xref: /openbmc/linux/drivers/xen/platform-pci.c (revision b9ccfda2)
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 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_DISABLED | 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 void __devinit prepare_shared_info(void)
105 {
106 #ifdef CONFIG_KEXEC
107 	unsigned long addr;
108 	struct shared_info *hvm_shared_info;
109 
110 	addr = alloc_xen_mmio(PAGE_SIZE);
111 	hvm_shared_info = ioremap(addr, PAGE_SIZE);
112 	memset(hvm_shared_info, 0, PAGE_SIZE);
113 	xen_hvm_prepare_kexec(hvm_shared_info, addr >> PAGE_SHIFT);
114 #endif
115 }
116 
117 static int __devinit platform_pci_init(struct pci_dev *pdev,
118 				       const struct pci_device_id *ent)
119 {
120 	int i, ret;
121 	long ioaddr;
122 	long mmio_addr, mmio_len;
123 	unsigned int max_nr_gframes;
124 
125 	if (!xen_domain())
126 		return -ENODEV;
127 
128 	i = pci_enable_device(pdev);
129 	if (i)
130 		return i;
131 
132 	ioaddr = pci_resource_start(pdev, 0);
133 
134 	mmio_addr = pci_resource_start(pdev, 1);
135 	mmio_len = pci_resource_len(pdev, 1);
136 
137 	if (mmio_addr == 0 || ioaddr == 0) {
138 		dev_err(&pdev->dev, "no resources found\n");
139 		ret = -ENOENT;
140 		goto pci_out;
141 	}
142 
143 	ret = pci_request_region(pdev, 1, DRV_NAME);
144 	if (ret < 0)
145 		goto pci_out;
146 
147 	ret = pci_request_region(pdev, 0, DRV_NAME);
148 	if (ret < 0)
149 		goto mem_out;
150 
151 	platform_mmio = mmio_addr;
152 	platform_mmiolen = mmio_len;
153 
154 	prepare_shared_info();
155 
156 	if (!xen_have_vector_callback) {
157 		ret = xen_allocate_irq(pdev);
158 		if (ret) {
159 			dev_warn(&pdev->dev, "request_irq failed err=%d\n", ret);
160 			goto out;
161 		}
162 		callback_via = get_callback_via(pdev);
163 		ret = xen_set_callback_via(callback_via);
164 		if (ret) {
165 			dev_warn(&pdev->dev, "Unable to set the evtchn callback "
166 					 "err=%d\n", ret);
167 			goto out;
168 		}
169 	}
170 
171 	max_nr_gframes = gnttab_max_grant_frames();
172 	xen_hvm_resume_frames = alloc_xen_mmio(PAGE_SIZE * max_nr_gframes);
173 	ret = gnttab_init();
174 	if (ret)
175 		goto out;
176 	xenbus_probe(NULL);
177 	return 0;
178 
179 out:
180 	pci_release_region(pdev, 0);
181 mem_out:
182 	pci_release_region(pdev, 1);
183 pci_out:
184 	pci_disable_device(pdev);
185 	return ret;
186 }
187 
188 static struct pci_device_id platform_pci_tbl[] __devinitdata = {
189 	{PCI_VENDOR_ID_XEN, PCI_DEVICE_ID_XEN_PLATFORM,
190 		PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
191 	{0,}
192 };
193 
194 MODULE_DEVICE_TABLE(pci, platform_pci_tbl);
195 
196 static struct pci_driver platform_driver = {
197 	.name =           DRV_NAME,
198 	.probe =          platform_pci_init,
199 	.id_table =       platform_pci_tbl,
200 #ifdef CONFIG_PM
201 	.resume_early =   platform_pci_resume,
202 #endif
203 };
204 
205 static int __init platform_pci_module_init(void)
206 {
207 	return pci_register_driver(&platform_driver);
208 }
209 
210 module_init(platform_pci_module_init);
211