renesas/drm.git - libdrm, cloned from git://anongit.freedesktop.org/mesa/drm

Age	Commit message (Expand)	Author
2005-04-26	Convert NOMAN to the new preferred spelling NO_MAN to quiet warnings.	Eric Anholt
2004-05-09	Add mach64 DRM module for BSD (untested, but compiles).	Eric Anholt

/*- * 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> * Gareth Hughes <gareth@valinux.com> * */ /** @file drm_lock.c * Implementation of the ioctls and other support code for dealing with the * hardware lock. * * The DRM hardware lock is a shared structure between the kernel and userland. * * On uncontended access where the new context was the last context, the * client may take the lock without dropping down into the kernel, using atomic * compare-and-set. * * If the client finds during compare-and-set that it was not the last owner * of the lock, it calls the DRM lock ioctl, which may sleep waiting for the * lock, and may have side-effects of kernel-managed context switching. * * When the client releases the lock, if the lock is marked as being contended * by another client, then the DRM unlock ioctl is called so that the * contending client may be woken up. */ #include "drmP.h" int drm_lock(struct drm_device *dev, void *data, struct drm_file *file_priv) { struct drm_lock *lock = data; int ret = 0; if (lock->context == DRM_KERNEL_CONTEXT) { DRM_ERROR("Process %d using kernel context %d\n", DRM_CURRENTPID, lock->context); return EINVAL; } DRM_DEBUG("%d (pid %d) requests lock (0x%08x), flags = 0x%08x\n", lock->context, DRM_CURRENTPID, dev->lock.hw_lock->lock, lock->flags); if (drm_core_check_feature(dev, DRIVER_DMA_QUEUE) && lock->context < 0) return EINVAL; DRM_LOCK(); for (;;) { if (drm_lock_take(&dev->lock, lock->context)) { dev->lock.file_priv = file_priv; dev->lock.lock_time = jiffies; atomic_inc(&dev->counts[_DRM_STAT_LOCKS]); break; /* Got lock */ } /* Contention */ ret = mtx_sleep((void *)&dev->lock.lock_queue, &dev->dev_lock, PCATCH, "drmlk2", 0); if (ret != 0) break; } DRM_UNLOCK(); DRM_DEBUG("%d %s\n", lock->context, ret ? "interrupted" : "has lock"); if (ret != 0) return ret; /* XXX: Add signal blocking here */ if (dev->driver->dma_quiescent != NULL && (lock->flags & _DRM_LOCK_QUIESCENT)) dev->driver->dma_quiescent(dev); return 0; } int drm_unlock(struct drm_device *dev, void *data, struct drm_file *file_priv) { struct drm_lock *lock = data; DRM_DEBUG("%d (pid %d) requests unlock (0x%08x), flags = 0x%08x\n", lock->context, DRM_CURRENTPID, dev->lock.hw_lock->lock, lock->flags); if (lock->context == DRM_KERNEL_CONTEXT) { DRM_ERROR("Process %d using kernel context %d\n", DRM_CURRENTPID, lock->context); return EINVAL; } atomic_inc(&dev->counts[_DRM_STAT_UNLOCKS]); DRM_LOCK(); drm_lock_transfer(&dev->lock, DRM_KERNEL_CONTEXT); if (drm_lock_free(&dev->lock, DRM_KERNEL_CONTEXT)) { DRM_ERROR("\n"); } DRM_UNLOCK(); return 0; } int drm_lock_take(struct drm_lock_data *lock_data, unsigned int context) { volatile unsigned int *lock = &lock_data->hw_lock->lock; unsigned int old, new; do { old = *lock; if (old & _DRM_LOCK_HELD) new = old | _DRM_LOCK_CONT; else new = context | _DRM_LOCK_HELD; } while (!atomic_cmpset_int(lock, old, new)); if (_DRM_LOCKING_CONTEXT(old) == context) { if (old & _DRM_LOCK_HELD) { if (context != DRM_KERNEL_CONTEXT) { DRM_ERROR("%d holds heavyweight lock\n", context); } return 0; } } if (new == (context | _DRM_LOCK_HELD)) { /* Have lock */ return 1; } return 0; } /* This takes a lock forcibly and hands it to context. Should ONLY be used inside *_unlock to give lock to kernel before calling *_dma_schedule. */ int drm_lock_transfer(struct drm_lock_data *lock_data, unsigned int context) { volatile unsigned int *lock = &lock_data->hw_lock->lock; unsigned int old, new; lock_data->file_priv = NULL; do { old = *lock; new = context | _DRM_LOCK_HELD; } while (!atomic_cmpset_int(lock, old, new)); return 1; } int drm_lock_free(struct drm_lock_data *lock_data, unsigned int context) { volatile unsigned int *lock = &lock_data->hw_lock->lock; unsigned int old, new; lock_data->file_priv = NULL; do { old = *lock; new = 0; } while (!atomic_cmpset_int(lock, old, new)); if (_DRM_LOCK_IS_HELD(old) && _DRM_LOCKING_CONTEXT(old) != context) { DRM_ERROR("%d freed heavyweight lock held by %d\n", context, _DRM_LOCKING_CONTEXT(old)); return 1; } DRM_WAKEUP_INT((void *)&lock_data->lock_queue); return 0; }