xref: /openbmc/linux/drivers/xen/platform-pci.c (revision 293d5b43)
1 /******************************************************************************
2  * platform-pci.c
3  *
4  * Xen platform PCI device driver
5  *
6  * Authors: ssmith@xensource.com and stefano.stabellini@eu.citrix.com
7  *
8  * Copyright (c) 2005, Intel Corporation.
9  * Copyright (c) 2007, XenSource Inc.
10  * Copyright (c) 2010, Citrix
11  *
12  * This program is free software; you can redistribute it and/or modify it
13  * under the terms and conditions of the GNU General Public License,
14  * version 2, as published by the Free Software Foundation.
15  *
16  * This program is distributed in the hope it will be useful, but WITHOUT
17  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
18  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
19  * more details.
20  *
21  * You should have received a copy of the GNU General Public License along with
22  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
23  * Place - Suite 330, Boston, MA 02111-1307 USA.
24  *
25  */
26 
27 
28 #include <linux/interrupt.h>
29 #include <linux/io.h>
30 #include <linux/init.h>
31 #include <linux/pci.h>
32 
33 #include <xen/platform_pci.h>
34 #include <xen/grant_table.h>
35 #include <xen/xenbus.h>
36 #include <xen/events.h>
37 #include <xen/hvm.h>
38 #include <xen/xen-ops.h>
39 
40 #define DRV_NAME    "xen-platform-pci"
41 
42 static unsigned long platform_mmio;
43 static unsigned long platform_mmio_alloc;
44 static unsigned long platform_mmiolen;
45 static uint64_t callback_via;
46 
47 static unsigned long alloc_xen_mmio(unsigned long len)
48 {
49 	unsigned long addr;
50 
51 	addr = platform_mmio + platform_mmio_alloc;
52 	platform_mmio_alloc += len;
53 	BUG_ON(platform_mmio_alloc > platform_mmiolen);
54 
55 	return addr;
56 }
57 
58 static uint64_t get_callback_via(struct pci_dev *pdev)
59 {
60 	u8 pin;
61 	int irq;
62 
63 	irq = pdev->irq;
64 	if (irq < 16)
65 		return irq; /* ISA IRQ */
66 
67 	pin = pdev->pin;
68 
69 	/* We don't know the GSI. Specify the PCI INTx line instead. */
70 	return ((uint64_t)0x01 << 56) | /* PCI INTx identifier */
71 		((uint64_t)pci_domain_nr(pdev->bus) << 32) |
72 		((uint64_t)pdev->bus->number << 16) |
73 		((uint64_t)(pdev->devfn & 0xff) << 8) |
74 		((uint64_t)(pin - 1) & 3);
75 }
76 
77 static irqreturn_t do_hvm_evtchn_intr(int irq, void *dev_id)
78 {
79 	xen_hvm_evtchn_do_upcall();
80 	return IRQ_HANDLED;
81 }
82 
83 static int xen_allocate_irq(struct pci_dev *pdev)
84 {
85 	return request_irq(pdev->irq, do_hvm_evtchn_intr,
86 			IRQF_NOBALANCING | IRQF_TRIGGER_RISING,
87 			"xen-platform-pci", pdev);
88 }
89 
90 static int platform_pci_resume(struct pci_dev *pdev)
91 {
92 	int err;
93 	if (xen_have_vector_callback)
94 		return 0;
95 	err = xen_set_callback_via(callback_via);
96 	if (err) {
97 		dev_err(&pdev->dev, "platform_pci_resume failure!\n");
98 		return err;
99 	}
100 	return 0;
101 }
102 
103 static int platform_pci_probe(struct pci_dev *pdev,
104 			      const struct pci_device_id *ent)
105 {
106 	int i, ret;
107 	long ioaddr;
108 	long mmio_addr, mmio_len;
109 	unsigned int max_nr_gframes;
110 	unsigned long grant_frames;
111 
112 	if (!xen_domain())
113 		return -ENODEV;
114 
115 	i = pci_enable_device(pdev);
116 	if (i)
117 		return i;
118 
119 	ioaddr = pci_resource_start(pdev, 0);
120 
121 	mmio_addr = pci_resource_start(pdev, 1);
122 	mmio_len = pci_resource_len(pdev, 1);
123 
124 	if (mmio_addr == 0 || ioaddr == 0) {
125 		dev_err(&pdev->dev, "no resources found\n");
126 		ret = -ENOENT;
127 		goto pci_out;
128 	}
129 
130 	ret = pci_request_region(pdev, 1, DRV_NAME);
131 	if (ret < 0)
132 		goto pci_out;
133 
134 	ret = pci_request_region(pdev, 0, DRV_NAME);
135 	if (ret < 0)
136 		goto mem_out;
137 
138 	platform_mmio = mmio_addr;
139 	platform_mmiolen = mmio_len;
140 
141 	if (!xen_have_vector_callback) {
142 		ret = xen_allocate_irq(pdev);
143 		if (ret) {
144 			dev_warn(&pdev->dev, "request_irq failed err=%d\n", ret);
145 			goto out;
146 		}
147 		callback_via = get_callback_via(pdev);
148 		ret = xen_set_callback_via(callback_via);
149 		if (ret) {
150 			dev_warn(&pdev->dev, "Unable to set the evtchn callback "
151 					 "err=%d\n", ret);
152 			goto out;
153 		}
154 	}
155 
156 	max_nr_gframes = gnttab_max_grant_frames();
157 	grant_frames = alloc_xen_mmio(PAGE_SIZE * max_nr_gframes);
158 	ret = gnttab_setup_auto_xlat_frames(grant_frames);
159 	if (ret)
160 		goto out;
161 	ret = gnttab_init();
162 	if (ret)
163 		goto grant_out;
164 	xenbus_probe(NULL);
165 	return 0;
166 grant_out:
167 	gnttab_free_auto_xlat_frames();
168 out:
169 	pci_release_region(pdev, 0);
170 mem_out:
171 	pci_release_region(pdev, 1);
172 pci_out:
173 	pci_disable_device(pdev);
174 	return ret;
175 }
176 
177 static struct pci_device_id platform_pci_tbl[] = {
178 	{PCI_VENDOR_ID_XEN, PCI_DEVICE_ID_XEN_PLATFORM,
179 		PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
180 	{0,}
181 };
182 
183 static struct pci_driver platform_driver = {
184 	.name =           DRV_NAME,
185 	.probe =          platform_pci_probe,
186 	.id_table =       platform_pci_tbl,
187 #ifdef CONFIG_PM
188 	.resume_early =   platform_pci_resume,
189 #endif
190 };
191 
192 static int __init platform_pci_init(void)
193 {
194 	return pci_register_driver(&platform_driver);
195 }
196 device_initcall(platform_pci_init);
197