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drm: add framebuffer maps
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The patch makes drmAddBufs/drmMapBufs can handle buffers in video memory

The attached patch adds a new buffer type DRM_FB_BUFFER. It works like
AGP memory but uses video memory.

From: Austin Yuan <austinyuan@viatech.com.cn>
Signed-off-by: Dave Airlie <airlied@linux.ie>
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Dave Airlie authored and Dave Airlie committed Jul 10, 2005
1 parent 2d0f9ea commit b84397d
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Showing 3 changed files with 178 additions and 4 deletions.
3 changes: 2 additions & 1 deletion drivers/char/drm/drm.h
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Original file line number Diff line number Diff line change
Expand Up @@ -369,7 +369,8 @@ typedef struct drm_buf_desc {
enum {
_DRM_PAGE_ALIGN = 0x01, /**< Align on page boundaries for DMA */
_DRM_AGP_BUFFER = 0x02, /**< Buffer is in AGP space */
_DRM_SG_BUFFER = 0x04 /**< Scatter/gather memory buffer */
_DRM_SG_BUFFER = 0x04, /**< Scatter/gather memory buffer */
_DRM_FB_BUFFER = 0x08 /**< Buffer is in frame buffer */
} flags;
unsigned long agp_start; /**<
* Start address of where the AGP buffers are
Expand Down
4 changes: 3 additions & 1 deletion drivers/char/drm/drmP.h
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Original file line number Diff line number Diff line change
Expand Up @@ -96,6 +96,7 @@
#define DRIVER_IRQ_SHARED 0x80
#define DRIVER_IRQ_VBL 0x100
#define DRIVER_DMA_QUEUE 0x200
#define DRIVER_FB_DMA 0x400

/***********************************************************************/
/** \name Begin the DRM... */
Expand Down Expand Up @@ -474,7 +475,8 @@ typedef struct drm_device_dma {
unsigned long byte_count;
enum {
_DRM_DMA_USE_AGP = 0x01,
_DRM_DMA_USE_SG = 0x02
_DRM_DMA_USE_SG = 0x02,
_DRM_DMA_USE_FB = 0x04
} flags;

} drm_device_dma_t;
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175 changes: 173 additions & 2 deletions drivers/char/drm/drm_bufs.c
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Original file line number Diff line number Diff line change
Expand Up @@ -935,6 +935,172 @@ static int drm_addbufs_sg( struct inode *inode, struct file *filp,
return 0;
}

int drm_addbufs_fb(struct inode *inode, struct file *filp,
unsigned int cmd, unsigned long arg)
{
drm_file_t *priv = filp->private_data;
drm_device_t *dev = priv->head->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 (!drm_core_check_feature(dev, DRIVER_FB_DMA))
return -EINVAL;

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 = 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);
atomic_dec(&dev->buf_alloc);
return -ENOMEM; /* May only call once for each order */
}

if (count < 0 || count > 4096) {
up(&dev->struct_sem);
atomic_dec(&dev->buf_alloc);
return -EINVAL;
}

entry->buflist = drm_alloc(count * sizeof(*entry->buflist),
DRM_MEM_BUFS);
if (!entry->buflist) {
up(&dev->struct_sem);
atomic_dec(&dev->buf_alloc);
return -ENOMEM;
}
memset(entry->buflist, 0, count * sizeof(*entry->buflist));

entry->buf_size = size;
entry->page_order = page_order;

offset = 0;

while (entry->buf_count < count) {
buf = &entry->buflist[entry->buf_count];
buf->idx = dma->buf_count + entry->buf_count;
buf->total = alignment;
buf->order = order;
buf->used = 0;

buf->offset = (dma->byte_count + offset);
buf->bus_address = agp_offset + offset;
buf->address = (void *)(agp_offset + offset);
buf->next = NULL;
buf->waiting = 0;
buf->pending = 0;
init_waitqueue_head(&buf->dma_wait);
buf->filp = NULL;

buf->dev_priv_size = dev->driver->dev_priv_size;
buf->dev_private = drm_alloc(buf->dev_priv_size, DRM_MEM_BUFS);
if (!buf->dev_private) {
/* Set count correctly so we free the proper amount. */
entry->buf_count = count;
drm_cleanup_buf_error(dev, entry);
up(&dev->struct_sem);
atomic_dec(&dev->buf_alloc);
return -ENOMEM;
}
memset(buf->dev_private, 0, buf->dev_priv_size);

DRM_DEBUG("buffer %d @ %p\n", entry->buf_count, buf->address);

offset += alignment;
entry->buf_count++;
byte_count += PAGE_SIZE << page_order;
}

DRM_DEBUG("byte_count: %d\n", byte_count);

temp_buflist = drm_realloc(dma->buflist,
dma->buf_count * sizeof(*dma->buflist),
(dma->buf_count + entry->buf_count)
* sizeof(*dma->buflist), DRM_MEM_BUFS);
if (!temp_buflist) {
/* Free the entry because it isn't valid */
drm_cleanup_buf_error(dev, entry);
up(&dev->struct_sem);
atomic_dec(&dev->buf_alloc);
return -ENOMEM;
}
dma->buflist = temp_buflist;

for (i = 0; i < entry->buf_count; i++) {
dma->buflist[i + dma->buf_count] = &entry->buflist[i];
}

dma->buf_count += entry->buf_count;
dma->byte_count += byte_count;

DRM_DEBUG("dma->buf_count : %d\n", dma->buf_count);
DRM_DEBUG("entry->buf_count : %d\n", entry->buf_count);

up(&dev->struct_sem);

request.count = entry->buf_count;
request.size = size;

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

dma->flags = _DRM_DMA_USE_FB;

atomic_dec(&dev->buf_alloc);
return 0;
}

/**
* Add buffers for DMA transfers (ioctl).
*
Expand Down Expand Up @@ -970,6 +1136,8 @@ int drm_addbufs( struct inode *inode, struct file *filp,
#endif
if ( request.flags & _DRM_SG_BUFFER )
return drm_addbufs_sg( inode, filp, cmd, arg );
else if ( request.flags & _DRM_FB_BUFFER)
return drm_addbufs_fb( inode, filp, cmd, arg );
else
return drm_addbufs_pci( inode, filp, cmd, arg );
}
Expand Down Expand Up @@ -1214,8 +1382,11 @@ int drm_mapbufs( struct inode *inode, struct file *filp,
return -EFAULT;

if ( request.count >= dma->buf_count ) {
if ((drm_core_has_AGP(dev) && (dma->flags & _DRM_DMA_USE_AGP)) ||
(drm_core_check_feature(dev, DRIVER_SG) && (dma->flags & _DRM_DMA_USE_SG)) ) {
if ((drm_core_has_AGP(dev) && (dma->flags & _DRM_DMA_USE_AGP))
|| (drm_core_check_feature(dev, DRIVER_SG)
&& (dma->flags & _DRM_DMA_USE_SG))
|| (drm_core_check_feature(dev, DRIVER_FB_DMA)
&& (dma->flags & _DRM_DMA_USE_FB))) {
drm_map_t *map = dev->agp_buffer_map;

if ( !map ) {
Expand Down

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