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))
 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, *pci_res = NULL, *crs_res;
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		pci_res = &dev->resource[0];
141		ioapic->pdev = dev;
142	} else {
143		pci_dev_put(dev);
144		dev = NULL;
145	}
146
147	crs_res = &ioapic->res;
148	acpi_walk_resources(handle, METHOD_NAME__CRS, setup_res, crs_res);
149	crs_res->name = type;
150	crs_res->flags |= IORESOURCE_BUSY;
151	if (crs_res->flags == 0) {
152		acpi_handle_warn(handle, "failed to get resource\n");
153		goto exit_release;
154	} else if (insert_resource(&iomem_resource, crs_res)) {
155		acpi_handle_warn(handle, "failed to insert resource\n");
156		goto exit_release;
157	}
158
159	/* try pci resource first, then "_CRS" resource */
160	res = pci_res;
161	if (!res || !res->flags)
162		res = crs_res;
163
164	if (acpi_register_ioapic(handle, res->start, (u32)gsi_base)) {
165		acpi_handle_warn(handle, "failed to register IOAPIC\n");
166		goto exit_release;
167	}
168done:
169	list_add(&ioapic->list, &ioapic_list);
170	mutex_unlock(&ioapic_list_lock);
171
172	if (dev)
173		dev_info(&dev->dev, "%s at %pR, GSI %u\n",
174			 type, res, (u32)gsi_base);
175	else
176		acpi_handle_info(handle, "%s at %pR, GSI %u\n",
177				 type, res, (u32)gsi_base);
178
179	return AE_OK;
180
181exit_release:
182	if (dev)
183		pci_release_region(dev, 0);
184	if (ioapic->res.flags && ioapic->res.parent)
185		release_resource(&ioapic->res);
186exit_disable:
187	if (dev)
188		pci_disable_device(dev);
189exit_put:
190	pci_dev_put(dev);
191	kfree(ioapic);
192exit:
193	mutex_unlock(&ioapic_list_lock);
194	*(acpi_status *)rv = AE_ERROR;
195	return AE_OK;
196}
197
198int acpi_ioapic_add(acpi_handle root_handle)
199{
200	acpi_status status, retval = AE_OK;
201
202	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, root_handle,
203				     UINT_MAX, handle_ioapic_add, NULL,
204				     root_handle, (void **)&retval);
205
206	return ACPI_SUCCESS(status) && ACPI_SUCCESS(retval) ? 0 : -ENODEV;
207}
208
209int acpi_ioapic_remove(struct acpi_pci_root *root)
210{
211	int retval = 0;
212	struct acpi_pci_ioapic *ioapic, *tmp;
213
214	mutex_lock(&ioapic_list_lock);
215	list_for_each_entry_safe(ioapic, tmp, &ioapic_list, list) {
216		if (root->device->handle != ioapic->root_handle)
217			continue;
218
219		if (acpi_unregister_ioapic(ioapic->handle, ioapic->gsi_base))
220			retval = -EBUSY;
221
222		if (ioapic->pdev) {
223			pci_release_region(ioapic->pdev, 0);
224			pci_disable_device(ioapic->pdev);
225			pci_dev_put(ioapic->pdev);
226		}
227		if (ioapic->res.flags && ioapic->res.parent)
228			release_resource(&ioapic->res);
229		list_del(&ioapic->list);
230		kfree(ioapic);
231	}
232	mutex_unlock(&ioapic_list_lock);
233
234	return retval;
235}