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: Mauro Carvalho Chehab <mchehab@infradead.org>
diff --git a/drivers/media/video/video-buf.c b/drivers/media/video/video-buf.c
index 6504a58..459786f 100644
--- a/drivers/media/video/video-buf.c
+++ b/drivers/media/video/video-buf.c
@@ -148,6 +148,8 @@
dprintk(1,"init user [0x%lx+0x%lx => %d pages]\n",
data,size,dma->nr_pages);
+ dma->varea = (void *) data;
+
down_read(¤t->mm->mmap_sem);
err = get_user_pages(current,current->mm,
data & PAGE_MASK, dma->nr_pages,
@@ -285,6 +287,7 @@
vfree(dma->vmalloc);
dma->vmalloc = NULL;
+ dma->varea = NULL;
if (dma->bus_addr) {
dma->bus_addr = 0;
diff --git a/drivers/media/video/vivi.c b/drivers/media/video/vivi.c
index 1784419..0fb6d52 100644
--- a/drivers/media/video/vivi.c
+++ b/drivers/media/video/vivi.c
@@ -145,7 +145,9 @@
struct vivi_fmt *fmt;
+#ifdef CONFIG_VIVI_SCATTER
struct sg_to_addr *to_addr;
+#endif
};
struct vivi_dmaqueue {
@@ -230,6 +232,7 @@
#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 @@
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 @@
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 @@
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 @@
oldpg=pgpos;
}
p=basep+pos-to_addr[pgpos].pos;
+#else
+ p=basep+pos;
+#endif
switch (color) {
case 0:
@@ -343,6 +361,7 @@
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 @@
oldpg=pgpos;
}
p=basep+pos-to_addr[pgpos].pos;
+#else
+ p=basep+pos;
+#endif
y=TO_Y(r,g,b);
@@ -380,19 +402,27 @@
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 @@
/* 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 @@
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 @@
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 @@
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 @@
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 @@
// flush_write_buffers();
return 0;
}
+#endif
static struct videobuf_queue_ops vivi_video_qops = {
.buf_setup = buffer_setup,
@@ -825,9 +878,9 @@
.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 @@
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;
}
diff --git a/include/media/video-buf.h b/include/media/video-buf.h
index 1115a25..d6f0794 100644
--- a/include/media/video-buf.h
+++ b/include/media/video-buf.h
@@ -78,6 +78,9 @@
/* 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;