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 const struct pci_device_id pvpanic_pci_id_tbl[]  = {
  26         { PCI_DEVICE(PCI_VENDOR_ID_REDHAT, PCI_DEVICE_ID_REDHAT_PVPANIC)},
  27         {}
  28 };
  29
  30 static ssize_t capability_show(struct device *dev,
  31                                struct device_attribute *attr, char *buf)
  32 {
  33         struct pvpanic_instance *pi = dev_get_drvdata(dev);
  34
  35         return sysfs_emit(buf, "%x\n", pi->capability);
  36 }
  37 static DEVICE_ATTR_RO(capability);
  38
  39 static ssize_t events_show(struct device *dev,  struct device_attribute *attr, char *buf)
  40 {
  41         struct pvpanic_instance *pi = dev_get_drvdata(dev);
  42
  43         return sysfs_emit(buf, "%x\n", pi->events);
  44 }
  45
  46 static ssize_t events_store(struct device *dev,  struct device_attribute *attr,
  47                             const char *buf, size_t count)
  48 {
  49         struct pvpanic_instance *pi = dev_get_drvdata(dev);
  50         unsigned int tmp;
  51         int err;
  52
  53         err = kstrtouint(buf, 16, &tmp);
  54         if (err)
  55                 return err;
  56
  57         if ((tmp & pi->capability) != tmp)
  58                 return -EINVAL;
  59
  60         pi->events = tmp;
  61
  62         return count;
  63 }
  64 static DEVICE_ATTR_RW(events);
  65
  66 static struct attribute *pvpanic_pci_dev_attrs[] = {
  67         &dev_attr_capability.attr,
  68         &dev_attr_events.attr,
  69         NULL
  70 };
  71 ATTRIBUTE_GROUPS(pvpanic_pci_dev);
  72
  73 static int pvpanic_pci_probe(struct pci_dev *pdev,
  74                              const struct pci_device_id *ent)
  75 {
  76         struct pvpanic_instance *pi;
  77         void __iomem *base;
  78         int ret;
  79
  80         ret = pcim_enable_device(pdev);
  81         if (ret < 0)
  82                 return ret;
  83
  84         base = pcim_iomap(pdev, 0, 0);
  85         if (!base)
  86                 return -ENOMEM;
  87
  88         pi = devm_kmalloc(&pdev->dev, sizeof(*pi), GFP_KERNEL);
  89         if (!pi)
  90                 return -ENOMEM;
  91
  92         pi->base = base;
  93         pi->capability = PVPANIC_PANICKED | PVPANIC_CRASH_LOADED;
  94
  95         /* initlize capability by RDPT */
  96         pi->capability &= ioread8(base);
  97         pi->events = pi->capability;
  98
  99         return devm_pvpanic_probe(&pdev->dev, pi);
 100 }
 101
 102 static struct pci_driver pvpanic_pci_driver = {
 103         .name =         "pvpanic-pci",
 104         .id_table =     pvpanic_pci_id_tbl,
 105         .probe =        pvpanic_pci_probe,
 106         .driver = {
 107                 .dev_groups = pvpanic_pci_dev_groups,
 108         },
 109 };
 110
 111 module_pci_driver(pvpanic_pci_driver);