| /* |
| * The file intends to implement PE based on the information from |
| * platforms. Basically, there have 3 types of PEs: PHB/Bus/Device. |
| * All the PEs should be organized as hierarchy tree. The first level |
| * of the tree will be associated to existing PHBs since the particular |
| * PE is only meaningful in one PHB domain. |
| * |
| * Copyright Benjamin Herrenschmidt & Gavin Shan, IBM Corporation 2012. |
| * |
| * 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. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| */ |
| |
| #include <linux/export.h> |
| #include <linux/gfp.h> |
| #include <linux/init.h> |
| #include <linux/kernel.h> |
| #include <linux/pci.h> |
| #include <linux/string.h> |
| |
| #include <asm/pci-bridge.h> |
| #include <asm/ppc-pci.h> |
| |
| static LIST_HEAD(eeh_phb_pe); |
| |
| /** |
| * eeh_pe_alloc - Allocate PE |
| * @phb: PCI controller |
| * @type: PE type |
| * |
| * Allocate PE instance dynamically. |
| */ |
| static struct eeh_pe *eeh_pe_alloc(struct pci_controller *phb, int type) |
| { |
| struct eeh_pe *pe; |
| |
| /* Allocate PHB PE */ |
| pe = kzalloc(sizeof(struct eeh_pe), GFP_KERNEL); |
| if (!pe) return NULL; |
| |
| /* Initialize PHB PE */ |
| pe->type = type; |
| pe->phb = phb; |
| INIT_LIST_HEAD(&pe->child_list); |
| INIT_LIST_HEAD(&pe->child); |
| INIT_LIST_HEAD(&pe->edevs); |
| |
| return pe; |
| } |
| |
| /** |
| * eeh_phb_pe_create - Create PHB PE |
| * @phb: PCI controller |
| * |
| * The function should be called while the PHB is detected during |
| * system boot or PCI hotplug in order to create PHB PE. |
| */ |
| int eeh_phb_pe_create(struct pci_controller *phb) |
| { |
| struct eeh_pe *pe; |
| |
| /* Allocate PHB PE */ |
| pe = eeh_pe_alloc(phb, EEH_PE_PHB); |
| if (!pe) { |
| pr_err("%s: out of memory!\n", __func__); |
| return -ENOMEM; |
| } |
| |
| /* Put it into the list */ |
| eeh_lock(); |
| list_add_tail(&pe->child, &eeh_phb_pe); |
| eeh_unlock(); |
| |
| pr_debug("EEH: Add PE for PHB#%d\n", phb->global_number); |
| |
| return 0; |
| } |
| |
| /** |
| * eeh_phb_pe_get - Retrieve PHB PE based on the given PHB |
| * @phb: PCI controller |
| * |
| * The overall PEs form hierarchy tree. The first layer of the |
| * hierarchy tree is composed of PHB PEs. The function is used |
| * to retrieve the corresponding PHB PE according to the given PHB. |
| */ |
| static struct eeh_pe *eeh_phb_pe_get(struct pci_controller *phb) |
| { |
| struct eeh_pe *pe; |
| |
| list_for_each_entry(pe, &eeh_phb_pe, child) { |
| /* |
| * Actually, we needn't check the type since |
| * the PE for PHB has been determined when that |
| * was created. |
| */ |
| if ((pe->type & EEH_PE_PHB) && pe->phb == phb) |
| return pe; |
| } |
| |
| return NULL; |
| } |
| |
| /** |
| * eeh_pe_next - Retrieve the next PE in the tree |
| * @pe: current PE |
| * @root: root PE |
| * |
| * The function is used to retrieve the next PE in the |
| * hierarchy PE tree. |
| */ |
| static struct eeh_pe *eeh_pe_next(struct eeh_pe *pe, |
| struct eeh_pe *root) |
| { |
| struct list_head *next = pe->child_list.next; |
| |
| if (next == &pe->child_list) { |
| while (1) { |
| if (pe == root) |
| return NULL; |
| next = pe->child.next; |
| if (next != &pe->parent->child_list) |
| break; |
| pe = pe->parent; |
| } |
| } |
| |
| return list_entry(next, struct eeh_pe, child); |
| } |
| |
| /** |
| * eeh_pe_traverse - Traverse PEs in the specified PHB |
| * @root: root PE |
| * @fn: callback |
| * @flag: extra parameter to callback |
| * |
| * The function is used to traverse the specified PE and its |
| * child PEs. The traversing is to be terminated once the |
| * callback returns something other than NULL, or no more PEs |
| * to be traversed. |
| */ |
| static void *eeh_pe_traverse(struct eeh_pe *root, |
| eeh_traverse_func fn, void *flag) |
| { |
| struct eeh_pe *pe; |
| void *ret; |
| |
| for (pe = root; pe; pe = eeh_pe_next(pe, root)) { |
| ret = fn(pe, flag); |
| if (ret) return ret; |
| } |
| |
| return NULL; |
| } |
| |
| /** |
| * eeh_pe_dev_traverse - Traverse the devices from the PE |
| * @root: EEH PE |
| * @fn: function callback |
| * @flag: extra parameter to callback |
| * |
| * The function is used to traverse the devices of the specified |
| * PE and its child PEs. |
| */ |
| void *eeh_pe_dev_traverse(struct eeh_pe *root, |
| eeh_traverse_func fn, void *flag) |
| { |
| struct eeh_pe *pe; |
| struct eeh_dev *edev; |
| void *ret; |
| |
| if (!root) { |
| pr_warning("%s: Invalid PE %p\n", __func__, root); |
| return NULL; |
| } |
| |
| eeh_lock(); |
| |
| /* Traverse root PE */ |
| for (pe = root; pe; pe = eeh_pe_next(pe, root)) { |
| eeh_pe_for_each_dev(pe, edev) { |
| ret = fn(edev, flag); |
| if (ret) { |
| eeh_unlock(); |
| return ret; |
| } |
| } |
| } |
| |
| eeh_unlock(); |
| |
| return NULL; |
| } |
| |
| /** |
| * __eeh_pe_get - Check the PE address |
| * @data: EEH PE |
| * @flag: EEH device |
| * |
| * For one particular PE, it can be identified by PE address |
| * or tranditional BDF address. BDF address is composed of |
| * Bus/Device/Function number. The extra data referred by flag |
| * indicates which type of address should be used. |
| */ |
| static void *__eeh_pe_get(void *data, void *flag) |
| { |
| struct eeh_pe *pe = (struct eeh_pe *)data; |
| struct eeh_dev *edev = (struct eeh_dev *)flag; |
| |
| /* Unexpected PHB PE */ |
| if (pe->type & EEH_PE_PHB) |
| return NULL; |
| |
| /* We prefer PE address */ |
| if (edev->pe_config_addr && |
| (edev->pe_config_addr == pe->addr)) |
| return pe; |
| |
| /* Try BDF address */ |
| if (edev->pe_config_addr && |
| (edev->config_addr == pe->config_addr)) |
| return pe; |
| |
| return NULL; |
| } |
| |
| /** |
| * eeh_pe_get - Search PE based on the given address |
| * @edev: EEH device |
| * |
| * Search the corresponding PE based on the specified address which |
| * is included in the eeh device. The function is used to check if |
| * the associated PE has been created against the PE address. It's |
| * notable that the PE address has 2 format: traditional PE address |
| * which is composed of PCI bus/device/function number, or unified |
| * PE address. |
| */ |
| static struct eeh_pe *eeh_pe_get(struct eeh_dev *edev) |
| { |
| struct eeh_pe *root = eeh_phb_pe_get(edev->phb); |
| struct eeh_pe *pe; |
| |
| pe = eeh_pe_traverse(root, __eeh_pe_get, edev); |
| |
| return pe; |
| } |
| |
| /** |
| * eeh_pe_get_parent - Retrieve the parent PE |
| * @edev: EEH device |
| * |
| * The whole PEs existing in the system are organized as hierarchy |
| * tree. The function is used to retrieve the parent PE according |
| * to the parent EEH device. |
| */ |
| static struct eeh_pe *eeh_pe_get_parent(struct eeh_dev *edev) |
| { |
| struct device_node *dn; |
| struct eeh_dev *parent; |
| |
| /* |
| * It might have the case for the indirect parent |
| * EEH device already having associated PE, but |
| * the direct parent EEH device doesn't have yet. |
| */ |
| dn = edev->dn->parent; |
| while (dn) { |
| /* We're poking out of PCI territory */ |
| if (!PCI_DN(dn)) return NULL; |
| |
| parent = of_node_to_eeh_dev(dn); |
| /* We're poking out of PCI territory */ |
| if (!parent) return NULL; |
| |
| if (parent->pe) |
| return parent->pe; |
| |
| dn = dn->parent; |
| } |
| |
| return NULL; |
| } |
| |
| /** |
| * eeh_add_to_parent_pe - Add EEH device to parent PE |
| * @edev: EEH device |
| * |
| * Add EEH device to the parent PE. If the parent PE already |
| * exists, the PE type will be changed to EEH_PE_BUS. Otherwise, |
| * we have to create new PE to hold the EEH device and the new |
| * PE will be linked to its parent PE as well. |
| */ |
| int eeh_add_to_parent_pe(struct eeh_dev *edev) |
| { |
| struct eeh_pe *pe, *parent; |
| |
| eeh_lock(); |
| |
| /* |
| * Search the PE has been existing or not according |
| * to the PE address. If that has been existing, the |
| * PE should be composed of PCI bus and its subordinate |
| * components. |
| */ |
| pe = eeh_pe_get(edev); |
| if (pe && !(pe->type & EEH_PE_INVALID)) { |
| if (!edev->pe_config_addr) { |
| eeh_unlock(); |
| pr_err("%s: PE with addr 0x%x already exists\n", |
| __func__, edev->config_addr); |
| return -EEXIST; |
| } |
| |
| /* Mark the PE as type of PCI bus */ |
| pe->type = EEH_PE_BUS; |
| edev->pe = pe; |
| |
| /* Put the edev to PE */ |
| list_add_tail(&edev->list, &pe->edevs); |
| eeh_unlock(); |
| pr_debug("EEH: Add %s to Bus PE#%x\n", |
| edev->dn->full_name, pe->addr); |
| |
| return 0; |
| } else if (pe && (pe->type & EEH_PE_INVALID)) { |
| list_add_tail(&edev->list, &pe->edevs); |
| edev->pe = pe; |
| /* |
| * We're running to here because of PCI hotplug caused by |
| * EEH recovery. We need clear EEH_PE_INVALID until the top. |
| */ |
| parent = pe; |
| while (parent) { |
| if (!(parent->type & EEH_PE_INVALID)) |
| break; |
| parent->type &= ~EEH_PE_INVALID; |
| parent = parent->parent; |
| } |
| eeh_unlock(); |
| pr_debug("EEH: Add %s to Device PE#%x, Parent PE#%x\n", |
| edev->dn->full_name, pe->addr, pe->parent->addr); |
| |
| return 0; |
| } |
| |
| /* Create a new EEH PE */ |
| pe = eeh_pe_alloc(edev->phb, EEH_PE_DEVICE); |
| if (!pe) { |
| eeh_unlock(); |
| pr_err("%s: out of memory!\n", __func__); |
| return -ENOMEM; |
| } |
| pe->addr = edev->pe_config_addr; |
| pe->config_addr = edev->config_addr; |
| |
| /* |
| * Put the new EEH PE into hierarchy tree. If the parent |
| * can't be found, the newly created PE will be attached |
| * to PHB directly. Otherwise, we have to associate the |
| * PE with its parent. |
| */ |
| parent = eeh_pe_get_parent(edev); |
| if (!parent) { |
| parent = eeh_phb_pe_get(edev->phb); |
| if (!parent) { |
| eeh_unlock(); |
| pr_err("%s: No PHB PE is found (PHB Domain=%d)\n", |
| __func__, edev->phb->global_number); |
| edev->pe = NULL; |
| kfree(pe); |
| return -EEXIST; |
| } |
| } |
| pe->parent = parent; |
| |
| /* |
| * Put the newly created PE into the child list and |
| * link the EEH device accordingly. |
| */ |
| list_add_tail(&pe->child, &parent->child_list); |
| list_add_tail(&edev->list, &pe->edevs); |
| edev->pe = pe; |
| eeh_unlock(); |
| pr_debug("EEH: Add %s to Device PE#%x, Parent PE#%x\n", |
| edev->dn->full_name, pe->addr, pe->parent->addr); |
| |
| return 0; |
| } |
| |
| /** |
| * eeh_rmv_from_parent_pe - Remove one EEH device from the associated PE |
| * @edev: EEH device |
| * @purge_pe: remove PE or not |
| * |
| * The PE hierarchy tree might be changed when doing PCI hotplug. |
| * Also, the PCI devices or buses could be removed from the system |
| * during EEH recovery. So we have to call the function remove the |
| * corresponding PE accordingly if necessary. |
| */ |
| int eeh_rmv_from_parent_pe(struct eeh_dev *edev, int purge_pe) |
| { |
| struct eeh_pe *pe, *parent, *child; |
| int cnt; |
| |
| if (!edev->pe) { |
| pr_warning("%s: No PE found for EEH device %s\n", |
| __func__, edev->dn->full_name); |
| return -EEXIST; |
| } |
| |
| eeh_lock(); |
| |
| /* Remove the EEH device */ |
| pe = edev->pe; |
| edev->pe = NULL; |
| list_del(&edev->list); |
| |
| /* |
| * Check if the parent PE includes any EEH devices. |
| * If not, we should delete that. Also, we should |
| * delete the parent PE if it doesn't have associated |
| * child PEs and EEH devices. |
| */ |
| while (1) { |
| parent = pe->parent; |
| if (pe->type & EEH_PE_PHB) |
| break; |
| |
| if (purge_pe) { |
| if (list_empty(&pe->edevs) && |
| list_empty(&pe->child_list)) { |
| list_del(&pe->child); |
| kfree(pe); |
| } else { |
| break; |
| } |
| } else { |
| if (list_empty(&pe->edevs)) { |
| cnt = 0; |
| list_for_each_entry(child, &pe->child_list, child) { |
| if (!(child->type & EEH_PE_INVALID)) { |
| cnt++; |
| break; |
| } |
| } |
| |
| if (!cnt) |
| pe->type |= EEH_PE_INVALID; |
| else |
| break; |
| } |
| } |
| |
| pe = parent; |
| } |
| |
| eeh_unlock(); |
| |
| return 0; |
| } |
| |
| /** |
| * __eeh_pe_state_mark - Mark the state for the PE |
| * @data: EEH PE |
| * @flag: state |
| * |
| * The function is used to mark the indicated state for the given |
| * PE. Also, the associated PCI devices will be put into IO frozen |
| * state as well. |
| */ |
| static void *__eeh_pe_state_mark(void *data, void *flag) |
| { |
| struct eeh_pe *pe = (struct eeh_pe *)data; |
| int state = *((int *)flag); |
| struct eeh_dev *tmp; |
| struct pci_dev *pdev; |
| |
| /* |
| * Mark the PE with the indicated state. Also, |
| * the associated PCI device will be put into |
| * I/O frozen state to avoid I/O accesses from |
| * the PCI device driver. |
| */ |
| pe->state |= state; |
| eeh_pe_for_each_dev(pe, tmp) { |
| pdev = eeh_dev_to_pci_dev(tmp); |
| if (pdev) |
| pdev->error_state = pci_channel_io_frozen; |
| } |
| |
| return NULL; |
| } |
| |
| /** |
| * eeh_pe_state_mark - Mark specified state for PE and its associated device |
| * @pe: EEH PE |
| * |
| * EEH error affects the current PE and its child PEs. The function |
| * is used to mark appropriate state for the affected PEs and the |
| * associated devices. |
| */ |
| void eeh_pe_state_mark(struct eeh_pe *pe, int state) |
| { |
| eeh_lock(); |
| eeh_pe_traverse(pe, __eeh_pe_state_mark, &state); |
| eeh_unlock(); |
| } |
| |
| /** |
| * __eeh_pe_state_clear - Clear state for the PE |
| * @data: EEH PE |
| * @flag: state |
| * |
| * The function is used to clear the indicated state from the |
| * given PE. Besides, we also clear the check count of the PE |
| * as well. |
| */ |
| static void *__eeh_pe_state_clear(void *data, void *flag) |
| { |
| struct eeh_pe *pe = (struct eeh_pe *)data; |
| int state = *((int *)flag); |
| |
| pe->state &= ~state; |
| pe->check_count = 0; |
| |
| return NULL; |
| } |
| |
| /** |
| * eeh_pe_state_clear - Clear state for the PE and its children |
| * @pe: PE |
| * @state: state to be cleared |
| * |
| * When the PE and its children has been recovered from error, |
| * we need clear the error state for that. The function is used |
| * for the purpose. |
| */ |
| void eeh_pe_state_clear(struct eeh_pe *pe, int state) |
| { |
| eeh_lock(); |
| eeh_pe_traverse(pe, __eeh_pe_state_clear, &state); |
| eeh_unlock(); |
| } |
| |
| /** |
| * eeh_restore_one_device_bars - Restore the Base Address Registers for one device |
| * @data: EEH device |
| * @flag: Unused |
| * |
| * Loads the PCI configuration space base address registers, |
| * the expansion ROM base address, the latency timer, and etc. |
| * from the saved values in the device node. |
| */ |
| static void *eeh_restore_one_device_bars(void *data, void *flag) |
| { |
| int i; |
| u32 cmd; |
| struct eeh_dev *edev = (struct eeh_dev *)data; |
| struct device_node *dn = eeh_dev_to_of_node(edev); |
| |
| for (i = 4; i < 10; i++) |
| eeh_ops->write_config(dn, i*4, 4, edev->config_space[i]); |
| /* 12 == Expansion ROM Address */ |
| eeh_ops->write_config(dn, 12*4, 4, edev->config_space[12]); |
| |
| #define BYTE_SWAP(OFF) (8*((OFF)/4)+3-(OFF)) |
| #define SAVED_BYTE(OFF) (((u8 *)(edev->config_space))[BYTE_SWAP(OFF)]) |
| |
| eeh_ops->write_config(dn, PCI_CACHE_LINE_SIZE, 1, |
| SAVED_BYTE(PCI_CACHE_LINE_SIZE)); |
| eeh_ops->write_config(dn, PCI_LATENCY_TIMER, 1, |
| SAVED_BYTE(PCI_LATENCY_TIMER)); |
| |
| /* max latency, min grant, interrupt pin and line */ |
| eeh_ops->write_config(dn, 15*4, 4, edev->config_space[15]); |
| |
| /* |
| * Restore PERR & SERR bits, some devices require it, |
| * don't touch the other command bits |
| */ |
| eeh_ops->read_config(dn, PCI_COMMAND, 4, &cmd); |
| if (edev->config_space[1] & PCI_COMMAND_PARITY) |
| cmd |= PCI_COMMAND_PARITY; |
| else |
| cmd &= ~PCI_COMMAND_PARITY; |
| if (edev->config_space[1] & PCI_COMMAND_SERR) |
| cmd |= PCI_COMMAND_SERR; |
| else |
| cmd &= ~PCI_COMMAND_SERR; |
| eeh_ops->write_config(dn, PCI_COMMAND, 4, cmd); |
| |
| return NULL; |
| } |
| |
| /** |
| * eeh_pe_restore_bars - Restore the PCI config space info |
| * @pe: EEH PE |
| * |
| * This routine performs a recursive walk to the children |
| * of this device as well. |
| */ |
| void eeh_pe_restore_bars(struct eeh_pe *pe) |
| { |
| /* |
| * We needn't take the EEH lock since eeh_pe_dev_traverse() |
| * will take that. |
| */ |
| eeh_pe_dev_traverse(pe, eeh_restore_one_device_bars, NULL); |
| } |
| |
| /** |
| * eeh_pe_bus_get - Retrieve PCI bus according to the given PE |
| * @pe: EEH PE |
| * |
| * Retrieve the PCI bus according to the given PE. Basically, |
| * there're 3 types of PEs: PHB/Bus/Device. For PHB PE, the |
| * primary PCI bus will be retrieved. The parent bus will be |
| * returned for BUS PE. However, we don't have associated PCI |
| * bus for DEVICE PE. |
| */ |
| struct pci_bus *eeh_pe_bus_get(struct eeh_pe *pe) |
| { |
| struct pci_bus *bus = NULL; |
| struct eeh_dev *edev; |
| struct pci_dev *pdev; |
| |
| eeh_lock(); |
| |
| if (pe->type & EEH_PE_PHB) { |
| bus = pe->phb->bus; |
| } else if (pe->type & EEH_PE_BUS) { |
| edev = list_first_entry(&pe->edevs, struct eeh_dev, list); |
| pdev = eeh_dev_to_pci_dev(edev); |
| if (pdev) |
| bus = pdev->bus; |
| } |
| |
| eeh_unlock(); |
| |
| return bus; |
| } |