static int videobuf_dma_init_user_locked(struct videobuf_dmabuf *dma,
int direction, unsigned long data, unsigned long size)
{
unsigned long first, last;
int err, rw = 0;
unsigned int flags = FOLL_FORCE;
dma->direction = direction;
switch (dma->direction) {
case DMA_FROM_DEVICE:
rw = READ;
break;
case DMA_TO_DEVICE:
rw = WRITE;
break;
default:
BUG();
}
first = (data & PAGE_MASK) >> PAGE_SHIFT;
last = ((data+size-1) & PAGE_MASK) >> PAGE_SHIFT;
dma->offset = data & ~PAGE_MASK;
dma->size = size;
dma->nr_pages = last-first+1;
dma->pages = kmalloc(dma->nr_pages * sizeof(struct page *), GFP_KERNEL);
if (NULL == dma->pages)
return -ENOMEM;
if (rw == READ)
flags |= FOLL_WRITE;
dprintk(1, "init user [0x%lx+0x%lx => %d pages]\n",
data, size, dma->nr_pages);
err = get_user_pages_longterm(data & PAGE_MASK, dma->nr_pages,
flags, dma->pages, NULL);
if (err != dma->nr_pages) {
dma->nr_pages = (err >= 0) ? err : 0;
dprintk(1, "get_user_pages_longterm: err=%d [%d]\n", err,
dma->nr_pages);
return err < 0 ? err : -EINVAL;
}
return 0;
}
static int __gup_benchmark_ioctl(unsigned int cmd,
struct gup_benchmark *gup)
{
ktime_t start_time, end_time;
unsigned long i, nr_pages, addr, next;
int nr;
struct page **pages;
if (gup->size > ULONG_MAX)
return -EINVAL;
nr_pages = gup->size / PAGE_SIZE;
pages = kvcalloc(nr_pages, sizeof(void *), GFP_KERNEL);
if (!pages)
return -ENOMEM;
i = 0;
nr = gup->nr_pages_per_call;
start_time = ktime_get();
for (addr = gup->addr; addr < gup->addr + gup->size; addr = next) {
if (nr != gup->nr_pages_per_call)
break;
next = addr + nr * PAGE_SIZE;
if (next > gup->addr + gup->size) {
next = gup->addr + gup->size;
nr = (next - addr) / PAGE_SIZE;
}
switch (cmd) {
case GUP_FAST_BENCHMARK:
nr = get_user_pages_fast(addr, nr, gup->flags & 1,
pages + i);
break;
case GUP_LONGTERM_BENCHMARK:
nr = get_user_pages_longterm(addr, nr, gup->flags & 1,
pages + i, NULL);
break;
case GUP_BENCHMARK:
nr = get_user_pages(addr, nr, gup->flags & 1, pages + i,
NULL);
break;
default:
return -1;
}
if (nr <= 0)
break;
i += nr;
}
end_time = ktime_get();
gup->get_delta_usec = ktime_us_delta(end_time, start_time);
gup->size = addr - gup->addr;
start_time = ktime_get();
for (i = 0; i < nr_pages; i++) {
if (!pages[i])
break;
put_page(pages[i]);
}
end_time = ktime_get();
gup->put_delta_usec = ktime_us_delta(end_time, start_time);
kvfree(pages);
return 0;
}
