/* 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 * Daryll Strauss * Gareth Hughes */ #include "drmP.h" #include /* 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; }