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-rw-r--r--block/blk-mq.h396
1 files changed, 396 insertions, 0 deletions
diff --git a/block/blk-mq.h b/block/blk-mq.h
new file mode 100644
index 000000000..c6eca452e
--- /dev/null
+++ b/block/blk-mq.h
@@ -0,0 +1,396 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef INT_BLK_MQ_H
+#define INT_BLK_MQ_H
+
+#include "blk-stat.h"
+#include "blk-mq-tag.h"
+
+struct blk_mq_tag_set;
+
+struct blk_mq_ctxs {
+ struct kobject kobj;
+ struct blk_mq_ctx __percpu *queue_ctx;
+};
+
+/**
+ * struct blk_mq_ctx - State for a software queue facing the submitting CPUs
+ */
+struct blk_mq_ctx {
+ struct {
+ spinlock_t lock;
+ struct list_head rq_lists[HCTX_MAX_TYPES];
+ } ____cacheline_aligned_in_smp;
+
+ unsigned int cpu;
+ unsigned short index_hw[HCTX_MAX_TYPES];
+ struct blk_mq_hw_ctx *hctxs[HCTX_MAX_TYPES];
+
+ struct request_queue *queue;
+ struct blk_mq_ctxs *ctxs;
+ struct kobject kobj;
+} ____cacheline_aligned_in_smp;
+
+void blk_mq_submit_bio(struct bio *bio);
+int blk_mq_poll(struct request_queue *q, blk_qc_t cookie, struct io_comp_batch *iob,
+ unsigned int flags);
+void blk_mq_exit_queue(struct request_queue *q);
+int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
+void blk_mq_wake_waiters(struct request_queue *q);
+bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *,
+ unsigned int);
+void blk_mq_add_to_requeue_list(struct request *rq, bool at_head,
+ bool kick_requeue_list);
+void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list);
+struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx,
+ struct blk_mq_ctx *start);
+void blk_mq_put_rq_ref(struct request *rq);
+
+/*
+ * Internal helpers for allocating/freeing the request map
+ */
+void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
+ unsigned int hctx_idx);
+void blk_mq_free_rq_map(struct blk_mq_tags *tags);
+struct blk_mq_tags *blk_mq_alloc_map_and_rqs(struct blk_mq_tag_set *set,
+ unsigned int hctx_idx, unsigned int depth);
+void blk_mq_free_map_and_rqs(struct blk_mq_tag_set *set,
+ struct blk_mq_tags *tags,
+ unsigned int hctx_idx);
+/*
+ * Internal helpers for request insertion into sw queues
+ */
+void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
+ bool at_head);
+void blk_mq_request_bypass_insert(struct request *rq, bool at_head,
+ bool run_queue);
+void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
+ struct list_head *list);
+void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx,
+ struct list_head *list);
+
+/*
+ * CPU -> queue mappings
+ */
+extern int blk_mq_hw_queue_to_node(struct blk_mq_queue_map *qmap, unsigned int);
+
+/*
+ * blk_mq_map_queue_type() - map (hctx_type,cpu) to hardware queue
+ * @q: request queue
+ * @type: the hctx type index
+ * @cpu: CPU
+ */
+static inline struct blk_mq_hw_ctx *blk_mq_map_queue_type(struct request_queue *q,
+ enum hctx_type type,
+ unsigned int cpu)
+{
+ return xa_load(&q->hctx_table, q->tag_set->map[type].mq_map[cpu]);
+}
+
+static inline enum hctx_type blk_mq_get_hctx_type(blk_opf_t opf)
+{
+ enum hctx_type type = HCTX_TYPE_DEFAULT;
+
+ /*
+ * The caller ensure that if REQ_POLLED, poll must be enabled.
+ */
+ if (opf & REQ_POLLED)
+ type = HCTX_TYPE_POLL;
+ else if ((opf & REQ_OP_MASK) == REQ_OP_READ)
+ type = HCTX_TYPE_READ;
+ return type;
+}
+
+/*
+ * blk_mq_map_queue() - map (cmd_flags,type) to hardware queue
+ * @q: request queue
+ * @opf: operation type (REQ_OP_*) and flags (e.g. REQ_POLLED).
+ * @ctx: software queue cpu ctx
+ */
+static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
+ blk_opf_t opf,
+ struct blk_mq_ctx *ctx)
+{
+ return ctx->hctxs[blk_mq_get_hctx_type(opf)];
+}
+
+/*
+ * sysfs helpers
+ */
+extern void blk_mq_sysfs_init(struct request_queue *q);
+extern void blk_mq_sysfs_deinit(struct request_queue *q);
+int blk_mq_sysfs_register(struct gendisk *disk);
+void blk_mq_sysfs_unregister(struct gendisk *disk);
+int blk_mq_sysfs_register_hctxs(struct request_queue *q);
+void blk_mq_sysfs_unregister_hctxs(struct request_queue *q);
+extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
+void blk_mq_free_plug_rqs(struct blk_plug *plug);
+void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule);
+
+void blk_mq_cancel_work_sync(struct request_queue *q);
+
+void blk_mq_release(struct request_queue *q);
+
+static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
+ unsigned int cpu)
+{
+ return per_cpu_ptr(q->queue_ctx, cpu);
+}
+
+/*
+ * This assumes per-cpu software queueing queues. They could be per-node
+ * as well, for instance. For now this is hardcoded as-is. Note that we don't
+ * care about preemption, since we know the ctx's are persistent. This does
+ * mean that we can't rely on ctx always matching the currently running CPU.
+ */
+static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
+{
+ return __blk_mq_get_ctx(q, raw_smp_processor_id());
+}
+
+struct blk_mq_alloc_data {
+ /* input parameter */
+ struct request_queue *q;
+ blk_mq_req_flags_t flags;
+ unsigned int shallow_depth;
+ blk_opf_t cmd_flags;
+ req_flags_t rq_flags;
+
+ /* allocate multiple requests/tags in one go */
+ unsigned int nr_tags;
+ struct request **cached_rq;
+
+ /* input & output parameter */
+ struct blk_mq_ctx *ctx;
+ struct blk_mq_hw_ctx *hctx;
+};
+
+static inline bool blk_mq_is_shared_tags(unsigned int flags)
+{
+ return flags & BLK_MQ_F_TAG_HCTX_SHARED;
+}
+
+static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data)
+{
+ if (!(data->rq_flags & RQF_ELV))
+ return data->hctx->tags;
+ return data->hctx->sched_tags;
+}
+
+static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
+{
+ return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
+}
+
+static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
+{
+ return hctx->nr_ctx && hctx->tags;
+}
+
+unsigned int blk_mq_in_flight(struct request_queue *q,
+ struct block_device *part);
+void blk_mq_in_flight_rw(struct request_queue *q, struct block_device *part,
+ unsigned int inflight[2]);
+
+static inline void blk_mq_put_dispatch_budget(struct request_queue *q,
+ int budget_token)
+{
+ if (q->mq_ops->put_budget)
+ q->mq_ops->put_budget(q, budget_token);
+}
+
+static inline int blk_mq_get_dispatch_budget(struct request_queue *q)
+{
+ if (q->mq_ops->get_budget)
+ return q->mq_ops->get_budget(q);
+ return 0;
+}
+
+static inline void blk_mq_set_rq_budget_token(struct request *rq, int token)
+{
+ if (token < 0)
+ return;
+
+ if (rq->q->mq_ops->set_rq_budget_token)
+ rq->q->mq_ops->set_rq_budget_token(rq, token);
+}
+
+static inline int blk_mq_get_rq_budget_token(struct request *rq)
+{
+ if (rq->q->mq_ops->get_rq_budget_token)
+ return rq->q->mq_ops->get_rq_budget_token(rq);
+ return -1;
+}
+
+static inline void __blk_mq_inc_active_requests(struct blk_mq_hw_ctx *hctx)
+{
+ if (blk_mq_is_shared_tags(hctx->flags))
+ atomic_inc(&hctx->queue->nr_active_requests_shared_tags);
+ else
+ atomic_inc(&hctx->nr_active);
+}
+
+static inline void __blk_mq_sub_active_requests(struct blk_mq_hw_ctx *hctx,
+ int val)
+{
+ if (blk_mq_is_shared_tags(hctx->flags))
+ atomic_sub(val, &hctx->queue->nr_active_requests_shared_tags);
+ else
+ atomic_sub(val, &hctx->nr_active);
+}
+
+static inline void __blk_mq_dec_active_requests(struct blk_mq_hw_ctx *hctx)
+{
+ __blk_mq_sub_active_requests(hctx, 1);
+}
+
+static inline int __blk_mq_active_requests(struct blk_mq_hw_ctx *hctx)
+{
+ if (blk_mq_is_shared_tags(hctx->flags))
+ return atomic_read(&hctx->queue->nr_active_requests_shared_tags);
+ return atomic_read(&hctx->nr_active);
+}
+static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx,
+ struct request *rq)
+{
+ blk_mq_put_tag(hctx->tags, rq->mq_ctx, rq->tag);
+ rq->tag = BLK_MQ_NO_TAG;
+
+ if (rq->rq_flags & RQF_MQ_INFLIGHT) {
+ rq->rq_flags &= ~RQF_MQ_INFLIGHT;
+ __blk_mq_dec_active_requests(hctx);
+ }
+}
+
+static inline void blk_mq_put_driver_tag(struct request *rq)
+{
+ if (rq->tag == BLK_MQ_NO_TAG || rq->internal_tag == BLK_MQ_NO_TAG)
+ return;
+
+ __blk_mq_put_driver_tag(rq->mq_hctx, rq);
+}
+
+bool __blk_mq_get_driver_tag(struct blk_mq_hw_ctx *hctx, struct request *rq);
+
+static inline bool blk_mq_get_driver_tag(struct request *rq)
+{
+ struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
+
+ if (rq->tag != BLK_MQ_NO_TAG &&
+ !(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) {
+ hctx->tags->rqs[rq->tag] = rq;
+ return true;
+ }
+
+ return __blk_mq_get_driver_tag(hctx, rq);
+}
+
+static inline void blk_mq_clear_mq_map(struct blk_mq_queue_map *qmap)
+{
+ int cpu;
+
+ for_each_possible_cpu(cpu)
+ qmap->mq_map[cpu] = 0;
+}
+
+/*
+ * blk_mq_plug() - Get caller context plug
+ * @bio : the bio being submitted by the caller context
+ *
+ * Plugging, by design, may delay the insertion of BIOs into the elevator in
+ * order to increase BIO merging opportunities. This however can cause BIO
+ * insertion order to change from the order in which submit_bio() is being
+ * executed in the case of multiple contexts concurrently issuing BIOs to a
+ * device, even if these context are synchronized to tightly control BIO issuing
+ * order. While this is not a problem with regular block devices, this ordering
+ * change can cause write BIO failures with zoned block devices as these
+ * require sequential write patterns to zones. Prevent this from happening by
+ * ignoring the plug state of a BIO issuing context if it is for a zoned block
+ * device and the BIO to plug is a write operation.
+ *
+ * Return current->plug if the bio can be plugged and NULL otherwise
+ */
+static inline struct blk_plug *blk_mq_plug( struct bio *bio)
+{
+ /* Zoned block device write operation case: do not plug the BIO */
+ if (IS_ENABLED(CONFIG_BLK_DEV_ZONED) &&
+ bdev_op_is_zoned_write(bio->bi_bdev, bio_op(bio)))
+ return NULL;
+
+ /*
+ * For regular block devices or read operations, use the context plug
+ * which may be NULL if blk_start_plug() was not executed.
+ */
+ return current->plug;
+}
+
+/* Free all requests on the list */
+static inline void blk_mq_free_requests(struct list_head *list)
+{
+ while (!list_empty(list)) {
+ struct request *rq = list_entry_rq(list->next);
+
+ list_del_init(&rq->queuelist);
+ blk_mq_free_request(rq);
+ }
+}
+
+/*
+ * For shared tag users, we track the number of currently active users
+ * and attempt to provide a fair share of the tag depth for each of them.
+ */
+static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx,
+ struct sbitmap_queue *bt)
+{
+ unsigned int depth, users;
+
+ if (!hctx || !(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED))
+ return true;
+
+ /*
+ * Don't try dividing an ant
+ */
+ if (bt->sb.depth == 1)
+ return true;
+
+ if (blk_mq_is_shared_tags(hctx->flags)) {
+ struct request_queue *q = hctx->queue;
+
+ if (!test_bit(QUEUE_FLAG_HCTX_ACTIVE, &q->queue_flags))
+ return true;
+ } else {
+ if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state))
+ return true;
+ }
+
+ users = READ_ONCE(hctx->tags->active_queues);
+ if (!users)
+ return true;
+
+ /*
+ * Allow at least some tags
+ */
+ depth = max((bt->sb.depth + users - 1) / users, 4U);
+ return __blk_mq_active_requests(hctx) < depth;
+}
+
+/* run the code block in @dispatch_ops with rcu/srcu read lock held */
+#define __blk_mq_run_dispatch_ops(q, check_sleep, dispatch_ops) \
+do { \
+ if (!blk_queue_has_srcu(q)) { \
+ rcu_read_lock(); \
+ (dispatch_ops); \
+ rcu_read_unlock(); \
+ } else { \
+ int srcu_idx; \
+ \
+ might_sleep_if(check_sleep); \
+ srcu_idx = srcu_read_lock((q)->srcu); \
+ (dispatch_ops); \
+ srcu_read_unlock((q)->srcu, srcu_idx); \
+ } \
+} while (0)
+
+#define blk_mq_run_dispatch_ops(q, dispatch_ops) \
+ __blk_mq_run_dispatch_ops(q, true, dispatch_ops) \
+
+#endif
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-02 21:34:43 +0000