1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * IOAPIC/IOxAPIC/IOSAPIC driver
4 *
5 * Copyright (C) 2009 Fujitsu Limited.
6 * (c) Copyright 2009 Hewlett-Packard Development Company, L.P.
7 *
8 * Copyright (C) 2014 Intel Corporation
9 *
10 * Based on original drivers/pci/ioapic.c
11 *	Yinghai Lu <yinghai@kernel.org>
12 *	Jiang Liu <jiang.liu@intel.com>
13 */
14
15/*
16 * This driver manages I/O APICs added by hotplug after boot.
17 * We try to claim all I/O APIC devices, but those present at boot were
18 * registered when we parsed the ACPI MADT.
19 */
20
21#define pr_fmt(fmt) "ACPI: IOAPIC: " fmt
22
23#include <linux/slab.h>
24#include <linux/acpi.h>
25#include <linux/pci.h>
26#include <acpi/acpi.h>
27#include "internal.h"
28
29struct acpi_pci_ioapic {
30	acpi_handle	root_handle;
31	acpi_handle	handle;
32	u32		gsi_base;
33	struct resource	res;
34	struct pci_dev	*pdev;
35	struct list_head list;
36};
37
38static LIST_HEAD(ioapic_list);
39static DEFINE_MUTEX(ioapic_list_lock);
40
41static acpi_status setup_res(struct acpi_resource *acpi_res, void *data)
42{
43	struct resource *res = data;
44	struct resource_win win;
45
46	/*
47	 * We might assign this to 'res' later, make sure all pointers are
48	 * cleared before the resource is added to the global list
49	 */
50	memset(&win, 0, sizeof(win));
51
52	res->flags = 0;
53	if (acpi_dev_filter_resource_type(acpi_res, IORESOURCE_MEM))
54		return AE_OK;
55
56	if (!acpi_dev_resource_memory(acpi_res, res)) {
57		if (acpi_dev_resource_address_space(acpi_res, &win) ||
58		    acpi_dev_resource_ext_address_space(acpi_res, &win))
59			*res = win.res;
60	}
61	if ((res->flags & IORESOURCE_PREFETCH) ||
62	    (res->flags & IORESOURCE_DISABLED))
63		res->flags = 0;
64
65	return AE_CTRL_TERMINATE;
66}
67
68static bool acpi_is_ioapic(acpi_handle handle, char **type)
69{
70	acpi_status status;
71	struct acpi_device_info *info;
72	char *hid = NULL;
73	bool match = false;
74
75	if (!acpi_has_method(handle, "_GSB"))
76		return false;
77
78	status = acpi_get_object_info(handle, &info);
79	if (ACPI_SUCCESS(status)) {
80		if (info->valid & ACPI_VALID_HID)
81			hid = info->hardware_id.string;
82		if (hid) {
83			if (strcmp(hid, "ACPI0009") == 0) {
84				*type = "IOxAPIC";
85				match = true;
86			} else if (strcmp(hid, "ACPI000A") == 0) {
87				*type = "IOAPIC";
88				match = true;
89			}
90		}
91		kfree(info);
92	}
93
94	return match;
95}
96
97static acpi_status handle_ioapic_add(acpi_handle handle, u32 lvl,
98				     void *context, void **rv)
99{
100	acpi_status status;
101	unsigned long long gsi_base;
102	struct acpi_pci_ioapic *ioapic;
103	struct pci_dev *dev = NULL;
104	struct resource *res = NULL, *pci_res = NULL, *crs_res;
105	char *type = NULL;
106
107	if (!acpi_is_ioapic(handle, &type))
108		return AE_OK;
109
110	mutex_lock(&ioapic_list_lock);
111	list_for_each_entry(ioapic, &ioapic_list, list)
112		if (ioapic->handle == handle) {
113			mutex_unlock(&ioapic_list_lock);
114			return AE_OK;
115		}
116
117	status = acpi_evaluate_integer(handle, "_GSB", NULL, &gsi_base);
118	if (ACPI_FAILURE(status)) {
119		acpi_handle_warn(handle, "failed to evaluate _GSB method\n");
120		goto exit;
121	}
122
123	ioapic = kzalloc(sizeof(*ioapic), GFP_KERNEL);
124	if (!ioapic) {
125		pr_err("cannot allocate memory for new IOAPIC\n");
126		goto exit;
127	} else {
128		ioapic->root_handle = (acpi_handle)context;
129		ioapic->handle = handle;
130		ioapic->gsi_base = (u32)gsi_base;
131		INIT_LIST_HEAD(&ioapic->list);
132	}
133
134	if (acpi_ioapic_registered(handle, (u32)gsi_base))
135		goto done;
136
137	dev = acpi_get_pci_dev(handle);
138	if (dev && pci_resource_len(dev, 0)) {
139		if (pci_enable_device(dev) < 0)
140			goto exit_put;
141		pci_set_master(dev);
142		if (pci_request_region(dev, 0, type))
143			goto exit_disable;
144		pci_res = &dev->resource[0];
145		ioapic->pdev = dev;
146	} else {
147		pci_dev_put(dev);
148		dev = NULL;
149	}
150
151	crs_res = &ioapic->res;
152	acpi_walk_resources(handle, METHOD_NAME__CRS, setup_res, crs_res);
153	crs_res->name = type;
154	crs_res->flags |= IORESOURCE_BUSY;
155	if (crs_res->flags == 0) {
156		acpi_handle_warn(handle, "failed to get resource\n");
157		goto exit_release;
158	} else if (insert_resource(&iomem_resource, crs_res)) {
159		acpi_handle_warn(handle, "failed to insert resource\n");
160		goto exit_release;
161	}
162
163	/* try pci resource first, then "_CRS" resource */
164	res = pci_res;
165	if (!res || !res->flags)
166		res = crs_res;
167
168	if (acpi_register_ioapic(handle, res->start, (u32)gsi_base)) {
169		acpi_handle_warn(handle, "failed to register IOAPIC\n");
170		goto exit_release;
171	}
172done:
173	list_add(&ioapic->list, &ioapic_list);
174	mutex_unlock(&ioapic_list_lock);
175
176	if (dev)
177		dev_info(&dev->dev, "%s at %pR, GSI %u\n",
178			 type, res, (u32)gsi_base);
179	else
180		acpi_handle_info(handle, "%s at %pR, GSI %u\n",
181				 type, res, (u32)gsi_base);
182
183	return AE_OK;
184
185exit_release:
186	if (dev)
187		pci_release_region(dev, 0);
188	if (ioapic->res.flags && ioapic->res.parent)
189		release_resource(&ioapic->res);
190exit_disable:
191	if (dev)
192		pci_disable_device(dev);
193exit_put:
194	pci_dev_put(dev);
195	kfree(ioapic);
196exit:
197	mutex_unlock(&ioapic_list_lock);
198	*(acpi_status *)rv = AE_ERROR;
199	return AE_OK;
200}
201
202int acpi_ioapic_add(acpi_handle root_handle)
203{
204	acpi_status status, retval = AE_OK;
205
206	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, root_handle,
207				     UINT_MAX, handle_ioapic_add, NULL,
208				     root_handle, (void **)&retval);
209
210	return ACPI_SUCCESS(status) && ACPI_SUCCESS(retval) ? 0 : -ENODEV;
211}
212
213void pci_ioapic_remove(struct acpi_pci_root *root)
214{
215	struct acpi_pci_ioapic *ioapic, *tmp;
216
217	mutex_lock(&ioapic_list_lock);
218	list_for_each_entry_safe(ioapic, tmp, &ioapic_list, list) {
219		if (root->device->handle != ioapic->root_handle)
220			continue;
221		if (ioapic->pdev) {
222			pci_release_region(ioapic->pdev, 0);
223			pci_disable_device(ioapic->pdev);
224			pci_dev_put(ioapic->pdev);
225		}
226	}
227	mutex_unlock(&ioapic_list_lock);
228}
229
230int acpi_ioapic_remove(struct acpi_pci_root *root)
231{
232	int retval = 0;
233	struct acpi_pci_ioapic *ioapic, *tmp;
234
235	mutex_lock(&ioapic_list_lock);
236	list_for_each_entry_safe(ioapic, tmp, &ioapic_list, list) {
237		if (root->device->handle != ioapic->root_handle)
238			continue;
239		if (acpi_unregister_ioapic(ioapic->handle, ioapic->gsi_base))
240			retval = -EBUSY;
241		if (ioapic->res.flags && ioapic->res.parent)
242			release_resource(&ioapic->res);
243		list_del(&ioapic->list);
244		kfree(ioapic);
245	}
246	mutex_unlock(&ioapic_list_lock);
247
248	return retval;
249}
250