diff options
Diffstat (limited to 'drivers/net/ethernet/netronome/nfp/ccm.c')
| -rw-r--r-- | drivers/net/ethernet/netronome/nfp/ccm.c | 217 |
1 files changed, 217 insertions, 0 deletions
diff --git a/drivers/net/ethernet/netronome/nfp/ccm.c b/drivers/net/ethernet/netronome/nfp/ccm.c new file mode 100644 index 000000000..71afd111b --- /dev/null +++ b/drivers/net/ethernet/netronome/nfp/ccm.c @@ -0,0 +1,217 @@ +// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +/* Copyright (C) 2016-2019 Netronome Systems, Inc. */ + +#include <linux/bitops.h> + +#include "ccm.h" +#include "nfp_app.h" +#include "nfp_net.h" + +#define ccm_warn(app, msg...) nn_dp_warn(&(app)->ctrl->dp, msg) + +#define NFP_CCM_TAG_ALLOC_SPAN (U16_MAX / 4) + +static bool nfp_ccm_all_tags_busy(struct nfp_ccm *ccm) +{ + u16 used_tags; + + used_tags = ccm->tag_alloc_next - ccm->tag_alloc_last; + + return used_tags > NFP_CCM_TAG_ALLOC_SPAN; +} + +static int nfp_ccm_alloc_tag(struct nfp_ccm *ccm) +{ + /* CCM is for FW communication which is request-reply. To make sure + * we don't reuse the message ID too early after timeout - limit the + * number of requests in flight. + */ + if (unlikely(nfp_ccm_all_tags_busy(ccm))) { + ccm_warn(ccm->app, "all FW request contexts busy!\n"); + return -EAGAIN; + } + + WARN_ON(__test_and_set_bit(ccm->tag_alloc_next, ccm->tag_allocator)); + return ccm->tag_alloc_next++; +} + +static void nfp_ccm_free_tag(struct nfp_ccm *ccm, u16 tag) +{ + WARN_ON(!__test_and_clear_bit(tag, ccm->tag_allocator)); + + while (!test_bit(ccm->tag_alloc_last, ccm->tag_allocator) && + ccm->tag_alloc_last != ccm->tag_alloc_next) + ccm->tag_alloc_last++; +} + +static struct sk_buff *__nfp_ccm_reply(struct nfp_ccm *ccm, u16 tag) +{ + unsigned int msg_tag; + struct sk_buff *skb; + + skb_queue_walk(&ccm->replies, skb) { + msg_tag = nfp_ccm_get_tag(skb); + if (msg_tag == tag) { + nfp_ccm_free_tag(ccm, tag); + __skb_unlink(skb, &ccm->replies); + return skb; + } + } + + return NULL; +} + +static struct sk_buff * +nfp_ccm_reply(struct nfp_ccm *ccm, struct nfp_app *app, u16 tag) +{ + struct sk_buff *skb; + + nfp_ctrl_lock(app->ctrl); + skb = __nfp_ccm_reply(ccm, tag); + nfp_ctrl_unlock(app->ctrl); + + return skb; +} + +static struct sk_buff * +nfp_ccm_reply_drop_tag(struct nfp_ccm *ccm, struct nfp_app *app, u16 tag) +{ + struct sk_buff *skb; + + nfp_ctrl_lock(app->ctrl); + skb = __nfp_ccm_reply(ccm, tag); + if (!skb) + nfp_ccm_free_tag(ccm, tag); + nfp_ctrl_unlock(app->ctrl); + + return skb; +} + +static struct sk_buff * +nfp_ccm_wait_reply(struct nfp_ccm *ccm, struct nfp_app *app, + enum nfp_ccm_type type, int tag) +{ + struct sk_buff *skb; + int i, err; + + for (i = 0; i < 50; i++) { + udelay(4); + skb = nfp_ccm_reply(ccm, app, tag); + if (skb) + return skb; + } + + err = wait_event_interruptible_timeout(ccm->wq, + skb = nfp_ccm_reply(ccm, app, + tag), + msecs_to_jiffies(5000)); + /* We didn't get a response - try last time and atomically drop + * the tag even if no response is matched. + */ + if (!skb) + skb = nfp_ccm_reply_drop_tag(ccm, app, tag); + if (err < 0) { + ccm_warn(app, "%s waiting for response to 0x%02x: %d\n", + err == ERESTARTSYS ? "interrupted" : "error", + type, err); + return ERR_PTR(err); + } + if (!skb) { + ccm_warn(app, "timeout waiting for response to 0x%02x\n", type); + return ERR_PTR(-ETIMEDOUT); + } + + return skb; +} + +struct sk_buff * +nfp_ccm_communicate(struct nfp_ccm *ccm, struct sk_buff *skb, + enum nfp_ccm_type type, unsigned int reply_size) +{ + struct nfp_app *app = ccm->app; + struct nfp_ccm_hdr *hdr; + int reply_type, tag; + + nfp_ctrl_lock(app->ctrl); + tag = nfp_ccm_alloc_tag(ccm); + if (tag < 0) { + nfp_ctrl_unlock(app->ctrl); + dev_kfree_skb_any(skb); + return ERR_PTR(tag); + } + + hdr = (void *)skb->data; + hdr->ver = NFP_CCM_ABI_VERSION; + hdr->type = type; + hdr->tag = cpu_to_be16(tag); + + __nfp_app_ctrl_tx(app, skb); + + nfp_ctrl_unlock(app->ctrl); + + skb = nfp_ccm_wait_reply(ccm, app, type, tag); + if (IS_ERR(skb)) + return skb; + + reply_type = nfp_ccm_get_type(skb); + if (reply_type != __NFP_CCM_REPLY(type)) { + ccm_warn(app, "cmsg drop - wrong type 0x%02x != 0x%02lx!\n", + reply_type, __NFP_CCM_REPLY(type)); + goto err_free; + } + /* 0 reply_size means caller will do the validation */ + if (reply_size && skb->len != reply_size) { + ccm_warn(app, "cmsg drop - type 0x%02x wrong size %d != %d!\n", + type, skb->len, reply_size); + goto err_free; + } + + return skb; +err_free: + dev_kfree_skb_any(skb); + return ERR_PTR(-EIO); +} + +void nfp_ccm_rx(struct nfp_ccm *ccm, struct sk_buff *skb) +{ + struct nfp_app *app = ccm->app; + unsigned int tag; + + if (unlikely(skb->len < sizeof(struct nfp_ccm_hdr))) { + ccm_warn(app, "cmsg drop - too short %d!\n", skb->len); + goto err_free; + } + + nfp_ctrl_lock(app->ctrl); + + tag = nfp_ccm_get_tag(skb); + if (unlikely(!test_bit(tag, ccm->tag_allocator))) { + ccm_warn(app, "cmsg drop - no one is waiting for tag %u!\n", + tag); + goto err_unlock; + } + + __skb_queue_tail(&ccm->replies, skb); + wake_up_interruptible_all(&ccm->wq); + + nfp_ctrl_unlock(app->ctrl); + return; + +err_unlock: + nfp_ctrl_unlock(app->ctrl); +err_free: + dev_kfree_skb_any(skb); +} + +int nfp_ccm_init(struct nfp_ccm *ccm, struct nfp_app *app) +{ + ccm->app = app; + skb_queue_head_init(&ccm->replies); + init_waitqueue_head(&ccm->wq); + return 0; +} + +void nfp_ccm_clean(struct nfp_ccm *ccm) +{ + WARN_ON(!skb_queue_empty(&ccm->replies)); +} |