diff options
Diffstat (limited to 'arch/powerpc/platforms/pseries/eeh_pe.c')
-rw-r--r-- | arch/powerpc/platforms/pseries/eeh_pe.c | 652 |
1 files changed, 652 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/eeh_pe.c b/arch/powerpc/platforms/pseries/eeh_pe.c new file mode 100644 index 0000000..797cd18 --- /dev/null +++ b/arch/powerpc/platforms/pseries/eeh_pe.c @@ -0,0 +1,652 @@ +/* + * 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 __devinit 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 (!(pe->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; +} |