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