@@ -21,6 +21,10 @@
#include <net/busy_poll.h>
#include <trace/events/sock.h>
+#ifdef CONFIG_ULP_DDP
+#include <net/ulp_ddp.h>
+#endif
+
#include "nvme.h"
#include "fabrics.h"
@@ -46,6 +50,16 @@ MODULE_PARM_DESC(tls_handshake_timeout,
"nvme TLS handshake timeout in seconds (default 10)");
#endif
+#ifdef CONFIG_ULP_DDP
+/* NVMeTCP direct data placement and data digest offload will not
+ * happen if this parameter false (default), regardless of what the
+ * underlying netdev capabilities are.
+ */
+static bool ddp_offload;
+module_param(ddp_offload, bool, 0644);
+MODULE_PARM_DESC(ddp_offload, "Enable or disable NVMeTCP direct data placement support");
+#endif
+
#ifdef CONFIG_DEBUG_LOCK_ALLOC
/* lockdep can detect a circular dependency of the form
* sk_lock -> mmap_lock (page fault) -> fs locks -> sk_lock
@@ -119,6 +133,7 @@ enum nvme_tcp_queue_flags {
NVME_TCP_Q_ALLOCATED = 0,
NVME_TCP_Q_LIVE = 1,
NVME_TCP_Q_POLLING = 2,
+ NVME_TCP_Q_OFF_DDP = 3,
};
enum nvme_tcp_recv_state {
@@ -146,6 +161,18 @@ struct nvme_tcp_queue {
size_t ddgst_remaining;
unsigned int nr_cqe;
+#ifdef CONFIG_ULP_DDP
+ /*
+ * resync_tcp_seq is a speculative PDU header tcp seq number (with
+ * an additional flag in the lower 32 bits) that the HW send to
+ * the SW, for the SW to verify.
+ * - The 32 high bits store the seq number
+ * - The 32 low bits are used as a flag to know if a request
+ * is pending (ULP_DDP_RESYNC_PENDING).
+ */
+ atomic64_t resync_tcp_seq;
+#endif
+
/* send state */
struct nvme_tcp_request *request;
@@ -186,6 +213,13 @@ struct nvme_tcp_ctrl {
struct delayed_work connect_work;
struct nvme_tcp_request async_req;
u32 io_queues[HCTX_MAX_TYPES];
+
+ struct net_device *ddp_netdev;
+ netdevice_tracker netdev_tracker;
+ u32 ddp_threshold;
+#ifdef CONFIG_ULP_DDP
+ struct ulp_ddp_limits ddp_limits;
+#endif
};
static LIST_HEAD(nvme_tcp_ctrl_list);
@@ -297,6 +331,171 @@ static inline size_t nvme_tcp_pdu_last_send(struct nvme_tcp_request *req,
return nvme_tcp_pdu_data_left(req) <= len;
}
+#ifdef CONFIG_ULP_DDP
+
+static struct net_device *
+nvme_tcp_get_ddp_netdev_with_limits(struct nvme_tcp_ctrl *ctrl)
+{
+ struct net_device *netdev;
+ int ret;
+
+ if (!ddp_offload)
+ return NULL;
+
+ /* netdev ref is put in nvme_tcp_stop_admin_queue() */
+ netdev = get_netdev_for_sock(ctrl->queues[0].sock->sk, &ctrl->netdev_tracker, GFP_KERNEL);
+ if (!netdev) {
+ dev_dbg(ctrl->ctrl.device, "netdev not found\n");
+ return NULL;
+ }
+
+ if (!ulp_ddp_is_cap_active(netdev, ULP_DDP_CAP_NVME_TCP))
+ goto err;
+
+ ret = ulp_ddp_get_limits(netdev, &ctrl->ddp_limits, ULP_DDP_NVME);
+ if (ret)
+ goto err;
+
+ if (ctrl->ctrl.opts->tls && !ctrl->ddp_limits.tls)
+ goto err;
+
+ return netdev;
+err:
+ netdev_put(netdev, &ctrl->netdev_tracker);
+ return NULL;
+}
+
+static bool nvme_tcp_resync_request(struct sock *sk, u32 seq, u32 flags);
+static const struct ulp_ddp_ulp_ops nvme_tcp_ddp_ulp_ops = {
+ .resync_request = nvme_tcp_resync_request,
+};
+
+static int nvme_tcp_offload_socket(struct nvme_tcp_queue *queue)
+{
+ struct ulp_ddp_config config = {.type = ULP_DDP_NVME};
+ int ret;
+
+ config.nvmeotcp.pfv = NVME_TCP_PFV_1_0;
+ config.nvmeotcp.cpda = 0;
+ config.nvmeotcp.dgst =
+ queue->hdr_digest ? NVME_TCP_HDR_DIGEST_ENABLE : 0;
+ config.nvmeotcp.dgst |=
+ queue->data_digest ? NVME_TCP_DATA_DIGEST_ENABLE : 0;
+ config.nvmeotcp.queue_size = queue->ctrl->ctrl.sqsize + 1;
+ config.nvmeotcp.queue_id = nvme_tcp_queue_id(queue);
+
+ ret = ulp_ddp_sk_add(queue->ctrl->ddp_netdev,
+ queue->sock->sk,
+ &config,
+ &nvme_tcp_ddp_ulp_ops);
+ if (ret)
+ return ret;
+
+ set_bit(NVME_TCP_Q_OFF_DDP, &queue->flags);
+
+ return 0;
+}
+
+static void nvme_tcp_unoffload_socket(struct nvme_tcp_queue *queue)
+{
+ clear_bit(NVME_TCP_Q_OFF_DDP, &queue->flags);
+ ulp_ddp_sk_del(queue->ctrl->ddp_netdev, queue->sock->sk);
+}
+
+static void nvme_tcp_ddp_apply_limits(struct nvme_tcp_ctrl *ctrl)
+{
+ ctrl->ctrl.max_segments = ctrl->ddp_limits.max_ddp_sgl_len;
+ ctrl->ctrl.max_hw_sectors =
+ ctrl->ddp_limits.max_ddp_sgl_len << (ilog2(SZ_4K) - SECTOR_SHIFT);
+ ctrl->ddp_threshold = ctrl->ddp_limits.io_threshold;
+
+ /* offloading HW doesn't support full ccid range, apply the quirk */
+ ctrl->ctrl.quirks |=
+ ctrl->ddp_limits.nvmeotcp.full_ccid_range ? 0 : NVME_QUIRK_SKIP_CID_GEN;
+}
+
+/* In presence of packet drops or network packet reordering, the device may lose
+ * synchronization between the TCP stream and the L5P framing, and require a
+ * resync with the kernel's TCP stack.
+ *
+ * - NIC HW identifies a PDU header at some TCP sequence number,
+ * and asks NVMe-TCP to confirm it.
+ * - When NVMe-TCP observes the requested TCP sequence, it will compare
+ * it with the PDU header TCP sequence, and report the result to the
+ * NIC driver
+ */
+static void nvme_tcp_resync_response(struct nvme_tcp_queue *queue,
+ struct sk_buff *skb, unsigned int offset)
+{
+ u64 pdu_seq = TCP_SKB_CB(skb)->seq + offset - queue->pdu_offset;
+ struct net_device *netdev = queue->ctrl->ddp_netdev;
+ u64 pdu_val = (pdu_seq << 32) | ULP_DDP_RESYNC_PENDING;
+ u64 resync_val;
+ u32 resync_seq;
+
+ resync_val = atomic64_read(&queue->resync_tcp_seq);
+ /* Lower 32 bit flags. Check validity of the request */
+ if ((resync_val & ULP_DDP_RESYNC_PENDING) == 0)
+ return;
+
+ /*
+ * Obtain and check requested sequence number: is this PDU header
+ * before the request?
+ */
+ resync_seq = resync_val >> 32;
+ if (before(pdu_seq, resync_seq))
+ return;
+
+ /*
+ * The atomic operation guarantees that we don't miss any NIC driver
+ * resync requests submitted after the above checks.
+ */
+ if (atomic64_cmpxchg(&queue->resync_tcp_seq, pdu_val,
+ pdu_val & ~ULP_DDP_RESYNC_PENDING) !=
+ atomic64_read(&queue->resync_tcp_seq))
+ ulp_ddp_resync(netdev, queue->sock->sk, pdu_seq);
+}
+
+static bool nvme_tcp_resync_request(struct sock *sk, u32 seq, u32 flags)
+{
+ struct nvme_tcp_queue *queue = sk->sk_user_data;
+
+ /*
+ * "seq" (TCP seq number) is what the HW assumes is the
+ * beginning of a PDU. The nvme-tcp layer needs to store the
+ * number along with the "flags" (ULP_DDP_RESYNC_PENDING) to
+ * indicate that a request is pending.
+ */
+ atomic64_set(&queue->resync_tcp_seq, (((uint64_t)seq << 32) | flags));
+
+ return true;
+}
+
+#else
+
+static struct net_device *
+nvme_tcp_get_ddp_netdev_with_limits(struct nvme_tcp_ctrl *ctrl)
+{
+ return NULL;
+}
+
+static void nvme_tcp_ddp_apply_limits(struct nvme_tcp_ctrl *ctrl)
+{}
+
+static int nvme_tcp_offload_socket(struct nvme_tcp_queue *queue)
+{
+ return 0;
+}
+
+static void nvme_tcp_unoffload_socket(struct nvme_tcp_queue *queue)
+{}
+
+static void nvme_tcp_resync_response(struct nvme_tcp_queue *queue,
+ struct sk_buff *skb, unsigned int offset)
+{}
+
+#endif
+
static void nvme_tcp_init_iter(struct nvme_tcp_request *req,
unsigned int dir)
{
@@ -739,6 +938,9 @@ static int nvme_tcp_recv_pdu(struct nvme_tcp_queue *queue, struct sk_buff *skb,
size_t rcv_len = min_t(size_t, *len, queue->pdu_remaining);
int ret;
+ if (test_bit(NVME_TCP_Q_OFF_DDP, &queue->flags))
+ nvme_tcp_resync_response(queue, skb, *offset);
+
ret = skb_copy_bits(skb, *offset,
&pdu[queue->pdu_offset], rcv_len);
if (unlikely(ret))
@@ -1804,6 +2006,8 @@ static void __nvme_tcp_stop_queue(struct nvme_tcp_queue *queue)
kernel_sock_shutdown(queue->sock, SHUT_RDWR);
nvme_tcp_restore_sock_ops(queue);
cancel_work_sync(&queue->io_work);
+ if (test_bit(NVME_TCP_Q_OFF_DDP, &queue->flags))
+ nvme_tcp_unoffload_socket(queue);
}
static void nvme_tcp_stop_queue(struct nvme_ctrl *nctrl, int qid)
@@ -1820,6 +2024,20 @@ static void nvme_tcp_stop_queue(struct nvme_ctrl *nctrl, int qid)
mutex_unlock(&queue->queue_lock);
}
+static void nvme_tcp_stop_admin_queue(struct nvme_ctrl *nctrl)
+{
+ struct nvme_tcp_ctrl *ctrl = to_tcp_ctrl(nctrl);
+
+ nvme_tcp_stop_queue(nctrl, 0);
+
+ /*
+ * We are called twice by nvme_tcp_teardown_admin_queue()
+ * Set ddp_netdev to NULL to avoid putting it twice
+ */
+ netdev_put(ctrl->ddp_netdev, &ctrl->netdev_tracker);
+ ctrl->ddp_netdev = NULL;
+}
+
static void nvme_tcp_setup_sock_ops(struct nvme_tcp_queue *queue)
{
write_lock_bh(&queue->sock->sk->sk_callback_lock);
@@ -1846,19 +2064,37 @@ static int nvme_tcp_start_queue(struct nvme_ctrl *nctrl, int idx)
nvme_tcp_init_recv_ctx(queue);
nvme_tcp_setup_sock_ops(queue);
- if (idx)
+ if (idx) {
ret = nvmf_connect_io_queue(nctrl, idx);
- else
+ if (ret)
+ goto err;
+
+ if (ctrl->ddp_netdev) {
+ ret = nvme_tcp_offload_socket(queue);
+ if (ret) {
+ dev_info(nctrl->device,
+ "failed to setup offload on queue %d ret=%d\n",
+ idx, ret);
+ }
+ }
+ } else {
ret = nvmf_connect_admin_queue(nctrl);
+ if (ret)
+ goto err;
+
+ ctrl->ddp_netdev = nvme_tcp_get_ddp_netdev_with_limits(ctrl);
+ if (ctrl->ddp_netdev)
+ nvme_tcp_ddp_apply_limits(ctrl);
- if (!ret) {
- set_bit(NVME_TCP_Q_LIVE, &queue->flags);
- } else {
- if (test_bit(NVME_TCP_Q_ALLOCATED, &queue->flags))
- __nvme_tcp_stop_queue(queue);
- dev_err(nctrl->device,
- "failed to connect queue: %d ret=%d\n", idx, ret);
}
+
+ set_bit(NVME_TCP_Q_LIVE, &queue->flags);
+ return 0;
+err:
+ if (test_bit(NVME_TCP_Q_ALLOCATED, &queue->flags))
+ __nvme_tcp_stop_queue(queue);
+ dev_err(nctrl->device,
+ "failed to connect queue: %d ret=%d\n", idx, ret);
return ret;
}
@@ -2070,7 +2306,7 @@ static int nvme_tcp_configure_io_queues(struct nvme_ctrl *ctrl, bool new)
static void nvme_tcp_destroy_admin_queue(struct nvme_ctrl *ctrl, bool remove)
{
- nvme_tcp_stop_queue(ctrl, 0);
+ nvme_tcp_stop_admin_queue(ctrl);
if (remove)
nvme_remove_admin_tag_set(ctrl);
nvme_tcp_free_admin_queue(ctrl);
@@ -2113,7 +2349,7 @@ static int nvme_tcp_configure_admin_queue(struct nvme_ctrl *ctrl, bool new)
nvme_quiesce_admin_queue(ctrl);
blk_sync_queue(ctrl->admin_q);
out_stop_queue:
- nvme_tcp_stop_queue(ctrl, 0);
+ nvme_tcp_stop_admin_queue(ctrl);
nvme_cancel_admin_tagset(ctrl);
out_cleanup_tagset:
if (new)
@@ -2128,7 +2364,7 @@ static void nvme_tcp_teardown_admin_queue(struct nvme_ctrl *ctrl,
{
nvme_quiesce_admin_queue(ctrl);
blk_sync_queue(ctrl->admin_q);
- nvme_tcp_stop_queue(ctrl, 0);
+ nvme_tcp_stop_admin_queue(ctrl);
nvme_cancel_admin_tagset(ctrl);
if (remove)
nvme_unquiesce_admin_queue(ctrl);
@@ -2413,7 +2649,10 @@ static void nvme_tcp_complete_timed_out(struct request *rq)
struct nvme_tcp_request *req = blk_mq_rq_to_pdu(rq);
struct nvme_ctrl *ctrl = &req->queue->ctrl->ctrl;
- nvme_tcp_stop_queue(ctrl, nvme_tcp_queue_id(req->queue));
+ if (nvme_tcp_admin_queue(req->queue))
+ nvme_tcp_stop_admin_queue(ctrl);
+ else
+ nvme_tcp_stop_queue(ctrl, nvme_tcp_queue_id(req->queue));
nvmf_complete_timed_out_request(rq);
}