// SPDX-License-Identifier: GPL-2.0+/* * PCI Hotplug Driver for PowerPC PowerNV platform. * * Copyright Gavin Shan, IBM Corporation 2016. */ #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" #define SLOT_WARN(sl, x...) \ ((sl)->pdev ? pci_warn((sl)->pdev, x) : dev_warn(&(sl)->bus->dev, x)) struct pnv_php_event { bool added; struct pnv_php_slot *php_slot; struct work_struct work;}; 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_disable_irq(struct pnv_php_slot *php_slot, bool disable_device){ struct pci_dev *pdev = php_slot->pdev; int irq = php_slot->irq; u16 ctrl; if (php_slot->irq > 0) { pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &ctrl); ctrl &= ~(PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_PDCE | PCI_EXP_SLTCTL_DLLSCE); pcie_capability_write_word(pdev, PCI_EXP_SLTCTL, ctrl); free_irq(php_slot->irq, php_slot); php_slot->irq = 0; } if (php_slot->wq) { destroy_workqueue(php_slot->wq); php_slot->wq = NULL; } if (disable_device || irq > 0) { if (pdev->msix_enabled) pci_disable_msix(pdev); else if (pdev->msi_enabled) pci_disable_msi(pdev); pci_disable_device(pdev); }} 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)); pnv_php_disable_irq(php_slot, false); kfree(php_slot->name); kfree(php_slot);} static inline void pnv_php_put_slot(struct pnv_php_slot *php_slot){ if (!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; for_each_child_of_node(parent, dn) { pnv_php_detach_device_nodes(dn); of_node_put(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 (ret) { of_node_put(child); break; } ret = pnv_php_populate_changeset(ocs, child); if (ret) { of_node_put(child); 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 (!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 (!fdt1) { ret = -ENOMEM; goto out; } ret = pnv_pci_get_device_tree(php_slot->dn->phandle, fdt1, 0x10000); if (ret) { SLOT_WARN(php_slot, "Error %d getting FDT blob\n", ret); goto free_fdt1; } fdt = kmemdup(fdt1, fdt_totalsize(fdt1), GFP_KERNEL); if (!fdt) { ret = -ENOMEM; goto free_fdt1; } /* Unflatten device tree blob */ dt = of_fdt_unflatten_tree(fdt, php_slot->dn, NULL); if (!dt) { ret = -EINVAL; SLOT_WARN(php_slot, "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 (ret) { pnv_php_reverse_nodes(php_slot->dn); SLOT_WARN(php_slot, "Error %d populating changeset\n", ret); goto free_dt; } php_slot->dn->child = NULL; ret = of_changeset_apply(&php_slot->ocs); if (ret) { SLOT_WARN(php_slot, "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 inline struct pnv_php_slot *to_pnv_php_slot(struct hotplug_slot *slot){ return container_of(slot, struct pnv_php_slot, slot);} int pnv_php_set_slot_power_state(struct hotplug_slot *slot, uint8_t state){ struct pnv_php_slot *php_slot = to_pnv_php_slot(slot); struct opal_msg msg; int ret; ret = pnv_pci_set_power_state(php_slot->id, state, &msg); if (ret > 0) { if (be64_to_cpu(msg.params[1]) != php_slot->dn->phandle || be64_to_cpu(msg.params[2]) != state) { SLOT_WARN(php_slot, "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; } if (be64_to_cpu(msg.params[3]) != OPAL_SUCCESS) { ret = -ENODEV; goto error; } } else if (ret < 0) { goto error; } 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; error: SLOT_WARN(php_slot, "Error %d powering %s\n", ret, (state == OPAL_PCI_SLOT_POWER_ON) ? "on" : "off"); 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 = to_pnv_php_slot(slot); 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 (ret) { SLOT_WARN(php_slot, "Error %d getting power status\n", ret); } else { *state = power_state; } return 0;} static int pnv_php_get_adapter_state(struct hotplug_slot *slot, u8 *state){ struct pnv_php_slot *php_slot = to_pnv_php_slot(slot); 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 (ret >= 0) { *state = presence; ret = 0; } else { SLOT_WARN(php_slot, "Error %d getting presence\n", ret); } return ret;} static int pnv_php_get_attention_state(struct hotplug_slot *slot, u8 *state){ struct pnv_php_slot *php_slot = to_pnv_php_slot(slot); *state = php_slot->attention_state; return 0;} static int pnv_php_set_attention_state(struct hotplug_slot *slot, u8 state){ struct pnv_php_slot *php_slot = to_pnv_php_slot(slot); struct pci_dev *bridge = php_slot->pdev; u16 new, mask; php_slot->attention_state = state; if (!bridge) return 0; mask = PCI_EXP_SLTCTL_AIC; if (state) new = PCI_EXP_SLTCTL_ATTN_IND_ON; else new = PCI_EXP_SLTCTL_ATTN_IND_OFF; pcie_capability_clear_and_set_word(bridge, PCI_EXP_SLTCTL, mask, new); 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 (ret) return ret; /* * Proceed if there have nothing behind the slot. However, * we should leave the slot in registered state at the * beginning. Otherwise, the PCI devices inserted afterwards * won't be probed and populated. */ if (presence == OPAL_PCI_SLOT_EMPTY) { if (!php_slot->power_state_check) { php_slot->power_state_check = true; return 0; } 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 (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 (ret) return ret;Lines 1–500 of 1048. Load more
// SPDX-License-Identifier: GPL-2.0+ /* * PCI Hotplug Driver for PowerPC PowerNV platform. * * Copyright Gavin Shan, IBM Corporation 2016. */ #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" #define SLOT_WARN(sl, x...) \ ((sl)->pdev ? pci_warn((sl)->pdev, x) : dev_warn(&(sl)->bus->dev, x)) struct pnv_php_event { bool added; struct pnv_php_slot *php_slot; struct work_struct work; }; 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_disable_irq(struct pnv_php_slot *php_slot, bool disable_device) { struct pci_dev *pdev = php_slot->pdev; int irq = php_slot->irq; u16 ctrl; if (php_slot->irq > 0) { pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &ctrl); ctrl &= ~(PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_PDCE | PCI_EXP_SLTCTL_DLLSCE); pcie_capability_write_word(pdev, PCI_EXP_SLTCTL, ctrl); free_irq(php_slot->irq, php_slot); php_slot->irq = 0; } if (php_slot->wq) { destroy_workqueue(php_slot->wq); php_slot->wq = NULL; } if (disable_device || irq > 0) { if (pdev->msix_enabled) pci_disable_msix(pdev); else if (pdev->msi_enabled) pci_disable_msi(pdev); pci_disable_device(pdev); } } 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)); pnv_php_disable_irq(php_slot, false); kfree(php_slot->name); kfree(php_slot); } static inline void pnv_php_put_slot(struct pnv_php_slot *php_slot) { if (!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; for_each_child_of_node(parent, dn) { pnv_php_detach_device_nodes(dn); of_node_put(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 (ret) { of_node_put(child); break; } ret = pnv_php_populate_changeset(ocs, child); if (ret) { of_node_put(child); 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 (!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 (!fdt1) { ret = -ENOMEM; goto out; } ret = pnv_pci_get_device_tree(php_slot->dn->phandle, fdt1, 0x10000); if (ret) { SLOT_WARN(php_slot, "Error %d getting FDT blob\n", ret); goto free_fdt1; } fdt = kmemdup(fdt1, fdt_totalsize(fdt1), GFP_KERNEL); if (!fdt) { ret = -ENOMEM; goto free_fdt1; } /* Unflatten device tree blob */ dt = of_fdt_unflatten_tree(fdt, php_slot->dn, NULL); if (!dt) { ret = -EINVAL; SLOT_WARN(php_slot, "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 (ret) { pnv_php_reverse_nodes(php_slot->dn); SLOT_WARN(php_slot, "Error %d populating changeset\n", ret); goto free_dt; } php_slot->dn->child = NULL; ret = of_changeset_apply(&php_slot->ocs); if (ret) { SLOT_WARN(php_slot, "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 inline struct pnv_php_slot *to_pnv_php_slot(struct hotplug_slot *slot) { return container_of(slot, struct pnv_php_slot, slot); } int pnv_php_set_slot_power_state(struct hotplug_slot *slot, uint8_t state) { struct pnv_php_slot *php_slot = to_pnv_php_slot(slot); struct opal_msg msg; int ret; ret = pnv_pci_set_power_state(php_slot->id, state, &msg); if (ret > 0) { if (be64_to_cpu(msg.params[1]) != php_slot->dn->phandle || be64_to_cpu(msg.params[2]) != state) { SLOT_WARN(php_slot, "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; } if (be64_to_cpu(msg.params[3]) != OPAL_SUCCESS) { ret = -ENODEV; goto error; } } else if (ret < 0) { goto error; } 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; error: SLOT_WARN(php_slot, "Error %d powering %s\n", ret, (state == OPAL_PCI_SLOT_POWER_ON) ? "on" : "off"); 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 = to_pnv_php_slot(slot); 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 (ret) { SLOT_WARN(php_slot, "Error %d getting power status\n", ret); } else { *state = power_state; } return 0; } static int pnv_php_get_adapter_state(struct hotplug_slot *slot, u8 *state) { struct pnv_php_slot *php_slot = to_pnv_php_slot(slot); 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 (ret >= 0) { *state = presence; ret = 0; } else { SLOT_WARN(php_slot, "Error %d getting presence\n", ret); } return ret; } static int pnv_php_get_attention_state(struct hotplug_slot *slot, u8 *state) { struct pnv_php_slot *php_slot = to_pnv_php_slot(slot); *state = php_slot->attention_state; return 0; } static int pnv_php_set_attention_state(struct hotplug_slot *slot, u8 state) { struct pnv_php_slot *php_slot = to_pnv_php_slot(slot); struct pci_dev *bridge = php_slot->pdev; u16 new, mask; php_slot->attention_state = state; if (!bridge) return 0; mask = PCI_EXP_SLTCTL_AIC; if (state) new = PCI_EXP_SLTCTL_ATTN_IND_ON; else new = PCI_EXP_SLTCTL_ATTN_IND_OFF; pcie_capability_clear_and_set_word(bridge, PCI_EXP_SLTCTL, mask, new); 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 (ret) return ret; /* * Proceed if there have nothing behind the slot. However, * we should leave the slot in registered state at the * beginning. Otherwise, the PCI devices inserted afterwards * won't be probed and populated. */ if (presence == OPAL_PCI_SLOT_EMPTY) { if (!php_slot->power_state_check) { php_slot->power_state_check = true; return 0; } 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 (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 (ret) return ret;