xref: /linux/drivers/xen/platform-pci.c (revision 93df8a1ed6231727c5db94a80b1a6bd5ee67cec3)
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 
39 MODULE_AUTHOR("ssmith@xensource.com and stefano.stabellini@eu.citrix.com");
40 MODULE_DESCRIPTION("Xen platform PCI device");
41 MODULE_LICENSE("GPL");
42 
43 static unsigned long platform_mmio;
44 static unsigned long platform_mmio_alloc;
45 static unsigned long platform_mmiolen;
46 static uint64_t callback_via;
47 
48 static 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 
59 static 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 
78 static irqreturn_t do_hvm_evtchn_intr(int irq, void *dev_id)
79 {
80 	xen_hvm_evtchn_do_upcall();
81 	return IRQ_HANDLED;
82 }
83 
84 static 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 
91 static 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 
104 static 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;
167 grant_out:
168 	gnttab_free_auto_xlat_frames();
169 out:
170 	pci_release_region(pdev, 0);
171 mem_out:
172 	pci_release_region(pdev, 1);
173 pci_out:
174 	pci_disable_device(pdev);
175 	return ret;
176 }
177 
178 static 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 
184 MODULE_DEVICE_TABLE(pci, platform_pci_tbl);
185 
186 static 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 
195 static int __init platform_pci_module_init(void)
196 {
197 	return pci_register_driver(&platform_driver);
198 }
199 
200 module_init(platform_pci_module_init);
201