Viewing file:  drm_fops.h (6.6 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
/* drm_fops.h -- File operations for DRM -*- linux-c -*-
* Created: Mon Jan 4 08:58:31 1999 by faith@valinux.com
*
* Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
* Copyright 2000 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
* VA LINUX SYSTEMS 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.
*
* Authors:
* Rickard E. (Rik) Faith <faith@valinux.com>
* Daryll Strauss <daryll@valinux.com>
* Gareth Hughes <gareth@valinux.com>
*/
#define __NO_VERSION__
#include "drmP.h"
#include <linux/poll.h>
/* drm_open is called whenever a process opens /dev/drm. */
int DRM(open_helper)(struct inode *inode, struct file *filp, drm_device_t *dev)
{
kdev_t minor = MINOR(inode->i_rdev);
drm_file_t *priv;
if (filp->f_flags & O_EXCL) return -EBUSY; /* No exclusive opens */
if (!DRM(cpu_valid)()) return -EINVAL;
DRM_DEBUG("pid = %d, minor = %d\n", current->pid, minor);
priv = DRM(alloc)(sizeof(*priv), DRM_MEM_FILES);
if(!priv) return -ENOMEM;
memset(priv, 0, sizeof(*priv));
filp->private_data = priv;
priv->uid = current->euid;
priv->pid = current->pid;
priv->minor = minor;
priv->dev = dev;
priv->ioctl_count = 0;
priv->authenticated = capable(CAP_SYS_ADMIN);
down(&dev->struct_sem);
if (!dev->file_last) {
priv->next = NULL;
priv->prev = NULL;
dev->file_first = priv;
dev->file_last = priv;
} else {
priv->next = NULL;
priv->prev = dev->file_last;
dev->file_last->next = priv;
dev->file_last = priv;
}
up(&dev->struct_sem);
#ifdef __alpha__
/*
* Default the hose
*/
if (!dev->hose) {
struct pci_dev *pci_dev;
pci_dev = pci_find_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
if (pci_dev) dev->hose = pci_dev->sysdata;
if (!dev->hose) {
struct pci_bus *b = pci_bus_b(pci_root_buses.next);
if (b) dev->hose = b->sysdata;
}
}
#endif
return 0;
}
int DRM(flush)(struct file *filp)
{
drm_file_t *priv = filp->private_data;
drm_device_t *dev = priv->dev;
DRM_DEBUG("pid = %d, device = 0x%x, open_count = %d\n",
current->pid, dev->device, dev->open_count);
return 0;
}
int DRM(fasync)(int fd, struct file *filp, int on)
{
drm_file_t *priv = filp->private_data;
drm_device_t *dev = priv->dev;
int retcode;
DRM_DEBUG("fd = %d, device = 0x%x\n", fd, dev->device);
retcode = fasync_helper(fd, filp, on, &dev->buf_async);
if (retcode < 0) return retcode;
return 0;
}
/* The drm_read and drm_write_string code (especially that which manages
the circular buffer), is based on Alessandro Rubini's LINUX DEVICE
DRIVERS (Cambridge: O'Reilly, 1998), pages 111-113. */
ssize_t DRM(read)(struct file *filp, char *buf, size_t count, loff_t *off)
{
drm_file_t *priv = filp->private_data;
drm_device_t *dev = priv->dev;
int left;
int avail;
int send;
int cur;
DRM_DEBUG("%p, %p\n", dev->buf_rp, dev->buf_wp);
while (dev->buf_rp == dev->buf_wp) {
DRM_DEBUG(" sleeping\n");
if (filp->f_flags & O_NONBLOCK) {
return -EAGAIN;
}
interruptible_sleep_on(&dev->buf_readers);
if (signal_pending(current)) {
DRM_DEBUG(" interrupted\n");
return -ERESTARTSYS;
}
DRM_DEBUG(" awake\n");
}
left = (dev->buf_rp + DRM_BSZ - dev->buf_wp) % DRM_BSZ;
avail = DRM_BSZ - left;
send = DRM_MIN(avail, count);
while (send) {
if (dev->buf_wp > dev->buf_rp) {
cur = DRM_MIN(send, dev->buf_wp - dev->buf_rp);
} else {
cur = DRM_MIN(send, dev->buf_end - dev->buf_rp);
}
if (copy_to_user(buf, dev->buf_rp, cur))
return -EFAULT;
dev->buf_rp += cur;
if (dev->buf_rp == dev->buf_end) dev->buf_rp = dev->buf;
send -= cur;
}
wake_up_interruptible(&dev->buf_writers);
return DRM_MIN(avail, count);;
}
int DRM(write_string)(drm_device_t *dev, const char *s)
{
int left = (dev->buf_rp + DRM_BSZ - dev->buf_wp) % DRM_BSZ;
int send = strlen(s);
int count;
DRM_DEBUG("%d left, %d to send (%p, %p)\n",
left, send, dev->buf_rp, dev->buf_wp);
if (left == 1 || dev->buf_wp != dev->buf_rp) {
DRM_ERROR("Buffer not empty (%d left, wp = %p, rp = %p)\n",
left,
dev->buf_wp,
dev->buf_rp);
}
while (send) {
if (dev->buf_wp >= dev->buf_rp) {
count = DRM_MIN(send, dev->buf_end - dev->buf_wp);
if (count == left) --count; /* Leave a hole */
} else {
count = DRM_MIN(send, dev->buf_rp - dev->buf_wp - 1);
}
strncpy(dev->buf_wp, s, count);
dev->buf_wp += count;
if (dev->buf_wp == dev->buf_end) dev->buf_wp = dev->buf;
send -= count;
}
#if LINUX_VERSION_CODE < 0x020315 && !defined(KILLFASYNCHASTHREEPARAMETERS)
/* The extra parameter to kill_fasync was added in 2.3.21, and is
_not_ present in _stock_ 2.2.14 and 2.2.15. However, some
distributions patch 2.2.x kernels to add this parameter. The
Makefile.linux attempts to detect this addition and defines
KILLFASYNCHASTHREEPARAMETERS if three parameters are found. */
if (dev->buf_async) kill_fasync(dev->buf_async, SIGIO);
#else
/* Parameter added in 2.3.21. */
#if LINUX_VERSION_CODE < 0x020400
if (dev->buf_async) kill_fasync(dev->buf_async, SIGIO, POLL_IN);
#else
/* Type of first parameter changed in
Linux 2.4.0-test2... */
if (dev->buf_async) kill_fasync(&dev->buf_async, SIGIO, POLL_IN);
#endif
#endif
DRM_DEBUG("waking\n");
wake_up_interruptible(&dev->buf_readers);
return 0;
}
unsigned int DRM(poll)(struct file *filp, struct poll_table_struct *wait)
{
drm_file_t *priv = filp->private_data;
drm_device_t *dev = priv->dev;
poll_wait(filp, &dev->buf_readers, wait);
if (dev->buf_wp != dev->buf_rp) return POLLIN | POLLRDNORM;
return 0;
}
|