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 pci_dev * pdev)77 static int platform_pci_resume(struct pci_dev *pdev)
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(&pdev->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 callback_via = get_callback_via(pdev);
136 ret = xen_set_callback_via(callback_via);
137 if (ret) {
138 dev_warn(&pdev->dev, "Unable to set the evtchn callback "
139 "err=%d\n", ret);
140 goto out;
141 }
142 }
143
144 max_nr_gframes = gnttab_max_grant_frames();
145 grant_frames = alloc_xen_mmio(PAGE_SIZE * max_nr_gframes);
146 ret = gnttab_setup_auto_xlat_frames(grant_frames);
147 if (ret)
148 goto out;
149 ret = gnttab_init();
150 if (ret)
151 goto grant_out;
152 xenbus_probe(NULL);
153 return 0;
154 grant_out:
155 gnttab_free_auto_xlat_frames();
156 out:
157 pci_release_region(pdev, 0);
158 mem_out:
159 pci_release_region(pdev, 1);
160 pci_out:
161 pci_disable_device(pdev);
162 return ret;
163 }
164
165 static const struct pci_device_id platform_pci_tbl[] = {
166 {PCI_VENDOR_ID_XEN, PCI_DEVICE_ID_XEN_PLATFORM,
167 PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
168 {0,}
169 };
170
171 static struct pci_driver platform_driver = {
172 .name = DRV_NAME,
173 .probe = platform_pci_probe,
174 .id_table = platform_pci_tbl,
175 #ifdef CONFIG_PM
176 .resume_early = platform_pci_resume,
177 #endif
178 };
179
180 builtin_pci_driver(platform_driver);
181