1 files changed, 711 insertions, 0 deletions

diff --git a/drivers/pci/hotplug/pnv_php.c b/drivers/pci/hotplug/pnv_php.c
new file mode 100644
index 000000000000..e6245b03f0a1
--- /dev/null
+++ b/drivers/pci/hotplug/pnv_php.c
@@ -0,0 +1,711 @@
+/*
+ * 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);