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Diffstat (limited to 'drivers/infiniband/hw/hfi1/iowait.h')
| -rw-r--r-- | drivers/infiniband/hw/hfi1/iowait.h | 498 |
1 files changed, 498 insertions, 0 deletions
diff --git a/drivers/infiniband/hw/hfi1/iowait.h b/drivers/infiniband/hw/hfi1/iowait.h new file mode 100644 index 000000000..d580aa17a --- /dev/null +++ b/drivers/infiniband/hw/hfi1/iowait.h @@ -0,0 +1,498 @@ +#ifndef _HFI1_IOWAIT_H +#define _HFI1_IOWAIT_H +/* + * Copyright(c) 2015 - 2018 Intel Corporation. + * + * This file is provided under a dual BSD/GPLv2 license. When using or + * redistributing this file, you may do so under either license. + * + * GPL LICENSE SUMMARY + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of version 2 of the GNU General Public License as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * BSD LICENSE + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * - Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * - Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * - Neither the name of Intel Corporation nor the names of its + * contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + */ + +#include <linux/list.h> +#include <linux/workqueue.h> +#include <linux/wait.h> +#include <linux/sched.h> + +#include "sdma_txreq.h" + +/* + * typedef (*restart_t)() - restart callback + * @work: pointer to work structure + */ +typedef void (*restart_t)(struct work_struct *work); + +#define IOWAIT_PENDING_IB 0x0 +#define IOWAIT_PENDING_TID 0x1 + +/* + * A QP can have multiple Send Engines (SEs). + * + * The current use case is for supporting a TID RDMA + * packet build/xmit mechanism independent from verbs. + */ +#define IOWAIT_SES 2 +#define IOWAIT_IB_SE 0 +#define IOWAIT_TID_SE 1 + +struct sdma_txreq; +struct sdma_engine; +/** + * @iowork: the work struct + * @tx_head: list of prebuilt packets + * @iow: the parent iowait structure + * + * This structure is the work item (process) specific + * details associated with the each of the two SEs of the + * QP. + * + * The workstruct and the queued TXs are unique to each + * SE. + */ +struct iowait; +struct iowait_work { + struct work_struct iowork; + struct list_head tx_head; + struct iowait *iow; +}; + +/** + * @list: used to add/insert into QP/PQ wait lists + * @tx_head: overflow list of sdma_txreq's + * @sleep: no space callback + * @wakeup: space callback wakeup + * @sdma_drained: sdma count drained + * @init_priority: callback to manipulate priority + * @lock: lock protected head of wait queue + * @iowork: workqueue overhead + * @wait_dma: wait for sdma_busy == 0 + * @wait_pio: wait for pio_busy == 0 + * @sdma_busy: # of packets in flight + * @count: total number of descriptors in tx_head'ed list + * @tx_limit: limit for overflow queuing + * @tx_count: number of tx entry's in tx_head'ed list + * @flags: wait flags (one per QP) + * @wait: SE array for multiple legs + * + * This is to be embedded in user's state structure + * (QP or PQ). + * + * The sleep and wakeup members are a + * bit misnamed. They do not strictly + * speaking sleep or wake up, but they + * are callbacks for the ULP to implement + * what ever queuing/dequeuing of + * the embedded iowait and its containing struct + * when a resource shortage like SDMA ring space + * or PIO credit space is seen. + * + * Both potentially have locks help + * so sleeping is not allowed and it is not + * supported to submit txreqs from the wakeup + * call directly because of lock conflicts. + * + * The wait_dma member along with the iow + * + * The lock field is used by waiters to record + * the seqlock_t that guards the list head. + * Waiters explicity know that, but the destroy + * code that unwaits QPs does not. + */ +struct iowait { + struct list_head list; + int (*sleep)( + struct sdma_engine *sde, + struct iowait_work *wait, + struct sdma_txreq *tx, + uint seq, + bool pkts_sent + ); + void (*wakeup)(struct iowait *wait, int reason); + void (*sdma_drained)(struct iowait *wait); + void (*init_priority)(struct iowait *wait); + seqlock_t *lock; + wait_queue_head_t wait_dma; + wait_queue_head_t wait_pio; + atomic_t sdma_busy; + atomic_t pio_busy; + u32 count; + u32 tx_limit; + u32 tx_count; + u8 starved_cnt; + u8 priority; + unsigned long flags; + struct iowait_work wait[IOWAIT_SES]; +}; + +#define SDMA_AVAIL_REASON 0 + +void iowait_set_flag(struct iowait *wait, u32 flag); +bool iowait_flag_set(struct iowait *wait, u32 flag); +void iowait_clear_flag(struct iowait *wait, u32 flag); + +void iowait_init(struct iowait *wait, u32 tx_limit, + void (*func)(struct work_struct *work), + void (*tidfunc)(struct work_struct *work), + int (*sleep)(struct sdma_engine *sde, + struct iowait_work *wait, + struct sdma_txreq *tx, + uint seq, + bool pkts_sent), + void (*wakeup)(struct iowait *wait, int reason), + void (*sdma_drained)(struct iowait *wait), + void (*init_priority)(struct iowait *wait)); + +/** + * iowait_schedule() - schedule the default send engine work + * @wait: wait struct to schedule + * @wq: workqueue for schedule + * @cpu: cpu + */ +static inline bool iowait_schedule(struct iowait *wait, + struct workqueue_struct *wq, int cpu) +{ + return !!queue_work_on(cpu, wq, &wait->wait[IOWAIT_IB_SE].iowork); +} + +/** + * iowait_tid_schedule - schedule the tid SE + * @wait: the iowait structure + * @wq: the work queue + * @cpu: the cpu + */ +static inline bool iowait_tid_schedule(struct iowait *wait, + struct workqueue_struct *wq, int cpu) +{ + return !!queue_work_on(cpu, wq, &wait->wait[IOWAIT_TID_SE].iowork); +} + +/** + * iowait_sdma_drain() - wait for DMAs to drain + * + * @wait: iowait structure + * + * This will delay until the iowait sdmas have + * completed. + */ +static inline void iowait_sdma_drain(struct iowait *wait) +{ + wait_event(wait->wait_dma, !atomic_read(&wait->sdma_busy)); +} + +/** + * iowait_sdma_pending() - return sdma pending count + * + * @wait: iowait structure + * + */ +static inline int iowait_sdma_pending(struct iowait *wait) +{ + return atomic_read(&wait->sdma_busy); +} + +/** + * iowait_sdma_inc - note sdma io pending + * @wait: iowait structure + */ +static inline void iowait_sdma_inc(struct iowait *wait) +{ + atomic_inc(&wait->sdma_busy); +} + +/** + * iowait_sdma_add - add count to pending + * @wait: iowait structure + */ +static inline void iowait_sdma_add(struct iowait *wait, int count) +{ + atomic_add(count, &wait->sdma_busy); +} + +/** + * iowait_sdma_dec - note sdma complete + * @wait: iowait structure + */ +static inline int iowait_sdma_dec(struct iowait *wait) +{ + if (!wait) + return 0; + return atomic_dec_and_test(&wait->sdma_busy); +} + +/** + * iowait_pio_drain() - wait for pios to drain + * + * @wait: iowait structure + * + * This will delay until the iowait pios have + * completed. + */ +static inline void iowait_pio_drain(struct iowait *wait) +{ + wait_event_timeout(wait->wait_pio, + !atomic_read(&wait->pio_busy), + HZ); +} + +/** + * iowait_pio_pending() - return pio pending count + * + * @wait: iowait structure + * + */ +static inline int iowait_pio_pending(struct iowait *wait) +{ + return atomic_read(&wait->pio_busy); +} + +/** + * iowait_pio_inc - note pio pending + * @wait: iowait structure + */ +static inline void iowait_pio_inc(struct iowait *wait) +{ + atomic_inc(&wait->pio_busy); +} + +/** + * iowait_pio_dec - note pio complete + * @wait: iowait structure + */ +static inline int iowait_pio_dec(struct iowait *wait) +{ + if (!wait) + return 0; + return atomic_dec_and_test(&wait->pio_busy); +} + +/** + * iowait_drain_wakeup() - trigger iowait_drain() waiter + * + * @wait: iowait structure + * + * This will trigger any waiters. + */ +static inline void iowait_drain_wakeup(struct iowait *wait) +{ + wake_up(&wait->wait_dma); + wake_up(&wait->wait_pio); + if (wait->sdma_drained) + wait->sdma_drained(wait); +} + +/** + * iowait_get_txhead() - get packet off of iowait list + * + * @wait iowait_work struture + */ +static inline struct sdma_txreq *iowait_get_txhead(struct iowait_work *wait) +{ + struct sdma_txreq *tx = NULL; + + if (!list_empty(&wait->tx_head)) { + tx = list_first_entry( + &wait->tx_head, + struct sdma_txreq, + list); + list_del_init(&tx->list); + } + return tx; +} + +static inline u16 iowait_get_desc(struct iowait_work *w) +{ + u16 num_desc = 0; + struct sdma_txreq *tx = NULL; + + if (!list_empty(&w->tx_head)) { + tx = list_first_entry(&w->tx_head, struct sdma_txreq, + list); + num_desc = tx->num_desc; + if (tx->flags & SDMA_TXREQ_F_VIP) + w->iow->priority++; + } + return num_desc; +} + +static inline u32 iowait_get_all_desc(struct iowait *w) +{ + u32 num_desc = 0; + + num_desc = iowait_get_desc(&w->wait[IOWAIT_IB_SE]); + num_desc += iowait_get_desc(&w->wait[IOWAIT_TID_SE]); + return num_desc; +} + +static inline void iowait_update_priority(struct iowait_work *w) +{ + struct sdma_txreq *tx = NULL; + + if (!list_empty(&w->tx_head)) { + tx = list_first_entry(&w->tx_head, struct sdma_txreq, + list); + if (tx->flags & SDMA_TXREQ_F_VIP) + w->iow->priority++; + } +} + +static inline void iowait_update_all_priority(struct iowait *w) +{ + iowait_update_priority(&w->wait[IOWAIT_IB_SE]); + iowait_update_priority(&w->wait[IOWAIT_TID_SE]); +} + +static inline void iowait_init_priority(struct iowait *w) +{ + w->priority = 0; + if (w->init_priority) + w->init_priority(w); +} + +static inline void iowait_get_priority(struct iowait *w) +{ + iowait_init_priority(w); + iowait_update_all_priority(w); +} + +/** + * iowait_queue - Put the iowait on a wait queue + * @pkts_sent: have some packets been sent before queuing? + * @w: the iowait struct + * @wait_head: the wait queue + * + * This function is called to insert an iowait struct into a + * wait queue after a resource (eg, sdma descriptor or pio + * buffer) is run out. + */ +static inline void iowait_queue(bool pkts_sent, struct iowait *w, + struct list_head *wait_head) +{ + /* + * To play fair, insert the iowait at the tail of the wait queue if it + * has already sent some packets; Otherwise, put it at the head. + * However, if it has priority packets to send, also put it at the + * head. + */ + if (pkts_sent) + w->starved_cnt = 0; + else + w->starved_cnt++; + + if (w->priority > 0 || !pkts_sent) + list_add(&w->list, wait_head); + else + list_add_tail(&w->list, wait_head); +} + +/** + * iowait_starve_clear - clear the wait queue's starve count + * @pkts_sent: have some packets been sent? + * @w: the iowait struct + * + * This function is called to clear the starve count. If no + * packets have been sent, the starve count will not be cleared. + */ +static inline void iowait_starve_clear(bool pkts_sent, struct iowait *w) +{ + if (pkts_sent) + w->starved_cnt = 0; +} + +/* Update the top priority index */ +uint iowait_priority_update_top(struct iowait *w, + struct iowait *top, + uint idx, uint top_idx); + +/** + * iowait_packet_queued() - determine if a packet is queued + * @wait: the iowait_work structure + */ +static inline bool iowait_packet_queued(struct iowait_work *wait) +{ + return !list_empty(&wait->tx_head); +} + +/** + * inc_wait_count - increment wait counts + * @w: the log work struct + * @n: the count + */ +static inline void iowait_inc_wait_count(struct iowait_work *w, u16 n) +{ + if (!w) + return; + w->iow->tx_count++; + w->iow->count += n; +} + +/** + * iowait_get_tid_work - return iowait_work for tid SE + * @w: the iowait struct + */ +static inline struct iowait_work *iowait_get_tid_work(struct iowait *w) +{ + return &w->wait[IOWAIT_TID_SE]; +} + +/** + * iowait_get_ib_work - return iowait_work for ib SE + * @w: the iowait struct + */ +static inline struct iowait_work *iowait_get_ib_work(struct iowait *w) +{ + return &w->wait[IOWAIT_IB_SE]; +} + +/** + * iowait_ioww_to_iow - return iowait given iowait_work + * @w: the iowait_work struct + */ +static inline struct iowait *iowait_ioww_to_iow(struct iowait_work *w) +{ + if (likely(w)) + return w->iow; + return NULL; +} + +void iowait_cancel_work(struct iowait *w); +int iowait_set_work_flag(struct iowait_work *w); + +#endif |