xref: /openbmc/linux/drivers/pci/hotplug/rpaphp_pci.c (revision a4b4f61d)
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 			eeh_add_device_tree_early(PCI_DN(slot->dn));
100 			pci_hp_add_devices(bus);
101 		}
102 
103 		if (!list_empty(&bus->devices)) {
104 			slot->state = CONFIGURED;
105 		}
106 
107 		if (rpaphp_debug) {
108 			struct pci_dev *dev;
109 			dbg("%s: pci_devs of slot[%pOF]\n", __func__, slot->dn);
110 			list_for_each_entry(dev, &bus->devices, bus_list)
111 				dbg("\t%s\n", pci_name(dev));
112 		}
113 	}
114 
115 	return 0;
116 }
117