1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  *  Pvpanic PCI Device Support
4  *
5  *  Copyright (C) 2021 Oracle.
6  */
7 
8 #include <linux/kernel.h>
9 #include <linux/module.h>
10 #include <linux/pci.h>
11 #include <linux/types.h>
12 #include <linux/slab.h>
13 
14 #include <uapi/misc/pvpanic.h>
15 
16 #include "pvpanic.h"
17 
18 #define PCI_VENDOR_ID_REDHAT             0x1b36
19 #define PCI_DEVICE_ID_REDHAT_PVPANIC     0x0011
20 
21 MODULE_AUTHOR("Mihai Carabas <mihai.carabas@oracle.com>");
22 MODULE_DESCRIPTION("pvpanic device driver ");
23 MODULE_LICENSE("GPL");
24 
25 static ssize_t capability_show(struct device *dev,
26 			       struct device_attribute *attr, char *buf)
27 {
28 	struct pvpanic_instance *pi = dev_get_drvdata(dev);
29 
30 	return sysfs_emit(buf, "%x\n", pi->capability);
31 }
32 static DEVICE_ATTR_RO(capability);
33 
34 static ssize_t events_show(struct device *dev,  struct device_attribute *attr, char *buf)
35 {
36 	struct pvpanic_instance *pi = dev_get_drvdata(dev);
37 
38 	return sysfs_emit(buf, "%x\n", pi->events);
39 }
40 
41 static ssize_t events_store(struct device *dev,  struct device_attribute *attr,
42 			    const char *buf, size_t count)
43 {
44 	struct pvpanic_instance *pi = dev_get_drvdata(dev);
45 	unsigned int tmp;
46 	int err;
47 
48 	err = kstrtouint(buf, 16, &tmp);
49 	if (err)
50 		return err;
51 
52 	if ((tmp & pi->capability) != tmp)
53 		return -EINVAL;
54 
55 	pi->events = tmp;
56 
57 	return count;
58 }
59 static DEVICE_ATTR_RW(events);
60 
61 static struct attribute *pvpanic_pci_dev_attrs[] = {
62 	&dev_attr_capability.attr,
63 	&dev_attr_events.attr,
64 	NULL
65 };
66 ATTRIBUTE_GROUPS(pvpanic_pci_dev);
67 
68 static int pvpanic_pci_probe(struct pci_dev *pdev,
69 			     const struct pci_device_id *ent)
70 {
71 	struct pvpanic_instance *pi;
72 	void __iomem *base;
73 	int ret;
74 
75 	ret = pcim_enable_device(pdev);
76 	if (ret < 0)
77 		return ret;
78 
79 	base = pcim_iomap(pdev, 0, 0);
80 	if (!base)
81 		return -ENOMEM;
82 
83 	pi = devm_kmalloc(&pdev->dev, sizeof(*pi), GFP_KERNEL);
84 	if (!pi)
85 		return -ENOMEM;
86 
87 	pi->base = base;
88 	pi->capability = PVPANIC_PANICKED | PVPANIC_CRASH_LOADED;
89 
90 	/* initlize capability by RDPT */
91 	pi->capability &= ioread8(base);
92 	pi->events = pi->capability;
93 
94 	return devm_pvpanic_probe(&pdev->dev, pi);
95 }
96 
97 static const struct pci_device_id pvpanic_pci_id_tbl[]  = {
98 	{ PCI_DEVICE(PCI_VENDOR_ID_REDHAT, PCI_DEVICE_ID_REDHAT_PVPANIC)},
99 	{}
100 };
101 MODULE_DEVICE_TABLE(pci, pvpanic_pci_id_tbl);
102 
103 static struct pci_driver pvpanic_pci_driver = {
104 	.name =         "pvpanic-pci",
105 	.id_table =     pvpanic_pci_id_tbl,
106 	.probe =        pvpanic_pci_probe,
107 	.driver = {
108 		.dev_groups = pvpanic_pci_dev_groups,
109 	},
110 };
111 module_pci_driver(pvpanic_pci_driver);
112