i830_dma.c

一个2.4.21版本的嵌入式linux内核

/* i830_dma.c -- DMA support for the I830 -*- linux-c -*-
 * Created: Mon Dec 13 01:50:01 1999 by [e-mail]
 *
 * 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
 * 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.
 *
 * Authors: Rickard E. (Rik) Faith <[e-mail]>
 *	    Jeff Hartmann <[e-mail]>
 *      Keith Whitwell <[e-mail]>
 *      Abraham vd Merwe <[e-mail]>
 *
 */

#include "i830.h"
#include "drmP.h"
#include "i830_drv.h"
#include <linux/interrupt.h>	/* For task queue support */
#include <linux/delay.h>
/* in case we don't have a 2.3.99-pre6 kernel or later: */
#ifndef VM_DONTCOPY
#define VM_DONTCOPY 0
#endif

#define I830_BUF_FREE		2
#define I830_BUF_CLIENT		1
#define I830_BUF_HARDWARE      	0

#define I830_BUF_UNMAPPED 0
#define I830_BUF_MAPPED   1

#define RING_LOCALS	unsigned int outring, ringmask; volatile char *virt;


#define DO_IDLE_WORKAROUND()					\
do {								\
   int _head;							\
   int _tail;							\
   do { 							\
      _head = I830_READ(LP_RING + RING_HEAD) & HEAD_ADDR;	\
      _tail = I830_READ(LP_RING + RING_TAIL) & TAIL_ADDR;	\
      udelay(1);						\
   } while(_head != _tail);					\
} while(0)

#define I830_SYNC_WORKAROUND 0

#define BEGIN_LP_RING(n) do {				\
	if (I830_VERBOSE)				\
		DRM_DEBUG("BEGIN_LP_RING(%d) in %s\n",	\
			  n, __FUNCTION__);		\
	if (I830_SYNC_WORKAROUND)			\
		DO_IDLE_WORKAROUND();			\
	if (dev_priv->ring.space < n*4) 		\
		i830_wait_ring(dev, n*4);		\
	dev_priv->ring.space -= n*4;			\
	outring = dev_priv->ring.tail;			\
	ringmask = dev_priv->ring.tail_mask;		\
	virt = dev_priv->ring.virtual_start;		\
} while (0)

#define ADVANCE_LP_RING() do {					\
	if (I830_VERBOSE) DRM_DEBUG("ADVANCE_LP_RING\n");	\
	dev_priv->ring.tail = outring;				\
	I830_WRITE(LP_RING + RING_TAIL, outring);		\
} while(0)

#define OUT_RING(n) do {						\
	if (I830_VERBOSE) DRM_DEBUG("   OUT_RING %x\n", (int)(n));	\
	*(volatile unsigned int *)(virt + outring) = n;			\
	outring += 4;							\
	outring &= ringmask;						\
} while (0);

static inline void i830_print_status_page(drm_device_t *dev)
{
   	drm_device_dma_t *dma = dev->dma;
      	drm_i830_private_t *dev_priv = dev->dev_private;
	u8 *temp = dev_priv->hw_status_page;
   	int i;

   	DRM_DEBUG(  "hw_status: Interrupt Status : %x\n", temp[0]);
   	DRM_DEBUG(  "hw_status: LpRing Head ptr : %x\n", temp[1]);
   	DRM_DEBUG(  "hw_status: IRing Head ptr : %x\n", temp[2]);
      	DRM_DEBUG(  "hw_status: Reserved : %x\n", temp[3]);
   	DRM_DEBUG(  "hw_status: Driver Counter : %d\n", temp[5]);
   	for(i = 9; i < dma->buf_count + 9; i++) {
	   	DRM_DEBUG( "buffer status idx : %d used: %d\n", i - 9, temp[i]);
	}
}

static drm_buf_t *i830_freelist_get(drm_device_t *dev)
{
   	drm_device_dma_t *dma = dev->dma;
	int		 i;
   	int 		 used;
   
	/* Linear search might not be the best solution */

   	for (i = 0; i < dma->buf_count; i++) {
	   	drm_buf_t *buf = dma->buflist[ i ];
	   	drm_i830_buf_priv_t *buf_priv = buf->dev_private;
		/* In use is already a pointer */
	   	used = cmpxchg(buf_priv->in_use, I830_BUF_FREE, 
			       I830_BUF_CLIENT);
	   	if(used == I830_BUF_FREE) {
			return buf;
		}
	}
   	return NULL;
}

/* This should only be called if the buffer is not sent to the hardware
 * yet, the hardware updates in use for us once its on the ring buffer.
 */

static int i830_freelist_put(drm_device_t *dev, drm_buf_t *buf)
{
   	drm_i830_buf_priv_t *buf_priv = buf->dev_private;
   	int used;
   
   	/* In use is already a pointer */
   	used = cmpxchg(buf_priv->in_use, I830_BUF_CLIENT, I830_BUF_FREE);
   	if(used != I830_BUF_CLIENT) {
	   	DRM_ERROR("Freeing buffer thats not in use : %d\n", buf->idx);
	   	return -EINVAL;
	}
   
   	return 0;
}

static struct file_operations i830_buffer_fops = {
	open:	 DRM(open),
	flush:	 DRM(flush),
	release: DRM(release),
	ioctl:	 DRM(ioctl),
	mmap:	 i830_mmap_buffers,
	read:	 DRM(read),
	fasync:	 DRM(fasync),
      	poll:	 DRM(poll),
};

int i830_mmap_buffers(struct file *filp, struct vm_area_struct *vma)
{
	drm_file_t	    *priv	  = filp->private_data;
	drm_device_t	    *dev;
	drm_i830_private_t  *dev_priv;
	drm_buf_t           *buf;
	drm_i830_buf_priv_t *buf_priv;

	lock_kernel();
	dev	 = priv->dev;
	dev_priv = dev->dev_private;
	buf      = dev_priv->mmap_buffer;
	buf_priv = buf->dev_private;
   
	vma->vm_flags |= (VM_IO | VM_DONTCOPY);
	vma->vm_file = filp;
   
   	buf_priv->currently_mapped = I830_BUF_MAPPED;
	unlock_kernel();

	if (remap_page_range(vma->vm_start,
			     VM_OFFSET(vma),
			     vma->vm_end - vma->vm_start,
			     vma->vm_page_prot)) return -EAGAIN;
	return 0;
}

static int i830_map_buffer(drm_buf_t *buf, struct file *filp)
{
	drm_file_t	  *priv	  = filp->private_data;
	drm_device_t	  *dev	  = priv->dev;
	drm_i830_buf_priv_t *buf_priv = buf->dev_private;
      	drm_i830_private_t *dev_priv = dev->dev_private;
   	struct file_operations *old_fops;
	int retcode = 0;

	if(buf_priv->currently_mapped == I830_BUF_MAPPED) return -EINVAL;

	if(VM_DONTCOPY != 0) {
		down_write( &current->mm->mmap_sem );
		old_fops = filp->f_op;
		filp->f_op = &i830_buffer_fops;
		dev_priv->mmap_buffer = buf;
		buf_priv->virtual = (void *)do_mmap(filp, 0, buf->total, 
						    PROT_READ|PROT_WRITE,
						    MAP_SHARED, 
						    buf->bus_address);
		dev_priv->mmap_buffer = NULL;
   		filp->f_op = old_fops;
		if ((unsigned long)buf_priv->virtual > -1024UL) {
			/* Real error */
			DRM_DEBUG("mmap error\n");
			retcode = (signed int)buf_priv->virtual;
			buf_priv->virtual = 0;
		}
		up_write( &current->mm->mmap_sem );
	} else {
		buf_priv->virtual = buf_priv->kernel_virtual;
   		buf_priv->currently_mapped = I830_BUF_MAPPED;
	}
	return retcode;
}

static int i830_unmap_buffer(drm_buf_t *buf)
{
	drm_i830_buf_priv_t *buf_priv = buf->dev_private;
	int retcode = 0;

	if(VM_DONTCOPY != 0) {
		if(buf_priv->currently_mapped != I830_BUF_MAPPED) 
			return -EINVAL;
		down_write( &current->mm->mmap_sem );
        	retcode = do_munmap(current->mm, 
				    (unsigned long)buf_priv->virtual, 
				    (size_t) buf->total);
   		up_write( &current->mm->mmap_sem );
	}
   	buf_priv->currently_mapped = I830_BUF_UNMAPPED;
   	buf_priv->virtual = 0;

	return retcode;
}

static int i830_dma_get_buffer(drm_device_t *dev, drm_i830_dma_t *d, 
			       struct file *filp)
{
	drm_file_t	  *priv	  = filp->private_data;
	drm_buf_t	  *buf;
	drm_i830_buf_priv_t *buf_priv;
	int retcode = 0;

	buf = i830_freelist_get(dev);
	if (!buf) {
		retcode = -ENOMEM;
	   	DRM_DEBUG("retcode=%d\n", retcode);
		return retcode;
	}
   
	retcode = i830_map_buffer(buf, filp);
	if(retcode) {
		i830_freelist_put(dev, buf);
	   	DRM_DEBUG("mapbuf failed, retcode %d\n", retcode);
		return retcode;
	}
	buf->pid     = priv->pid;
	buf_priv = buf->dev_private;	
	d->granted = 1;
   	d->request_idx = buf->idx;
   	d->request_size = buf->total;
   	d->virtual = buf_priv->virtual;

	return retcode;
}

static int i830_dma_cleanup(drm_device_t *dev)
{
	drm_device_dma_t *dma = dev->dma;

	if(dev->dev_private) {
		int i;
	   	drm_i830_private_t *dev_priv = 
	     		(drm_i830_private_t *) dev->dev_private;
	   
	   	if(dev_priv->ring.virtual_start) {
		   	DRM(ioremapfree)((void *) dev_priv->ring.virtual_start,
					 dev_priv->ring.Size);
		}
	   	if(dev_priv->hw_status_page != NULL) {
	   		pci_free_consistent(dev->pdev, PAGE_SIZE, 
	   		    dev_priv->hw_status_page, dev_priv->dma_status_page);
		   	/* Need to rewrite hardware status page */
		   	I830_WRITE(0x02080, 0x1ffff000);
		}
	   	DRM(free)(dev->dev_private, sizeof(drm_i830_private_t), 
			 DRM_MEM_DRIVER);
	   	dev->dev_private = NULL;

		for (i = 0; i < dma->buf_count; i++) {
			drm_buf_t *buf = dma->buflist[ i ];
			drm_i830_buf_priv_t *buf_priv = buf->dev_private;
			DRM(ioremapfree)(buf_priv->kernel_virtual, buf->total);
		}
	}
   	return 0;
}

static int i830_wait_ring(drm_device_t *dev, int n)
{
   	drm_i830_private_t *dev_priv = dev->dev_private;
   	drm_i830_ring_buffer_t *ring = &(dev_priv->ring);
   	int iters = 0;
   	unsigned long end;
	unsigned int last_head = I830_READ(LP_RING + RING_HEAD) & HEAD_ADDR;

	end = jiffies + (HZ*3);
   	while (ring->space < n) {
	   	ring->head = I830_READ(LP_RING + RING_HEAD) & HEAD_ADDR;
	   	ring->space = ring->head - (ring->tail+8);
		if (ring->space < 0) ring->space += ring->Size;
	   
		if (ring->head != last_head) {
			end = jiffies + (HZ*3);
			last_head = ring->head;
		}
	  
	   	iters++;
		if(time_before(end,jiffies)) {
		   	DRM_ERROR("space: %d wanted %d\n", ring->space, n);
		   	DRM_ERROR("lockup\n");
		   	goto out_wait_ring;
		}

	   	udelay(1);
	}

out_wait_ring:   
   	return iters;
}

static void i830_kernel_lost_context(drm_device_t *dev)
{
      	drm_i830_private_t *dev_priv = dev->dev_private;
   	drm_i830_ring_buffer_t *ring = &(dev_priv->ring);
      
   	ring->head = I830_READ(LP_RING + RING_HEAD) & HEAD_ADDR;
     	ring->tail = I830_READ(LP_RING + RING_TAIL);
     	ring->space = ring->head - (ring->tail+8);
     	if (ring->space < 0) ring->space += ring->Size;
}

static int i830_freelist_init(drm_device_t *dev, drm_i830_private_t *dev_priv)
{
      	drm_device_dma_t *dma = dev->dma;
   	int my_idx = 36;
   	u32 *hw_status = (u32 *)(dev_priv->hw_status_page + my_idx);
   	int i;

   	if(dma->buf_count > 1019) {
	   	/* Not enough space in the status page for the freelist */
	   	return -EINVAL;
	}

   	for (i = 0; i < dma->buf_count; i++) {
	   	drm_buf_t *buf = dma->buflist[ i ];
	   	drm_i830_buf_priv_t *buf_priv = buf->dev_private;

	   	buf_priv->in_use = hw_status++;
	   	buf_priv->my_use_idx = my_idx;
	   	my_idx += 4;

	   	*buf_priv->in_use = I830_BUF_FREE;

		buf_priv->kernel_virtual = DRM(ioremap)(buf->bus_address, 
							buf->total);
	}
	return 0;
}

static int i830_dma_initialize(drm_device_t *dev, 
			       drm_i830_private_t *dev_priv,
			       drm_i830_init_t *init)
{
	struct list_head *list;

   	memset(dev_priv, 0, sizeof(drm_i830_private_t));

	list_for_each(list, &dev->maplist->head) {
		drm_map_list_t *r_list = (drm_map_list_t *)list;
		if( r_list->map &&
		    r_list->map->type == _DRM_SHM &&
		    r_list->map->flags & _DRM_CONTAINS_LOCK ) {
			dev_priv->sarea_map = r_list->map;
 			break;
 		}
 	}

	if(!dev_priv->sarea_map) {
		dev->dev_private = (void *)dev_priv;
		i830_dma_cleanup(dev);
		DRM_ERROR("can not find sarea!\n");
		return -EINVAL;
	}
	DRM_FIND_MAP( dev_priv->mmio_map, init->mmio_offset );
	if(!dev_priv->mmio_map) {
		dev->dev_private = (void *)dev_priv;
		i830_dma_cleanup(dev);
		DRM_ERROR("can not find mmio map!\n");
		return -EINVAL;
	}
	DRM_FIND_MAP( dev_priv->buffer_map, init->buffers_offset );
	if(!dev_priv->buffer_map) {
		dev->dev_private = (void *)dev_priv;
		i830_dma_cleanup(dev);
		DRM_ERROR("can not find dma buffer map!\n");
		return -EINVAL;
	}

	dev_priv->sarea_priv = (drm_i830_sarea_t *)
		((u8 *)dev_priv->sarea_map->handle +
		 init->sarea_priv_offset);

   	atomic_set(&dev_priv->flush_done, 0);
	init_waitqueue_head(&dev_priv->flush_queue);

   	dev_priv->ring.Start = init->ring_start;
   	dev_priv->ring.End = init->ring_end;
   	dev_priv->ring.Size = init->ring_size;

   	dev_priv->ring.virtual_start = DRM(ioremap)(dev->agp->base + 
						    init->ring_start, 
						    init->ring_size);

   	if (dev_priv->ring.virtual_start == NULL) {
		dev->dev_private = (void *) dev_priv;
	   	i830_dma_cleanup(dev);
	   	DRM_ERROR("can not ioremap virtual address for"
			  " ring buffer\n");
	   	return -ENOMEM;
	}

   	dev_priv->ring.tail_mask = dev_priv->ring.Size - 1;
   
	dev_priv->w = init->w;
	dev_priv->h = init->h;
	dev_priv->pitch = init->pitch;
	dev_priv->back_offset = init->back_offset;
	dev_priv->depth_offset = init->depth_offset;

	dev_priv->front_di1 = init->front_offset | init->pitch_bits;
	dev_priv->back_di1 = init->back_offset | init->pitch_bits;
	dev_priv->zi1 = init->depth_offset | init->pitch_bits;

	dev_priv->cpp = init->cpp;
	/* We are using seperate values as placeholders for mechanisms for
	 * private backbuffer/depthbuffer usage.
	 */