static int p9_get_mapped_pages(struct virtio_chan *chan,
struct page **pages, char *data,
int nr_pages, int write, int kern_buf)
{
int err;
if (!kern_buf) {
/*
* We allow only p9_max_pages pinned. We wait for the
* Other zc request to finish here
*/
if (atomic_read(&vp_pinned) >= chan->p9_max_pages) {
err = wait_event_interruptible(vp_wq,
(atomic_read(&vp_pinned) < chan->p9_max_pages));
if (err == -ERESTARTSYS)
return err;
}
err = p9_payload_gup(data, &nr_pages, pages, write);
if (err < 0)
return err;
atomic_add(nr_pages, &vp_pinned);
} else {
/* kernel buffer, no need to pin pages */
int s, index = 0;
int count = nr_pages;
while (nr_pages) {
s = rest_of_page(data);
pages[index++] = kmap_to_page(data);
data += s;
nr_pages--;
}
nr_pages = count;
}
return nr_pages;
}
static void render_state_free(struct i915_render_state *so)
{
kunmap(kmap_to_page(so->batch));
i915_gem_object_ggtt_unpin(so->obj);
drm_gem_object_unreference(&so->obj->base);
kfree(so);
}
/*
* get_kernel_pages() - pin kernel pages in memory
* @kiov: An array of struct kvec structures
* @nr_segs: number of segments to pin
* @write: pinning for read/write, currently ignored
* @pages: array that receives pointers to the pages pinned.
* Should be at least nr_segs long.
*
* Returns number of pages pinned. This may be fewer than the number
* requested. If nr_pages is 0 or negative, returns 0. If no pages
* were pinned, returns -errno. Each page returned must be released
* with a put_page() call when it is finished with.
*/
int get_kernel_pages(const struct kvec *kiov, int nr_segs, int write,
struct page **pages)
{
int seg;
for (seg = 0; seg < nr_segs; seg++) {
if (WARN_ON(kiov[seg].iov_len != PAGE_SIZE))
return seg;
pages[seg] = kmap_to_page(kiov[seg].iov_base);
page_cache_get(pages[seg]);
}
return seg;
}
