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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/infiniband/hw/hfi1/iowait.h
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/infiniband/hw/hfi1/iowait.h')
-rw-r--r--drivers/infiniband/hw/hfi1/iowait.h457
1 files changed, 457 insertions, 0 deletions
diff --git a/drivers/infiniband/hw/hfi1/iowait.h b/drivers/infiniband/hw/hfi1/iowait.h
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+/* SPDX-License-Identifier: GPL-2.0 or BSD-3-Clause */
+/*
+ * Copyright(c) 2015 - 2018 Intel Corporation.
+ */
+
+#ifndef _HFI1_IOWAIT_H
+#define _HFI1_IOWAIT_H
+
+#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 structure
+ */
+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