1 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2 /* Copyright (C) 2016-2019 Netronome Systems, Inc. */
4 #include <linux/bitops.h>
10 #define ccm_warn(app, msg...) nn_dp_warn(&(app)->ctrl->dp, msg)
12 #define NFP_CCM_TAG_ALLOC_SPAN (U16_MAX / 4)
14 static bool nfp_ccm_all_tags_busy(struct nfp_ccm *ccm)
18 used_tags = ccm->tag_alloc_next - ccm->tag_alloc_last;
20 return used_tags > NFP_CCM_TAG_ALLOC_SPAN;
23 static int nfp_ccm_alloc_tag(struct nfp_ccm *ccm)
25 /* CCM is for FW communication which is request-reply. To make sure
26 * we don't reuse the message ID too early after timeout - limit the
27 * number of requests in flight.
29 if (unlikely(nfp_ccm_all_tags_busy(ccm))) {
30 ccm_warn(ccm->app, "all FW request contexts busy!\n");
34 WARN_ON(__test_and_set_bit(ccm->tag_alloc_next, ccm->tag_allocator));
35 return ccm->tag_alloc_next++;
38 static void nfp_ccm_free_tag(struct nfp_ccm *ccm, u16 tag)
40 WARN_ON(!__test_and_clear_bit(tag, ccm->tag_allocator));
42 while (!test_bit(ccm->tag_alloc_last, ccm->tag_allocator) &&
43 ccm->tag_alloc_last != ccm->tag_alloc_next)
44 ccm->tag_alloc_last++;
47 static struct sk_buff *__nfp_ccm_reply(struct nfp_ccm *ccm, u16 tag)
52 skb_queue_walk(&ccm->replies, skb) {
53 msg_tag = nfp_ccm_get_tag(skb);
55 nfp_ccm_free_tag(ccm, tag);
56 __skb_unlink(skb, &ccm->replies);
64 static struct sk_buff *
65 nfp_ccm_reply(struct nfp_ccm *ccm, struct nfp_app *app, u16 tag)
69 nfp_ctrl_lock(app->ctrl);
70 skb = __nfp_ccm_reply(ccm, tag);
71 nfp_ctrl_unlock(app->ctrl);
76 static struct sk_buff *
77 nfp_ccm_reply_drop_tag(struct nfp_ccm *ccm, struct nfp_app *app, u16 tag)
81 nfp_ctrl_lock(app->ctrl);
82 skb = __nfp_ccm_reply(ccm, tag);
84 nfp_ccm_free_tag(ccm, tag);
85 nfp_ctrl_unlock(app->ctrl);
90 static struct sk_buff *
91 nfp_ccm_wait_reply(struct nfp_ccm *ccm, struct nfp_app *app,
92 enum nfp_ccm_type type, int tag)
97 for (i = 0; i < 50; i++) {
99 skb = nfp_ccm_reply(ccm, app, tag);
104 err = wait_event_interruptible_timeout(ccm->wq,
105 skb = nfp_ccm_reply(ccm, app,
107 msecs_to_jiffies(5000));
108 /* We didn't get a response - try last time and atomically drop
109 * the tag even if no response is matched.
112 skb = nfp_ccm_reply_drop_tag(ccm, app, tag);
114 ccm_warn(app, "%s waiting for response to 0x%02x: %d\n",
115 err == ERESTARTSYS ? "interrupted" : "error",
120 ccm_warn(app, "timeout waiting for response to 0x%02x\n", type);
121 return ERR_PTR(-ETIMEDOUT);
128 nfp_ccm_communicate(struct nfp_ccm *ccm, struct sk_buff *skb,
129 enum nfp_ccm_type type, unsigned int reply_size)
131 struct nfp_app *app = ccm->app;
132 struct nfp_ccm_hdr *hdr;
135 nfp_ctrl_lock(app->ctrl);
136 tag = nfp_ccm_alloc_tag(ccm);
138 nfp_ctrl_unlock(app->ctrl);
139 dev_kfree_skb_any(skb);
143 hdr = (void *)skb->data;
144 hdr->ver = NFP_CCM_ABI_VERSION;
146 hdr->tag = cpu_to_be16(tag);
148 __nfp_app_ctrl_tx(app, skb);
150 nfp_ctrl_unlock(app->ctrl);
152 skb = nfp_ccm_wait_reply(ccm, app, type, tag);
156 reply_type = nfp_ccm_get_type(skb);
157 if (reply_type != __NFP_CCM_REPLY(type)) {
158 ccm_warn(app, "cmsg drop - wrong type 0x%02x != 0x%02lx!\n",
159 reply_type, __NFP_CCM_REPLY(type));
162 /* 0 reply_size means caller will do the validation */
163 if (reply_size && skb->len != reply_size) {
164 ccm_warn(app, "cmsg drop - type 0x%02x wrong size %d != %d!\n",
165 type, skb->len, reply_size);
171 dev_kfree_skb_any(skb);
172 return ERR_PTR(-EIO);
175 void nfp_ccm_rx(struct nfp_ccm *ccm, struct sk_buff *skb)
177 struct nfp_app *app = ccm->app;
180 if (unlikely(skb->len < sizeof(struct nfp_ccm_hdr))) {
181 ccm_warn(app, "cmsg drop - too short %d!\n", skb->len);
185 nfp_ctrl_lock(app->ctrl);
187 tag = nfp_ccm_get_tag(skb);
188 if (unlikely(!test_bit(tag, ccm->tag_allocator))) {
189 ccm_warn(app, "cmsg drop - no one is waiting for tag %u!\n",
194 __skb_queue_tail(&ccm->replies, skb);
195 wake_up_interruptible_all(&ccm->wq);
197 nfp_ctrl_unlock(app->ctrl);
201 nfp_ctrl_unlock(app->ctrl);
203 dev_kfree_skb_any(skb);
206 int nfp_ccm_init(struct nfp_ccm *ccm, struct nfp_app *app)
209 skb_queue_head_init(&ccm->replies);
210 init_waitqueue_head(&ccm->wq);
214 void nfp_ccm_clean(struct nfp_ccm *ccm)
216 WARN_ON(!skb_queue_empty(&ccm->replies));