1 // SPDX-License-Identifier: GPL-2.0-only
2 /******************************************************************************
3 * platform-pci.c
4 *
5 * Xen platform PCI device driver
6 *
7 * Authors: ssmith@xensource.com and stefano.stabellini@eu.citrix.com
8 *
9 * Copyright (c) 2005, Intel Corporation.
10 * Copyright (c) 2007, XenSource Inc.
11 * Copyright (c) 2010, Citrix
12 */
13
14
15 #include <linux/interrupt.h>
16 #include <linux/io.h>
17 #include <linux/init.h>
18 #include <linux/pci.h>
19
20 #include <xen/platform_pci.h>
21 #include <xen/grant_table.h>
22 #include <xen/xenbus.h>
23 #include <xen/events.h>
24 #include <xen/hvm.h>
25 #include <xen/xen-ops.h>
26
27 #define DRV_NAME "xen-platform-pci"
28
29 static unsigned long platform_mmio;
30 static unsigned long platform_mmio_alloc;
31 static unsigned long platform_mmiolen;
32 static uint64_t callback_via;
33
alloc_xen_mmio(unsigned long len)34 static unsigned long alloc_xen_mmio(unsigned long len)
35 {
36 unsigned long addr;
37
38 addr = platform_mmio + platform_mmio_alloc;
39 platform_mmio_alloc += len;
40 BUG_ON(platform_mmio_alloc > platform_mmiolen);
41
42 return addr;
43 }
44
get_callback_via(struct pci_dev * pdev)45 static uint64_t get_callback_via(struct pci_dev *pdev)
46 {
47 u8 pin;
48 int irq;
49
50 irq = pdev->irq;
51 if (irq < 16)
52 return irq; /* ISA IRQ */
53
54 pin = pdev->pin;
55
56 /* We don't know the GSI. Specify the PCI INTx line instead. */
57 return ((uint64_t)HVM_PARAM_CALLBACK_TYPE_PCI_INTX <<
58 HVM_CALLBACK_VIA_TYPE_SHIFT) |
59 ((uint64_t)pci_domain_nr(pdev->bus) << 32) |
60 ((uint64_t)pdev->bus->number << 16) |
61 ((uint64_t)(pdev->devfn & 0xff) << 8) |
62 ((uint64_t)(pin - 1) & 3);
63 }
64
do_hvm_evtchn_intr(int irq,void * dev_id)65 static irqreturn_t do_hvm_evtchn_intr(int irq, void *dev_id)
66 {
67 xen_hvm_evtchn_do_upcall();
68 return IRQ_HANDLED;
69 }
70
xen_allocate_irq(struct pci_dev * pdev)71 static int xen_allocate_irq(struct pci_dev *pdev)
72 {
73 return request_irq(pdev->irq, do_hvm_evtchn_intr,
74 IRQF_NOBALANCING | IRQF_TRIGGER_RISING,
75 "xen-platform-pci", pdev);
76 }
77
platform_pci_resume(struct device * dev)78 static int platform_pci_resume(struct device *dev)
79 {
80 int err;
81
82 if (xen_have_vector_callback)
83 return 0;
84
85 err = xen_set_callback_via(callback_via);
86 if (err) {
87 dev_err(dev, "platform_pci_resume failure!\n");
88 return err;
89 }
90 return 0;
91 }
92
platform_pci_probe(struct pci_dev * pdev,const struct pci_device_id * ent)93 static int platform_pci_probe(struct pci_dev *pdev,
94 const struct pci_device_id *ent)
95 {
96 int i, ret;
97 long ioaddr;
98 long mmio_addr, mmio_len;
99 unsigned int max_nr_gframes;
100 unsigned long grant_frames;
101
102 if (!xen_domain())
103 return -ENODEV;
104
105 i = pci_enable_device(pdev);
106 if (i)
107 return i;
108
109 ioaddr = pci_resource_start(pdev, 0);
110
111 mmio_addr = pci_resource_start(pdev, 1);
112 mmio_len = pci_resource_len(pdev, 1);
113
114 if (mmio_addr == 0 || ioaddr == 0) {
115 dev_err(&pdev->dev, "no resources found\n");
116 ret = -ENOENT;
117 goto pci_out;
118 }
119
120 ret = pci_request_region(pdev, 1, DRV_NAME);
121 if (ret < 0)
122 goto pci_out;
123
124 ret = pci_request_region(pdev, 0, DRV_NAME);
125 if (ret < 0)
126 goto mem_out;
127
128 platform_mmio = mmio_addr;
129 platform_mmiolen = mmio_len;
130 if (!xen_have_vector_callback) {
131 ret = xen_allocate_irq(pdev);
132 if (ret) {
133 dev_warn(&pdev->dev, "request_irq failed err=%d\n", ret);
134 goto out;
135 }
136 /*
137 * It doesn't strictly *have* to run on CPU0 but it sure
138 * as hell better process the event channel ports delivered
139 * to CPU0.
140 */
141 irq_set_affinity(pdev->irq, cpumask_of(0));
142
143 callback_via = get_callback_via(pdev);
144 ret = xen_set_callback_via(callback_via);
145 if (ret) {
146 dev_warn(&pdev->dev, "Unable to set the evtchn callback "
147 "err=%d\n", ret);
148 goto irq_out;
149 }
150 }
151
152 max_nr_gframes = gnttab_max_grant_frames();
153 grant_frames = alloc_xen_mmio(PAGE_SIZE * max_nr_gframes);
154 ret = gnttab_setup_auto_xlat_frames(grant_frames);
155 if (ret)
156 goto irq_out;
157 ret = gnttab_init();
158 if (ret)
159 goto grant_out;
160 return 0;
161 grant_out:
162 gnttab_free_auto_xlat_frames();
163 irq_out:
164 if (!xen_have_vector_callback)
165 free_irq(pdev->irq, pdev);
166 out:
167 pci_release_region(pdev, 0);
168 mem_out:
169 pci_release_region(pdev, 1);
170 pci_out:
171 pci_disable_device(pdev);
172 return ret;
173 }
174
175 static const struct pci_device_id platform_pci_tbl[] = {
176 {PCI_VENDOR_ID_XEN, PCI_DEVICE_ID_XEN_PLATFORM,
177 PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
178 {0,}
179 };
180
181 static const struct dev_pm_ops platform_pm_ops = {
182 .resume_noirq = platform_pci_resume,
183 };
184
185 static struct pci_driver platform_driver = {
186 .name = DRV_NAME,
187 .probe = platform_pci_probe,
188 .id_table = platform_pci_tbl,
189 .driver = {
190 .pm = &platform_pm_ops,
191 },
192 };
193
194 builtin_pci_driver(platform_driver);
195
