Import 2.3.18pre1

[davej-history.git] / drivers / char / drm / dma.c

/* dma.c -- DMA IOCTL and function support -*- linux-c -*-
 * Created: Fri Mar 19 14:30:16 1999 by faith@precisioninsight.com
 * Revised: Fri Aug 20 13:06:51 1999 by faith@precisioninsight.com
 *
 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
 * 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
 * PRECISION INSIGHT 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.
 * 
 * $PI: xc/programs/Xserver/hw/xfree86/os-support/linux/drm/generic/dma.c,v 1.6 1999/08/20 20:00:53 faith Exp $
 * $XFree86$
 *
 */

#define __NO_VERSION__
#include "drmP.h"

#include <linux/interrupt.h>    /* For task queue support */

void drm_dma_setup(drm_device_t *dev)
{
        int i;
        
        dev->dma = drm_alloc(sizeof(*dev->dma), DRM_MEM_DRIVER);
        memset(dev->dma, 0, sizeof(*dev->dma));
        for (i = 0; i <= DRM_MAX_ORDER; i++)
                memset(&dev->dma->bufs[i], 0, sizeof(dev->dma->bufs[0]));
}

void drm_dma_takedown(drm_device_t *dev)
{
        drm_device_dma_t  *dma = dev->dma;
        int               i, j;

        if (!dma) return;
        
                                /* Clear dma buffers */
        for (i = 0; i <= DRM_MAX_ORDER; i++) {
                if (dma->bufs[i].seg_count) {
                        DRM_DEBUG("order %d: buf_count = %d,"
                                  " seg_count = %d\n",
                                  i,
                                  dma->bufs[i].buf_count,
                                  dma->bufs[i].seg_count);
                        for (j = 0; j < dma->bufs[i].seg_count; j++) {
                                drm_free_pages(dma->bufs[i].seglist[j],
                                               dma->bufs[i].page_order,
                                               DRM_MEM_DMA);
                        }
                        drm_free(dma->bufs[i].buflist,
                                 dma->buf_count
                                 * sizeof(*dma->bufs[0].buflist),
                                 DRM_MEM_BUFS);
                        drm_free(dma->bufs[i].seglist,
                                 dma->buf_count
                                 * sizeof(*dma->bufs[0].seglist),
                                 DRM_MEM_SEGS);
                        drm_freelist_destroy(&dma->bufs[i].freelist);
                }
        }
        
        if (dma->buflist) {
                drm_free(dma->buflist,
                         dma->buf_count * sizeof(*dma->buflist),
                         DRM_MEM_BUFS);
        }

        if (dma->pagelist) {
                drm_free(dma->pagelist,
                         dma->page_count * sizeof(*dma->pagelist),
                         DRM_MEM_PAGES);
        }
        drm_free(dev->dma, sizeof(*dev->dma), DRM_MEM_DRIVER);
        dev->dma = NULL;
}

#if DRM_DMA_HISTOGRAM
/* This is slow, but is useful for debugging. */
int drm_histogram_slot(unsigned long count)
{
        int value = DRM_DMA_HISTOGRAM_INITIAL;
        int slot;

        for (slot = 0;
             slot < DRM_DMA_HISTOGRAM_SLOTS;
             ++slot, value = DRM_DMA_HISTOGRAM_NEXT(value)) {
                if (count < value) return slot;
        }
        return DRM_DMA_HISTOGRAM_SLOTS - 1;
}

void drm_histogram_compute(drm_device_t *dev, drm_buf_t *buf)
{
        cycles_t queued_to_dispatched;
        cycles_t dispatched_to_completed;
        cycles_t completed_to_freed;
        int      q2d, d2c, c2f, q2c, q2f;
        
        if (buf->time_queued) {
                queued_to_dispatched    = (buf->time_dispatched
                                           - buf->time_queued);
                dispatched_to_completed = (buf->time_completed
                                           - buf->time_dispatched);
                completed_to_freed      = (buf->time_freed
                                           - buf->time_completed);

                q2d = drm_histogram_slot(queued_to_dispatched);
                d2c = drm_histogram_slot(dispatched_to_completed);
                c2f = drm_histogram_slot(completed_to_freed);

                q2c = drm_histogram_slot(queued_to_dispatched
                                         + dispatched_to_completed);
                q2f = drm_histogram_slot(queued_to_dispatched
                                         + dispatched_to_completed
                                         + completed_to_freed);
                
                atomic_inc(&dev->histo.total);
                atomic_inc(&dev->histo.queued_to_dispatched[q2d]);
                atomic_inc(&dev->histo.dispatched_to_completed[d2c]);
                atomic_inc(&dev->histo.completed_to_freed[c2f]);
                
                atomic_inc(&dev->histo.queued_to_completed[q2c]);
                atomic_inc(&dev->histo.queued_to_freed[q2f]);

        }
        buf->time_queued     = 0;
        buf->time_dispatched = 0;
        buf->time_completed  = 0;
        buf->time_freed      = 0;
}
#endif

void drm_free_buffer(drm_device_t *dev, drm_buf_t *buf)
{
        drm_device_dma_t *dma = dev->dma;

        if (!buf) return;
        
        buf->waiting  = 0;
        buf->pending  = 0;
        buf->pid      = 0;
        buf->used     = 0;
#if DRM_DMA_HISTOGRAM
        buf->time_completed = get_cycles();
#endif
        if (waitqueue_active(&buf->dma_wait)) {
                wake_up_interruptible(&buf->dma_wait);
        } else {
                                /* If processes are waiting, the last one
                                   to wake will put the buffer on the free
                                   list.  If no processes are waiting, we
                                   put the buffer on the freelist here. */
                drm_freelist_put(dev, &dma->bufs[buf->order].freelist, buf);
        }
}

void drm_reclaim_buffers(drm_device_t *dev, pid_t pid)
{
        drm_device_dma_t *dma = dev->dma;
        int              i;

        for (i = 0; i < dma->buf_count; i++) {
                if (dma->buflist[i]->pid == pid) {
                        switch (dma->buflist[i]->list) {
                        case DRM_LIST_NONE:
                                drm_free_buffer(dev, dma->buflist[i]);
                                break;
                        case DRM_LIST_WAIT:
                                dma->buflist[i]->list = DRM_LIST_RECLAIM;
                                break;
                        default:
                                /* Buffer already on hardware. */
                                break;
                        }
                }
        }
}

int drm_context_switch(drm_device_t *dev, int old, int new)
{
        char        buf[64];
        drm_queue_t *q;

        atomic_inc(&dev->total_ctx);

        if (test_and_set_bit(0, &dev->context_flag)) {
                DRM_ERROR("Reentering -- FIXME\n");
                return -EBUSY;
        }

#if DRM_DMA_HISTOGRAM
        dev->ctx_start = get_cycles();
#endif
        
        DRM_DEBUG("Context switch from %d to %d\n", old, new);

        if (new >= dev->queue_count) {
                clear_bit(0, &dev->context_flag);
                return -EINVAL;
        }

        if (new == dev->last_context) {
                clear_bit(0, &dev->context_flag);
                return 0;
        }
        
        q = dev->queuelist[new];
        atomic_inc(&q->use_count);
        if (atomic_read(&q->use_count) == 1) {
                atomic_dec(&q->use_count);
                clear_bit(0, &dev->context_flag);
                return -EINVAL;
        }

        if (drm_flags & DRM_FLAG_NOCTX) {
                drm_context_switch_complete(dev, new);
        } else {
                sprintf(buf, "C %d %d\n", old, new);
                drm_write_string(dev, buf);
        }
        
        atomic_dec(&q->use_count);
        
        return 0;
}

int drm_context_switch_complete(drm_device_t *dev, int new)
{
        drm_device_dma_t *dma = dev->dma;
        
        dev->last_context = new;  /* PRE/POST: This is the _only_ writer. */
        dev->last_switch  = jiffies;
        
        if (!_DRM_LOCK_IS_HELD(dev->lock.hw_lock->lock)) {
                DRM_ERROR("Lock isn't held after context switch\n");
        }

        if (!dma || !(dma->next_buffer && dma->next_buffer->while_locked)) {
                if (drm_lock_free(dev, &dev->lock.hw_lock->lock,
                                  DRM_KERNEL_CONTEXT)) {
                        DRM_ERROR("Cannot free lock\n");
                }
        }
        
#if DRM_DMA_HISTOGRAM
        atomic_inc(&dev->histo.ctx[drm_histogram_slot(get_cycles()
                                                      - dev->ctx_start)]);
                   
#endif
        clear_bit(0, &dev->context_flag);
        wake_up_interruptible(&dev->context_wait);
        
        return 0;
}

void drm_clear_next_buffer(drm_device_t *dev)
{
        drm_device_dma_t *dma = dev->dma;
        
        dma->next_buffer = NULL;
        if (dma->next_queue && !DRM_BUFCOUNT(&dma->next_queue->waitlist)) {
                wake_up_interruptible(&dma->next_queue->flush_queue);
        }
        dma->next_queue  = NULL;
}


int drm_select_queue(drm_device_t *dev, void (*wrapper)(unsigned long))
{
        int        i;
        int        candidate = -1;
        int        j         = jiffies;

        if (!dev) {
                DRM_ERROR("No device\n");
                return -1;
        }
        if (!dev->queuelist || !dev->queuelist[DRM_KERNEL_CONTEXT]) {
                                /* This only happens between the time the
                                   interrupt is initialized and the time
                                   the queues are initialized. */
                return -1;
        }

                                /* Doing "while locked" DMA? */
        if (DRM_WAITCOUNT(dev, DRM_KERNEL_CONTEXT)) {
                return DRM_KERNEL_CONTEXT;
        }

                                /* If there are buffers on the last_context
                                   queue, and we have not been executing
                                   this context very long, continue to
                                   execute this context. */
        if (dev->last_switch <= j
            && dev->last_switch + DRM_TIME_SLICE > j
            && DRM_WAITCOUNT(dev, dev->last_context)) {
                return dev->last_context;
        }

                                /* Otherwise, find a candidate */
        for (i = dev->last_checked + 1; i < dev->queue_count; i++) {
                if (DRM_WAITCOUNT(dev, i)) {
                        candidate = dev->last_checked = i;
                        break;
                }
        }

        if (candidate < 0) {
                for (i = 0; i < dev->queue_count; i++) {
                        if (DRM_WAITCOUNT(dev, i)) {
                                candidate = dev->last_checked = i;
                                break;
                        }
                }
        }

        if (wrapper
            && candidate >= 0
            && candidate != dev->last_context
            && dev->last_switch <= j
            && dev->last_switch + DRM_TIME_SLICE > j) {
                if (dev->timer.expires != dev->last_switch + DRM_TIME_SLICE) {
                        del_timer(&dev->timer);
                        dev->timer.function = wrapper;
                        dev->timer.data     = (unsigned long)dev;
                        dev->timer.expires  = dev->last_switch+DRM_TIME_SLICE;
                        add_timer(&dev->timer);
                }
                return -1;
        }

        return candidate;
}


int drm_dma_enqueue(drm_device_t *dev, drm_dma_t *d)
{
        int               i;
        drm_queue_t       *q;
        drm_buf_t         *buf;
        int               idx;
        int               while_locked = 0;
        drm_device_dma_t  *dma = dev->dma;
        DECLARE_WAITQUEUE(entry, current);

        DRM_DEBUG("%d\n", d->send_count);

        if (d->flags & _DRM_DMA_WHILE_LOCKED) {
                int context = dev->lock.hw_lock->lock;
                
                if (!_DRM_LOCK_IS_HELD(context)) {
                        DRM_ERROR("No lock held during \"while locked\""
                                  " request\n");
                        return -EINVAL;
                }
                if (d->context != _DRM_LOCKING_CONTEXT(context)
                    && _DRM_LOCKING_CONTEXT(context) != DRM_KERNEL_CONTEXT) {
                        DRM_ERROR("Lock held by %d while %d makes"
                                  " \"while locked\" request\n",
                                  _DRM_LOCKING_CONTEXT(context),
                                  d->context);
                        return -EINVAL;
                }
                q = dev->queuelist[DRM_KERNEL_CONTEXT];
                while_locked = 1;
        } else {
                q = dev->queuelist[d->context];
        }


        atomic_inc(&q->use_count);
        if (atomic_read(&q->block_write)) {
                current->state = TASK_INTERRUPTIBLE;
                add_wait_queue(&q->write_queue, &entry);
                atomic_inc(&q->block_count);
                for (;;) {
                        if (!atomic_read(&q->block_write)) break;
                        schedule();
                        if (signal_pending(current)) {
                                atomic_dec(&q->use_count);
                                return -EINTR;
                        }
                }
                atomic_dec(&q->block_count);
                current->state = TASK_RUNNING;
                remove_wait_queue(&q->write_queue, &entry);
        }
        
        for (i = 0; i < d->send_count; i++) {
                idx = d->send_indices[i];
                if (idx < 0 || idx >= dma->buf_count) {
                        atomic_dec(&q->use_count);
                        DRM_ERROR("Index %d (of %d max)\n",
                                  d->send_indices[i], dma->buf_count - 1);
                        return -EINVAL;
                }
                buf = dma->buflist[ idx ];
                if (buf->pid != current->pid) {
                        atomic_dec(&q->use_count);
                        DRM_ERROR("Process %d using buffer owned by %d\n",
                                  current->pid, buf->pid);
                        return -EINVAL;
                }
                if (buf->list != DRM_LIST_NONE) {
                        atomic_dec(&q->use_count);
                        DRM_ERROR("Process %d using buffer %d on list %d\n",
                                  current->pid, buf->idx, buf->list);
                }
                buf->used         = d->send_sizes[i];
                buf->while_locked = while_locked;
                buf->context      = d->context;
                if (!buf->used) {
                        DRM_ERROR("Queueing 0 length buffer\n");
                }
                if (buf->pending) {
                        atomic_dec(&q->use_count);
                        DRM_ERROR("Queueing pending buffer:"
                                  " buffer %d, offset %d\n",
                                  d->send_indices[i], i);
                        return -EINVAL;
                }
                if (buf->waiting) {
                        atomic_dec(&q->use_count);
                        DRM_ERROR("Queueing waiting buffer:"
                                  " buffer %d, offset %d\n",
                                  d->send_indices[i], i);
                        return -EINVAL;
                }
                buf->waiting = 1;
                if (atomic_read(&q->use_count) == 1
                    || atomic_read(&q->finalization)) {
                        drm_free_buffer(dev, buf);
                } else {
                        drm_waitlist_put(&q->waitlist, buf);
                        atomic_inc(&q->total_queued);
                }
        }
        atomic_dec(&q->use_count);
        
        return 0;
}

static int drm_dma_get_buffers_of_order(drm_device_t *dev, drm_dma_t *d,
                                        int order)
{
        int               i;
        drm_buf_t         *buf;
        drm_device_dma_t  *dma = dev->dma;
        
        for (i = d->granted_count; i < d->request_count; i++) {
                buf = drm_freelist_get(&dma->bufs[order].freelist,
                                       d->flags & _DRM_DMA_WAIT);
                if (!buf) break;
                if (buf->pending || buf->waiting) {
                        DRM_ERROR("Free buffer %d in use by %d (w%d, p%d)\n",
                                  buf->idx,
                                  buf->pid,
                                  buf->waiting,
                                  buf->pending);
                }
                buf->pid     = current->pid;
                copy_to_user_ret(&d->request_indices[i],
                                 &buf->idx,
                                 sizeof(buf->idx),
                                 -EFAULT);
                copy_to_user_ret(&d->request_sizes[i],
                                 &buf->total,
                                 sizeof(buf->total),
                                 -EFAULT);
                ++d->granted_count;
        }
        return 0;
}


int drm_dma_get_buffers(drm_device_t *dev, drm_dma_t *dma)
{
        int               order;
        int               retcode = 0;
        int               tmp_order;
        
        order = drm_order(dma->request_size);

        dma->granted_count = 0;
        retcode            = drm_dma_get_buffers_of_order(dev, dma, order);

        if (dma->granted_count < dma->request_count
            && (dma->flags & _DRM_DMA_SMALLER_OK)) {
                for (tmp_order = order - 1;
                     !retcode
                             && dma->granted_count < dma->request_count
                             && tmp_order >= DRM_MIN_ORDER;
                     --tmp_order) {
                        
                        retcode = drm_dma_get_buffers_of_order(dev, dma,
                                                               tmp_order);
                }
        }

        if (dma->granted_count < dma->request_count
            && (dma->flags & _DRM_DMA_LARGER_OK)) {
                for (tmp_order = order + 1;
                     !retcode
                             && dma->granted_count < dma->request_count
                             && tmp_order <= DRM_MAX_ORDER;
                     ++tmp_order) {
                        
                        retcode = drm_dma_get_buffers_of_order(dev, dma,
                                                               tmp_order);
                }
        }
        return 0;
}