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