mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 17:30:02 +00:00
sfc: Implement asynchronous MCDI requests
This will allow use of MCDI from the data path, in particular for accelerated RFS. Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
This commit is contained in:
parent
251111d9a1
commit
cade715ff1
3 changed files with 291 additions and 30 deletions
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@ -1368,6 +1368,9 @@ static void efx_soft_disable_interrupts(struct efx_nic *efx)
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if (!channel->type->keep_eventq)
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efx_fini_eventq(channel);
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}
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/* Flush the asynchronous MCDI request queue */
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efx_mcdi_flush_async(efx);
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}
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static void efx_enable_interrupts(struct efx_nic *efx)
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@ -37,6 +37,18 @@
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#define SEQ_MASK \
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EFX_MASK32(EFX_WIDTH(MCDI_HEADER_SEQ))
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struct efx_mcdi_async_param {
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struct list_head list;
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unsigned int cmd;
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size_t inlen;
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size_t outlen;
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efx_mcdi_async_completer *complete;
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unsigned long cookie;
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/* followed by request/response buffer */
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};
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static void efx_mcdi_timeout_async(unsigned long context);
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static inline struct efx_mcdi_iface *efx_mcdi(struct efx_nic *efx)
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{
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EFX_BUG_ON_PARANOID(!efx->mcdi);
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@ -52,10 +64,15 @@ int efx_mcdi_init(struct efx_nic *efx)
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return -ENOMEM;
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mcdi = efx_mcdi(efx);
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mcdi->efx = efx;
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init_waitqueue_head(&mcdi->wq);
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spin_lock_init(&mcdi->iface_lock);
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mcdi->state = MCDI_STATE_QUIESCENT;
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mcdi->mode = MCDI_MODE_POLL;
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spin_lock_init(&mcdi->async_lock);
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INIT_LIST_HEAD(&mcdi->async_list);
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setup_timer(&mcdi->async_timer, efx_mcdi_timeout_async,
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(unsigned long)mcdi);
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(void) efx_mcdi_poll_reboot(efx);
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mcdi->new_epoch = true;
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@ -253,13 +270,21 @@ int efx_mcdi_poll_reboot(struct efx_nic *efx)
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return efx->type->mcdi_poll_reboot(efx);
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}
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static void efx_mcdi_acquire(struct efx_mcdi_iface *mcdi)
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static bool efx_mcdi_acquire_async(struct efx_mcdi_iface *mcdi)
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{
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return cmpxchg(&mcdi->state,
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MCDI_STATE_QUIESCENT, MCDI_STATE_RUNNING_ASYNC) ==
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MCDI_STATE_QUIESCENT;
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}
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static void efx_mcdi_acquire_sync(struct efx_mcdi_iface *mcdi)
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{
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/* Wait until the interface becomes QUIESCENT and we win the race
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* to mark it RUNNING. */
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* to mark it RUNNING_SYNC.
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*/
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wait_event(mcdi->wq,
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cmpxchg(&mcdi->state,
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MCDI_STATE_QUIESCENT, MCDI_STATE_RUNNING) ==
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MCDI_STATE_QUIESCENT, MCDI_STATE_RUNNING_SYNC) ==
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MCDI_STATE_QUIESCENT);
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}
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@ -285,16 +310,14 @@ static int efx_mcdi_await_completion(struct efx_nic *efx)
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return 0;
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}
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static bool efx_mcdi_complete(struct efx_mcdi_iface *mcdi)
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/* If the interface is RUNNING_SYNC, switch to COMPLETED and wake the
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* requester. Return whether this was done. Does not take any locks.
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*/
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static bool efx_mcdi_complete_sync(struct efx_mcdi_iface *mcdi)
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{
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/* If the interface is RUNNING, then move to COMPLETED and wake any
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* waiters. If the interface isn't in RUNNING then we've received a
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* duplicate completion after we've already transitioned back to
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* QUIESCENT. [A subsequent invocation would increment seqno, so would
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* have failed the seqno check].
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*/
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if (cmpxchg(&mcdi->state, MCDI_STATE_RUNNING, MCDI_STATE_COMPLETED) ==
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MCDI_STATE_RUNNING) {
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if (cmpxchg(&mcdi->state,
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MCDI_STATE_RUNNING_SYNC, MCDI_STATE_COMPLETED) ==
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MCDI_STATE_RUNNING_SYNC) {
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wake_up(&mcdi->wq);
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return true;
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}
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@ -304,10 +327,91 @@ static bool efx_mcdi_complete(struct efx_mcdi_iface *mcdi)
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static void efx_mcdi_release(struct efx_mcdi_iface *mcdi)
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{
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if (mcdi->mode == MCDI_MODE_EVENTS) {
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struct efx_mcdi_async_param *async;
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struct efx_nic *efx = mcdi->efx;
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/* Process the asynchronous request queue */
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spin_lock_bh(&mcdi->async_lock);
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async = list_first_entry_or_null(
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&mcdi->async_list, struct efx_mcdi_async_param, list);
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if (async) {
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mcdi->state = MCDI_STATE_RUNNING_ASYNC;
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efx_mcdi_send_request(efx, async->cmd,
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(const efx_dword_t *)(async + 1),
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async->inlen);
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mod_timer(&mcdi->async_timer,
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jiffies + MCDI_RPC_TIMEOUT);
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}
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spin_unlock_bh(&mcdi->async_lock);
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if (async)
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return;
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}
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mcdi->state = MCDI_STATE_QUIESCENT;
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wake_up(&mcdi->wq);
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}
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/* If the interface is RUNNING_ASYNC, switch to COMPLETED, call the
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* asynchronous completion function, and release the interface.
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* Return whether this was done. Must be called in bh-disabled
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* context. Will take iface_lock and async_lock.
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*/
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static bool efx_mcdi_complete_async(struct efx_mcdi_iface *mcdi, bool timeout)
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{
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struct efx_nic *efx = mcdi->efx;
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struct efx_mcdi_async_param *async;
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size_t hdr_len, data_len;
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efx_dword_t *outbuf;
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int rc;
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if (cmpxchg(&mcdi->state,
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MCDI_STATE_RUNNING_ASYNC, MCDI_STATE_COMPLETED) !=
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MCDI_STATE_RUNNING_ASYNC)
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return false;
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spin_lock(&mcdi->iface_lock);
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if (timeout) {
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/* Ensure that if the completion event arrives later,
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* the seqno check in efx_mcdi_ev_cpl() will fail
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*/
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++mcdi->seqno;
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++mcdi->credits;
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rc = -ETIMEDOUT;
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hdr_len = 0;
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data_len = 0;
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} else {
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rc = mcdi->resprc;
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hdr_len = mcdi->resp_hdr_len;
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data_len = mcdi->resp_data_len;
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}
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spin_unlock(&mcdi->iface_lock);
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/* Stop the timer. In case the timer function is running, we
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* must wait for it to return so that there is no possibility
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* of it aborting the next request.
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*/
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if (!timeout)
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del_timer_sync(&mcdi->async_timer);
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spin_lock(&mcdi->async_lock);
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async = list_first_entry(&mcdi->async_list,
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struct efx_mcdi_async_param, list);
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list_del(&async->list);
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spin_unlock(&mcdi->async_lock);
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outbuf = (efx_dword_t *)(async + 1);
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efx->type->mcdi_read_response(efx, outbuf, hdr_len,
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min(async->outlen, data_len));
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async->complete(efx, async->cookie, rc, outbuf, data_len);
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kfree(async);
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efx_mcdi_release(mcdi);
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return true;
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}
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static void efx_mcdi_ev_cpl(struct efx_nic *efx, unsigned int seqno,
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unsigned int datalen, unsigned int mcdi_err)
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{
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@ -339,8 +443,24 @@ static void efx_mcdi_ev_cpl(struct efx_nic *efx, unsigned int seqno,
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spin_unlock(&mcdi->iface_lock);
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if (wake)
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efx_mcdi_complete(mcdi);
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if (wake) {
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if (!efx_mcdi_complete_async(mcdi, false))
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(void) efx_mcdi_complete_sync(mcdi);
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/* If the interface isn't RUNNING_ASYNC or
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* RUNNING_SYNC then we've received a duplicate
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* completion after we've already transitioned back to
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* QUIESCENT. [A subsequent invocation would increment
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* seqno, so would have failed the seqno check].
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*/
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}
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}
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static void efx_mcdi_timeout_async(unsigned long context)
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{
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struct efx_mcdi_iface *mcdi = (struct efx_mcdi_iface *)context;
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efx_mcdi_complete_async(mcdi, true);
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}
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static int
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@ -383,11 +503,80 @@ int efx_mcdi_rpc_start(struct efx_nic *efx, unsigned cmd,
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if (rc)
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return rc;
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efx_mcdi_acquire(mcdi);
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efx_mcdi_acquire_sync(mcdi);
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efx_mcdi_send_request(efx, cmd, inbuf, inlen);
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return 0;
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}
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/**
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* efx_mcdi_rpc_async - Schedule an MCDI command to run asynchronously
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* @efx: NIC through which to issue the command
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* @cmd: Command type number
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* @inbuf: Command parameters
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* @inlen: Length of command parameters, in bytes
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* @outlen: Length to allocate for response buffer, in bytes
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* @complete: Function to be called on completion or cancellation.
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* @cookie: Arbitrary value to be passed to @complete.
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*
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* This function does not sleep and therefore may be called in atomic
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* context. It will fail if event queues are disabled or if MCDI
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* event completions have been disabled due to an error.
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*
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* If it succeeds, the @complete function will be called exactly once
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* in atomic context, when one of the following occurs:
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* (a) the completion event is received (in NAPI context)
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* (b) event queues are disabled (in the process that disables them)
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* (c) the request times-out (in timer context)
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*/
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int
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efx_mcdi_rpc_async(struct efx_nic *efx, unsigned int cmd,
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const efx_dword_t *inbuf, size_t inlen, size_t outlen,
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efx_mcdi_async_completer *complete, unsigned long cookie)
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{
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struct efx_mcdi_iface *mcdi = efx_mcdi(efx);
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struct efx_mcdi_async_param *async;
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int rc;
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rc = efx_mcdi_check_supported(efx, cmd, inlen);
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if (rc)
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return rc;
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async = kmalloc(sizeof(*async) + ALIGN(max(inlen, outlen), 4),
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GFP_ATOMIC);
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if (!async)
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return -ENOMEM;
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async->cmd = cmd;
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async->inlen = inlen;
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async->outlen = outlen;
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async->complete = complete;
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async->cookie = cookie;
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memcpy(async + 1, inbuf, inlen);
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spin_lock_bh(&mcdi->async_lock);
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if (mcdi->mode == MCDI_MODE_EVENTS) {
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list_add_tail(&async->list, &mcdi->async_list);
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/* If this is at the front of the queue, try to start it
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* immediately
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*/
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if (mcdi->async_list.next == &async->list &&
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efx_mcdi_acquire_async(mcdi)) {
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efx_mcdi_send_request(efx, cmd, inbuf, inlen);
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mod_timer(&mcdi->async_timer,
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jiffies + MCDI_RPC_TIMEOUT);
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}
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} else {
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kfree(async);
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rc = -ENETDOWN;
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}
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spin_unlock_bh(&mcdi->async_lock);
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return rc;
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}
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int efx_mcdi_rpc_finish(struct efx_nic *efx, unsigned cmd, size_t inlen,
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efx_dword_t *outbuf, size_t outlen,
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size_t *outlen_actual)
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@ -455,6 +644,10 @@ int efx_mcdi_rpc_finish(struct efx_nic *efx, unsigned cmd, size_t inlen,
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return rc;
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}
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/* Switch to polled MCDI completions. This can be called in various
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* error conditions with various locks held, so it must be lockless.
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* Caller is responsible for flushing asynchronous requests later.
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*/
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void efx_mcdi_mode_poll(struct efx_nic *efx)
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{
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struct efx_mcdi_iface *mcdi;
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@ -472,11 +665,50 @@ void efx_mcdi_mode_poll(struct efx_nic *efx)
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* efx_mcdi_await_completion() will then call efx_mcdi_poll().
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*
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* We need an smp_wmb() to synchronise with efx_mcdi_await_completion(),
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* which efx_mcdi_complete() provides for us.
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* which efx_mcdi_complete_sync() provides for us.
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*/
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mcdi->mode = MCDI_MODE_POLL;
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efx_mcdi_complete(mcdi);
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efx_mcdi_complete_sync(mcdi);
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}
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/* Flush any running or queued asynchronous requests, after event processing
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* is stopped
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*/
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void efx_mcdi_flush_async(struct efx_nic *efx)
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{
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struct efx_mcdi_async_param *async, *next;
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struct efx_mcdi_iface *mcdi;
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if (!efx->mcdi)
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return;
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mcdi = efx_mcdi(efx);
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/* We must be in polling mode so no more requests can be queued */
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BUG_ON(mcdi->mode != MCDI_MODE_POLL);
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del_timer_sync(&mcdi->async_timer);
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/* If a request is still running, make sure we give the MC
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* time to complete it so that the response won't overwrite our
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* next request.
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*/
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if (mcdi->state == MCDI_STATE_RUNNING_ASYNC) {
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efx_mcdi_poll(efx);
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mcdi->state = MCDI_STATE_QUIESCENT;
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}
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/* Nothing else will access the async list now, so it is safe
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* to walk it without holding async_lock. If we hold it while
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* calling a completer then lockdep may warn that we have
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* acquired locks in the wrong order.
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*/
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list_for_each_entry_safe(async, next, &mcdi->async_list, list) {
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async->complete(efx, async->cookie, -ENETDOWN, NULL, 0);
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list_del(&async->list);
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kfree(async);
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}
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}
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void efx_mcdi_mode_event(struct efx_nic *efx)
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@ -498,7 +730,7 @@ void efx_mcdi_mode_event(struct efx_nic *efx)
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* write memory barrier ensure that efx_mcdi_rpc() sees it, which
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* efx_mcdi_acquire() provides.
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*/
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efx_mcdi_acquire(mcdi);
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efx_mcdi_acquire_sync(mcdi);
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mcdi->mode = MCDI_MODE_EVENTS;
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efx_mcdi_release(mcdi);
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}
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@ -515,16 +747,21 @@ static void efx_mcdi_ev_death(struct efx_nic *efx, int rc)
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* are sent to the same queue, we can't be racing with
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* efx_mcdi_ev_cpl()]
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*
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* There's a race here with efx_mcdi_rpc(), because we might receive
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* a REBOOT event *before* the request has been copied out. In polled
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* mode (during startup) this is irrelevant, because efx_mcdi_complete()
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* is ignored. In event mode, this condition is just an edge-case of
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* receiving a REBOOT event after posting the MCDI request. Did the mc
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* reboot before or after the copyout? The best we can do always is
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* just return failure.
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* If there is an outstanding asynchronous request, we can't
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* complete it now (efx_mcdi_complete() would deadlock). The
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* reset process will take care of this.
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*
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* There's a race here with efx_mcdi_send_request(), because
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* we might receive a REBOOT event *before* the request has
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* been copied out. In polled mode (during startup) this is
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* irrelevant, because efx_mcdi_complete_sync() is ignored. In
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* event mode, this condition is just an edge-case of
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* receiving a REBOOT event after posting the MCDI
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* request. Did the mc reboot before or after the copyout? The
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* best we can do always is just return failure.
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*/
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spin_lock(&mcdi->iface_lock);
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if (efx_mcdi_complete(mcdi)) {
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if (efx_mcdi_complete_sync(mcdi)) {
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if (mcdi->mode == MCDI_MODE_EVENTS) {
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mcdi->resprc = rc;
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mcdi->resp_hdr_len = 0;
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@ -14,15 +14,17 @@
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* enum efx_mcdi_state - MCDI request handling state
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* @MCDI_STATE_QUIESCENT: No pending MCDI requests. If the caller holds the
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* mcdi @iface_lock then they are able to move to %MCDI_STATE_RUNNING
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* @MCDI_STATE_RUNNING: There is an MCDI request pending. Only the thread that
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* moved into this state is allowed to move out of it.
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* @MCDI_STATE_RUNNING_SYNC: There is a synchronous MCDI request pending.
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* Only the thread that moved into this state is allowed to move out of it.
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* @MCDI_STATE_RUNNING_ASYNC: There is an asynchronous MCDI request pending.
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* @MCDI_STATE_COMPLETED: An MCDI request has completed, but the owning thread
|
||||
* has not yet consumed the result. For all other threads, equivalent to
|
||||
* %MCDI_STATE_RUNNING.
|
||||
*/
|
||||
enum efx_mcdi_state {
|
||||
MCDI_STATE_QUIESCENT,
|
||||
MCDI_STATE_RUNNING,
|
||||
MCDI_STATE_RUNNING_SYNC,
|
||||
MCDI_STATE_RUNNING_ASYNC,
|
||||
MCDI_STATE_COMPLETED,
|
||||
};
|
||||
|
||||
|
@ -33,19 +35,25 @@ enum efx_mcdi_mode {
|
|||
|
||||
/**
|
||||
* struct efx_mcdi_iface - MCDI protocol context
|
||||
* @efx: The associated NIC.
|
||||
* @state: Request handling state. Waited for by @wq.
|
||||
* @mode: Poll for mcdi completion, or wait for an mcdi_event.
|
||||
* @wq: Wait queue for threads waiting for @state != %MCDI_STATE_RUNNING
|
||||
* @new_epoch: Indicates start of day or start of MC reboot recovery
|
||||
* @iface_lock: Serialises access to all the following fields
|
||||
* @iface_lock: Serialises access to @seqno, @credits and response metadata
|
||||
* @seqno: The next sequence number to use for mcdi requests.
|
||||
* @credits: Number of spurious MCDI completion events allowed before we
|
||||
* trigger a fatal error
|
||||
* @resprc: Response error/success code (Linux numbering)
|
||||
* @resp_hdr_len: Response header length
|
||||
* @resp_data_len: Response data (SDU or error) length
|
||||
* @async_lock: Serialises access to @async_list while event processing is
|
||||
* enabled
|
||||
* @async_list: Queue of asynchronous requests
|
||||
* @async_timer: Timer for asynchronous request timeout
|
||||
*/
|
||||
struct efx_mcdi_iface {
|
||||
struct efx_nic *efx;
|
||||
enum efx_mcdi_state state;
|
||||
enum efx_mcdi_mode mode;
|
||||
wait_queue_head_t wq;
|
||||
|
@ -56,6 +64,9 @@ struct efx_mcdi_iface {
|
|||
int resprc;
|
||||
size_t resp_hdr_len;
|
||||
size_t resp_data_len;
|
||||
spinlock_t async_lock;
|
||||
struct list_head async_list;
|
||||
struct timer_list async_timer;
|
||||
};
|
||||
|
||||
struct efx_mcdi_mon {
|
||||
|
@ -111,10 +122,20 @@ extern int efx_mcdi_rpc_finish(struct efx_nic *efx, unsigned cmd, size_t inlen,
|
|||
efx_dword_t *outbuf, size_t outlen,
|
||||
size_t *outlen_actual);
|
||||
|
||||
typedef void efx_mcdi_async_completer(struct efx_nic *efx,
|
||||
unsigned long cookie, int rc,
|
||||
efx_dword_t *outbuf,
|
||||
size_t outlen_actual);
|
||||
extern int efx_mcdi_rpc_async(struct efx_nic *efx, unsigned int cmd,
|
||||
const efx_dword_t *inbuf, size_t inlen,
|
||||
size_t outlen,
|
||||
efx_mcdi_async_completer *complete,
|
||||
unsigned long cookie);
|
||||
|
||||
extern int efx_mcdi_poll_reboot(struct efx_nic *efx);
|
||||
extern void efx_mcdi_mode_poll(struct efx_nic *efx);
|
||||
extern void efx_mcdi_mode_event(struct efx_nic *efx);
|
||||
extern void efx_mcdi_flush_async(struct efx_nic *efx);
|
||||
|
||||
extern void efx_mcdi_process_event(struct efx_channel *channel,
|
||||
efx_qword_t *event);
|
||||
|
|
Loading…
Reference in a new issue