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Diffstat (limited to 'arch/powerpc/kernel/eeh_pe.c')
-rw-r--r-- | arch/powerpc/kernel/eeh_pe.c | 867 |
1 files changed, 867 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/eeh_pe.c b/arch/powerpc/kernel/eeh_pe.c new file mode 100644 index 0000000000..e0ce812796 --- /dev/null +++ b/arch/powerpc/kernel/eeh_pe.c @@ -0,0 +1,867 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * 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. + */ + +#include <linux/delay.h> +#include <linux/export.h> +#include <linux/gfp.h> +#include <linux/kernel.h> +#include <linux/of.h> +#include <linux/pci.h> +#include <linux/string.h> + +#include <asm/pci-bridge.h> +#include <asm/ppc-pci.h> + +static int eeh_pe_aux_size = 0; +static LIST_HEAD(eeh_phb_pe); + +/** + * eeh_set_pe_aux_size - Set PE auxillary data size + * @size: PE auxillary data size + * + * Set PE auxillary data size + */ +void eeh_set_pe_aux_size(int size) +{ + if (size < 0) + return; + + eeh_pe_aux_size = size; +} + +/** + * 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; + size_t alloc_size; + + alloc_size = sizeof(struct eeh_pe); + if (eeh_pe_aux_size) { + alloc_size = ALIGN(alloc_size, cache_line_size()); + alloc_size += eeh_pe_aux_size; + } + + /* Allocate PHB PE */ + pe = kzalloc(alloc_size, 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->edevs); + + pe->data = (void *)pe + ALIGN(sizeof(struct eeh_pe), + cache_line_size()); + 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 */ + list_add_tail(&pe->child, &eeh_phb_pe); + + pr_debug("EEH: Add PE for PHB#%x\n", phb->global_number); + + return 0; +} + +/** + * eeh_wait_state - Wait for PE state + * @pe: EEH PE + * @max_wait: maximal period in millisecond + * + * Wait for the state of associated PE. It might take some time + * to retrieve the PE's state. + */ +int eeh_wait_state(struct eeh_pe *pe, int max_wait) +{ + int ret; + int mwait; + + /* + * According to PAPR, the state of PE might be temporarily + * unavailable. Under the circumstance, we have to wait + * for indicated time determined by firmware. The maximal + * wait time is 5 minutes, which is acquired from the original + * EEH implementation. Also, the original implementation + * also defined the minimal wait time as 1 second. + */ +#define EEH_STATE_MIN_WAIT_TIME (1000) +#define EEH_STATE_MAX_WAIT_TIME (300 * 1000) + + while (1) { + ret = eeh_ops->get_state(pe, &mwait); + + if (ret != EEH_STATE_UNAVAILABLE) + return ret; + + if (max_wait <= 0) { + pr_warn("%s: Timeout when getting PE's state (%d)\n", + __func__, max_wait); + return EEH_STATE_NOT_SUPPORT; + } + + if (mwait < EEH_STATE_MIN_WAIT_TIME) { + pr_warn("%s: Firmware returned bad wait value %d\n", + __func__, mwait); + mwait = EEH_STATE_MIN_WAIT_TIME; + } else if (mwait > EEH_STATE_MAX_WAIT_TIME) { + pr_warn("%s: Firmware returned too long wait value %d\n", + __func__, mwait); + mwait = EEH_STATE_MAX_WAIT_TIME; + } + + msleep(min(mwait, max_wait)); + max_wait -= mwait; + } +} + +/** + * 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. + */ +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. + */ +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. + */ +void *eeh_pe_traverse(struct eeh_pe *root, + eeh_pe_traverse_func fn, void *flag) +{ + struct eeh_pe *pe; + void *ret; + + eeh_for_each_pe(root, pe) { + 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_edev_traverse_func fn, void *flag) +{ + struct eeh_pe *pe; + struct eeh_dev *edev, *tmp; + + if (!root) { + pr_warn("%s: Invalid PE %p\n", + __func__, root); + return; + } + + /* Traverse root PE */ + eeh_for_each_pe(root, pe) + eeh_pe_for_each_dev(pe, edev, tmp) + fn(edev, flag); +} + +/** + * __eeh_pe_get - Check the PE address + * + * 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(struct eeh_pe *pe, void *flag) +{ + int *target_pe = flag; + + /* PHB PEs are special and should be ignored */ + if (pe->type & EEH_PE_PHB) + return NULL; + + if (*target_pe == pe->addr) + return pe; + + return NULL; +} + +/** + * eeh_pe_get - Search PE based on the given address + * @phb: PCI controller + * @pe_no: PE number + * + * 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. + */ +struct eeh_pe *eeh_pe_get(struct pci_controller *phb, int pe_no) +{ + struct eeh_pe *root = eeh_phb_pe_get(phb); + + return eeh_pe_traverse(root, __eeh_pe_get, &pe_no); +} + +/** + * eeh_pe_tree_insert - Add EEH device to parent PE + * @edev: EEH device + * @new_pe_parent: PE to create additional PEs under + * + * Add EEH device to the PE in edev->pe_config_addr. If a PE already + * exists with that address then @edev is added to that PE. Otherwise + * a new PE is created and inserted into the PE tree as a child of + * @new_pe_parent. + * + * If @new_pe_parent is NULL then the new PE will be inserted under + * directly under the PHB. + */ +int eeh_pe_tree_insert(struct eeh_dev *edev, struct eeh_pe *new_pe_parent) +{ + struct pci_controller *hose = edev->controller; + struct eeh_pe *pe, *parent; + + /* + * 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(hose, edev->pe_config_addr); + if (pe) { + if (pe->type & EEH_PE_INVALID) { + list_add_tail(&edev->entry, &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_edev_dbg(edev, "Added to existing PE (parent: PE#%x)\n", + pe->parent->addr); + } else { + /* 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->entry, &pe->edevs); + eeh_edev_dbg(edev, "Added to bus PE\n"); + } + return 0; + } + + /* Create a new EEH PE */ + if (edev->physfn) + pe = eeh_pe_alloc(hose, EEH_PE_VF); + else + pe = eeh_pe_alloc(hose, EEH_PE_DEVICE); + if (!pe) { + pr_err("%s: out of memory!\n", __func__); + return -ENOMEM; + } + + pe->addr = edev->pe_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. + */ + if (!new_pe_parent) { + new_pe_parent = eeh_phb_pe_get(hose); + if (!new_pe_parent) { + pr_err("%s: No PHB PE is found (PHB Domain=%d)\n", + __func__, hose->global_number); + edev->pe = NULL; + kfree(pe); + return -EEXIST; + } + } + + /* link new PE into the tree */ + pe->parent = new_pe_parent; + list_add_tail(&pe->child, &new_pe_parent->child_list); + + /* + * Put the newly created PE into the child list and + * link the EEH device accordingly. + */ + list_add_tail(&edev->entry, &pe->edevs); + edev->pe = pe; + eeh_edev_dbg(edev, "Added to new (parent: PE#%x)\n", + new_pe_parent->addr); + + return 0; +} + +/** + * eeh_pe_tree_remove - Remove one EEH device from the associated PE + * @edev: EEH device + * + * 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_pe_tree_remove(struct eeh_dev *edev) +{ + struct eeh_pe *pe, *parent, *child; + bool keep, recover; + int cnt; + + pe = eeh_dev_to_pe(edev); + if (!pe) { + eeh_edev_dbg(edev, "No PE found for device.\n"); + return -EEXIST; + } + + /* Remove the EEH device */ + edev->pe = NULL; + list_del(&edev->entry); + + /* + * 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; + + /* PHB PEs should never be removed */ + if (pe->type & EEH_PE_PHB) + break; + + /* + * XXX: KEEP is set while resetting a PE. I don't think it's + * ever set without RECOVERING also being set. I could + * be wrong though so catch that with a WARN. + */ + keep = !!(pe->state & EEH_PE_KEEP); + recover = !!(pe->state & EEH_PE_RECOVERING); + WARN_ON(keep && !recover); + + if (!keep && !recover) { + if (list_empty(&pe->edevs) && + list_empty(&pe->child_list)) { + list_del(&pe->child); + kfree(pe); + } else { + break; + } + } else { + /* + * Mark the PE as invalid. At the end of the recovery + * process any invalid PEs will be garbage collected. + * + * We need to delay the free()ing of them since we can + * remove edev's while traversing the PE tree which + * might trigger the removal of a PE and we can't + * deal with that (yet). + */ + 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; + } + + return 0; +} + +/** + * eeh_pe_update_time_stamp - Update PE's frozen time stamp + * @pe: EEH PE + * + * We have time stamp for each PE to trace its time of getting + * frozen in last hour. The function should be called to update + * the time stamp on first error of the specific PE. On the other + * handle, we needn't account for errors happened in last hour. + */ +void eeh_pe_update_time_stamp(struct eeh_pe *pe) +{ + time64_t tstamp; + + if (!pe) return; + + if (pe->freeze_count <= 0) { + pe->freeze_count = 0; + pe->tstamp = ktime_get_seconds(); + } else { + tstamp = ktime_get_seconds(); + if (tstamp - pe->tstamp > 3600) { + pe->tstamp = tstamp; + pe->freeze_count = 0; + } + } +} + +/** + * 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 *root, int state) +{ + struct eeh_pe *pe; + + eeh_for_each_pe(root, pe) + if (!(pe->state & EEH_PE_REMOVED)) + pe->state |= state; +} +EXPORT_SYMBOL_GPL(eeh_pe_state_mark); + +/** + * eeh_pe_mark_isolated + * @pe: EEH PE + * + * Record that a PE has been isolated by marking the PE and it's children as + * EEH_PE_ISOLATED (and EEH_PE_CFG_BLOCKED, if required) and their PCI devices + * as pci_channel_io_frozen. + */ +void eeh_pe_mark_isolated(struct eeh_pe *root) +{ + struct eeh_pe *pe; + struct eeh_dev *edev; + struct pci_dev *pdev; + + eeh_pe_state_mark(root, EEH_PE_ISOLATED); + eeh_for_each_pe(root, pe) { + list_for_each_entry(edev, &pe->edevs, entry) { + pdev = eeh_dev_to_pci_dev(edev); + if (pdev) + pdev->error_state = pci_channel_io_frozen; + } + /* Block PCI config access if required */ + if (pe->state & EEH_PE_CFG_RESTRICTED) + pe->state |= EEH_PE_CFG_BLOCKED; + } +} +EXPORT_SYMBOL_GPL(eeh_pe_mark_isolated); + +static void __eeh_pe_dev_mode_mark(struct eeh_dev *edev, void *flag) +{ + int mode = *((int *)flag); + + edev->mode |= mode; +} + +/** + * eeh_pe_dev_state_mark - Mark state for all device under the PE + * @pe: EEH PE + * + * Mark specific state for all child devices of the PE. + */ +void eeh_pe_dev_mode_mark(struct eeh_pe *pe, int mode) +{ + eeh_pe_dev_traverse(pe, __eeh_pe_dev_mode_mark, &mode); +} + +/** + * eeh_pe_state_clear - Clear state for the PE + * @data: EEH PE + * @state: state + * @include_passed: include passed-through devices? + * + * 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. + */ +void eeh_pe_state_clear(struct eeh_pe *root, int state, bool include_passed) +{ + struct eeh_pe *pe; + struct eeh_dev *edev, *tmp; + struct pci_dev *pdev; + + eeh_for_each_pe(root, pe) { + /* Keep the state of permanently removed PE intact */ + if (pe->state & EEH_PE_REMOVED) + continue; + + if (!include_passed && eeh_pe_passed(pe)) + continue; + + pe->state &= ~state; + + /* + * Special treatment on clearing isolated state. Clear + * check count since last isolation and put all affected + * devices to normal state. + */ + if (!(state & EEH_PE_ISOLATED)) + continue; + + pe->check_count = 0; + eeh_pe_for_each_dev(pe, edev, tmp) { + pdev = eeh_dev_to_pci_dev(edev); + if (!pdev) + continue; + + pdev->error_state = pci_channel_io_normal; + } + + /* Unblock PCI config access if required */ + if (pe->state & EEH_PE_CFG_RESTRICTED) + pe->state &= ~EEH_PE_CFG_BLOCKED; + } +} + +/* + * Some PCI bridges (e.g. PLX bridges) have primary/secondary + * buses assigned explicitly by firmware, and we probably have + * lost that after reset. So we have to delay the check until + * the PCI-CFG registers have been restored for the parent + * bridge. + * + * Don't use normal PCI-CFG accessors, which probably has been + * blocked on normal path during the stage. So we need utilize + * eeh operations, which is always permitted. + */ +static void eeh_bridge_check_link(struct eeh_dev *edev) +{ + int cap; + uint32_t val; + int timeout = 0; + + /* + * We only check root port and downstream ports of + * PCIe switches + */ + if (!(edev->mode & (EEH_DEV_ROOT_PORT | EEH_DEV_DS_PORT))) + return; + + eeh_edev_dbg(edev, "Checking PCIe link...\n"); + + /* Check slot status */ + cap = edev->pcie_cap; + eeh_ops->read_config(edev, cap + PCI_EXP_SLTSTA, 2, &val); + if (!(val & PCI_EXP_SLTSTA_PDS)) { + eeh_edev_dbg(edev, "No card in the slot (0x%04x) !\n", val); + return; + } + + /* Check power status if we have the capability */ + eeh_ops->read_config(edev, cap + PCI_EXP_SLTCAP, 2, &val); + if (val & PCI_EXP_SLTCAP_PCP) { + eeh_ops->read_config(edev, cap + PCI_EXP_SLTCTL, 2, &val); + if (val & PCI_EXP_SLTCTL_PCC) { + eeh_edev_dbg(edev, "In power-off state, power it on ...\n"); + val &= ~(PCI_EXP_SLTCTL_PCC | PCI_EXP_SLTCTL_PIC); + val |= (0x0100 & PCI_EXP_SLTCTL_PIC); + eeh_ops->write_config(edev, cap + PCI_EXP_SLTCTL, 2, val); + msleep(2 * 1000); + } + } + + /* Enable link */ + eeh_ops->read_config(edev, cap + PCI_EXP_LNKCTL, 2, &val); + val &= ~PCI_EXP_LNKCTL_LD; + eeh_ops->write_config(edev, cap + PCI_EXP_LNKCTL, 2, val); + + /* Check link */ + if (!edev->pdev->link_active_reporting) { + eeh_edev_dbg(edev, "No link reporting capability\n"); + msleep(1000); + return; + } + + /* Wait the link is up until timeout (5s) */ + timeout = 0; + while (timeout < 5000) { + msleep(20); + timeout += 20; + + eeh_ops->read_config(edev, cap + PCI_EXP_LNKSTA, 2, &val); + if (val & PCI_EXP_LNKSTA_DLLLA) + break; + } + + if (val & PCI_EXP_LNKSTA_DLLLA) + eeh_edev_dbg(edev, "Link up (%s)\n", + (val & PCI_EXP_LNKSTA_CLS_2_5GB) ? "2.5GB" : "5GB"); + else + eeh_edev_dbg(edev, "Link not ready (0x%04x)\n", val); +} + +#define BYTE_SWAP(OFF) (8*((OFF)/4)+3-(OFF)) +#define SAVED_BYTE(OFF) (((u8 *)(edev->config_space))[BYTE_SWAP(OFF)]) + +static void eeh_restore_bridge_bars(struct eeh_dev *edev) +{ + int i; + + /* + * Device BARs: 0x10 - 0x18 + * Bus numbers and windows: 0x18 - 0x30 + */ + for (i = 4; i < 13; i++) + eeh_ops->write_config(edev, i*4, 4, edev->config_space[i]); + /* Rom: 0x38 */ + eeh_ops->write_config(edev, 14*4, 4, edev->config_space[14]); + + /* Cache line & Latency timer: 0xC 0xD */ + eeh_ops->write_config(edev, PCI_CACHE_LINE_SIZE, 1, + SAVED_BYTE(PCI_CACHE_LINE_SIZE)); + eeh_ops->write_config(edev, PCI_LATENCY_TIMER, 1, + SAVED_BYTE(PCI_LATENCY_TIMER)); + /* Max latency, min grant, interrupt ping and line: 0x3C */ + eeh_ops->write_config(edev, 15*4, 4, edev->config_space[15]); + + /* PCI Command: 0x4 */ + eeh_ops->write_config(edev, PCI_COMMAND, 4, edev->config_space[1] | + PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER); + + /* Check the PCIe link is ready */ + eeh_bridge_check_link(edev); +} + +static void eeh_restore_device_bars(struct eeh_dev *edev) +{ + int i; + u32 cmd; + + for (i = 4; i < 10; i++) + eeh_ops->write_config(edev, i*4, 4, edev->config_space[i]); + /* 12 == Expansion ROM Address */ + eeh_ops->write_config(edev, 12*4, 4, edev->config_space[12]); + + eeh_ops->write_config(edev, PCI_CACHE_LINE_SIZE, 1, + SAVED_BYTE(PCI_CACHE_LINE_SIZE)); + eeh_ops->write_config(edev, PCI_LATENCY_TIMER, 1, + SAVED_BYTE(PCI_LATENCY_TIMER)); + + /* max latency, min grant, interrupt pin and line */ + eeh_ops->write_config(edev, 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(edev, 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(edev, PCI_COMMAND, 4, cmd); +} + +/** + * 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(struct eeh_dev *edev, void *flag) +{ + /* Do special restore for bridges */ + if (edev->mode & EEH_DEV_BRIDGE) + eeh_restore_bridge_bars(edev); + else + eeh_restore_device_bars(edev); + + if (eeh_ops->restore_config) + eeh_ops->restore_config(edev); +} + +/** + * 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_loc_get - Retrieve location code binding to the given PE + * @pe: EEH PE + * + * Retrieve the location code of the given PE. If the primary PE bus + * is root bus, we will grab location code from PHB device tree node + * or root port. Otherwise, the upstream bridge's device tree node + * of the primary PE bus will be checked for the location code. + */ +const char *eeh_pe_loc_get(struct eeh_pe *pe) +{ + struct pci_bus *bus = eeh_pe_bus_get(pe); + struct device_node *dn; + const char *loc = NULL; + + while (bus) { + dn = pci_bus_to_OF_node(bus); + if (!dn) { + bus = bus->parent; + continue; + } + + if (pci_is_root_bus(bus)) + loc = of_get_property(dn, "ibm,io-base-loc-code", NULL); + else + loc = of_get_property(dn, "ibm,slot-location-code", + NULL); + + if (loc) + return loc; + + bus = bus->parent; + } + + return "N/A"; +} + +/** + * 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 eeh_dev *edev; + struct pci_dev *pdev; + + if (pe->type & EEH_PE_PHB) + return pe->phb->bus; + + /* The primary bus might be cached during probe time */ + if (pe->state & EEH_PE_PRI_BUS) + return pe->bus; + + /* Retrieve the parent PCI bus of first (top) PCI device */ + edev = list_first_entry_or_null(&pe->edevs, struct eeh_dev, entry); + pdev = eeh_dev_to_pci_dev(edev); + if (pdev) + return pdev->bus; + + return NULL; +} |