php_free_slot);
}
static struct pnv_php_slot *pnv_php_match(struct device_node *dn,
struct pnv_php_slot *php_slot)
{
struct pnv_php_slot *target, *tmp;
if (php_slot->dn == dn) {
kref_get(&php_slot->kref);
return php_slot;
}
list_for_each_entry(tmp, &php_slot->children, link) {
target = pnv_php_match(dn, tmp);
if (target)
return target;
}
return NULL;
}
struct pnv_php_slot *pnv_php_find_slot(struct device_node *dn)
{
struct pnv_php_slot *php_slot, *tmp;
unsigned long flags;
spin_lock_irqsave(&pnv_php_lock, flags);
list_for_each_entry(tmp, &pnv_php_slot_list, link) {
php_slot = pnv_php_match(dn, tmp);
if (php_slot) {
spin_unlock_irqrestore(&pnv_php_lock, flags);
return php_slot;
}
}
spin_unlock_irqrestore(&pnv_php_lock, flags);
return NULL;
}
EXPORT_SYMBOL_GPL(pnv_php_find_slot);
/*
* 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);
}
}
/*
* Detach all child nodes of the indicated device nodes. The
* function should handle device nodes in depth-first manner.
*
* We should not invoke of_node_release() as the memory for
* individual device node is part of large memory block. The
* large block is allocated from memblock (system bootup) or
* kmalloc() when unflattening the device tree by OF changeset.
* We can not free the large block allocated from memblock. For
* later case, it should be released at once.
*/
static void pnv_php_detach_device_nodes(struct device_node *parent)
{
struct device_node *dn;
int refcount;
for_each_child_of_node(parent, dn) {
pnv_php_detach_device_nodes(dn);
of_node_put(dn);
refcount = atomic_read(&dn->kobj.kref.refcount);
if (unlikely(refcount != 1))
pr_warn("Invalid refcount %d on <%s>\n",
refcount, of_node_full_name(dn));
of_detach_node(dn);
}
}
static void pnv_php_rmv_devtree(struct pnv_php_slot *php_slot)
{
pnv_php_rmv_pdns(php_slot->dn);
/*
* Decrease the refcount if the device nodes were created
* through OF changeset before detaching them.
*/
if (php_slot->fdt)
of_changeset_destroy(&php_slot->ocs);
pnv_php_detach_device_nodes(php_slot->dn);
if (php_slot->fdt) {
kfree(php_slot->dt);
kfree(php_slot->fdt);
php_slot->dt = NULL;
php_slot->dn->child = NULL;
php_slot->fdt = NULL;
}
}
/*
* As the nodes in OF changeset are applied in reverse order, we
* need revert the nodes in advance so that we have correct node
* order after the changeset is applied.
*/
static void pnv_php_reverse_nodes(struct device_node *parent)
{
struct device_node *child, *next;
/* In-depth first */
for_each_child_of_node(parent, child)
pnv_php_reverse_nodes(child);
/* Reverse the nodes in the child list */
child = parent->child;
parent->child = NULL;
while (child) {
next = child->sibling;
child->sibling = parent->child;
parent->child = child;
child = next;
}
}
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 (unlikely(ret))
break;
ret = pnv_php_populate_changeset(ocs, child);
if (unlikely(ret))
break;
}
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 (unlikely(!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 int pnv_php_add_devtree(struct pnv_php_slot *php_slot)
{
void *fdt, *fdt1, *dt;
int ret;
/* We don't know the FDT blob size. We try to get it through
* maximal memory chunk and then copy it to another chunk that
* fits the real size.
*/
fdt1 = kzalloc(0x10000, GFP_KERNEL);
if (unlikely(!fdt1)) {
ret = -ENOMEM;
dev_warn(&php_slot->pdev->dev, "Cannot alloc FDT blob\n");
goto out;
}
ret = pnv_pci_get_device_tree(php_slot->dn->phandle, fdt1, 0x10000);
if (unlikely(ret)) {
dev_warn(&php_slot->pdev->dev, "Error %d getting FDT blob\n",
ret);
goto free_fdt1;
}
fdt = kzalloc(fdt_totalsize(fdt1), GFP_KERNEL);
if (unlikely(!fdt)) {
ret = -ENOMEM;
dev_warn(&php_slot->pdev->dev, "Cannot %d bytes memory\n",
fdt_totalsize(fdt1));
goto free_fdt1;
}
/* Unflatten device tree blob */
memcpy(fdt, fdt1, fdt_totalsize(fdt1));
dt = of_fdt_unflatten_tree(fdt, php_slot->dn, NULL);
if (unlikely(!dt)) {
ret = -EINVAL;
dev_warn(&php_slot->pdev->dev, "Cannot unflatten FDT\n");
goto free_fdt;
}
/* Initialize and apply the changeset */
of_changeset_init(&php_slot->ocs);
pnv_php_reverse_nodes(php_slot->dn);
ret = pnv_php_populate_changeset(&php_slot->ocs, php_slot->dn);
if (unlikely(ret)) {
pnv_php_reverse_nodes(php_slot->dn);
dev_warn(&php_slot->pdev->dev, "Error %d populating changeset\n",
ret);
goto free_dt;
}
php_slot->dn->child = NULL;
ret = of_changeset_apply(&php_slot->ocs);
if (unlikely(ret)) {
dev_warn(&php_slot->pdev->dev, "Error %d applying changeset\n",
ret);
goto destroy_changeset;
}
/* Add device node firmware data */
pnv_php_add_pdns(php_slot);
php_slot->fdt = fdt;
php_slot->dt = dt;
kfree(fdt1);
goto out;
destroy_changeset:
of_changeset_destroy(&php_slot->ocs);
free_dt:
kfree(dt);
php_slot->dn->child = NULL;
free_fdt:
kfree(fdt);
free_fdt1:
kfree(fdt1);
out:
return ret;
}
int pnv_php_set_slot_power_state(struct hotplug_slot *slot,
uint8_t state)
{
struct pnv_php_slot *php_slot = slot->private;
struct opal_msg msg;
int ret;
ret = pnv_pci_set_power_state(php_slot->id, state, &msg);
if (likely(ret > 0)) {
if (be64_to_cpu(msg.params[1]) != php_slot->dn->phandle ||
be64_to_cpu(msg.params[2]) != state ||
be64_to_cpu(msg.params[3]) != OPAL_SUCCESS) {
dev_warn(&php_slot->pdev->dev, "Wrong msg (%lld, %lld, %lld)\n",
be64_to_cpu(msg.params[1]),
be64_to_cpu(msg.params[2]),
be64_to_cpu(msg.params[3]));
return -ENOMSG;
}
} else if (unlikely(ret < 0)) {
dev_warn(&php_slot->pdev->dev, "Error %d powering %s\n",
ret, (state == OPAL_PCI_SLOT_POWER_ON) ? "on" : "off");
return ret;
}
if (state == OPAL_PCI_SLOT_POWER_OFF || state == OPAL_PCI_SLOT_OFFLINE)
pnv_php_rmv_devtree(php_slot);
else
ret = pnv_php_add_devtree(php_slot);
return ret;
}
EXPORT_SYMBOL_GPL(pnv_php_set_slot_power_state);
static int pnv_php_get_power_state(struct hotplug_slot *slot, u8 *state)
{
struct pnv_php_slot *php_slot = slot->private;
uint8_t power_state = OPAL_PCI_SLOT_POWER_ON;
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(php_slot->id, &power_state);
if (unlikely(ret)) {
dev_warn(&php_slot->pdev->dev, "Error %d getting power status\n",
ret);
} else {
*state = power_state;
slot->info->power_status = power_state;
}
return 0;
}
static int pnv_php_get_adapter_state(struct hotplug_slot *slot, u8 *state)
{
struct pnv_php_slot *php_slot = slot->private;
uint8_t presence = OPAL_PCI_SLOT_EMPTY;
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(php_slot->id, &presence);
if (likely(ret >= 0)) {
*state = presence;
slot->info->adapter_status = presence;
ret = 0;
} else {
dev_warn(&php_slot->pdev->dev, "Error %d getting presence\n",
ret);
}
return ret;
}
static int pnv_php_set_attention_state(struct hotplug_slot *slot, u8 state)
{
/* FIXME: Make it real once firmware supports it */
slot->info->attention_status = state;
return 0;
}
static int pnv_php_enable(struct pnv_php_slot *php_slot, bool rescan)
{
struct hotplug_slot *slot = &php_slot->slot;
uint8_t presence = OPAL_PCI_SLOT_EMPTY;
uint8_t power_status = OPAL_PCI_SLOT_POWER_ON;
int ret;
/* Check if the slot has been configured */
if (php_slot->state != PNV_PHP_STATE_REGISTERED)
return 0;
/* Retrieve slot presence status */
ret = pnv_php_get_adapter_state(slot, &presence);
if (unlikely(ret))
return ret;
/* Proceed if there have nothing behind the slot */
if (presence == OPAL_PCI_SLOT_EMPTY)
goto scan;
/*
* If the power supply to the slot is off, we can't detect
* adapter presence state. That means we have to turn the
* slot on before going to probe slot's presence state.
*
* 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 (!php_slot->power_state_check) {
php_slot->power_state_check = true;
ret = pnv_php_get_power_state(slot, &power_status);
if (unlikely(ret))
return ret;
if (power_status != OPAL_PCI_SLOT_POWER_ON)
return 0;
}
/* Check the power status. Scan the slot if it is already on */
ret = pnv_php_get_power_state(slot, &power_status);
if (unlikely(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_slot_power_state(slot, OPAL_PCI_SLOT_POWER_ON);
if (unlikely(ret))
return ret;
scan:
if (presence == OPAL_PCI_SLOT_PRESENT) {
if (rescan) {
pci_lock_rescan_remove();
pci_hp_add_devices(php_slot->bus);
pci_unlock_rescan_remove();
}
/* Rescan for child hotpluggable slots */
php_slot->state = PNV_PHP_STATE_POPULATED;
if (rescan)
pnv_php_register(php_slot->dn);
} else {
php_slot->state = PNV_PHP_STATE_POPULATED;
}
return 0;
}
static int pnv_php_enable_slot(struct hotplug_slot *slot)
{
struct pnv_php_slot *php_slot = container_of(slot,
struct pnv_php_slot, slot);
return pnv_php_enable(php_slot, true);
}
static int pnv_php_disable_slot(struct hotplug_slot *slot)
{
struct pnv_php_slot *php_slot = slot->private;
int ret;
if (php_slot->state != PNV_PHP_STATE_POPULATED)
return 0;
/* Remove all devices behind the slot */
pci_lock_rescan_remove();
pci_hp_remove_devices(php_slot->bus);
pci_unlock_rescan_remove();
/* Detach the child hotpluggable slots */
pnv_php_unregister(php_slot->dn);
/* Notify firmware and remove device nodes */
ret = pnv_php_set_slot_power_state(slot, OPAL_PCI_SLOT_POWER_OFF);
php_slot->state = PNV_PHP_STATE_REGISTERED;
return ret;
}
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 *slot)
{
struct pnv_php_slot *php_slot = slot->private;
unsigned long flags;
/* Remove from global or child list */
spin_lock_irqsave(&pnv_php_lock, flags);
list_del(&php_slot->link);
spin_unlock_irqrestore(&pnv_php_lock, flags);
/* Detach from parent */
pnv_php_put_slot(php_slot);
pnv_php_put_slot(php_slot->parent);
}
static struct pnv_php_slot *pnv_php_alloc_slot(struct device_node *dn)
{
struct pnv_php_slot *php_slot;
struct pci_bus *bus;
const char *label;
uint64_t id;
label = of_get_property(dn, "ibm,slot-label", NULL);
if (unlikely(!label))
return NULL;
if (pnv_pci_get_slot_id(dn, &id))
return NULL;
bus = pci_find_bus_by_node(dn);
if (unlikely(!bus))
return NULL;
php_slot = kzalloc(sizeof(*php_slot), GFP_KERNEL);
if (unlikely(!php_slot))
return NULL;
php_slot->name = kstrdup(label, GFP_KERNEL);
if (unlikely(!php_slot->name)) {
kfree(php_slot);
return NULL;
}
if (likely(dn->child && PCI_DN(dn->child)))
php_slot->slot_no = PCI_SLOT(PCI_DN(dn->child)->devfn);
else
php_slot->slot_no = -1; /* Placeholder slot */
kref_init(&php_slot->kref);
php_slot->state = PNV_PHP_STATE_INITIALIZED;
php_slot->dn = dn;
php_slot->pdev = bus->self;
php_slot->bus = bus;
php_slot->id = id;
php_slot->power_state_check = false;
php_slot->slot.ops = &php_slot_ops;
php_slot->slot.info = &php_slot->slot_info;
php_slot->slot.release = pnv_php_release;
php_slot->slot.private = php_slot;
INIT_LIST_HEAD(&php_slot->children);
INIT_LIST_HEAD(&php_slot->link);
return php_slot;
}
static int pnv_php_register_slot(struct pnv_php_slot *php_slot)
{
struct pnv_php_slot *parent;
struct device_node *dn = php_slot->dn;
unsigned long flags;
int ret;
/* Check if the slot is registered or not */
parent = pnv_php_find_slot(php_slot->dn);
if (unlikely(parent)) {
pnv_php_put_slot(parent);
return -EEXIST;
}
/* Register PCI slot */
ret = pci_hp_register(&php_slot->slot, php_slot->bus,
php_slot->slot_no, php_slot->name);
if (unlikely(ret)) {
dev_warn(&php_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;
}
of_node_put(dn);
}
spin_lock_irqsave(&pnv_php_lock, flags);
php_slot->parent = parent;
if (parent)
list_add_tail(&php_slot->link, &parent->children);
else
list_add_tail(&php_slot->link, &pnv_php_slot_list);
spin_unlock_irqrestore(&pnv_php_lock, flags);
php_slot->state = PNV_PHP_STATE_REGISTERED;
return 0;
}
static int pnv_php_register_one(struct device_node *dn)
{
struct pnv_php_slot *php_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;
php_slot = pnv_php_alloc_slot(dn);
if (unlikely(!php_slot))
return -ENODEV;
ret = pnv_php_register_slot(php_slot);
if (unlikely(ret))
goto free_slot;
ret = pnv_php_enable(php_slot, false);
if (unlikely(ret))
goto unregister_slot;
return 0;
unregister_slot:
pnv_php_unregister_one(php_slot->dn);
free_slot:
pnv_php_put_slot(php_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 *php_slot;
php_slot = pnv_php_find_slot(dn);
if (!php_slot)
return;
php_slot->state = PNV_PHP_STATE_OFFLINE;
pnv_php_put_slot(php_slot);
pci_hp_deregister(&php_slot->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 int __init pnv_php_init(void)
{
struct device_node *dn;
pr_info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
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,ioda2-phb")
pnv_php_unregister(dn);
}
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);