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/**
* \file drm_stub.h
* Stub support
*
* \author Rickard E. (Rik) Faith <faith@valinux.com>
*/
/*
* Created: Fri Jan 19 10:48:35 2001 by faith@acm.org
*
* Copyright 2001 VA Linux Systems, Inc., Sunnyvale, California.
* All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*/
#define __NO_VERSION__
#include "drmP.h"
#define DRM_STUB_MAXCARDS 16 /* Enough for one machine */
/** Stub list. One for each minor. */
static struct drm_stub_list {
const char *name;
struct file_operations *fops; /**< file operations */
struct proc_dir_entry *dev_root; /**< proc directory entry */
} *DRM(stub_list);
static struct proc_dir_entry *DRM(stub_root);
/** Stub information */
static struct drm_stub_info {
int (*info_register)(const char *name, struct file_operations *fops,
drm_device_t *dev);
int (*info_unregister)(int minor);
} DRM(stub_info);
/**
* File \c open operation.
*
* \param inode device inode.
* \param filp file pointer.
*
* Puts the drm_stub_list::fops corresponding to the device minor number into
* \p filp, call the \c open method, and restore the file operations.
*/
static int DRM(stub_open)(struct inode *inode, struct file *filp)
{
int minor = iminor(inode);
int err = -ENODEV;
struct file_operations *old_fops;
if (!DRM(stub_list) || !DRM(stub_list)[minor].fops) return -ENODEV;
old_fops = filp->f_op;
filp->f_op = fops_get(DRM(stub_list)[minor].fops);
if (filp->f_op->open && (err = filp->f_op->open(inode, filp))) {
fops_put(filp->f_op);
filp->f_op = fops_get(old_fops);
}
fops_put(old_fops);
return err;
}
/** File operations structure */
static struct file_operations DRM(stub_fops) = {
.owner = THIS_MODULE,
.open = DRM(stub_open)
};
/**
* Get a device minor number.
*
* \param name driver name.
* \param fops file operations.
* \param dev DRM device.
* \return minor number on success, or a negative number on failure.
*
* Allocate and initialize ::stub_list if one doesn't exist already. Search an
* empty entry and initialize it to the given parameters, and create the proc
* init entry via proc_init().
*/
static int DRM(stub_getminor)(const char *name, struct file_operations *fops,
drm_device_t *dev)
{
int i;
if (!DRM(stub_list)) {
DRM(stub_list) = DRM(alloc)(sizeof(*DRM(stub_list))
* DRM_STUB_MAXCARDS, DRM_MEM_STUB);
if(!DRM(stub_list)) return -1;
for (i = 0; i < DRM_STUB_MAXCARDS; i++) {
DRM(stub_list)[i].name = NULL;
DRM(stub_list)[i].fops = NULL;
}
}
for (i = 0; i < DRM_STUB_MAXCARDS; i++) {
if (!DRM(stub_list)[i].fops) {
DRM(stub_list)[i].name = name;
DRM(stub_list)[i].fops = fops;
DRM(stub_root) = DRM(proc_init)(dev, i, DRM(stub_root),
&DRM(stub_list)[i]
.dev_root);
return i;
}
}
return -1;
}
/**
* Put a device minor number.
*
* \param minor minor number.
* \return always zero.
*
* Cleans up the proc resources. If a minor is zero then release the foreign
* "drm" data, otherwise unregisters the "drm" data, frees the stub list and
* unregisters the character device.
*/
static int DRM(stub_putminor)(int minor)
{
if (minor < 0 || minor >= DRM_STUB_MAXCARDS) return -1;
DRM(stub_list)[minor].name = NULL;
DRM(stub_list)[minor].fops = NULL;
DRM(proc_cleanup)(minor, DRM(stub_root),
DRM(stub_list)[minor].dev_root);
if (minor) {
inter_module_put("drm");
} else {
inter_module_unregister("drm");
DRM(free)(DRM(stub_list),
sizeof(*DRM(stub_list)) * DRM_STUB_MAXCARDS,
DRM_MEM_STUB);
unregister_chrdev(DRM_MAJOR, "drm");
}
return 0;
}
/**
* Register.
*
* \param name driver name.
* \param fops file operations
* \param dev DRM device.
* \return zero on success or a negative number on failure.
*
* Attempt to register the char device and get the foreign "drm" data. If
* successful then another module already registered so gets the stub info,
* otherwise use this module stub info and make it available for other modules.
*
* Finally calls stub_info::info_register.
*/
int DRM(stub_register)(const char *name, struct file_operations *fops,
drm_device_t *dev)
{
struct drm_stub_info *i = NULL;
DRM_DEBUG("\n");
if (register_chrdev(DRM_MAJOR, "drm", &DRM(stub_fops)))
i = (struct drm_stub_info *)inter_module_get("drm");
if (i) {
/* Already registered */
DRM(stub_info).info_register = i->info_register;
DRM(stub_info).info_unregister = i->info_unregister;
DRM_DEBUG("already registered\n");
} else if (DRM(stub_info).info_register != DRM(stub_getminor)) {
DRM(stub_info).info_register = DRM(stub_getminor);
DRM(stub_info).info_unregister = DRM(stub_putminor);
DRM_DEBUG("calling inter_module_register\n");
inter_module_register("drm", THIS_MODULE, &DRM(stub_info));
}
if (DRM(stub_info).info_register)
return DRM(stub_info).info_register(name, fops, dev);
return -1;
}
/**
* Unregister.
*
* \param minor
*
* Calls drm_stub_info::unregister.
*/
int DRM(stub_unregister)(int minor)
{
DRM_DEBUG("%d\n", minor);
if (DRM(stub_info).info_unregister)
return DRM(stub_info).info_unregister(minor);
return -1;
}
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