drm_lock.c revision 60405de4d8688d96dd05157c28db3ade5c9bc234
60405de4d8688d96dd05157c28db3ade5c9bc234kz/*
60405de4d8688d96dd05157c28db3ade5c9bc234kz * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
60405de4d8688d96dd05157c28db3ade5c9bc234kz * Use is subject to license terms.
60405de4d8688d96dd05157c28db3ade5c9bc234kz */
60405de4d8688d96dd05157c28db3ade5c9bc234kz
60405de4d8688d96dd05157c28db3ade5c9bc234kz/*
60405de4d8688d96dd05157c28db3ade5c9bc234kz * lock.c -- IOCTLs for locking -*- linux-c -*-
60405de4d8688d96dd05157c28db3ade5c9bc234kz * Created: Tue Feb 2 08:37:54 1999 by faith@valinux.com
60405de4d8688d96dd05157c28db3ade5c9bc234kz */
60405de4d8688d96dd05157c28db3ade5c9bc234kz/*
60405de4d8688d96dd05157c28db3ade5c9bc234kz * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
60405de4d8688d96dd05157c28db3ade5c9bc234kz * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
60405de4d8688d96dd05157c28db3ade5c9bc234kz * All Rights Reserved.
60405de4d8688d96dd05157c28db3ade5c9bc234kz *
60405de4d8688d96dd05157c28db3ade5c9bc234kz * Permission is hereby granted, free of charge, to any person obtaining a
60405de4d8688d96dd05157c28db3ade5c9bc234kz * copy of this software and associated documentation files (the "Software"),
60405de4d8688d96dd05157c28db3ade5c9bc234kz * to deal in the Software without restriction, including without limitation
60405de4d8688d96dd05157c28db3ade5c9bc234kz * the rights to use, copy, modify, merge, publish, distribute, sublicense,
60405de4d8688d96dd05157c28db3ade5c9bc234kz * and/or sell copies of the Software, and to permit persons to whom the
60405de4d8688d96dd05157c28db3ade5c9bc234kz * Software is furnished to do so, subject to the following conditions:
60405de4d8688d96dd05157c28db3ade5c9bc234kz *
60405de4d8688d96dd05157c28db3ade5c9bc234kz * The above copyright notice and this permission notice (including the next
60405de4d8688d96dd05157c28db3ade5c9bc234kz * paragraph) shall be included in all copies or substantial portions of the
60405de4d8688d96dd05157c28db3ade5c9bc234kz * Software.
60405de4d8688d96dd05157c28db3ade5c9bc234kz *
60405de4d8688d96dd05157c28db3ade5c9bc234kz * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
60405de4d8688d96dd05157c28db3ade5c9bc234kz * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
60405de4d8688d96dd05157c28db3ade5c9bc234kz * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
60405de4d8688d96dd05157c28db3ade5c9bc234kz * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
60405de4d8688d96dd05157c28db3ade5c9bc234kz * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
60405de4d8688d96dd05157c28db3ade5c9bc234kz * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
60405de4d8688d96dd05157c28db3ade5c9bc234kz * OTHER DEALINGS IN THE SOFTWARE.
60405de4d8688d96dd05157c28db3ade5c9bc234kz *
60405de4d8688d96dd05157c28db3ade5c9bc234kz * Authors:
60405de4d8688d96dd05157c28db3ade5c9bc234kz * Rickard E. (Rik) Faith <faith@valinux.com>
60405de4d8688d96dd05157c28db3ade5c9bc234kz * Gareth Hughes <gareth@valinux.com>
60405de4d8688d96dd05157c28db3ade5c9bc234kz *
60405de4d8688d96dd05157c28db3ade5c9bc234kz */
60405de4d8688d96dd05157c28db3ade5c9bc234kz
60405de4d8688d96dd05157c28db3ade5c9bc234kz#pragma ident "%Z%%M% %I% %E% SMI"
60405de4d8688d96dd05157c28db3ade5c9bc234kz
60405de4d8688d96dd05157c28db3ade5c9bc234kz#include "drmP.h"
60405de4d8688d96dd05157c28db3ade5c9bc234kz
60405de4d8688d96dd05157c28db3ade5c9bc234kzint
60405de4d8688d96dd05157c28db3ade5c9bc234kzdrm_lock_held(void *info)
60405de4d8688d96dd05157c28db3ade5c9bc234kz{
60405de4d8688d96dd05157c28db3ade5c9bc234kz __volatile__ unsigned int *lock;
60405de4d8688d96dd05157c28db3ade5c9bc234kz
60405de4d8688d96dd05157c28db3ade5c9bc234kz lock = (__volatile__ unsigned int *)info;
60405de4d8688d96dd05157c28db3ade5c9bc234kz return (_DRM_LOCK_IS_HELD(*lock));
60405de4d8688d96dd05157c28db3ade5c9bc234kz}
60405de4d8688d96dd05157c28db3ade5c9bc234kz
60405de4d8688d96dd05157c28db3ade5c9bc234kzint
60405de4d8688d96dd05157c28db3ade5c9bc234kzdrm_lock_take(__volatile__ unsigned int *lock, unsigned int context)
60405de4d8688d96dd05157c28db3ade5c9bc234kz{
60405de4d8688d96dd05157c28db3ade5c9bc234kz unsigned int old, new;
60405de4d8688d96dd05157c28db3ade5c9bc234kz
60405de4d8688d96dd05157c28db3ade5c9bc234kz do {
60405de4d8688d96dd05157c28db3ade5c9bc234kz old = *lock;
60405de4d8688d96dd05157c28db3ade5c9bc234kz if (old & _DRM_LOCK_HELD) new = old | _DRM_LOCK_CONT;
60405de4d8688d96dd05157c28db3ade5c9bc234kz else new = context | _DRM_LOCK_HELD;
60405de4d8688d96dd05157c28db3ade5c9bc234kz } while (!atomic_cmpset_int(lock, old, new));
60405de4d8688d96dd05157c28db3ade5c9bc234kz
60405de4d8688d96dd05157c28db3ade5c9bc234kz if (_DRM_LOCKING_CONTEXT(old) == context) {
60405de4d8688d96dd05157c28db3ade5c9bc234kz if (old & _DRM_LOCK_HELD) {
60405de4d8688d96dd05157c28db3ade5c9bc234kz if (context != DRM_KERNEL_CONTEXT) {
60405de4d8688d96dd05157c28db3ade5c9bc234kz DRM_ERROR("%d holds heavyweight lock\n",
60405de4d8688d96dd05157c28db3ade5c9bc234kz context);
60405de4d8688d96dd05157c28db3ade5c9bc234kz }
60405de4d8688d96dd05157c28db3ade5c9bc234kz return (0);
60405de4d8688d96dd05157c28db3ade5c9bc234kz }
60405de4d8688d96dd05157c28db3ade5c9bc234kz }
60405de4d8688d96dd05157c28db3ade5c9bc234kz if (new == (context | _DRM_LOCK_HELD)) {
60405de4d8688d96dd05157c28db3ade5c9bc234kz /* Have lock */
60405de4d8688d96dd05157c28db3ade5c9bc234kz return (1);
60405de4d8688d96dd05157c28db3ade5c9bc234kz }
60405de4d8688d96dd05157c28db3ade5c9bc234kz return (0);
60405de4d8688d96dd05157c28db3ade5c9bc234kz}
60405de4d8688d96dd05157c28db3ade5c9bc234kz
60405de4d8688d96dd05157c28db3ade5c9bc234kz/*
60405de4d8688d96dd05157c28db3ade5c9bc234kz * This takes a lock forcibly and hands it to context. Should ONLY be used
60405de4d8688d96dd05157c28db3ade5c9bc234kz * inside *_unlock to give lock to kernel before calling *_dma_schedule.
60405de4d8688d96dd05157c28db3ade5c9bc234kz */
60405de4d8688d96dd05157c28db3ade5c9bc234kzint
60405de4d8688d96dd05157c28db3ade5c9bc234kzdrm_lock_transfer(drm_device_t *dev, __volatile__ unsigned int *lock,
60405de4d8688d96dd05157c28db3ade5c9bc234kz unsigned int context)
60405de4d8688d96dd05157c28db3ade5c9bc234kz{
60405de4d8688d96dd05157c28db3ade5c9bc234kz unsigned int old, new;
60405de4d8688d96dd05157c28db3ade5c9bc234kz
60405de4d8688d96dd05157c28db3ade5c9bc234kz dev->lock.filp = NULL;
60405de4d8688d96dd05157c28db3ade5c9bc234kz do {
60405de4d8688d96dd05157c28db3ade5c9bc234kz old = *lock;
60405de4d8688d96dd05157c28db3ade5c9bc234kz new = context | _DRM_LOCK_HELD;
60405de4d8688d96dd05157c28db3ade5c9bc234kz } while (!atomic_cmpset_int(lock, old, new));
60405de4d8688d96dd05157c28db3ade5c9bc234kz
60405de4d8688d96dd05157c28db3ade5c9bc234kz return (1);
60405de4d8688d96dd05157c28db3ade5c9bc234kz}
60405de4d8688d96dd05157c28db3ade5c9bc234kz
60405de4d8688d96dd05157c28db3ade5c9bc234kzint
60405de4d8688d96dd05157c28db3ade5c9bc234kzdrm_lock_free(drm_device_t *dev, __volatile__ unsigned int *lock,
60405de4d8688d96dd05157c28db3ade5c9bc234kz unsigned int context)
60405de4d8688d96dd05157c28db3ade5c9bc234kz{
60405de4d8688d96dd05157c28db3ade5c9bc234kz unsigned int old, new;
60405de4d8688d96dd05157c28db3ade5c9bc234kz
60405de4d8688d96dd05157c28db3ade5c9bc234kz mutex_enter(&(dev->lock.lock_mutex));
60405de4d8688d96dd05157c28db3ade5c9bc234kz dev->lock.filp = NULL;
60405de4d8688d96dd05157c28db3ade5c9bc234kz do {
60405de4d8688d96dd05157c28db3ade5c9bc234kz old = *lock;
60405de4d8688d96dd05157c28db3ade5c9bc234kz new = 0;
60405de4d8688d96dd05157c28db3ade5c9bc234kz } while (!atomic_cmpset_int(lock, old, new));
60405de4d8688d96dd05157c28db3ade5c9bc234kz
60405de4d8688d96dd05157c28db3ade5c9bc234kz if (_DRM_LOCK_IS_HELD(old) && _DRM_LOCKING_CONTEXT(old) != context) {
60405de4d8688d96dd05157c28db3ade5c9bc234kz DRM_ERROR("%d freed heavyweight lock held by %d\n",
60405de4d8688d96dd05157c28db3ade5c9bc234kz context, _DRM_LOCKING_CONTEXT(old));
60405de4d8688d96dd05157c28db3ade5c9bc234kz return (1);
60405de4d8688d96dd05157c28db3ade5c9bc234kz }
60405de4d8688d96dd05157c28db3ade5c9bc234kz cv_broadcast(&(dev->lock.lock_cv));
60405de4d8688d96dd05157c28db3ade5c9bc234kz mutex_exit(&(dev->lock.lock_mutex));
60405de4d8688d96dd05157c28db3ade5c9bc234kz return (0);
60405de4d8688d96dd05157c28db3ade5c9bc234kz}
60405de4d8688d96dd05157c28db3ade5c9bc234kz
60405de4d8688d96dd05157c28db3ade5c9bc234kz/*ARGSUSED*/
60405de4d8688d96dd05157c28db3ade5c9bc234kzint
60405de4d8688d96dd05157c28db3ade5c9bc234kzdrm_lock(DRM_IOCTL_ARGS)
60405de4d8688d96dd05157c28db3ade5c9bc234kz{
60405de4d8688d96dd05157c28db3ade5c9bc234kz DRM_DEVICE;
60405de4d8688d96dd05157c28db3ade5c9bc234kz drm_lock_t lock;
60405de4d8688d96dd05157c28db3ade5c9bc234kz int ret = 0;
60405de4d8688d96dd05157c28db3ade5c9bc234kz
60405de4d8688d96dd05157c28db3ade5c9bc234kz DRM_COPY_FROM_USER_IOCTL(lock, (drm_lock_t *)data, sizeof (lock));
60405de4d8688d96dd05157c28db3ade5c9bc234kz
60405de4d8688d96dd05157c28db3ade5c9bc234kz if (lock.context == DRM_KERNEL_CONTEXT) {
60405de4d8688d96dd05157c28db3ade5c9bc234kz return (DRM_ERR(EINVAL));
60405de4d8688d96dd05157c28db3ade5c9bc234kz }
60405de4d8688d96dd05157c28db3ade5c9bc234kz
60405de4d8688d96dd05157c28db3ade5c9bc234kz DRM_DEBUG("%d (pid %d) requests lock (0x%08x), flags = 0x%08x\n",
60405de4d8688d96dd05157c28db3ade5c9bc234kz lock.context, DRM_CURRENTPID, dev->lock.hw_lock->lock, lock.flags);
60405de4d8688d96dd05157c28db3ade5c9bc234kz
60405de4d8688d96dd05157c28db3ade5c9bc234kz if (dev->use_dma_queue && lock.context < 0)
60405de4d8688d96dd05157c28db3ade5c9bc234kz return (DRM_ERR(EINVAL));
60405de4d8688d96dd05157c28db3ade5c9bc234kz
60405de4d8688d96dd05157c28db3ade5c9bc234kz mutex_enter(&(dev->lock.lock_mutex));
60405de4d8688d96dd05157c28db3ade5c9bc234kz DRM_DEBUG("mutex enter\n");
60405de4d8688d96dd05157c28db3ade5c9bc234kz for (;;) {
60405de4d8688d96dd05157c28db3ade5c9bc234kz if (drm_lock_take(&dev->lock.hw_lock->lock, lock.context)) {
60405de4d8688d96dd05157c28db3ade5c9bc234kz DRM_DEBUG("drm_lock_take enter\n");
60405de4d8688d96dd05157c28db3ade5c9bc234kz dev->lock.filp = (void *)(uintptr_t)DRM_CURRENTPID;
60405de4d8688d96dd05157c28db3ade5c9bc234kz dev->lock.lock_time = jiffies;
60405de4d8688d96dd05157c28db3ade5c9bc234kz atomic_inc_32(&dev->counts[_DRM_STAT_LOCKS]);
60405de4d8688d96dd05157c28db3ade5c9bc234kz break; /* Got lock */
60405de4d8688d96dd05157c28db3ade5c9bc234kz }
60405de4d8688d96dd05157c28db3ade5c9bc234kz DRM_DEBUG("Drm_lock: cv_wait\n");
60405de4d8688d96dd05157c28db3ade5c9bc234kz ret = cv_wait_sig(&(dev->lock.lock_cv),
60405de4d8688d96dd05157c28db3ade5c9bc234kz &(dev->lock.lock_mutex));
60405de4d8688d96dd05157c28db3ade5c9bc234kz
60405de4d8688d96dd05157c28db3ade5c9bc234kz if (ret == 0) {
60405de4d8688d96dd05157c28db3ade5c9bc234kz mutex_exit(&(dev->lock.lock_mutex));
60405de4d8688d96dd05157c28db3ade5c9bc234kz return (-1);
60405de4d8688d96dd05157c28db3ade5c9bc234kz }
60405de4d8688d96dd05157c28db3ade5c9bc234kz }
60405de4d8688d96dd05157c28db3ade5c9bc234kz DRM_DEBUG("before mutex_exit\n");
60405de4d8688d96dd05157c28db3ade5c9bc234kz mutex_exit(&(dev->lock.lock_mutex));
60405de4d8688d96dd05157c28db3ade5c9bc234kz DRM_DEBUG("drm_lock: %d %s\n", lock.context,
60405de4d8688d96dd05157c28db3ade5c9bc234kz ret ? "interrupted" : "has lock");
60405de4d8688d96dd05157c28db3ade5c9bc234kz
60405de4d8688d96dd05157c28db3ade5c9bc234kz if (dev->dma_quiescent != NULL &&
60405de4d8688d96dd05157c28db3ade5c9bc234kz (lock.flags & _DRM_LOCK_QUIESCENT))
60405de4d8688d96dd05157c28db3ade5c9bc234kz dev->dma_quiescent(dev);
60405de4d8688d96dd05157c28db3ade5c9bc234kz
60405de4d8688d96dd05157c28db3ade5c9bc234kz return (0);
60405de4d8688d96dd05157c28db3ade5c9bc234kz}
60405de4d8688d96dd05157c28db3ade5c9bc234kz
60405de4d8688d96dd05157c28db3ade5c9bc234kz/*ARGSUSED*/
60405de4d8688d96dd05157c28db3ade5c9bc234kzint
60405de4d8688d96dd05157c28db3ade5c9bc234kzdrm_unlock(DRM_IOCTL_ARGS)
60405de4d8688d96dd05157c28db3ade5c9bc234kz{
60405de4d8688d96dd05157c28db3ade5c9bc234kz DRM_DEVICE;
60405de4d8688d96dd05157c28db3ade5c9bc234kz drm_lock_t lock;
60405de4d8688d96dd05157c28db3ade5c9bc234kz
60405de4d8688d96dd05157c28db3ade5c9bc234kz DRM_COPY_FROM_USER_IOCTL(lock, (drm_lock_t *)data, sizeof (lock));
60405de4d8688d96dd05157c28db3ade5c9bc234kz
60405de4d8688d96dd05157c28db3ade5c9bc234kz if (lock.context == DRM_KERNEL_CONTEXT) {
60405de4d8688d96dd05157c28db3ade5c9bc234kz DRM_ERROR("Process %d using kernel context %d\n",
60405de4d8688d96dd05157c28db3ade5c9bc234kz DRM_CURRENTPID, lock.context);
60405de4d8688d96dd05157c28db3ade5c9bc234kz return (DRM_ERR(EINVAL));
60405de4d8688d96dd05157c28db3ade5c9bc234kz }
60405de4d8688d96dd05157c28db3ade5c9bc234kz
60405de4d8688d96dd05157c28db3ade5c9bc234kz atomic_inc_32(&dev->counts[_DRM_STAT_UNLOCKS]);
60405de4d8688d96dd05157c28db3ade5c9bc234kz
60405de4d8688d96dd05157c28db3ade5c9bc234kz DRM_LOCK();
60405de4d8688d96dd05157c28db3ade5c9bc234kz (void) drm_lock_transfer(dev, &dev->lock.hw_lock->lock,
60405de4d8688d96dd05157c28db3ade5c9bc234kz DRM_KERNEL_CONTEXT);
60405de4d8688d96dd05157c28db3ade5c9bc234kz
60405de4d8688d96dd05157c28db3ade5c9bc234kz if (drm_lock_free(dev, &dev->lock.hw_lock->lock, DRM_KERNEL_CONTEXT)) {
60405de4d8688d96dd05157c28db3ade5c9bc234kz DRM_ERROR("drm_unlock\n");
60405de4d8688d96dd05157c28db3ade5c9bc234kz }
60405de4d8688d96dd05157c28db3ade5c9bc234kz DRM_UNLOCK();
60405de4d8688d96dd05157c28db3ade5c9bc234kz
60405de4d8688d96dd05157c28db3ade5c9bc234kz return (0);
60405de4d8688d96dd05157c28db3ade5c9bc234kz}