Re: [PATCH for-next 3/4] RDMA/hns: Support rq record doorbell for kernel space

[Leon Romanovsky <leon-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>]

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On Thu, Jan 18, 2018 at 10:34:30AM +0800, Yixian Liu wrote:
> This patch updates to support rq record doorbell for
> the kernel space.
>
> Signed-off-by: Yixian Liu <liuyixian-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
> Signed-off-by: Lijun Ou <oulijun-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
> Signed-off-by: Wei Hu (Xavier) <xavier.huwei-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
> Signed-off-by: Shaobo Xu <xushaobo2-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
> ---
>  drivers/infiniband/hw/hns/hns_roce_db.c     | 112 ++++++++++++++++++++++++++++
>  drivers/infiniband/hw/hns/hns_roce_device.h |   6 ++
>  drivers/infiniband/hw/hns/hns_roce_hw_v2.c  |  15 +---
>  drivers/infiniband/hw/hns/hns_roce_main.c   |   5 ++
>  drivers/infiniband/hw/hns/hns_roce_qp.c     |  18 ++++-
>  5 files changed, 143 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/infiniband/hw/hns/hns_roce_db.c b/drivers/infiniband/hw/hns/hns_roce_db.c
> index 0908208..de3fa94 100644
> --- a/drivers/infiniband/hw/hns/hns_roce_db.c
> +++ b/drivers/infiniband/hw/hns/hns_roce_db.c
> @@ -92,3 +92,115 @@ void hns_roce_db_unmap_user(struct hns_roce_ucontext *context,
>  	mutex_unlock(&context->db_page_mutex);
>  }
>  EXPORT_SYMBOL(hns_roce_db_unmap_user);
> +
> +static struct hns_roce_db_pgdir *hns_roce_alloc_db_pgdir(
> +					struct device *dma_device, gfp_t gfp)
> +{
> +	struct hns_roce_db_pgdir *pgdir;
> +
> +	pgdir = kzalloc(sizeof(*pgdir), gfp);
> +	if (!pgdir)
> +		return NULL;
> +
> +	bitmap_fill(pgdir->order1, HNS_ROCE_DB_PER_PAGE / 2);
> +	pgdir->bits[0] = pgdir->order0;

order0? isn't it equal to zero?

> +	pgdir->bits[1] = pgdir->order1;
> +	pgdir->db_page = dma_alloc_coherent(dma_device, PAGE_SIZE,
> +					    &pgdir->db_dma, gfp);
> +	if (!pgdir->db_page) {
> +		kfree(pgdir);
> +		return NULL;
> +	}
> +
> +	return pgdir;
> +}
> +
> +static int hns_roce_alloc_db_from_pgdir(struct hns_roce_db_pgdir *pgdir,
> +					struct hns_roce_db *db, int order)
> +{
> +	int o;
> +	int i;
> +
> +	for (o = order; o <= 1; ++o) {
> +		i = find_first_bit(pgdir->bits[o], HNS_ROCE_DB_PER_PAGE >> o);
> +		if (i < HNS_ROCE_DB_PER_PAGE >> o)
> +			goto found;
> +	}
> +
> +	return -ENOMEM;
> +
> +found:
> +	clear_bit(i, pgdir->bits[o]);
> +
> +	i <<= o;
> +
> +	if (o > order)
> +		set_bit(i ^ 1, pgdir->bits[order]);
> +
> +	db->u.pgdir	= pgdir;
> +	db->index	= i;
> +	db->db_record	= pgdir->db_page + db->index;
> +	db->dma		= pgdir->db_dma  + db->index * 4;
> +	db->order	= order;
> +
> +	return 0;
> +}
> +
> +int hns_roce_alloc_db(struct hns_roce_dev *hr_dev, struct hns_roce_db *db,
> +		      int order, gfp_t gfp)

I don't see any reason to provide "order" and "gfp" for one caller who has
hard-coded values.

> +{
> +	struct hns_roce_db_pgdir *pgdir;
> +	int ret = 0;
> +
> +	mutex_lock(&hr_dev->pgdir_mutex);
> +
> +	list_for_each_entry(pgdir, &hr_dev->pgdir_list, list)
> +		if (!hns_roce_alloc_db_from_pgdir(pgdir, db, order))
> +			goto out;
> +
> +	pgdir = hns_roce_alloc_db_pgdir(hr_dev->dev, gfp);
> +	if (!pgdir) {
> +		ret = -ENOMEM;
> +		goto out;
> +	}
> +
> +	list_add(&pgdir->list, &hr_dev->pgdir_list);
> +
> +	/* This should never fail -- we just allocated an empty page: */
> +	WARN_ON(hns_roce_alloc_db_from_pgdir(pgdir, db, order));
> +
> +out:
> +	mutex_unlock(&hr_dev->pgdir_mutex);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(hns_roce_alloc_db);
> +
> +void hns_roce_free_db(struct hns_roce_dev *hr_dev, struct hns_roce_db *db)
> +{
> +	int o;
> +	int i;
> +
> +	mutex_lock(&hr_dev->pgdir_mutex);
> +
> +	o = db->order;
> +	i = db->index;
> +
> +	if (db->order == 0 && test_bit(i ^ 1, db->u.pgdir->order0)) {
> +		clear_bit(i ^ 1, db->u.pgdir->order0);
> +		++o;
> +	}
> +
> +	i >>= o;
> +	set_bit(i, db->u.pgdir->bits[o]);
> +
> +	if (bitmap_full(db->u.pgdir->order1, HNS_ROCE_DB_PER_PAGE / 2)) {
> +		dma_free_coherent(hr_dev->dev, PAGE_SIZE, db->u.pgdir->db_page,
> +				  db->u.pgdir->db_dma);
> +		list_del(&db->u.pgdir->list);
> +		kfree(db->u.pgdir);
> +	}
> +
> +	mutex_unlock(&hr_dev->pgdir_mutex);
> +}
> +EXPORT_SYMBOL_GPL(hns_roce_free_db);
> diff --git a/drivers/infiniband/hw/hns/hns_roce_device.h b/drivers/infiniband/hw/hns/hns_roce_device.h
> index 9ee6da6..dd48559 100644
> --- a/drivers/infiniband/hw/hns/hns_roce_device.h
> +++ b/drivers/infiniband/hw/hns/hns_roce_device.h
> @@ -761,6 +761,8 @@ struct hns_roce_dev {
>  	spinlock_t		bt_cmd_lock;
>  	struct hns_roce_ib_iboe iboe;
>
> +	struct list_head        pgdir_list;
> +	struct mutex            pgdir_mutex;
>  	int			irq[HNS_ROCE_MAX_IRQ_NUM];
>  	u8 __iomem		*reg_base;
>  	struct hns_roce_caps	caps;
> @@ -970,6 +972,10 @@ int hns_roce_db_map_user(struct hns_roce_ucontext *context, unsigned long virt,
>  			 struct hns_roce_db *db);
>  void hns_roce_db_unmap_user(struct hns_roce_ucontext *context,
>  			    struct hns_roce_db *db);
> +int hns_roce_alloc_db(struct hns_roce_dev *hr_dev, struct hns_roce_db *db,
> +		      int order, gfp_t gfp);
> +void hns_roce_free_db(struct hns_roce_dev *hr_dev, struct hns_roce_db *db);
> +
>  void hns_roce_cq_completion(struct hns_roce_dev *hr_dev, u32 cqn);
>  void hns_roce_cq_event(struct hns_roce_dev *hr_dev, u32 cqn, int event_type);
>  void hns_roce_qp_event(struct hns_roce_dev *hr_dev, u32 qpn, int event_type);
> diff --git a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
> index 07129d2..cb0e5ee 100644
> --- a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
> +++ b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
> @@ -470,7 +470,6 @@ static int hns_roce_v2_post_recv(struct ib_qp *ibqp, struct ib_recv_wr *wr,
>  	struct hns_roce_v2_wqe_data_seg *dseg;
>  	struct hns_roce_rinl_sge *sge_list;
>  	struct device *dev = hr_dev->dev;
> -	struct hns_roce_v2_db rq_db;
>  	unsigned long flags;
>  	void *wqe = NULL;
>  	int ret = 0;
> @@ -536,17 +535,7 @@ static int hns_roce_v2_post_recv(struct ib_qp *ibqp, struct ib_recv_wr *wr,
>  		/* Memory barrier */
>  		wmb();
>
> -		rq_db.byte_4 = 0;
> -		rq_db.parameter = 0;
> -
> -		roce_set_field(rq_db.byte_4, V2_DB_BYTE_4_TAG_M,
> -			       V2_DB_BYTE_4_TAG_S, hr_qp->qpn);
> -		roce_set_field(rq_db.byte_4, V2_DB_BYTE_4_CMD_M,
> -			       V2_DB_BYTE_4_CMD_S, HNS_ROCE_V2_RQ_DB);
> -		roce_set_field(rq_db.parameter, V2_DB_PARAMETER_CONS_IDX_M,
> -			       V2_DB_PARAMETER_CONS_IDX_S, hr_qp->rq.head);
> -
> -		hns_roce_write64_k((__be32 *)&rq_db, hr_qp->rq.db_reg_l);
> +		*hr_qp->rdb.db_record = hr_qp->rq.head & 0xffff;
>  	}
>  	spin_unlock_irqrestore(&hr_qp->rq.lock, flags);
>
> @@ -3443,6 +3432,8 @@ static int hns_roce_v2_destroy_qp_common(struct hns_roce_dev *hr_dev,
>  		kfree(hr_qp->sq.wrid);
>  		kfree(hr_qp->rq.wrid);
>  		hns_roce_buf_free(hr_dev, hr_qp->buff_size, &hr_qp->hr_buf);
> +		if (hr_qp->rq.wqe_cnt)
> +			hns_roce_free_db(hr_dev, &hr_qp->rdb);
>  	}
>
>  	if (hr_dev->caps.flags & HNS_ROCE_CAP_FLAG_RQ_INLINE) {
> diff --git a/drivers/infiniband/hw/hns/hns_roce_main.c b/drivers/infiniband/hw/hns/hns_roce_main.c
> index dd7d882..7f4dd22d 100644
> --- a/drivers/infiniband/hw/hns/hns_roce_main.c
> +++ b/drivers/infiniband/hw/hns/hns_roce_main.c
> @@ -665,6 +665,11 @@ static int hns_roce_setup_hca(struct hns_roce_dev *hr_dev)
>  	spin_lock_init(&hr_dev->sm_lock);
>  	spin_lock_init(&hr_dev->bt_cmd_lock);
>
> +	if (hr_dev->caps.flags & HNS_ROCE_CAP_FLAG_RECORD_DB) {
> +		INIT_LIST_HEAD(&hr_dev->pgdir_list);
> +		mutex_init(&hr_dev->pgdir_mutex);
> +	}
> +
>  	ret = hns_roce_init_uar_table(hr_dev);
>  	if (ret) {
>  		dev_err(dev, "Failed to initialize uar table. aborting\n");
> diff --git a/drivers/infiniband/hw/hns/hns_roce_qp.c b/drivers/infiniband/hw/hns/hns_roce_qp.c
> index 300f760..4f7d2d1 100644
> --- a/drivers/infiniband/hw/hns/hns_roce_qp.c
> +++ b/drivers/infiniband/hw/hns/hns_roce_qp.c
> @@ -650,6 +650,17 @@ static int hns_roce_create_qp_common(struct hns_roce_dev *hr_dev,
>  		hr_qp->rq.db_reg_l = hr_dev->reg_base + hr_dev->odb_offset +
>  				     DB_REG_OFFSET * hr_dev->priv_uar.index;
>
> +		if ((hr_dev->caps.flags & HNS_ROCE_CAP_FLAG_RECORD_DB) &&
> +		    hns_roce_qp_has_rq(init_attr)) {
> +			ret = hns_roce_alloc_db(hr_dev, &hr_qp->rdb, 0,
> +						GFP_KERNEL);
> +			if (ret) {
> +				dev_err(dev, "rq record doorbell alloc failed!\n");
> +				goto err_rq_sge_list;
> +			}
> +			*hr_qp->rdb.db_record = 0;
> +		}
> +
>  		/* Allocate QP buf */
>  		page_shift = PAGE_SHIFT + hr_dev->caps.mtt_buf_pg_sz;
>  		if (hns_roce_buf_alloc(hr_dev, hr_qp->buff_size,
> @@ -657,7 +668,7 @@ static int hns_roce_create_qp_common(struct hns_roce_dev *hr_dev,
>  				       &hr_qp->hr_buf, page_shift)) {
>  			dev_err(dev, "hns_roce_buf_alloc error!\n");
>  			ret = -ENOMEM;
> -			goto err_rq_sge_list;
> +			goto err_db;
>  		}
>
>  		hr_qp->mtt.mtt_type = MTT_TYPE_WQE;
> @@ -747,6 +758,11 @@ static int hns_roce_create_qp_common(struct hns_roce_dev *hr_dev,
>  	else
>  		hns_roce_buf_free(hr_dev, hr_qp->buff_size, &hr_qp->hr_buf);
>
> +err_db:
> +	if (!ib_pd->uobject && hns_roce_qp_has_rq(init_attr) &&
> +	    (hr_dev->caps.flags & HNS_ROCE_CAP_FLAG_RECORD_DB))
> +		hns_roce_free_db(hr_dev, &hr_qp->rdb);
> +
>  err_rq_sge_list:
>  	if (hr_dev->caps.flags & HNS_ROCE_CAP_FLAG_RQ_INLINE)
>  		kfree(hr_qp->rq_inl_buf.wqe_list[0].sg_list);
> --
> 1.9.1
>

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