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1// SPDX-License-Identifier: GPL-2.0+2/*3 * PCI Hot Plug Controller Driver for RPA-compliant PPC64 platform.4 * Copyright (C) 2003 Linda Xie <lxie@us.ibm.com>5 *6 * All rights reserved.7 *8 * Send feedback to <lxie@us.ibm.com>9 *10 */11#include <linux/of.h>12#include <linux/pci.h>13#include <linux/string.h>14 15#include <asm/pci-bridge.h>16#include <asm/rtas.h>17#include <asm/machdep.h>18 19#include "../pci.h" /* for pci_add_new_bus */20#include "rpaphp.h"21 22/*23 * RTAS call get-sensor-state(DR_ENTITY_SENSE) return values as per PAPR:24 * -- generic return codes ---25 * -1: Hardware Error26 * -2: RTAS_BUSY27 * -3: Invalid sensor. RTAS Parameter Error.28 * -- rtas_get_sensor function specific return codes ---29 * -9000: Need DR entity to be powered up and unisolated before RTAS call30 * -9001: Need DR entity to be powered up, but not unisolated, before RTAS call31 * -9002: DR entity unusable32 * 990x: Extended delay - where x is a number in the range of 0-533 */34#define RTAS_SLOT_UNISOLATED -900035#define RTAS_SLOT_NOT_UNISOLATED -900136#define RTAS_SLOT_NOT_USABLE -900237 38static int rtas_get_sensor_errno(int rtas_rc)39{40 switch (rtas_rc) {41 case 0:42 /* Success case */43 return 0;44 case RTAS_SLOT_UNISOLATED:45 case RTAS_SLOT_NOT_UNISOLATED:46 return -EFAULT;47 case RTAS_SLOT_NOT_USABLE:48 return -ENODEV;49 case RTAS_BUSY:50 case RTAS_EXTENDED_DELAY_MIN...RTAS_EXTENDED_DELAY_MAX:51 return -EBUSY;52 default:53 return rtas_error_rc(rtas_rc);54 }55}56 57/*58 * get_adapter_status() can be called by the EEH handler during EEH recovery.59 * On certain PHB failures, the RTAS call rtas_call(get-sensor-state) returns60 * extended busy error (9902) until PHB is recovered by pHyp. The RTAS call61 * interface rtas_get_sensor() loops over the RTAS call on extended delay62 * return code (9902) until the return value is either success (0) or error63 * (-1). This causes the EEH handler to get stuck for ~6 seconds before it64 * could notify that the PCI error has been detected and stop any active65 * operations. This sometimes causes EEH recovery to fail. To avoid this issue,66 * invoke rtas_call(get-sensor-state) directly if the respective PE is in EEH67 * recovery state and return -EBUSY error based on RTAS return status. This68 * will help the EEH handler to notify the driver about the PCI error69 * immediately and successfully proceed with EEH recovery steps.70 */71 72static int __rpaphp_get_sensor_state(struct slot *slot, int *state)73{74 int rc;75 int token = rtas_token("get-sensor-state");76 struct pci_dn *pdn;77 struct eeh_pe *pe;78 struct pci_controller *phb = PCI_DN(slot->dn)->phb;79 80 if (token == RTAS_UNKNOWN_SERVICE)81 return -ENOENT;82 83 /*84 * Fallback to existing method for empty slot or PE isn't in EEH85 * recovery.86 */87 pdn = list_first_entry_or_null(&PCI_DN(phb->dn)->child_list,88 struct pci_dn, list);89 if (!pdn)90 goto fallback;91 92 pe = eeh_dev_to_pe(pdn->edev);93 if (pe && (pe->state & EEH_PE_RECOVERING)) {94 rc = rtas_call(token, 2, 2, state, DR_ENTITY_SENSE,95 slot->index);96 return rtas_get_sensor_errno(rc);97 }98fallback:99 return rtas_get_sensor(DR_ENTITY_SENSE, slot->index, state);100}101 102int rpaphp_get_sensor_state(struct slot *slot, int *state)103{104 int rc;105 int setlevel;106 107 rc = __rpaphp_get_sensor_state(slot, state);108 109 if (rc < 0) {110 if (rc == -EFAULT || rc == -EEXIST) {111 dbg("%s: slot must be power up to get sensor-state\n",112 __func__);113 114 /* some slots have to be powered up115 * before get-sensor will succeed.116 */117 rc = rtas_set_power_level(slot->power_domain, POWER_ON,118 &setlevel);119 if (rc < 0) {120 dbg("%s: power on slot[%s] failed rc=%d.\n",121 __func__, slot->name, rc);122 } else {123 rc = __rpaphp_get_sensor_state(slot, state);124 }125 } else if (rc == -ENODEV)126 info("%s: slot is unusable\n", __func__);127 else128 err("%s failed to get sensor state\n", __func__);129 }130 return rc;131}132 133/**134 * rpaphp_enable_slot - record slot state, config pci device135 * @slot: target &slot136 *137 * Initialize values in the slot structure to indicate if there is a pci card138 * plugged into the slot. If the slot is not empty, run the pcibios routine139 * to get pcibios stuff correctly set up.140 */141int rpaphp_enable_slot(struct slot *slot)142{143 int rc, level, state;144 struct pci_bus *bus;145 146 slot->state = EMPTY;147 148 /* Find out if the power is turned on for the slot */149 rc = rtas_get_power_level(slot->power_domain, &level);150 if (rc)151 return rc;152 153 /* Figure out if there is an adapter in the slot */154 rc = rpaphp_get_sensor_state(slot, &state);155 if (rc)156 return rc;157 158 bus = pci_find_bus_by_node(slot->dn);159 if (!bus) {160 err("%s: no pci_bus for dn %pOF\n", __func__, slot->dn);161 return -EINVAL;162 }163 164 slot->bus = bus;165 slot->pci_devs = &bus->devices;166 167 /* if there's an adapter in the slot, go add the pci devices */168 if (state == PRESENT) {169 slot->state = NOT_CONFIGURED;170 171 /* non-empty slot has to have child */172 if (!slot->dn->child) {173 err("%s: slot[%s]'s device_node doesn't have child for adapter\n",174 __func__, slot->name);175 return -EINVAL;176 }177 178 if (list_empty(&bus->devices)) {179 pseries_eeh_init_edev_recursive(PCI_DN(slot->dn));180 pci_hp_add_devices(bus);181 }182 183 if (!list_empty(&bus->devices)) {184 slot->state = CONFIGURED;185 }186 187 if (rpaphp_debug) {188 struct pci_dev *dev;189 dbg("%s: pci_devs of slot[%pOF]\n", __func__, slot->dn);190 list_for_each_entry(dev, &bus->devices, bus_list)191 dbg("\t%s\n", pci_name(dev));192 }193 }194 195 return 0;196}197