diff options
Diffstat (limited to 'drivers/pci/hotplug/pnv_php.c')
| -rw-r--r-- | drivers/pci/hotplug/pnv_php.c | 733 |
1 files changed, 733 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..6086db6c0a48 --- /dev/null +++ b/drivers/pci/hotplug/pnv_php.c @@ -0,0 +1,733 @@ +/* + * 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); |