drm_bufs.h

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/**
 * \file drm_bufs.h 
 * Generic buffer template
 * 
 * \author Rickard E. (Rik) Faith <[e-mail]>
 * \author Gareth Hughes <[e-mail]>
 */

/*
 * Created: Thu Nov 23 03:10:50 2000 by [e-mail]
 *
 * Copyright 1999, 2000 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.
 */

#include <linux/vmalloc.h>
#include "drmP.h"

#ifndef __HAVE_PCI_DMA
#define __HAVE_PCI_DMA		0
#endif

#ifndef __HAVE_SG
#define __HAVE_SG		0
#endif

#ifndef DRIVER_BUF_PRIV_T
#define DRIVER_BUF_PRIV_T		u32
#endif
#ifndef DRIVER_AGP_BUFFERS_MAP
#if __HAVE_AGP && __HAVE_DMA
#error "You must define DRIVER_AGP_BUFFERS_MAP()"
#else
#define DRIVER_AGP_BUFFERS_MAP( dev )	NULL
#endif
#endif


/**
 * Compute size order.  Returns the exponent of the smaller power of two which
 * is greater or equal to given number.
 * 
 * \param size size.
 * \return order.
 *
 * \todo Can be made faster.
 */
int DRM(order)( unsigned long size )
{
	int order;
	unsigned long tmp;

	for (order = 0, tmp = size >> 1; tmp; tmp >>= 1, order++)
		;

	if (size & (size - 1))
		++order;

	return order;
}

/**
 * Ioctl to specify a range of memory that is available for mapping by a non-root process.
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param arg pointer to a drm_map structure.
 * \return zero on success or a negative value on error.
 *
 * Adjusts the memory offset to its absolute value according to the mapping
 * type.  Adds the map to the map list drm_device::maplist. Adds MTRR's where
 * applicable and if supported by the kernel.
 */
int DRM(addmap)( struct inode *inode, struct file *filp,
		 unsigned int cmd, unsigned long arg )
{
	drm_file_t *priv = filp->private_data;
	drm_device_t *dev = priv->dev;
	drm_map_t *map;
	drm_map_t __user *argp = (void __user *)arg;
	drm_map_list_t *list;

	if ( !(filp->f_mode & 3) ) return -EACCES; /* Require read/write */

	map = DRM(alloc)( sizeof(*map), DRM_MEM_MAPS );
	if ( !map )
		return -ENOMEM;

	if ( copy_from_user( map, argp, sizeof(*map) ) ) {
		DRM(free)( map, sizeof(*map), DRM_MEM_MAPS );
		return -EFAULT;
	}

	/* Only allow shared memory to be removable since we only keep enough
	 * book keeping information about shared memory to allow for removal
	 * when processes fork.
	 */
	if ( (map->flags & _DRM_REMOVABLE) && map->type != _DRM_SHM ) {
		DRM(free)( map, sizeof(*map), DRM_MEM_MAPS );
		return -EINVAL;
	}
	DRM_DEBUG( "offset = 0x%08lx, size = 0x%08lx, type = %d\n",
		   map->offset, map->size, map->type );
	if ( (map->offset & (~PAGE_MASK)) || (map->size & (~PAGE_MASK)) ) {
		DRM(free)( map, sizeof(*map), DRM_MEM_MAPS );
		return -EINVAL;
	}
	map->mtrr   = -1;
	map->handle = NULL;

	switch ( map->type ) {
	case _DRM_REGISTERS:
	case _DRM_FRAME_BUFFER:
#if !defined(__sparc__) && !defined(__alpha__) && !defined(__ia64__)
		if ( map->offset + map->size < map->offset ||
		     map->offset < virt_to_phys(high_memory) ) {
			DRM(free)( map, sizeof(*map), DRM_MEM_MAPS );
			return -EINVAL;
		}
#endif
#ifdef __alpha__
		map->offset += dev->hose->mem_space->start;
#endif
#if __REALLY_HAVE_MTRR
		if ( map->type == _DRM_FRAME_BUFFER ||
		     (map->flags & _DRM_WRITE_COMBINING) ) {
			map->mtrr = mtrr_add( map->offset, map->size,
					      MTRR_TYPE_WRCOMB, 1 );
		}
#endif
		if (map->type == _DRM_REGISTERS)
			map->handle = DRM(ioremap)( map->offset, map->size,
						    dev );
		break;

	case _DRM_SHM:
		map->handle = vmalloc_32(map->size);
		DRM_DEBUG( "%lu %d %p\n",
			   map->size, DRM(order)( map->size ), map->handle );
		if ( !map->handle ) {
			DRM(free)( map, sizeof(*map), DRM_MEM_MAPS );
			return -ENOMEM;
		}
		map->offset = (unsigned long)map->handle;
		if ( map->flags & _DRM_CONTAINS_LOCK ) {
			/* Prevent a 2nd X Server from creating a 2nd lock */
			if (dev->lock.hw_lock != NULL) {
				vfree( map->handle );
				DRM(free)( map, sizeof(*map), DRM_MEM_MAPS );
				return -EBUSY;
			}
			dev->sigdata.lock =
			dev->lock.hw_lock = map->handle; /* Pointer to lock */
		}
		break;
#if __REALLY_HAVE_AGP
	case _DRM_AGP:
#ifdef __alpha__
		map->offset += dev->hose->mem_space->start;
#endif
		map->offset += dev->agp->base;
		map->mtrr   = dev->agp->agp_mtrr; /* for getmap */
		break;
#endif
	case _DRM_SCATTER_GATHER:
		if (!dev->sg) {
			DRM(free)(map, sizeof(*map), DRM_MEM_MAPS);
			return -EINVAL;
		}
		map->offset += dev->sg->handle;
		break;

	default:
		DRM(free)( map, sizeof(*map), DRM_MEM_MAPS );
		return -EINVAL;
	}

	list = DRM(alloc)(sizeof(*list), DRM_MEM_MAPS);
	if(!list) {
		DRM(free)(map, sizeof(*map), DRM_MEM_MAPS);
		return -EINVAL;
	}
	memset(list, 0, sizeof(*list));
	list->map = map;

	down(&dev->struct_sem);
	list_add(&list->head, &dev->maplist->head);
 	up(&dev->struct_sem);

	if ( copy_to_user( argp, map, sizeof(*map) ) )
		return -EFAULT;
	if ( map->type != _DRM_SHM ) {
		if ( copy_to_user( &argp->handle,
				   &map->offset,
				   sizeof(map->offset) ) )
			return -EFAULT;
	}
	return 0;
}


/**
 * Remove a map private from list and deallocate resources if the mapping
 * isn't in use.
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param arg pointer to a drm_map_t structure.
 * \return zero on success or a negative value on error.
 *
 * Searches the map on drm_device::maplist, removes it from the list, see if
 * its being used, and free any associate resource (such as MTRR's) if it's not
 * being on use.
 *
 * \sa addmap().
 */
int DRM(rmmap)(struct inode *inode, struct file *filp,
	       unsigned int cmd, unsigned long arg)
{
	drm_file_t	*priv	= filp->private_data;
	drm_device_t	*dev	= priv->dev;
	struct list_head *list;
	drm_map_list_t *r_list = NULL;
	drm_vma_entry_t *pt, *prev;
	drm_map_t *map;
	drm_map_t request;
	int found_maps = 0;

	if (copy_from_user(&request, (drm_map_t __user *)arg,
			   sizeof(request))) {
		return -EFAULT;
	}

	down(&dev->struct_sem);
	list = &dev->maplist->head;
	list_for_each(list, &dev->maplist->head) {
		r_list = list_entry(list, drm_map_list_t, head);

		if(r_list->map &&
		   r_list->map->handle == request.handle &&
		   r_list->map->flags & _DRM_REMOVABLE) break;
	}

	/* List has wrapped around to the head pointer, or its empty we didn't
	 * find anything.
	 */
	if(list == (&dev->maplist->head)) {
		up(&dev->struct_sem);
		return -EINVAL;
	}
	map = r_list->map;
	list_del(list);
	DRM(free)(list, sizeof(*list), DRM_MEM_MAPS);

	for (pt = dev->vmalist, prev = NULL; pt; prev = pt, pt = pt->next) {
		if (pt->vma->vm_private_data == map) found_maps++;
	}

	if(!found_maps) {
		switch (map->type) {
		case _DRM_REGISTERS:
		case _DRM_FRAME_BUFFER:
#if __REALLY_HAVE_MTRR
			if (map->mtrr >= 0) {
				int retcode;
				retcode = mtrr_del(map->mtrr,
						   map->offset,
						   map->size);
				DRM_DEBUG("mtrr_del = %d\n", retcode);
			}
#endif
			DRM(ioremapfree)(map->handle, map->size, dev);
			break;
		case _DRM_SHM:
			vfree(map->handle);
			break;
		case _DRM_AGP:
		case _DRM_SCATTER_GATHER:
			break;
		}
		DRM(free)(map, sizeof(*map), DRM_MEM_MAPS);
	}
	up(&dev->struct_sem);
	return 0;
}

#if __HAVE_DMA

/**
 * Cleanup after an error on one of the addbufs() functions.
 *
 * \param entry buffer entry where the error occurred.
 *
 * Frees any pages and buffers associated with the given entry.
 */
static void DRM(cleanup_buf_error)(drm_buf_entry_t *entry)
{
	int i;

	if (entry->seg_count) {
		for (i = 0; i < entry->seg_count; i++) {
			if (entry->seglist[i]) {
				DRM(free_pages)(entry->seglist[i],
					        entry->page_order,
					        DRM_MEM_DMA);
			}
		}
		DRM(free)(entry->seglist,
			  entry->seg_count *
			  sizeof(*entry->seglist),
			  DRM_MEM_SEGS);

		entry->seg_count = 0;
	}

   	if (entry->buf_count) {
	   	for (i = 0; i < entry->buf_count; i++) {
			if (entry->buflist[i].dev_private) {
				DRM(free)(entry->buflist[i].dev_private,
					  entry->buflist[i].dev_priv_size,
					  DRM_MEM_BUFS);
			}
		}
		DRM(free)(entry->buflist,
			  entry->buf_count *
			  sizeof(*entry->buflist),
			  DRM_MEM_BUFS);

#if __HAVE_DMA_FREELIST
	   	DRM(freelist_destroy)(&entry->freelist);
#endif

		entry->buf_count = 0;
	}
}

#if __REALLY_HAVE_AGP
/**
 * Add AGP buffers for DMA transfers (ioctl).
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param arg pointer to a drm_buf_desc_t request.
 * \return zero on success or a negative number on failure.
 * 
 * After some sanity checks creates a drm_buf structure for each buffer and
 * reallocates the buffer list of the same size order to accommodate the new
 * buffers.
 */
int DRM(addbufs_agp)( struct inode *inode, struct file *filp,
		      unsigned int cmd, unsigned long arg )
{
	drm_file_t *priv = filp->private_data;
	drm_device_t *dev = priv->dev;
	drm_device_dma_t *dma = dev->dma;
	drm_buf_desc_t request;
	drm_buf_entry_t *entry;
	drm_buf_t *buf;
	unsigned long offset;
	unsigned long agp_offset;
	int count;
	int order;
	int size;
	int alignment;
	int page_order;
	int total;
	int byte_count;
	int i;
	drm_buf_t **temp_buflist;
	drm_buf_desc_t __user *argp = (void __user *)arg;

	if ( !dma ) return -EINVAL;

	if ( copy_from_user( &request, argp,
			     sizeof(request) ) )
		return -EFAULT;

	count = request.count;
	order = DRM(order)( request.size );
	size = 1 << order;

	alignment  = (request.flags & _DRM_PAGE_ALIGN)
		? PAGE_ALIGN(size) : size;
	page_order = order - PAGE_SHIFT > 0 ? order - PAGE_SHIFT : 0;
	total = PAGE_SIZE << page_order;

	byte_count = 0;
	agp_offset = dev->agp->base + request.agp_start;

	DRM_DEBUG( "count:      %d\n",  count );
	DRM_DEBUG( "order:      %d\n",  order );
	DRM_DEBUG( "size:       %d\n",  size );
	DRM_DEBUG( "agp_offset: %lu\n", agp_offset );
	DRM_DEBUG( "alignment:  %d\n",  alignment );
	DRM_DEBUG( "page_order: %d\n",  page_order );
	DRM_DEBUG( "total:      %d\n",  total );

	if ( order < DRM_MIN_ORDER || order > DRM_MAX_ORDER ) return -EINVAL;
	if ( dev->queue_count ) return -EBUSY; /* Not while in use */

	spin_lock( &dev->count_lock );
	if ( dev->buf_use ) {
		spin_unlock( &dev->count_lock );
		return -EBUSY;
	}
	atomic_inc( &dev->buf_alloc );
	spin_unlock( &dev->count_lock );

	down( &dev->struct_sem );
	entry = &dma->bufs[order];
	if ( entry->buf_count ) {
		up( &dev->struct_sem );