--- /dev/null
+/*
+ * 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"
+
+struct pnv_php_slot {
+ struct hotplug_slot slot;
+ struct hotplug_slot_info slot_info;
+ uint64_t id;
+ char *name;
+ int slot_no;
+ struct kref kref;
+#define PNV_PHP_STATE_INITIALIZED 0
+#define PNV_PHP_STATE_REGISTERED 1
+#define PNV_PHP_STATE_POPULATED 2
+#define PNV_PHP_STATE_OFFLINE 3
+ int state;
+ struct device_node *dn;
+ struct pci_dev *pdev;
+ struct pci_bus *bus;
+ bool power_state_check;
+ void *fdt;
+ void *dt;
+ struct of_changeset ocs;
+ 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 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;
+}
+
+static 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;
+}
+
+/*
+ * 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;
+}
+
+static 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)
+ pnv_php_rmv_devtree(php_slot);
+ else
+ ret = pnv_php_add_devtree(php_slot);
+
+ return ret;
+}
+
+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);
projects / linux-platform-drivers-x86.git / commitdiff