drivers/misc/pvpanic/pvpanic-pci.c

   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, struct device_attribute *attr, char *buf)
  26 {
  27         struct pvpanic_instance *pi = dev_get_drvdata(dev);
  28
  29         return sysfs_emit(buf, "%x\n", pi->capability);
  30 }
  31 static DEVICE_ATTR_RO(capability);
  32
  33 static ssize_t events_show(struct device *dev, struct device_attribute *attr, char *buf)
  34 {
  35         struct pvpanic_instance *pi = dev_get_drvdata(dev);
  36
  37         return sysfs_emit(buf, "%x\n", pi->events);
  38 }
  39
  40 static ssize_t events_store(struct device *dev, struct device_attribute *attr,
  41                             const char *buf, size_t count)
  42 {
  43         struct pvpanic_instance *pi = dev_get_drvdata(dev);
  44         unsigned int tmp;
  45         int err;
  46
  47         err = kstrtouint(buf, 16, &tmp);
  48         if (err)
  49                 return err;
  50
  51         if ((tmp & pi->capability) != tmp)
  52                 return -EINVAL;
  53
  54         pi->events = tmp;
  55
  56         return count;
  57 }
  58 static DEVICE_ATTR_RW(events);
  59
  60 static struct attribute *pvpanic_pci_dev_attrs[] = {
  61         &dev_attr_capability.attr,
  62         &dev_attr_events.attr,
  63         NULL
  64 };
  65 ATTRIBUTE_GROUPS(pvpanic_pci_dev);
  66
  67 static int pvpanic_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
  68 {
  69         struct pvpanic_instance *pi;
  70         void __iomem *base;
  71         int ret;
  72
  73         ret = pcim_enable_device(pdev);
  74         if (ret < 0)
  75                 return ret;
  76
  77         base = pcim_iomap(pdev, 0, 0);
  78         if (!base)
  79                 return -ENOMEM;
  80
  81         pi = devm_kmalloc(&pdev->dev, sizeof(*pi), GFP_KERNEL);
  82         if (!pi)
  83                 return -ENOMEM;
  84
  85         pi->base = base;
  86         pi->capability = PVPANIC_PANICKED | PVPANIC_CRASH_LOADED;
  87
  88         /* initlize capability by RDPT */
  89         pi->capability &= ioread8(base);
  90         pi->events = pi->capability;
  91
  92         return devm_pvpanic_probe(&pdev->dev, pi);
  93 }
  94
  95 static const struct pci_device_id pvpanic_pci_id_tbl[]  = {
  96         { PCI_DEVICE(PCI_VENDOR_ID_REDHAT, PCI_DEVICE_ID_REDHAT_PVPANIC)},
  97         {}
  98 };
  99 MODULE_DEVICE_TABLE(pci, pvpanic_pci_id_tbl);
 100
 101 static struct pci_driver pvpanic_pci_driver = {
 102         .name =         "pvpanic-pci",
 103         .id_table =     pvpanic_pci_id_tbl,
 104         .probe =        pvpanic_pci_probe,
 105         .driver = {
 106                 .dev_groups = pvpanic_pci_dev_groups,
 107         },
 108 };
 109 module_pci_driver(pvpanic_pci_driver);