@@ -15,6 +15,7 @@
#include "zctap.h"
#include "rsrc.h"
#include "kbuf.h"
+#include "refs.h"
#define NR_ZCTAP_IFQS 1
@@ -26,6 +27,7 @@ struct ifq_region {
int cache_count;
int free_count;
int nr_pages;
+ int taken;
u16 id;
spinlock_t freelist_lock;
@@ -44,8 +46,14 @@ struct ifq_region {
struct io_zctap_ifq_priv {
struct io_zctap_ifq ifq;
struct ubuf_info uarg;
+ struct io_kiocb req;
};
+static struct io_kiocb *io_zctap_ifq_notifier(struct io_zctap_ifq *ifq)
+{
+ return &((struct io_zctap_ifq_priv *)ifq)->req;
+}
+
static void io_zctap_ifq_put(struct io_zctap_ifq *ifq);
typedef int (*bpf_op_t)(struct net_device *dev, struct netdev_bpf *bpf);
@@ -131,6 +139,17 @@ static void io_zctap_recycle_buf(struct ifq_region *ifr,
}
}
+static void io_zctap_fillq_notify(struct io_kiocb *req, bool *locked)
+{
+ int res = *(int *)&req->cmd.data;
+
+ io_post_aux_cqe(req->ctx, 0xface0000, res,
+ IORING_CQE_F_BUFFER|IORING_CQE_F_NOTIF,
+ true);
+
+ io_req_task_complete(req, locked);
+}
+
/* gets a user-supplied buffer from the fill queue
* note: may drain N entries, but still have no usable buffers
* XXX add retry limit?
@@ -159,6 +178,7 @@ static struct io_zctap_buf *io_zctap_get_buffer(struct io_zctap_ifq *ifq,
if (!addr)
return NULL;
+ ifr->taken++;
pgid = addr & 0xffff;
// region_id = (addr >> 16) & 0xffff;
@@ -192,6 +212,7 @@ struct io_zctap_buf *io_zctap_get_buf(struct io_zctap_ifq *ifq, int refc)
{
struct io_zctap_buf *buf;
struct ifq_region *ifr;
+ struct io_kiocb *req;
int count;
u16 pgid;
@@ -214,6 +235,19 @@ struct io_zctap_buf *io_zctap_get_buf(struct io_zctap_ifq *ifq, int refc)
count = io_zctap_get_buffers(ifq, ifr->cache, REGION_REFILL_COUNT);
ifr->cache_count += count;
+ req = io_zctap_ifq_notifier(ifq);
+ if (ifr->taken && atomic_read(&req->refs) == 1) {
+ int res;
+
+ res = (ifq->fill_bgid << 16) | ifr->taken;
+ *(int *)&req->cmd.data = res;
+ ifr->taken = 0;
+
+ req_ref_get(req);
+ req->io_task_work.func = io_zctap_fillq_notify;
+ io_req_task_work_add(req);
+ }
+
if (ifr->cache_count)
goto out;
@@ -441,6 +475,7 @@ int io_provide_ifq_region(struct io_zctap_ifq *ifq, u16 id)
ifr->id = id;
ifr->ifq = ifq;
ifr->delay_end = 0;
+ ifr->taken = 0;
ifr->cache_count = 0;
err = io_zctap_map_region(ifr, imu);
@@ -529,6 +564,11 @@ static struct io_zctap_ifq *io_zctap_ifq_alloc(struct io_ring_ctx *ctx)
priv->ifq.ctx = ctx;
priv->ifq.queue_id = -1;
priv->ifq.uarg = &priv->uarg;
+
+ priv->req.ctx = ctx;
+ priv->req.task = current;
+ io_req_set_refcount(&priv->req);
+
return &priv->ifq;
}
Userspace maintains a free count of space available in the fillq, and only returns entries based on the available space. As the kernel removes these entries, it needs to notify the application so more buffers can be queued. Only one outstanding notifier per queue is used, and it provides the most recent count of entries removed from the queue. Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com> --- io_uring/zctap.c | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+)