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)0x01 << HVM_CALLBACK_VIA_TYPE_SHIFT) | /* PCI INTx identifier */
58 ((uint64_t)pci_domain_nr(pdev->bus) << 32) |
59 ((uint64_t)pdev->bus->number << 16) |
60 ((uint64_t)(pdev->devfn & 0xff) << 8) |
61 ((uint64_t)(pin - 1) & 3);
62 }
63
do_hvm_evtchn_intr(int irq,void * dev_id)64 static irqreturn_t do_hvm_evtchn_intr(int irq, void *dev_id)
65 {
66 xen_hvm_evtchn_do_upcall();
67 return IRQ_HANDLED;
68 }
69
xen_allocate_irq(struct pci_dev * pdev)70 static int xen_allocate_irq(struct pci_dev *pdev)
71 {
72 return request_irq(pdev->irq, do_hvm_evtchn_intr,
73 IRQF_NOBALANCING | IRQF_TRIGGER_RISING,
74 "xen-platform-pci", pdev);
75 }
76
platform_pci_resume(struct device * dev)77 static int platform_pci_resume(struct device *dev)
78 {
79 int err;
80
81 if (xen_have_vector_callback)
82 return 0;
83
84 err = xen_set_callback_via(callback_via);
85 if (err) {
86 dev_err(dev, "platform_pci_resume failure!\n");
87 return err;
88 }
89 return 0;
90 }
91
platform_pci_probe(struct pci_dev * pdev,const struct pci_device_id * ent)92 static int platform_pci_probe(struct pci_dev *pdev,
93 const struct pci_device_id *ent)
94 {
95 int i, ret;
96 long ioaddr;
97 long mmio_addr, mmio_len;
98 unsigned int max_nr_gframes;
99 unsigned long grant_frames;
100
101 if (!xen_domain())
102 return -ENODEV;
103
104 i = pci_enable_device(pdev);
105 if (i)
106 return i;
107
108 ioaddr = pci_resource_start(pdev, 0);
109
110 mmio_addr = pci_resource_start(pdev, 1);
111 mmio_len = pci_resource_len(pdev, 1);
112
113 if (mmio_addr == 0 || ioaddr == 0) {
114 dev_err(&pdev->dev, "no resources found\n");
115 ret = -ENOENT;
116 goto pci_out;
117 }
118
119 ret = pci_request_region(pdev, 1, DRV_NAME);
120 if (ret < 0)
121 goto pci_out;
122
123 ret = pci_request_region(pdev, 0, DRV_NAME);
124 if (ret < 0)
125 goto mem_out;
126
127 platform_mmio = mmio_addr;
128 platform_mmiolen = mmio_len;
129 if (!xen_have_vector_callback) {
130 ret = xen_allocate_irq(pdev);
131 if (ret) {
132 dev_warn(&pdev->dev, "request_irq failed err=%d\n", ret);
133 goto out;
134 }
135 /*
136 * It doesn't strictly *have* to run on CPU0 but it sure
137 * as hell better process the event channel ports delivered
138 * to CPU0.
139 */
140 irq_set_affinity(pdev->irq, cpumask_of(0));
141
142 callback_via = get_callback_via(pdev);
143 ret = xen_set_callback_via(callback_via);
144 if (ret) {
145 dev_warn(&pdev->dev, "Unable to set the evtchn callback "
146 "err=%d\n", ret);
147 goto out;
148 }
149 }
150
151 max_nr_gframes = gnttab_max_grant_frames();
152 grant_frames = alloc_xen_mmio(PAGE_SIZE * max_nr_gframes);
153 ret = gnttab_setup_auto_xlat_frames(grant_frames);
154 if (ret)
155 goto out;
156 ret = gnttab_init();
157 if (ret)
158 goto grant_out;
159 return 0;
160 grant_out:
161 gnttab_free_auto_xlat_frames();
162 out:
163 pci_release_region(pdev, 0);
164 mem_out:
165 pci_release_region(pdev, 1);
166 pci_out:
167 pci_disable_device(pdev);
168 return ret;
169 }
170
171 static const struct pci_device_id platform_pci_tbl[] = {
172 {PCI_VENDOR_ID_XEN, PCI_DEVICE_ID_XEN_PLATFORM,
173 PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
174 {0,}
175 };
176
177 static const struct dev_pm_ops platform_pm_ops = {
178 .resume_noirq = platform_pci_resume,
179 };
180
181 static struct pci_driver platform_driver = {
182 .name = DRV_NAME,
183 .probe = platform_pci_probe,
184 .id_table = platform_pci_tbl,
185 .driver = {
186 .pm = &platform_pm_ops,
187 },
188 };
189
190 builtin_pci_driver(platform_driver);
191