drivers/dma/idxd/compat.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright(c) 2021 Intel Corporation. All rights rsvd. */
   3 #include <linux/init.h>
   4 #include <linux/kernel.h>
   5 #include <linux/module.h>
   6 #include <linux/device.h>
   7 #include <linux/device/bus.h>
   8 #include "idxd.h"
   9
  10 extern void device_driver_detach(struct device *dev);
  11
  12 #define DRIVER_ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) \
  13         struct driver_attribute driver_attr_##_name =           \
  14         __ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store)
  15
  16 static ssize_t unbind_store(struct device_driver *drv, const char *buf, size_t count)
  17 {
  18         const struct bus_type *bus = drv->bus;
  19         struct device *dev;
  20         int rc = -ENODEV;
  21
  22         dev = bus_find_device_by_name(bus, NULL, buf);
  23         if (dev && dev->driver) {
  24                 device_driver_detach(dev);
  25                 rc = count;
  26         }
  27
  28         return rc;
  29 }
  30 static DRIVER_ATTR_IGNORE_LOCKDEP(unbind, 0200, NULL, unbind_store);
  31
  32 static ssize_t bind_store(struct device_driver *drv, const char *buf, size_t count)
  33 {
  34         const struct bus_type *bus = drv->bus;
  35         struct device *dev;
  36         struct device_driver *alt_drv = NULL;
  37         int rc = -ENODEV;
  38         struct idxd_dev *idxd_dev;
  39
  40         dev = bus_find_device_by_name(bus, NULL, buf);
  41         if (!dev || dev->driver || drv != &dsa_drv.drv)
  42                 return -ENODEV;
  43
  44         idxd_dev = confdev_to_idxd_dev(dev);
  45         if (is_idxd_dev(idxd_dev)) {
  46                 alt_drv = driver_find("idxd", bus);
  47         } else if (is_idxd_wq_dev(idxd_dev)) {
  48                 struct idxd_wq *wq = confdev_to_wq(dev);
  49
  50                 if (is_idxd_wq_kernel(wq))
  51                         alt_drv = driver_find("dmaengine", bus);
  52                 else if (is_idxd_wq_user(wq))
  53                         alt_drv = driver_find("user", bus);
  54         }
  55         if (!alt_drv)
  56                 return -ENODEV;
  57
  58         rc = device_driver_attach(alt_drv, dev);
  59         if (rc < 0)
  60                 return rc;
  61
  62         return count;
  63 }
  64 static DRIVER_ATTR_IGNORE_LOCKDEP(bind, 0200, NULL, bind_store);
  65
  66 static struct attribute *dsa_drv_compat_attrs[] = {
  67         &driver_attr_bind.attr,
  68         &driver_attr_unbind.attr,
  69         NULL,
  70 };
  71
  72 static const struct attribute_group dsa_drv_compat_attr_group = {
  73         .attrs = dsa_drv_compat_attrs,
  74 };
  75
  76 static const struct attribute_group *dsa_drv_compat_groups[] = {
  77         &dsa_drv_compat_attr_group,
  78         NULL,
  79 };
  80
  81 static int idxd_dsa_drv_probe(struct idxd_dev *idxd_dev)
  82 {
  83         return -ENODEV;
  84 }
  85
  86 static void idxd_dsa_drv_remove(struct idxd_dev *idxd_dev)
  87 {
  88 }
  89
  90 static enum idxd_dev_type dev_types[] = {
  91         IDXD_DEV_NONE,
  92 };
  93
  94 struct idxd_device_driver dsa_drv = {
  95         .name = "dsa",
  96         .probe = idxd_dsa_drv_probe,
  97         .remove = idxd_dsa_drv_remove,
  98         .type = dev_types,
  99         .drv = {
 100                 .suppress_bind_attrs = true,
 101                 .groups = dsa_drv_compat_groups,
 102         },
 103 };
 104
 105 module_idxd_driver(dsa_drv);
 106 MODULE_IMPORT_NS("IDXD");