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 Error |
26 | * -2: RTAS_BUSY |
27 | * -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 call |
30 | * -9001: Need DR entity to be powered up, but not unisolated, before RTAS call |
31 | * -9002: DR entity unusable |
32 | * 990x: Extended delay - where x is a number in the range of 0-5 |
33 | */ |
34 | #define RTAS_SLOT_UNISOLATED -9000 |
35 | #define RTAS_SLOT_NOT_UNISOLATED -9001 |
36 | #define RTAS_SLOT_NOT_USABLE -9002 |
37 | |
38 | static 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) returns |
60 | * extended busy error (9902) until PHB is recovered by pHyp. The RTAS call |
61 | * interface rtas_get_sensor() loops over the RTAS call on extended delay |
62 | * return code (9902) until the return value is either success (0) or error |
63 | * (-1). This causes the EEH handler to get stuck for ~6 seconds before it |
64 | * could notify that the PCI error has been detected and stop any active |
65 | * 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 EEH |
67 | * recovery state and return -EBUSY error based on RTAS return status. This |
68 | * will help the EEH handler to notify the driver about the PCI error |
69 | * immediately and successfully proceed with EEH recovery steps. |
70 | */ |
71 | |
72 | static 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 EEH |
85 | * 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(rtas_rc: rc); |
97 | } |
98 | fallback: |
99 | return rtas_get_sensor(DR_ENTITY_SENSE, slot->index, state); |
100 | } |
101 | |
102 | int 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 up |
115 | * 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 | else |
128 | 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 device |
135 | * @slot: target &slot |
136 | * |
137 | * Initialize values in the slot structure to indicate if there is a pci card |
138 | * plugged into the slot. If the slot is not empty, run the pcibios routine |
139 | * to get pcibios stuff correctly set up. |
140 | */ |
141 | int 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: &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(head: &bus->devices)) { |
179 | pseries_eeh_init_edev_recursive(PCI_DN(slot->dn)); |
180 | pci_hp_add_devices(bus); |
181 | } |
182 | |
183 | if (!list_empty(head: &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 | |