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Date:   Mon, 2 Mar 2020 11:39:46 +0000
From:   Jonathan Cameron <Jonathan.Cameron@Huawei.com>
To:     Zaibo Xu <xuzaibo@huawei.com>
CC:     <herbert@gondor.apana.org.au>, <davem@davemloft.net>,
        <qianweili@huawei.com>, <tanghui20@huawei.com>,
        <forest.zhouchang@huawei.com>, <linuxarm@huawei.com>,
        <zhangwei375@huawei.com>, <yekai13@huawei.com>,
        <linux-crypto@vger.kernel.org>
Subject: Re: [PATCH v2 1/5] crypto: hisilicon - Use one workqueue per qm
 instead of per qp
Message-ID: <20200302113946.000062f0@Huawei.com>
In-Reply-To: <1583129716-28382-2-git-send-email-xuzaibo@huawei.com>
References: <1583129716-28382-1-git-send-email-xuzaibo@huawei.com>
        <1583129716-28382-2-git-send-email-xuzaibo@huawei.com>
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On Mon, 2 Mar 2020 14:15:12 +0800
Zaibo Xu <xuzaibo@huawei.com> wrote:

> From: Shukun Tan <tanshukun1@huawei.com>
> 
> Because so many work queues are not needed. Using one workqueue
> per QM will reduce the number of kworker threads as well as
> reducing usage of CPU.This would not degrade any performance.
> 
> Signed-off-by: Shukun Tan <tanshukun1@huawei.com>

Hi, this is more or less fine I think other than:

1) Needs a sign off from xuzaibo to reflect the handling of the patch.
2) The description doesn't mention that we aren't actually creating the
   per QM workqueue in this patch (it comes later in the series)
3) The fallback to the system workqueue needs documentation inline.

So tidy those up for v3 and I'm happy.
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Thanks,

Jonathan

> ---
>  drivers/crypto/hisilicon/qm.c | 38 +++++++++++++++-----------------------
>  drivers/crypto/hisilicon/qm.h |  5 +++--
>  2 files changed, 18 insertions(+), 25 deletions(-)
> 
> diff --git a/drivers/crypto/hisilicon/qm.c b/drivers/crypto/hisilicon/qm.c
> index ad7146a..13b0a6f 100644
> --- a/drivers/crypto/hisilicon/qm.c
> +++ b/drivers/crypto/hisilicon/qm.c
> @@ -494,17 +494,9 @@ static void qm_poll_qp(struct hisi_qp *qp, struct hisi_qm *qm)
>  	}
>  }
>  
> -static void qm_qp_work_func(struct work_struct *work)
> +static void qm_work_process(struct work_struct *work)
>  {
> -	struct hisi_qp *qp;
> -
> -	qp = container_of(work, struct hisi_qp, work);
> -	qm_poll_qp(qp, qp->qm);
> -}
> -
> -static irqreturn_t qm_irq_handler(int irq, void *data)
> -{
> -	struct hisi_qm *qm = data;
> +	struct hisi_qm *qm = container_of(work, struct hisi_qm, work);
>  	struct qm_eqe *eqe = qm->eqe + qm->status.eq_head;
>  	struct hisi_qp *qp;
>  	int eqe_num = 0;
> @@ -513,7 +505,7 @@ static irqreturn_t qm_irq_handler(int irq, void *data)
>  		eqe_num++;
>  		qp = qm_to_hisi_qp(qm, eqe);
>  		if (qp)
> -			queue_work(qp->wq, &qp->work);
> +			qm_poll_qp(qp, qm);
>  
>  		if (qm->status.eq_head == QM_Q_DEPTH - 1) {
>  			qm->status.eqc_phase = !qm->status.eqc_phase;
> @@ -531,6 +523,16 @@ static irqreturn_t qm_irq_handler(int irq, void *data)
>  	}
>  
>  	qm_db(qm, 0, QM_DOORBELL_CMD_EQ, qm->status.eq_head, 0);
> +}
> +
> +static irqreturn_t do_qm_irq(int irq, void *data)
> +{
> +	struct hisi_qm *qm = (struct hisi_qm *)data;
> +
> +	if (qm->wq)
> +		queue_work(qm->wq, &qm->work);
> +	else
> +		schedule_work(&qm->work);

This subtle difference between these two could do with an explanatory
comment.

From an initial look I'm not actually seeing qm->wq being set anywhere?
Ah it's in a later patch. Please add comment to say that in the introduction.


>  
>  	return IRQ_HANDLED;
>  }
> @@ -540,7 +542,7 @@ static irqreturn_t qm_irq(int irq, void *data)
>  	struct hisi_qm *qm = data;
>  
>  	if (readl(qm->io_base + QM_VF_EQ_INT_SOURCE))
> -		return qm_irq_handler(irq, data);
> +		return do_qm_irq(irq, data);
>  
>  	dev_err(&qm->pdev->dev, "invalid int source\n");
>  	qm_db(qm, 0, QM_DOORBELL_CMD_EQ, qm->status.eq_head, 0);
> @@ -1159,20 +1161,9 @@ struct hisi_qp *hisi_qm_create_qp(struct hisi_qm *qm, u8 alg_type)
>  
>  	qp->qp_id = qp_id;
>  	qp->alg_type = alg_type;
> -	INIT_WORK(&qp->work, qm_qp_work_func);
> -	qp->wq = alloc_workqueue("hisi_qm", WQ_UNBOUND | WQ_HIGHPRI |
> -				 WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 0);
> -	if (!qp->wq) {
> -		ret = -EFAULT;
> -		goto err_free_qp_mem;
> -	}
>  
>  	return qp;
>  
> -err_free_qp_mem:
> -	if (qm->use_dma_api)
> -		dma_free_coherent(dev, qp->qdma.size, qp->qdma.va,
> -				  qp->qdma.dma);
>  err_clear_bit:
>  	write_lock(&qm->qps_lock);
>  	qm->qp_array[qp_id] = NULL;
> @@ -1704,6 +1695,7 @@ int hisi_qm_init(struct hisi_qm *qm)
>  	qm->qp_in_used = 0;
>  	mutex_init(&qm->mailbox_lock);
>  	rwlock_init(&qm->qps_lock);
> +	INIT_WORK(&qm->work, qm_work_process);
>  
>  	dev_dbg(dev, "init qm %s with %s\n", pdev->is_physfn ? "pf" : "vf",
>  		qm->use_dma_api ? "dma api" : "iommu api");
> diff --git a/drivers/crypto/hisilicon/qm.h b/drivers/crypto/hisilicon/qm.h
> index 1a4f208..c72c2e6 100644
> --- a/drivers/crypto/hisilicon/qm.h
> +++ b/drivers/crypto/hisilicon/qm.h
> @@ -183,6 +183,9 @@ struct hisi_qm {
>  	u32 error_mask;
>  	u32 msi_mask;
>  
> +	struct workqueue_struct *wq;
> +	struct work_struct work;
> +
>  	const char *algs;
>  	bool use_dma_api;
>  	bool use_sva;
> @@ -219,8 +222,6 @@ struct hisi_qp {
>  	void *qp_ctx;
>  	void (*req_cb)(struct hisi_qp *qp, void *data);
>  	void (*event_cb)(struct hisi_qp *qp);
> -	struct work_struct work;
> -	struct workqueue_struct *wq;
>  
>  	struct hisi_qm *qm;
>  	u16 pasid;