@@ -27,18 +27,68 @@ struct ifq_region {
typedef int (*bpf_op_t)(struct net_device *dev, struct netdev_bpf *bpf);
+static void zctap_set_page_info(struct page *page, u64 info)
+{
+ set_page_private(page, info);
+}
+
+static u64 zctap_mk_page_info(u16 region_id, u16 pgid)
+{
+ return (u64)0xface << 48 | (u64)region_id << 16 | (u64)pgid;
+}
+
static void io_remove_ifq_region(struct ifq_region *ifr)
{
+ struct io_mapped_ubuf *imu;
+ struct page *page;
+ int i;
+
+ imu = ifr->imu;
+ for (i = 0; i < ifr->nr_pages; i++) {
+ page = imu->bvec[i].bv_page;
+
+ ClearPagePrivate(page);
+ set_page_private(page, 0);
+ }
+
kvfree(ifr);
}
+static int io_zctap_map_region(struct ifq_region *ifr)
+{
+ struct io_mapped_ubuf *imu;
+ struct page *page;
+ u64 info;
+ int i;
+
+ imu = ifr->imu;
+ for (i = 0; i < ifr->nr_pages; i++) {
+ page = imu->bvec[i].bv_page;
+ if (PagePrivate(page))
+ goto out;
+ SetPagePrivate(page);
+ info = zctap_mk_page_info(ifr->id, i);
+ zctap_set_page_info(page, info);
+ ifr->freelist[i] = page;
+ }
+ return 0;
+
+out:
+ while (i--) {
+ page = imu->bvec[i].bv_page;
+ ClearPagePrivate(page);
+ set_page_private(page, 0);
+ }
+ return -EEXIST;
+}
+
int io_provide_ifq_region(struct io_zctap_ifq *ifq, u16 id)
{
struct io_ring_ctx *ctx = ifq->ctx;
struct io_mapped_ubuf *imu;
struct ifq_region *ifr;
- int i, nr_pages;
- struct page *page;
+ int nr_pages;
+ int err;
/* XXX for now, only allow one region per ifq. */
if (ifq->region)
@@ -63,9 +113,10 @@ int io_provide_ifq_region(struct io_zctap_ifq *ifq, u16 id)
ifr->count = nr_pages;
ifr->id = id;
- for (i = 0; i < nr_pages; i++) {
- page = imu->bvec[i].bv_page;
- ifr->freelist[i] = page;
+ err = io_zctap_map_region(ifr);
+ if (err) {
+ kvfree(ifr);
+ return err;
}
ifq->region = ifr;
Create a freelist where the driver can obtain pages for the packet backing store. Use the page's page_private field to record lookup information. Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com> --- io_uring/zctap.c | 61 ++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 56 insertions(+), 5 deletions(-)