arch/powerpc/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 #include <asm/prom.h>
  25
  26 static const struct vio_device_id *vio_match_device(
  27                 const struct vio_device_id *, const struct vio_dev *);
  28
  29 struct vio_dev vio_bus_device  = { /* fake "parent" device */
  30         .name = vio_bus_device.dev.bus_id,
  31         .type = "",
  32         .dev.bus_id = "vio",
  33         .dev.bus = &vio_bus_type,
  34 };
  35
  36 static struct vio_bus_ops vio_bus_ops;
  37
  38 /*
  39  * Convert from struct device to struct vio_dev and pass to driver.
  40  * dev->driver has already been set by generic code because vio_bus_match
  41  * succeeded.
  42  */
  43 static int vio_bus_probe(struct device *dev)
  44 {
  45         struct vio_dev *viodev = to_vio_dev(dev);
  46         struct vio_driver *viodrv = to_vio_driver(dev->driver);
  47         const struct vio_device_id *id;
  48         int error = -ENODEV;
  49
  50         if (!viodrv->probe)
  51                 return error;
  52
  53         id = vio_match_device(viodrv->id_table, viodev);
  54         if (id)
  55                 error = viodrv->probe(viodev, id);
  56
  57         return error;
  58 }
  59
  60 /* convert from struct device to struct vio_dev and pass to driver. */
  61 static int vio_bus_remove(struct device *dev)
  62 {
  63         struct vio_dev *viodev = to_vio_dev(dev);
  64         struct vio_driver *viodrv = to_vio_driver(dev->driver);
  65
  66         if (viodrv->remove)
  67                 return viodrv->remove(viodev);
  68
  69         /* driver can't remove */
  70         return 1;
  71 }
  72
  73 /* convert from struct device to struct vio_dev and pass to driver. */
  74 static void vio_bus_shutdown(struct device *dev)
  75 {
  76         struct vio_dev *viodev = to_vio_dev(dev);
  77         struct vio_driver *viodrv = to_vio_driver(dev->driver);
  78
  79         if (viodrv->shutdown)
  80                 viodrv->shutdown(viodev);
  81 }
  82
  83 /**
  84  * vio_register_driver: - Register a new vio driver
  85  * @drv:        The vio_driver structure to be registered.
  86  */
  87 int vio_register_driver(struct vio_driver *viodrv)
  88 {
  89         printk(KERN_DEBUG "%s: driver %s registering\n", __FUNCTION__,
  90                 viodrv->driver.name);
  91
  92         /* fill in 'struct driver' fields */
  93         viodrv->driver.bus = &vio_bus_type;
  94         viodrv->driver.probe = vio_bus_probe;
  95         viodrv->driver.remove = vio_bus_remove;
  96         viodrv->driver.shutdown = vio_bus_shutdown;
  97
  98         return driver_register(&viodrv->driver);
  99 }
 100 EXPORT_SYMBOL(vio_register_driver);
 101
 102 /**
 103  * vio_unregister_driver - Remove registration of vio driver.
 104  * @driver:     The vio_driver struct to be removed form registration
 105  */
 106 void vio_unregister_driver(struct vio_driver *viodrv)
 107 {
 108         driver_unregister(&viodrv->driver);
 109 }
 110 EXPORT_SYMBOL(vio_unregister_driver);
 111
 112 /**
 113  * vio_match_device: - Tell if a VIO device has a matching
 114  *                      VIO device id structure.
 115  * @ids:        array of VIO device id structures to search in
 116  * @dev:        the VIO device structure to match against
 117  *
 118  * Used by a driver to check whether a VIO device present in the
 119  * system is in its list of supported devices. Returns the matching
 120  * vio_device_id structure or NULL if there is no match.
 121  */
 122 static const struct vio_device_id *vio_match_device(
 123                 const struct vio_device_id *ids, const struct vio_dev *dev)
 124 {
 125         while (ids->type[0] != '\0') {
 126                 if (vio_bus_ops.match(ids, dev))
 127                         return ids;
 128                 ids++;
 129         }
 130         return NULL;
 131 }
 132
 133 /**
 134  * vio_bus_init: - Initialize the virtual IO bus
 135  */
 136 int __init vio_bus_init(struct vio_bus_ops *ops)
 137 {
 138         int err;
 139
 140         vio_bus_ops = *ops;
 141
 142         err = bus_register(&vio_bus_type);
 143         if (err) {
 144                 printk(KERN_ERR "failed to register VIO bus\n");
 145                 return err;
 146         }
 147
 148         /*
 149          * The fake parent of all vio devices, just to give us
 150          * a nice directory
 151          */
 152         err = device_register(&vio_bus_device.dev);
 153         if (err) {
 154                 printk(KERN_WARNING "%s: device_register returned %i\n",
 155                                 __FUNCTION__, err);
 156                 return err;
 157         }
 158
 159         return 0;
 160 }
 161
 162 /* vio_dev refcount hit 0 */
 163 static void __devinit vio_dev_release(struct device *dev)
 164 {
 165         if (vio_bus_ops.release_device)
 166                 vio_bus_ops.release_device(dev);
 167         kfree(to_vio_dev(dev));
 168 }
 169
 170 static ssize_t viodev_show_name(struct device *dev,
 171                 struct device_attribute *attr, char *buf)
 172 {
 173         return sprintf(buf, "%s\n", to_vio_dev(dev)->name);
 174 }
 175 DEVICE_ATTR(name, S_IRUSR | S_IRGRP | S_IROTH, viodev_show_name, NULL);
 176
 177 struct vio_dev * __devinit vio_register_device(struct vio_dev *viodev)
 178 {
 179         /* init generic 'struct device' fields: */
 180         viodev->dev.parent = &vio_bus_device.dev;
 181         viodev->dev.bus = &vio_bus_type;
 182         viodev->dev.release = vio_dev_release;
 183
 184         /* register with generic device framework */
 185         if (device_register(&viodev->dev)) {
 186                 printk(KERN_ERR "%s: failed to register device %s\n",
 187                                 __FUNCTION__, viodev->dev.bus_id);
 188                 return NULL;
 189         }
 190         device_create_file(&viodev->dev, &dev_attr_name);
 191
 192         return viodev;
 193 }
 194
 195 void __devinit vio_unregister_device(struct vio_dev *viodev)
 196 {
 197         if (vio_bus_ops.unregister_device)
 198                 vio_bus_ops.unregister_device(viodev);
 199         device_remove_file(&viodev->dev, &dev_attr_name);
 200         device_unregister(&viodev->dev);
 201 }
 202 EXPORT_SYMBOL(vio_unregister_device);
 203
 204 static dma_addr_t vio_map_single(struct device *dev, void *vaddr,
 205                           size_t size, enum dma_data_direction direction)
 206 {
 207         return iommu_map_single(to_vio_dev(dev)->iommu_table, vaddr, size,
 208                         direction);
 209 }
 210
 211 static void vio_unmap_single(struct device *dev, dma_addr_t dma_handle,
 212                       size_t size, enum dma_data_direction direction)
 213 {
 214         iommu_unmap_single(to_vio_dev(dev)->iommu_table, dma_handle, size,
 215                         direction);
 216 }
 217
 218 static int vio_map_sg(struct device *dev, struct scatterlist *sglist,
 219                 int nelems, enum dma_data_direction direction)
 220 {
 221         return iommu_map_sg(dev, to_vio_dev(dev)->iommu_table, sglist,
 222                         nelems, direction);
 223 }
 224
 225 static void vio_unmap_sg(struct device *dev, struct scatterlist *sglist,
 226                 int nelems, enum dma_data_direction direction)
 227 {
 228         iommu_unmap_sg(to_vio_dev(dev)->iommu_table, sglist, nelems, direction);
 229 }
 230
 231 static void *vio_alloc_coherent(struct device *dev, size_t size,
 232                            dma_addr_t *dma_handle, gfp_t flag)
 233 {
 234         return iommu_alloc_coherent(to_vio_dev(dev)->iommu_table, size,
 235                         dma_handle, flag);
 236 }
 237
 238 static void vio_free_coherent(struct device *dev, size_t size,
 239                          void *vaddr, dma_addr_t dma_handle)
 240 {
 241         iommu_free_coherent(to_vio_dev(dev)->iommu_table, size, vaddr,
 242                         dma_handle);
 243 }
 244
 245 static int vio_dma_supported(struct device *dev, u64 mask)
 246 {
 247         return 1;
 248 }
 249
 250 struct dma_mapping_ops vio_dma_ops = {
 251         .alloc_coherent = vio_alloc_coherent,
 252         .free_coherent = vio_free_coherent,
 253         .map_single = vio_map_single,
 254         .unmap_single = vio_unmap_single,
 255         .map_sg = vio_map_sg,
 256         .unmap_sg = vio_unmap_sg,
 257         .dma_supported = vio_dma_supported,
 258 };
 259
 260 static int vio_bus_match(struct device *dev, struct device_driver *drv)
 261 {
 262         const struct vio_dev *vio_dev = to_vio_dev(dev);
 263         struct vio_driver *vio_drv = to_vio_driver(drv);
 264         const struct vio_device_id *ids = vio_drv->id_table;
 265
 266         return (ids != NULL) && (vio_match_device(ids, vio_dev) != NULL);
 267 }
 268
 269 static int vio_hotplug(struct device *dev, char **envp, int num_envp,
 270                         char *buffer, int buffer_size)
 271 {
 272         const struct vio_dev *vio_dev = to_vio_dev(dev);
 273         char *cp;
 274         int length;
 275
 276         if (!num_envp)
 277                 return -ENOMEM;
 278
 279         if (!vio_dev->dev.platform_data)
 280                 return -ENODEV;
 281         cp = (char *)get_property(vio_dev->dev.platform_data, "compatible", &length);
 282         if (!cp)
 283                 return -ENODEV;
 284
 285         envp[0] = buffer;
 286         length = scnprintf(buffer, buffer_size, "MODALIAS=vio:T%sS%s",
 287                                 vio_dev->type, cp);
 288         if (buffer_size - length <= 0)
 289                 return -ENOMEM;
 290         envp[1] = NULL;
 291         return 0;
 292 }
 293
 294 struct bus_type vio_bus_type = {
 295         .name = "vio",
 296         .uevent = vio_hotplug,
 297         .match = vio_bus_match,
 298 };