1/******************************************************************************
2 * platform-pci.c
3 *
4 * Xen platform PCI device driver
5 * Copyright (c) 2005, Intel Corporation.
6 * Copyright (c) 2007, XenSource Inc.
7 * Copyright (c) 2010, Citrix
8 *
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms and conditions of the GNU General Public License,
11 * version 2, as published by the Free Software Foundation.
12 *
13 * This program is distributed in the hope it will be useful, but WITHOUT
14 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
16 * more details.
17 *
18 * You should have received a copy of the GNU General Public License along with
19 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
20 * Place - Suite 330, Boston, MA 02111-1307 USA.
21 *
22 */
23
24
25#include <linux/interrupt.h>
26#include <linux/io.h>
27#include <linux/module.h>
28#include <linux/pci.h>
29
30#include <xen/platform_pci.h>
31#include <xen/grant_table.h>
32#include <xen/xenbus.h>
33#include <xen/events.h>
34#include <xen/hvm.h>
35#include <xen/xen-ops.h>
36
37#define DRV_NAME    "xen-platform-pci"
38
39MODULE_AUTHOR("ssmith@xensource.com and stefano.stabellini@eu.citrix.com");
40MODULE_DESCRIPTION("Xen platform PCI device");
41MODULE_LICENSE("GPL");
42
43static unsigned long platform_mmio;
44static unsigned long platform_mmio_alloc;
45static unsigned long platform_mmiolen;
46static uint64_t callback_via;
47
48static unsigned long alloc_xen_mmio(unsigned long len)
49{
50	unsigned long addr;
51
52	addr = platform_mmio + platform_mmio_alloc;
53	platform_mmio_alloc += len;
54	BUG_ON(platform_mmio_alloc > platform_mmiolen);
55
56	return addr;
57}
58
59static uint64_t get_callback_via(struct pci_dev *pdev)
60{
61	u8 pin;
62	int irq;
63
64	irq = pdev->irq;
65	if (irq < 16)
66		return irq; /* ISA IRQ */
67
68	pin = pdev->pin;
69
70	/* We don't know the GSI. Specify the PCI INTx line instead. */
71	return ((uint64_t)0x01 << 56) | /* PCI INTx identifier */
72		((uint64_t)pci_domain_nr(pdev->bus) << 32) |
73		((uint64_t)pdev->bus->number << 16) |
74		((uint64_t)(pdev->devfn & 0xff) << 8) |
75		((uint64_t)(pin - 1) & 3);
76}
77
78static irqreturn_t do_hvm_evtchn_intr(int irq, void *dev_id)
79{
80	xen_hvm_evtchn_do_upcall();
81	return IRQ_HANDLED;
82}
83
84static int xen_allocate_irq(struct pci_dev *pdev)
85{
86	return request_irq(pdev->irq, do_hvm_evtchn_intr,
87			IRQF_NOBALANCING | IRQF_TRIGGER_RISING,
88			"xen-platform-pci", pdev);
89}
90
91static int platform_pci_resume(struct pci_dev *pdev)
92{
93	int err;
94	if (xen_have_vector_callback)
95		return 0;
96	err = xen_set_callback_via(callback_via);
97	if (err) {
98		dev_err(&pdev->dev, "platform_pci_resume failure!\n");
99		return err;
100	}
101	return 0;
102}
103
104static int platform_pci_init(struct pci_dev *pdev,
105			     const struct pci_device_id *ent)
106{
107	int i, ret;
108	long ioaddr;
109	long mmio_addr, mmio_len;
110	unsigned int max_nr_gframes;
111	unsigned long grant_frames;
112
113	if (!xen_domain())
114		return -ENODEV;
115
116	i = pci_enable_device(pdev);
117	if (i)
118		return i;
119
120	ioaddr = pci_resource_start(pdev, 0);
121
122	mmio_addr = pci_resource_start(pdev, 1);
123	mmio_len = pci_resource_len(pdev, 1);
124
125	if (mmio_addr == 0 || ioaddr == 0) {
126		dev_err(&pdev->dev, "no resources found\n");
127		ret = -ENOENT;
128		goto pci_out;
129	}
130
131	ret = pci_request_region(pdev, 1, DRV_NAME);
132	if (ret < 0)
133		goto pci_out;
134
135	ret = pci_request_region(pdev, 0, DRV_NAME);
136	if (ret < 0)
137		goto mem_out;
138
139	platform_mmio = mmio_addr;
140	platform_mmiolen = mmio_len;
141
142	if (!xen_have_vector_callback) {
143		ret = xen_allocate_irq(pdev);
144		if (ret) {
145			dev_warn(&pdev->dev, "request_irq failed err=%d\n", ret);
146			goto out;
147		}
148		callback_via = get_callback_via(pdev);
149		ret = xen_set_callback_via(callback_via);
150		if (ret) {
151			dev_warn(&pdev->dev, "Unable to set the evtchn callback "
152					 "err=%d\n", ret);
153			goto out;
154		}
155	}
156
157	max_nr_gframes = gnttab_max_grant_frames();
158	grant_frames = alloc_xen_mmio(PAGE_SIZE * max_nr_gframes);
159	ret = gnttab_setup_auto_xlat_frames(grant_frames);
160	if (ret)
161		goto out;
162	ret = gnttab_init();
163	if (ret)
164		goto grant_out;
165	xenbus_probe(NULL);
166	return 0;
167grant_out:
168	gnttab_free_auto_xlat_frames();
169out:
170	pci_release_region(pdev, 0);
171mem_out:
172	pci_release_region(pdev, 1);
173pci_out:
174	pci_disable_device(pdev);
175	return ret;
176}
177
178static struct pci_device_id platform_pci_tbl[] = {
179	{PCI_VENDOR_ID_XEN, PCI_DEVICE_ID_XEN_PLATFORM,
180		PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
181	{0,}
182};
183
184MODULE_DEVICE_TABLE(pci, platform_pci_tbl);
185
186static struct pci_driver platform_driver = {
187	.name =           DRV_NAME,
188	.probe =          platform_pci_init,
189	.id_table =       platform_pci_tbl,
190#ifdef CONFIG_PM
191	.resume_early =   platform_pci_resume,
192#endif
193};
194
195static int __init platform_pci_module_init(void)
196{
197	return pci_register_driver(&platform_driver);
198}
199
200module_init(platform_pci_module_init);
201