xref: /openbmc/linux/drivers/xen/platform-pci.c (revision 711aab1d)
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 << HVM_CALLBACK_VIA_TYPE_SHIFT) | /* 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 
94 	if (xen_have_vector_callback)
95 		return 0;
96 
97 	err = xen_set_callback_via(callback_via);
98 	if (err) {
99 		dev_err(&pdev->dev, "platform_pci_resume failure!\n");
100 		return err;
101 	}
102 	return 0;
103 }
104 
105 static int platform_pci_probe(struct pci_dev *pdev,
106 			      const struct pci_device_id *ent)
107 {
108 	int i, ret;
109 	long ioaddr;
110 	long mmio_addr, mmio_len;
111 	unsigned int max_nr_gframes;
112 	unsigned long grant_frames;
113 
114 	if (!xen_domain())
115 		return -ENODEV;
116 
117 	i = pci_enable_device(pdev);
118 	if (i)
119 		return i;
120 
121 	ioaddr = pci_resource_start(pdev, 0);
122 
123 	mmio_addr = pci_resource_start(pdev, 1);
124 	mmio_len = pci_resource_len(pdev, 1);
125 
126 	if (mmio_addr == 0 || ioaddr == 0) {
127 		dev_err(&pdev->dev, "no resources found\n");
128 		ret = -ENOENT;
129 		goto pci_out;
130 	}
131 
132 	ret = pci_request_region(pdev, 1, DRV_NAME);
133 	if (ret < 0)
134 		goto pci_out;
135 
136 	ret = pci_request_region(pdev, 0, DRV_NAME);
137 	if (ret < 0)
138 		goto mem_out;
139 
140 	platform_mmio = mmio_addr;
141 	platform_mmiolen = mmio_len;
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 const 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 static struct pci_driver platform_driver = {
185 	.name =           DRV_NAME,
186 	.probe =          platform_pci_probe,
187 	.id_table =       platform_pci_tbl,
188 #ifdef CONFIG_PM
189 	.resume_early =   platform_pci_resume,
190 #endif
191 };
192 
193 builtin_pci_driver(platform_driver);
194