| /* 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> |
| */ |
| |
| #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) |
| { |
| int 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%lx, open_count = %d\n", |
| current->pid, (long)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%lx\n", fd, (long)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; |
| DECLARE_WAITQUEUE(wait, current); |
| |
| DRM_DEBUG("%p, %p\n", dev->buf_rp, dev->buf_wp); |
| |
| add_wait_queue(&dev->buf_readers, &wait); |
| set_current_state(TASK_INTERRUPTIBLE); |
| while (dev->buf_rp == dev->buf_wp) { |
| DRM_DEBUG(" sleeping\n"); |
| if (filp->f_flags & O_NONBLOCK) { |
| remove_wait_queue(&dev->buf_readers, &wait); |
| set_current_state(TASK_RUNNING); |
| return -EAGAIN; |
| } |
| schedule(); /* wait for dev->buf_readers */ |
| if (signal_pending(current)) { |
| DRM_DEBUG(" interrupted\n"); |
| remove_wait_queue(&dev->buf_readers, &wait); |
| set_current_state(TASK_RUNNING); |
| return -ERESTARTSYS; |
| } |
| DRM_DEBUG(" awake\n"); |
| set_current_state(TASK_INTERRUPTIBLE); |
| } |
| remove_wait_queue(&dev->buf_readers, &wait); |
| set_current_state(TASK_RUNNING); |
| |
| 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 (dev->buf_async) kill_fasync(&dev->buf_async, SIGIO, POLL_IN); |
| |
| 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; |
| } |