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bce5c2ea | 1 | // SPDX-License-Identifier: GPL-2.0 |
ccb86a69 MT |
2 | /* uio_pci_generic - generic UIO driver for PCI 2.3 devices |
3 | * | |
4 | * Copyright (C) 2009 Red Hat, Inc. | |
5 | * Author: Michael S. Tsirkin <mst@redhat.com> | |
6 | * | |
ccb86a69 MT |
7 | * Since the driver does not declare any device ids, you must allocate |
8 | * id and bind the device to the driver yourself. For example: | |
9 | * | |
10 | * # echo "8086 10f5" > /sys/bus/pci/drivers/uio_pci_generic/new_id | |
11 | * # echo -n 0000:00:19.0 > /sys/bus/pci/drivers/e1000e/unbind | |
12 | * # echo -n 0000:00:19.0 > /sys/bus/pci/drivers/uio_pci_generic/bind | |
13 | * # ls -l /sys/bus/pci/devices/0000:00:19.0/driver | |
14 | * .../0000:00:19.0/driver -> ../../../bus/pci/drivers/uio_pci_generic | |
15 | * | |
16 | * Driver won't bind to devices which do not support the Interrupt Disable Bit | |
17 | * in the command register. All devices compliant to PCI 2.3 (circa 2002) and | |
18 | * all compliant PCI Express devices should support this bit. | |
19 | */ | |
20 | ||
21 | #include <linux/device.h> | |
22 | #include <linux/module.h> | |
23 | #include <linux/pci.h> | |
5a0e3ad6 | 24 | #include <linux/slab.h> |
ccb86a69 | 25 | #include <linux/uio_driver.h> |
ccb86a69 MT |
26 | |
27 | #define DRIVER_VERSION "0.01.0" | |
28 | #define DRIVER_AUTHOR "Michael S. Tsirkin <mst@redhat.com>" | |
29 | #define DRIVER_DESC "Generic UIO driver for PCI 2.3 devices" | |
30 | ||
31 | struct uio_pci_generic_dev { | |
32 | struct uio_info info; | |
33 | struct pci_dev *pdev; | |
ccb86a69 MT |
34 | }; |
35 | ||
36 | static inline struct uio_pci_generic_dev * | |
37 | to_uio_pci_generic_dev(struct uio_info *info) | |
38 | { | |
39 | return container_of(info, struct uio_pci_generic_dev, info); | |
40 | } | |
41 | ||
865a11f9 VS |
42 | static int release(struct uio_info *info, struct inode *inode) |
43 | { | |
44 | struct uio_pci_generic_dev *gdev = to_uio_pci_generic_dev(info); | |
45 | ||
46 | /* | |
47 | * This driver is insecure when used with devices doing DMA, but some | |
48 | * people (mis)use it with such devices. | |
49 | * Let's at least make sure DMA isn't left enabled after the userspace | |
50 | * driver closes the fd. | |
51 | * Note that there's a non-zero chance doing this will wedge the device | |
52 | * at least until reset. | |
53 | */ | |
54 | pci_clear_master(gdev->pdev); | |
55 | return 0; | |
56 | } | |
57 | ||
ccb86a69 MT |
58 | /* Interrupt handler. Read/modify/write the command register to disable |
59 | * the interrupt. */ | |
60 | static irqreturn_t irqhandler(int irq, struct uio_info *info) | |
61 | { | |
62 | struct uio_pci_generic_dev *gdev = to_uio_pci_generic_dev(info); | |
ccb86a69 | 63 | |
2502dbdf JK |
64 | if (!pci_check_and_mask_intx(gdev->pdev)) |
65 | return IRQ_NONE; | |
ccb86a69 MT |
66 | |
67 | /* UIO core will signal the user process. */ | |
2502dbdf | 68 | return IRQ_HANDLED; |
ccb86a69 MT |
69 | } |
70 | ||
b17b75bb | 71 | static int probe(struct pci_dev *pdev, |
ccb86a69 MT |
72 | const struct pci_device_id *id) |
73 | { | |
74 | struct uio_pci_generic_dev *gdev; | |
e4e05016 | 75 | struct uio_mem *uiomem; |
ccb86a69 | 76 | int err; |
e4e05016 | 77 | int i; |
ccb86a69 | 78 | |
ef84928c | 79 | err = pcim_enable_device(pdev); |
ccb86a69 MT |
80 | if (err) { |
81 | dev_err(&pdev->dev, "%s: pci_enable_device failed: %d\n", | |
82 | __func__, err); | |
83 | return err; | |
84 | } | |
85 | ||
ef84928c | 86 | if (pdev->irq && !pci_intx_mask_supported(pdev)) |
156ed021 | 87 | return -ENODEV; |
ccb86a69 | 88 | |
ef84928c AA |
89 | gdev = devm_kzalloc(&pdev->dev, sizeof(struct uio_pci_generic_dev), GFP_KERNEL); |
90 | if (!gdev) | |
91 | return -ENOMEM; | |
ccb86a69 MT |
92 | |
93 | gdev->info.name = "uio_pci_generic"; | |
94 | gdev->info.version = DRIVER_VERSION; | |
865a11f9 | 95 | gdev->info.release = release; |
ccb86a69 | 96 | gdev->pdev = pdev; |
61de21a8 | 97 | if (pdev->irq && (pdev->irq != IRQ_NOTCONNECTED)) { |
acec09e6 JH |
98 | gdev->info.irq = pdev->irq; |
99 | gdev->info.irq_flags = IRQF_SHARED; | |
100 | gdev->info.handler = irqhandler; | |
101 | } else { | |
102 | dev_warn(&pdev->dev, "No IRQ assigned to device: " | |
103 | "no support for interrupts?\n"); | |
104 | } | |
ccb86a69 | 105 | |
e4e05016 FA |
106 | uiomem = &gdev->info.mem[0]; |
107 | for (i = 0; i < MAX_UIO_MAPS; ++i) { | |
108 | struct resource *r = &pdev->resource[i]; | |
109 | ||
110 | if (r->flags != (IORESOURCE_SIZEALIGN | IORESOURCE_MEM)) | |
111 | continue; | |
112 | ||
113 | if (uiomem >= &gdev->info.mem[MAX_UIO_MAPS]) { | |
114 | dev_warn( | |
115 | &pdev->dev, | |
116 | "device has more than " __stringify( | |
117 | MAX_UIO_MAPS) " I/O memory resources.\n"); | |
118 | break; | |
119 | } | |
120 | ||
121 | uiomem->memtype = UIO_MEM_PHYS; | |
122 | uiomem->addr = r->start & PAGE_MASK; | |
123 | uiomem->offs = r->start & ~PAGE_MASK; | |
124 | uiomem->size = | |
125 | (uiomem->offs + resource_size(r) + PAGE_SIZE - 1) & | |
126 | PAGE_MASK; | |
127 | uiomem->name = r->name; | |
128 | ++uiomem; | |
129 | } | |
130 | ||
131 | while (uiomem < &gdev->info.mem[MAX_UIO_MAPS]) { | |
132 | uiomem->size = 0; | |
133 | ++uiomem; | |
134 | } | |
135 | ||
4849e0ed | 136 | return devm_uio_register_device(&pdev->dev, &gdev->info); |
ccb86a69 MT |
137 | } |
138 | ||
cd437398 | 139 | static struct pci_driver uio_pci_driver = { |
ccb86a69 MT |
140 | .name = "uio_pci_generic", |
141 | .id_table = NULL, /* only dynamic id's */ | |
142 | .probe = probe, | |
ccb86a69 MT |
143 | }; |
144 | ||
cd437398 | 145 | module_pci_driver(uio_pci_driver); |
ccb86a69 MT |
146 | MODULE_VERSION(DRIVER_VERSION); |
147 | MODULE_LICENSE("GPL v2"); | |
148 | MODULE_AUTHOR(DRIVER_AUTHOR); | |
149 | MODULE_DESCRIPTION(DRIVER_DESC); |