arch/ppc64/kernel/vio.c

   1 /*
   2  * IBM PowerPC Virtual I/O Infrastructure Support.
   3  *
   4  *    Copyright (c) 2003-2005 IBM Corp.
   5  *     Dave Engebretsen engebret@us.ibm.com
   6  *     Santiago Leon santil@us.ibm.com
   7  *     Hollis Blanchard <hollisb@us.ibm.com>
   8  *     Stephen Rothwell
   9  *
  10  *      This program is free software; you can redistribute it and/or
  11  *      modify it under the terms of the GNU General Public License
  12  *      as published by the Free Software Foundation; either version
  13  *      2 of the License, or (at your option) any later version.
  14  */
  15
  16 #include <linux/init.h>
  17 #include <linux/console.h>
  18 #include <linux/module.h>
  19 #include <linux/mm.h>
  20 #include <linux/dma-mapping.h>
  21 #include <asm/iommu.h>
  22 #include <asm/dma.h>
  23 #include <asm/vio.h>
  24
  25 static const struct vio_device_id *vio_match_device(
  26                 const struct vio_device_id *, const struct vio_dev *);
  27
  28 struct vio_dev vio_bus_device  = { /* fake "parent" device */
  29         .name = vio_bus_device.dev.bus_id,
  30         .type = "",
  31         .dev.bus_id = "vio",
  32         .dev.bus = &vio_bus_type,
  33 };
  34
  35 static int (*is_match)(const struct vio_device_id *id,
  36                 const struct vio_dev *dev);
  37 static void (*unregister_device_callback)(struct vio_dev *dev);
  38 static void (*release_device_callback)(struct device *dev);
  39
  40 /*
  41  * Convert from struct device to struct vio_dev and pass to driver.
  42  * dev->driver has already been set by generic code because vio_bus_match
  43  * succeeded.
  44  */
  45 static int vio_bus_probe(struct device *dev)
  46 {
  47         struct vio_dev *viodev = to_vio_dev(dev);
  48         struct vio_driver *viodrv = to_vio_driver(dev->driver);
  49         const struct vio_device_id *id;
  50         int error = -ENODEV;
  51
  52         if (!viodrv->probe)
  53                 return error;
  54
  55         id = vio_match_device(viodrv->id_table, viodev);
  56         if (id)
  57                 error = viodrv->probe(viodev, id);
  58
  59         return error;
  60 }
  61
  62 /* convert from struct device to struct vio_dev and pass to driver. */
  63 static int vio_bus_remove(struct device *dev)
  64 {
  65         struct vio_dev *viodev = to_vio_dev(dev);
  66         struct vio_driver *viodrv = to_vio_driver(dev->driver);
  67
  68         if (viodrv->remove)
  69                 return viodrv->remove(viodev);
  70
  71         /* driver can't remove */
  72         return 1;
  73 }
  74
  75 /**
  76  * vio_register_driver: - Register a new vio driver
  77  * @drv:        The vio_driver structure to be registered.
  78  */
  79 int vio_register_driver(struct vio_driver *viodrv)
  80 {
  81         printk(KERN_DEBUG "%s: driver %s registering\n", __FUNCTION__,
  82                 viodrv->name);
  83
  84         /* fill in 'struct driver' fields */
  85         viodrv->driver.name = viodrv->name;
  86         viodrv->driver.bus = &vio_bus_type;
  87         viodrv->driver.probe = vio_bus_probe;
  88         viodrv->driver.remove = vio_bus_remove;
  89
  90         return driver_register(&viodrv->driver);
  91 }
  92 EXPORT_SYMBOL(vio_register_driver);
  93
  94 /**
  95  * vio_unregister_driver - Remove registration of vio driver.
  96  * @driver:     The vio_driver struct to be removed form registration
  97  */
  98 void vio_unregister_driver(struct vio_driver *viodrv)
  99 {
 100         driver_unregister(&viodrv->driver);
 101 }
 102 EXPORT_SYMBOL(vio_unregister_driver);
 103
 104 /**
 105  * vio_match_device: - Tell if a VIO device has a matching
 106  *                      VIO device id structure.
 107  * @ids:        array of VIO device id structures to search in
 108  * @dev:        the VIO device structure to match against
 109  *
 110  * Used by a driver to check whether a VIO device present in the
 111  * system is in its list of supported devices. Returns the matching
 112  * vio_device_id structure or NULL if there is no match.
 113  */
 114 static const struct vio_device_id *vio_match_device(
 115                 const struct vio_device_id *ids, const struct vio_dev *dev)
 116 {
 117         while (ids->type) {
 118                 if (is_match(ids, dev))
 119                         return ids;
 120                 ids++;
 121         }
 122         return NULL;
 123 }
 124
 125 /**
 126  * vio_bus_init: - Initialize the virtual IO bus
 127  */
 128 int __init vio_bus_init(int (*match_func)(const struct vio_device_id *id,
 129                         const struct vio_dev *dev),
 130                 void (*unregister_dev)(struct vio_dev *),
 131                 void (*release_dev)(struct device *))
 132 {
 133         int err;
 134
 135         is_match = match_func;
 136         unregister_device_callback = unregister_dev;
 137         release_device_callback = release_dev;
 138
 139         err = bus_register(&vio_bus_type);
 140         if (err) {
 141                 printk(KERN_ERR "failed to register VIO bus\n");
 142                 return err;
 143         }
 144
 145         /*
 146          * The fake parent of all vio devices, just to give us
 147          * a nice directory
 148          */
 149         err = device_register(&vio_bus_device.dev);
 150         if (err) {
 151                 printk(KERN_WARNING "%s: device_register returned %i\n",
 152                                 __FUNCTION__, err);
 153                 return err;
 154         }
 155
 156         return 0;
 157 }
 158
 159 /* vio_dev refcount hit 0 */
 160 static void __devinit vio_dev_release(struct device *dev)
 161 {
 162         if (release_device_callback)
 163                 release_device_callback(dev);
 164         kfree(to_vio_dev(dev));
 165 }
 166
 167 static ssize_t viodev_show_name(struct device *dev,
 168                 struct device_attribute *attr, char *buf)
 169 {
 170         return sprintf(buf, "%s\n", to_vio_dev(dev)->name);
 171 }
 172 DEVICE_ATTR(name, S_IRUSR | S_IRGRP | S_IROTH, viodev_show_name, NULL);
 173
 174 struct vio_dev * __devinit vio_register_device(struct vio_dev *viodev)
 175 {
 176         /* init generic 'struct device' fields: */
 177         viodev->dev.parent = &vio_bus_device.dev;
 178         viodev->dev.bus = &vio_bus_type;
 179         viodev->dev.release = vio_dev_release;
 180
 181         /* register with generic device framework */
 182         if (device_register(&viodev->dev)) {
 183                 printk(KERN_ERR "%s: failed to register device %s\n",
 184                                 __FUNCTION__, viodev->dev.bus_id);
 185                 return NULL;
 186         }
 187         device_create_file(&viodev->dev, &dev_attr_name);
 188
 189         return viodev;
 190 }
 191
 192 void __devinit vio_unregister_device(struct vio_dev *viodev)
 193 {
 194         if (unregister_device_callback)
 195                 unregister_device_callback(viodev);
 196         device_remove_file(&viodev->dev, &dev_attr_name);
 197         device_unregister(&viodev->dev);
 198 }
 199 EXPORT_SYMBOL(vio_unregister_device);
 200
 201 static dma_addr_t vio_map_single(struct device *dev, void *vaddr,
 202                           size_t size, enum dma_data_direction direction)
 203 {
 204         return iommu_map_single(to_vio_dev(dev)->iommu_table, vaddr, size,
 205                         direction);
 206 }
 207
 208 static void vio_unmap_single(struct device *dev, dma_addr_t dma_handle,
 209                       size_t size, enum dma_data_direction direction)
 210 {
 211         iommu_unmap_single(to_vio_dev(dev)->iommu_table, dma_handle, size,
 212                         direction);
 213 }
 214
 215 static int vio_map_sg(struct device *dev, struct scatterlist *sglist,
 216                 int nelems, enum dma_data_direction direction)
 217 {
 218         return iommu_map_sg(dev, to_vio_dev(dev)->iommu_table, sglist,
 219                         nelems, direction);
 220 }
 221
 222 static void vio_unmap_sg(struct device *dev, struct scatterlist *sglist,
 223                 int nelems, enum dma_data_direction direction)
 224 {
 225         iommu_unmap_sg(to_vio_dev(dev)->iommu_table, sglist, nelems, direction);
 226 }
 227
 228 static void *vio_alloc_coherent(struct device *dev, size_t size,
 229                            dma_addr_t *dma_handle, unsigned int __nocast flag)
 230 {
 231         return iommu_alloc_coherent(to_vio_dev(dev)->iommu_table, size,
 232                         dma_handle, flag);
 233 }
 234
 235 static void vio_free_coherent(struct device *dev, size_t size,
 236                          void *vaddr, dma_addr_t dma_handle)
 237 {
 238         iommu_free_coherent(to_vio_dev(dev)->iommu_table, size, vaddr,
 239                         dma_handle);
 240 }
 241
 242 static int vio_dma_supported(struct device *dev, u64 mask)
 243 {
 244         return 1;
 245 }
 246
 247 struct dma_mapping_ops vio_dma_ops = {
 248         .alloc_coherent = vio_alloc_coherent,
 249         .free_coherent = vio_free_coherent,
 250         .map_single = vio_map_single,
 251         .unmap_single = vio_unmap_single,
 252         .map_sg = vio_map_sg,
 253         .unmap_sg = vio_unmap_sg,
 254         .dma_supported = vio_dma_supported,
 255 };
 256
 257 static int vio_bus_match(struct device *dev, struct device_driver *drv)
 258 {
 259         const struct vio_dev *vio_dev = to_vio_dev(dev);
 260         struct vio_driver *vio_drv = to_vio_driver(drv);
 261         const struct vio_device_id *ids = vio_drv->id_table;
 262
 263         return (ids != NULL) && (vio_match_device(ids, vio_dev) != NULL);
 264 }
 265
 266 struct bus_type vio_bus_type = {
 267         .name = "vio",
 268         .match = vio_bus_match,
 269 };