drivers/pci/hotplug/rpaphp_pci.c

   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/pci.h>
  12 #include <linux/string.h>
  13
  14 #include <asm/pci-bridge.h>
  15 #include <asm/rtas.h>
  16 #include <asm/machdep.h>
  17
  18 #include "../pci.h"             /* for pci_add_new_bus */
  19 #include "rpaphp.h"
  20
  21 int rpaphp_get_sensor_state(struct slot *slot, int *state)
  22 {
  23         int rc;
  24         int setlevel;
  25
  26         rc = rtas_get_sensor(DR_ENTITY_SENSE, slot->index, state);
  27
  28         if (rc < 0) {
  29                 if (rc == -EFAULT || rc == -EEXIST) {
  30                         dbg("%s: slot must be power up to get sensor-state\n",
  31                             __func__);
  32
  33                         /* some slots have to be powered up
  34                          * before get-sensor will succeed.
  35                          */
  36                         rc = rtas_set_power_level(slot->power_domain, POWER_ON,
  37                                                   &setlevel);
  38                         if (rc < 0) {
  39                                 dbg("%s: power on slot[%s] failed rc=%d.\n",
  40                                     __func__, slot->name, rc);
  41                         } else {
  42                                 rc = rtas_get_sensor(DR_ENTITY_SENSE,
  43                                                      slot->index, state);
  44                         }
  45                 } else if (rc == -ENODEV)
  46                         info("%s: slot is unusable\n", __func__);
  47                 else
  48                         err("%s failed to get sensor state\n", __func__);
  49         }
  50         return rc;
  51 }
  52
  53 /**
  54  * rpaphp_enable_slot - record slot state, config pci device
  55  * @slot: target &slot
  56  *
  57  * Initialize values in the slot structure to indicate if there is a pci card
  58  * plugged into the slot. If the slot is not empty, run the pcibios routine
  59  * to get pcibios stuff correctly set up.
  60  */
  61 int rpaphp_enable_slot(struct slot *slot)
  62 {
  63         int rc, level, state;
  64         struct pci_bus *bus;
  65
  66         slot->state = EMPTY;
  67
  68         /* Find out if the power is turned on for the slot */
  69         rc = rtas_get_power_level(slot->power_domain, &level);
  70         if (rc)
  71                 return rc;
  72
  73         /* Figure out if there is an adapter in the slot */
  74         rc = rpaphp_get_sensor_state(slot, &state);
  75         if (rc)
  76                 return rc;
  77
  78         bus = pci_find_bus_by_node(slot->dn);
  79         if (!bus) {
  80                 err("%s: no pci_bus for dn %pOF\n", __func__, slot->dn);
  81                 return -EINVAL;
  82         }
  83
  84         slot->bus = bus;
  85         slot->pci_devs = &bus->devices;
  86
  87         /* if there's an adapter in the slot, go add the pci devices */
  88         if (state == PRESENT) {
  89                 slot->state = NOT_CONFIGURED;
  90
  91                 /* non-empty slot has to have child */
  92                 if (!slot->dn->child) {
  93                         err("%s: slot[%s]'s device_node doesn't have child for adapter\n",
  94                             __func__, slot->name);
  95                         return -EINVAL;
  96                 }
  97
  98                 if (list_empty(&bus->devices))
  99                         pci_hp_add_devices(bus);
 100
 101                 if (!list_empty(&bus->devices)) {
 102                         slot->state = CONFIGURED;
 103                 }
 104
 105                 if (rpaphp_debug) {
 106                         struct pci_dev *dev;
 107                         dbg("%s: pci_devs of slot[%pOF]\n", __func__, slot->dn);
 108                         list_for_each_entry(dev, &bus->devices, bus_list)
 109                                 dbg("\t%s\n", pci_name(dev));
 110                 }
 111         }
 112
 113         return 0;
 114 }