Commit b50e7fe9 authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab
Browse files

V4L/DVB (5147): Make vivi driver to use vmalloced pointers 



Before this patch, vivi were simulating a scatter gather DMA transfer.
While this is academic, showing how stuff really works on a real PCI 
device, this means a non-optimized code. 
There are only two memory models that vivi implements:
	1) kernel alloced memory. This is also used by read() method.
	   On this case, a vmalloc32 buffer is allocated at kernel;
	2) userspace allocated memory. This is used by most userspace apps.
	   video-buf will store this pointer.
	   a simple copy_to_user is enough to transfer data.
The third memory model scenario supported by video-buf is overlay mode. 
This model is not implemented on vivi and unlikely to be implemented on 
newer drivers, since now, most userspace apps do some post-processing 
(like de-interlacing).
After this patch, some cleanups may be done at video-buf.c to avoid 
allocating pages, when the driver doesn't need a PCI buffer. This is the 
case of vivi and usb drivers.

Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@infradead.org>
parent 52ebc763

drivers/media/video/video-buf.c

+3 −0
Original line number Diff line number Diff line
@@ -148,6 +148,8 @@ int videobuf_dma_init_user(struct videobuf_dmabuf *dma, int direction, 
	dprintk(1,"init user [0x%lx+0x%lx => %d pages]\n",

		data,size,dma->nr_pages);



	dma->varea = (void *) data;



	down_read(&current->mm->mmap_sem);

	err = get_user_pages(current,current->mm,

			     data & PAGE_MASK, dma->nr_pages,
@@ -285,6 +287,7 @@ int videobuf_dma_free(struct videobuf_dmabuf *dma) 


	vfree(dma->vmalloc);

	dma->vmalloc = NULL;

	dma->varea = NULL;



	if (dma->bus_addr) {

		dma->bus_addr = 0;

drivers/media/video/vivi.c

+72 −11
Original line number Diff line number Diff line
@@ -145,7 +145,9 @@ struct vivi_buffer { 


	struct vivi_fmt        *fmt;



#ifdef CONFIG_VIVI_SCATTER

	struct sg_to_addr      *to_addr;

#endif

};



struct vivi_dmaqueue {
@@ -230,6 +232,7 @@ static u8 bars[8][3] = { 
#define TSTAMP_MAX_Y TSTAMP_MIN_Y+15

#define TSTAMP_MIN_X 64



#ifdef CONFIG_VIVI_SCATTER

static void prep_to_addr(struct sg_to_addr to_addr[],

			 struct videobuf_buffer *vb)

{
@@ -262,14 +265,24 @@ static int get_addr_pos(int pos, int pages, struct sg_to_addr to_addr[]) 


	return (p1);

}

#endif



#ifdef CONFIG_VIVI_SCATTER

static void gen_line(struct sg_to_addr to_addr[],int inipos,int pages,int wmax,

		     int hmax, int line, char *timestr)

#else

static void gen_line(char *basep,int inipos,int wmax,

		     int hmax, int line, char *timestr)

#endif

{

	int  w,i,j,pos=inipos,pgpos,oldpg,y;

	char *p,*s,*basep;

	struct page *pg;

	int  w,i,j,pos=inipos,y;

	char *p,*s;

	u8   chr,r,g,b,color;

#ifdef CONFIG_VIVI_SCATTER

	int pgpos,oldpg;

	char *basep;

	struct page *pg;



	unsigned long flags;

	spinlock_t spinlock;
@@ -280,6 +293,7 @@ static void gen_line(struct sg_to_addr to_addr[],int inipos,int pages,int wmax, 
	pg=pfn_to_page(sg_dma_address(to_addr[oldpg].sg) >> PAGE_SHIFT);

	spin_lock_irqsave(&spinlock,flags);

	basep = kmap_atomic(pg, KM_BOUNCE_READ)+to_addr[oldpg].sg->offset;

#endif



	/* We will just duplicate the second pixel at the packet */

	wmax/=2;
@@ -291,6 +305,7 @@ static void gen_line(struct sg_to_addr to_addr[],int inipos,int pages,int wmax, 
		b=bars[w*7/wmax][2];



		for (color=0;color<4;color++) {

#ifdef CONFIG_VIVI_SCATTER

			pgpos=get_addr_pos(pos,pages,to_addr);

			if (pgpos!=oldpg) {

				pg=pfn_to_page(sg_dma_address(to_addr[pgpos].sg) >> PAGE_SHIFT);
@@ -299,6 +314,9 @@ static void gen_line(struct sg_to_addr to_addr[],int inipos,int pages,int wmax, 
				oldpg=pgpos;

			}

			p=basep+pos-to_addr[pgpos].pos;

#else

			p=basep+pos;

#endif



			switch (color) {

				case 0:
@@ -343,6 +361,7 @@ static void gen_line(struct sg_to_addr to_addr[],int inipos,int pages,int wmax, 


				pos=inipos+j*2;

				for (color=0;color<4;color++) {

#ifdef CONFIG_VIVI_SCATTER

					pgpos=get_addr_pos(pos,pages,to_addr);

					if (pgpos!=oldpg) {

						pg=pfn_to_page(sg_dma_address(
@@ -356,6 +375,9 @@ static void gen_line(struct sg_to_addr to_addr[],int inipos,int pages,int wmax, 
						oldpg=pgpos;

					}

					p=basep+pos-to_addr[pgpos].pos;

#else

					p=basep+pos;

#endif



					y=TO_Y(r,g,b);
@@ -380,19 +402,27 @@ static void gen_line(struct sg_to_addr to_addr[],int inipos,int pages,int wmax, 




end:

#ifdef CONFIG_VIVI_SCATTER

	kunmap_atomic(basep, KM_BOUNCE_READ);

	spin_unlock_irqrestore(&spinlock,flags);



#else

	return;

#endif

}

static void vivi_fillbuff(struct vivi_dev *dev,struct vivi_buffer *buf)

{

	int h,pos=0;

	int hmax  = buf->vb.height;

	int wmax  = buf->vb.width;

	struct videobuf_buffer *vb=&buf->vb;

	struct sg_to_addr *to_addr=buf->to_addr;

	struct timeval ts;

#ifdef CONFIG_VIVI_SCATTER

	struct sg_to_addr *to_addr=buf->to_addr;

	struct videobuf_buffer *vb=&buf->vb;

#else

	char *tmpbuf;

#endif



#ifdef CONFIG_VIVI_SCATTER

	/* Test if DMA mapping is ready */

	if (!sg_dma_address(&vb->dma.sglist[0]))

		return;
@@ -401,9 +431,27 @@ static void vivi_fillbuff(struct vivi_dev *dev,struct vivi_buffer *buf) 


	/* Check if there is enough memory */

	BUG_ON(buf->vb.dma.nr_pages << PAGE_SHIFT < (buf->vb.width*buf->vb.height)*2);

#else

	if (buf->vb.dma.varea) {

		tmpbuf=kmalloc (wmax*2, GFP_KERNEL);

	} else {

		tmpbuf=buf->vb.dma.vmalloc;

	}



#endif



	for (h=0;h<hmax;h++) {

#ifdef CONFIG_VIVI_SCATTER

		gen_line(to_addr,pos,vb->dma.nr_pages,wmax,hmax,h,dev->timestr);

#else

		if (buf->vb.dma.varea) {

			gen_line(tmpbuf,0,wmax,hmax,h,dev->timestr);

			/* FIXME: replacing to __copy_to_user */

			copy_to_user(buf->vb.dma.varea+pos,tmpbuf,wmax*2);

		} else {

			gen_line(tmpbuf,pos,wmax,hmax,h,dev->timestr);

		}

#endif

		pos += wmax*2;

	}
@@ -429,7 +477,7 @@ static void vivi_fillbuff(struct vivi_dev *dev,struct vivi_buffer *buf) 
			dev->h,dev->m,dev->s,(dev->us+500)/1000);



	dprintk(2,"vivifill at %s: Buffer 0x%08lx size= %d\n",dev->timestr,

			(unsigned long)buf->vb.dma.vmalloc,pos);

			(unsigned long)buf->vb.dma.varea,pos);



	/* Advice that buffer was filled */

	buf->vb.state = STATE_DONE;
@@ -668,9 +716,11 @@ static void free_buffer(struct videobuf_queue *vq, struct vivi_buffer *buf) 
	if (in_interrupt())

		BUG();



#ifdef CONFIG_VIVI_SCATTER

	/*FIXME: Maybe a spinlock is required here */

	kfree(buf->to_addr);

	buf->to_addr=NULL;

#endif



	videobuf_waiton(&buf->vb,0,0);

	videobuf_dma_unmap(vq, &buf->vb.dma);
@@ -716,11 +766,12 @@ buffer_prepare(struct videobuf_queue *vq, struct videobuf_buffer *vb, 


	buf->vb.state = STATE_PREPARED;



#ifdef CONFIG_VIVI_SCATTER

	if (NULL == (buf->to_addr = kmalloc(sizeof(*buf->to_addr) * vb->dma.nr_pages,GFP_KERNEL))) {

		rc=-ENOMEM;

		goto fail;

	}



#endif

	return 0;



fail:
@@ -785,6 +836,7 @@ static void buffer_release(struct videobuf_queue *vq, struct videobuf_buffer *vb 
	free_buffer(vq,buf);

}



#ifdef CONFIG_VIVI_SCATTER

static int vivi_map_sg(void *dev, struct scatterlist *sg, int nents,

		       int direction)

{
@@ -817,6 +869,7 @@ static int vivi_dma_sync_sg(void *dev,struct scatterlist *sglist, int nr_pages, 
//	flush_write_buffers();

	return 0;

}

#endif



static struct videobuf_queue_ops vivi_video_qops = {

	.buf_setup      = buffer_setup,
@@ -825,9 +878,9 @@ static struct videobuf_queue_ops vivi_video_qops = { 
	.buf_release    = buffer_release,



	/* Non-pci handling routines */

	.vb_map_sg      = vivi_map_sg,

	.vb_dma_sync_sg = vivi_dma_sync_sg,

	.vb_unmap_sg    = vivi_unmap_sg,

//	.vb_map_sg      = vivi_map_sg,

//	.vb_dma_sync_sg = vivi_dma_sync_sg,

//	.vb_unmap_sg    = vivi_unmap_sg,

};



/* ------------------------------------------------------------------
@@ -1205,11 +1258,19 @@ static int vivi_open(struct inode *inode, struct file *file) 
	sprintf(dev->timestr,"%02d:%02d:%02d:%03d",

			dev->h,dev->m,dev->s,(dev->us+500)/1000);



#ifdef CONFIG_VIVI_SCATTER

	videobuf_queue_init(&fh->vb_vidq,VIDEOBUF_DMA_SCATTER, &vivi_video_qops,

			NULL, NULL,

			fh->type,

			V4L2_FIELD_INTERLACED,

			sizeof(struct vivi_buffer),fh);

#else

	videobuf_queue_init(&fh->vb_vidq, &vivi_video_qops,

			NULL, NULL,

			fh->type,

			V4L2_FIELD_INTERLACED,

			sizeof(struct vivi_buffer),fh);

#endif



	return 0;

}

include/media/video-buf.h

+3 −0
Original line number Diff line number Diff line
@@ -78,6 +78,9 @@ struct videobuf_dmabuf { 
	/* for kernel buffers */

	void                *vmalloc;



	/* Stores the userspace pointer to vmalloc area */

	void                *varea;



	/* for overlay buffers (pci-pci dma) */

	dma_addr_t          bus_addr;