Message-ID: <610b5f73-f9e3-deb2-2754-e8939ed00ec3@allwinnertech.com>
Date:   Tue, 31 Jan 2023 21:12:50 +0800
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101
 Thunderbird/91.9.0
Subject: Re: [PATCH] mmc:mmc-cqhci:support interrupt coalescing
Content-Language: en-US
To:     Adrian Hunter <adrian.hunter@intel.com>, riteshh@codeaurora.org,
        asutoshd@codeaurora.org, ulf.hansson@linaro.org,
        chaotian.jing@mediatek.com, matthias.bgg@gmail.com,
        kdasu.kdev@gmail.com, alcooperx@gmail.com, f.fainelli@gmail.com,
        haibo.chen@nxp.com, shawnguo@kernel.org, agross@kernel.org,
        andersson@kernel.org, michal.simek@xilinx.com,
        thierry.reding@gmail.com, jonathanh@nvidia.com
Cc:     bcm-kernel-feedback-list@broadcom.com, kernel@pengutronix.de,
        festevam@gmail.com, linux-imx@nxp.com, konrad.dybcio@linaro.org,
        linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org, linux-arm-msm@vger.kernel.org,
        linux-tegra@vger.kernel.org
References: <20230130064656.106793-1-michael@allwinnertech.com>
 <2463a92b-c180-87d4-0c96-2f549a397164@intel.com>
From:   Michael Wu <michael@allwinnertech.com>
In-Reply-To: <2463a92b-c180-87d4-0c96-2f549a397164@intel.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Precedence: bulk

Dear Adrian，

On 2023/1/30 23:59, Adrian Hunter wrote:
> On 30/01/23 08:46, Michael Wu wrote:
>> Support interrupt coalescing to reduce the frequency of mmc interrupts
> 
> There doesn't seem to be any users.  The new parameter to
> cqhci_init() is always false.  New features are not usually
> accepted without users.

At present, I have only supported this feature on the Allwinner platform 
because I have not get enough information about other vendors.
> 
> There needs to be an explanation of why the change is being made.

I consider reducing the number of interrupt context switches. Can you 
tell me why the community does not support this feature? I wonder 
whether I'm doing is correct. If it's correct, i will improve this patch 
and incorporate it
> 
> Also there doesn't seem to be any configuration of the CQIC
> register.

At present, I am working on the hook function .cqe_enable that the ICCTH 
of CQIC is set in enable
> 
>>
>> Signed-off-by: Michael Wu <michael@allwinnertech.com>
>> ---
>>   drivers/mmc/host/cqhci-core.c      | 20 +++++++++++++++-----
>>   drivers/mmc/host/cqhci.h           |  5 ++++-
>>   drivers/mmc/host/mtk-sd.c          |  2 +-
>>   drivers/mmc/host/sdhci-brcmstb.c   |  2 +-
>>   drivers/mmc/host/sdhci-esdhc-imx.c |  2 +-
>>   drivers/mmc/host/sdhci-msm.c       |  2 +-
>>   drivers/mmc/host/sdhci-of-arasan.c |  2 +-
>>   drivers/mmc/host/sdhci-pci-core.c  |  2 +-
>>   drivers/mmc/host/sdhci-pci-gli.c   |  2 +-
>>   drivers/mmc/host/sdhci-tegra.c     |  2 +-
>>   drivers/mmc/host/sdhci_am654.c     |  2 +-
>>   11 files changed, 28 insertions(+), 15 deletions(-)
>>
>> diff --git a/drivers/mmc/host/cqhci-core.c b/drivers/mmc/host/cqhci-core.c
>> index b3d7d6d8d654..f9cdf9f04bfc 100644
>> --- a/drivers/mmc/host/cqhci-core.c
>> +++ b/drivers/mmc/host/cqhci-core.c
>> @@ -420,7 +420,7 @@ static void cqhci_disable(struct mmc_host *mmc)
>>   }
>>   
>>   static void cqhci_prep_task_desc(struct mmc_request *mrq,
>> -				 struct cqhci_host *cq_host, int tag)
>> +				 struct cqhci_host *cq_host, int tag, int intr)
>>   {
>>   	__le64 *task_desc = (__le64 __force *)get_desc(cq_host, tag);
>>   	u32 req_flags = mrq->data->flags;
>> @@ -428,7 +428,7 @@ static void cqhci_prep_task_desc(struct mmc_request *mrq,
>>   
>>   	desc0 = CQHCI_VALID(1) |
>>   		CQHCI_END(1) |
>> -		CQHCI_INT(1) |
>> +		CQHCI_INT(intr) |
>>   		CQHCI_ACT(0x5) |
>>   		CQHCI_FORCED_PROG(!!(req_flags & MMC_DATA_FORCED_PRG)) |
>>   		CQHCI_DATA_TAG(!!(req_flags & MMC_DATA_DAT_TAG)) |
>> @@ -621,7 +621,7 @@ static int cqhci_request(struct mmc_host *mmc, struct mmc_request *mrq)
>>   	}
>>   
>>   	if (mrq->data) {
>> -		cqhci_prep_task_desc(mrq, cq_host, tag);
>> +		cqhci_prep_task_desc(mrq, cq_host, tag, (cq_host->intr_clsc ? 0 : 1));
>>   
>>   		err = cqhci_prep_tran_desc(mrq, cq_host, tag);
>>   		if (err) {
>> @@ -812,7 +812,7 @@ static void cqhci_finish_mrq(struct mmc_host *mmc, unsigned int tag)
>>   irqreturn_t cqhci_irq(struct mmc_host *mmc, u32 intmask, int cmd_error,
>>   		      int data_error)
>>   {
>> -	u32 status;
>> +	u32 status, rval;
>>   	unsigned long tag = 0, comp_status;
>>   	struct cqhci_host *cq_host = mmc->cqe_private;
>>   
>> @@ -856,6 +856,15 @@ irqreturn_t cqhci_irq(struct mmc_host *mmc, u32 intmask, int cmd_error,
>>   		spin_unlock(&cq_host->lock);
>>   	}
>>   
>> +	if (cq_host->intr_clsc) {
>> +		rval = cqhci_readl(cq_host, CQHCI_IC);
>> +		rval |= CQHCI_IC_RESET;
>> +		cqhci_writel(cq_host, rval, CQHCI_IC);
>> +		rval = cqhci_readl(cq_host, CQHCI_IC);
>> +		rval &= (~CQHCI_IC_RESET);
>> +		cqhci_writel(cq_host, rval, CQHCI_IC);
>> +	}
>> +
>>   	if (status & CQHCI_IS_TCL)
>>   		wake_up(&cq_host->wait_queue);
>>   
>> @@ -1172,11 +1181,12 @@ static unsigned int cqhci_ver_minor(struct cqhci_host *cq_host)
>>   }
>>   
>>   int cqhci_init(struct cqhci_host *cq_host, struct mmc_host *mmc,
>> -	      bool dma64)
>> +	      bool dma64, bool intr_clsc)
>>   {
>>   	int err;
>>   
>>   	cq_host->dma64 = dma64;
>> +	cq_host->intr_clsc = intr_clsc;
>>   	cq_host->mmc = mmc;
>>   	cq_host->mmc->cqe_private = cq_host;
>>   
>> diff --git a/drivers/mmc/host/cqhci.h b/drivers/mmc/host/cqhci.h
>> index ba9387ed90eb..acf90773c30a 100644
>> --- a/drivers/mmc/host/cqhci.h
>> +++ b/drivers/mmc/host/cqhci.h
>> @@ -227,6 +227,9 @@ struct cqhci_host {
>>   
>>   	/* 64 bit DMA */
>>   	bool dma64;
>> +
>> +	/* interrupt coalescing*/
>> +	bool intr_clsc;
>>   	int num_slots;
>>   	int qcnt;
>>   
>> @@ -312,7 +315,7 @@ struct platform_device;
>>   
>>   irqreturn_t cqhci_irq(struct mmc_host *mmc, u32 intmask, int cmd_error,
>>   		      int data_error);
>> -int cqhci_init(struct cqhci_host *cq_host, struct mmc_host *mmc, bool dma64);
>> +int cqhci_init(struct cqhci_host *cq_host, struct mmc_host *mmc, bool dma64, bool intr_clsc);
>>   struct cqhci_host *cqhci_pltfm_init(struct platform_device *pdev);
>>   int cqhci_deactivate(struct mmc_host *mmc);
>>   static inline int cqhci_suspend(struct mmc_host *mmc)
>> diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
>> index edade0e54a0c..2c18f954d4b8 100644
>> --- a/drivers/mmc/host/mtk-sd.c
>> +++ b/drivers/mmc/host/mtk-sd.c
>> @@ -2796,7 +2796,7 @@ static int msdc_drv_probe(struct platform_device *pdev)
>>   		host->cq_host->caps |= CQHCI_TASK_DESC_SZ_128;
>>   		host->cq_host->mmio = host->base + 0x800;
>>   		host->cq_host->ops = &msdc_cmdq_ops;
>> -		ret = cqhci_init(host->cq_host, mmc, true);
>> +		ret = cqhci_init(host->cq_host, mmc, true, false);
>>   		if (ret)
>>   			goto host_free;
>>   		mmc->max_segs = 128;
>> diff --git a/drivers/mmc/host/sdhci-brcmstb.c b/drivers/mmc/host/sdhci-brcmstb.c
>> index f2cf3d70db79..4aeaeddbbf25 100644
>> --- a/drivers/mmc/host/sdhci-brcmstb.c
>> +++ b/drivers/mmc/host/sdhci-brcmstb.c
>> @@ -231,7 +231,7 @@ static int sdhci_brcmstb_add_host(struct sdhci_host *host,
>>   		cq_host->caps |= CQHCI_TASK_DESC_SZ_128;
>>   	}
>>   
>> -	ret = cqhci_init(cq_host, host->mmc, dma64);
>> +	ret = cqhci_init(cq_host, host->mmc, dma64, false);
>>   	if (ret)
>>   		goto cleanup;
>>   
>> diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
>> index 9e73c34b6401..7aef7abe71f1 100644
>> --- a/drivers/mmc/host/sdhci-esdhc-imx.c
>> +++ b/drivers/mmc/host/sdhci-esdhc-imx.c
>> @@ -1712,7 +1712,7 @@ static int sdhci_esdhc_imx_probe(struct platform_device *pdev)
>>   		cq_host->mmio = host->ioaddr + ESDHC_CQHCI_ADDR_OFFSET;
>>   		cq_host->ops = &esdhc_cqhci_ops;
>>   
>> -		err = cqhci_init(cq_host, host->mmc, false);
>> +		err = cqhci_init(cq_host, host->mmc, false, false);
>>   		if (err)
>>   			goto disable_ahb_clk;
>>   	}
>> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
>> index 4ac8651d0b29..b6549d1e43ec 100644
>> --- a/drivers/mmc/host/sdhci-msm.c
>> +++ b/drivers/mmc/host/sdhci-msm.c
>> @@ -2153,7 +2153,7 @@ static int sdhci_msm_cqe_add_host(struct sdhci_host *host,
>>   	if (ret)
>>   		goto cleanup;
>>   
>> -	ret = cqhci_init(cq_host, host->mmc, dma64);
>> +	ret = cqhci_init(cq_host, host->mmc, dma64, false);
>>   	if (ret) {
>>   		dev_err(&pdev->dev, "%s: CQE init: failed (%d)\n",
>>   				mmc_hostname(host->mmc), ret);
>> diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
>> index 89c431a34c43..811f8686532d 100644
>> --- a/drivers/mmc/host/sdhci-of-arasan.c
>> +++ b/drivers/mmc/host/sdhci-of-arasan.c
>> @@ -1610,7 +1610,7 @@ static int sdhci_arasan_add_host(struct sdhci_arasan_data *sdhci_arasan)
>>   	if (dma64)
>>   		cq_host->caps |= CQHCI_TASK_DESC_SZ_128;
>>   
>> -	ret = cqhci_init(cq_host, host->mmc, dma64);
>> +	ret = cqhci_init(cq_host, host->mmc, dma64, false);
>>   	if (ret)
>>   		goto cleanup;
>>   
>> diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c
>> index c359f867df0a..6f6cae6355a7 100644
>> --- a/drivers/mmc/host/sdhci-pci-core.c
>> +++ b/drivers/mmc/host/sdhci-pci-core.c
>> @@ -964,7 +964,7 @@ static int glk_emmc_add_host(struct sdhci_pci_slot *slot)
>>   	if (dma64)
>>   		cq_host->caps |= CQHCI_TASK_DESC_SZ_128;
>>   
>> -	ret = cqhci_init(cq_host, host->mmc, dma64);
>> +	ret = cqhci_init(cq_host, host->mmc, dma64, false);
>>   	if (ret)
>>   		goto cleanup;
>>   
>> diff --git a/drivers/mmc/host/sdhci-pci-gli.c b/drivers/mmc/host/sdhci-pci-gli.c
>> index 633a8ee8f8c5..6917ba339aa9 100644
>> --- a/drivers/mmc/host/sdhci-pci-gli.c
>> +++ b/drivers/mmc/host/sdhci-pci-gli.c
>> @@ -908,7 +908,7 @@ static int gl9763e_add_host(struct sdhci_pci_slot *slot)
>>   	if (dma64)
>>   		cq_host->caps |= CQHCI_TASK_DESC_SZ_128;
>>   
>> -	ret = cqhci_init(cq_host, host->mmc, dma64);
>> +	ret = cqhci_init(cq_host, host->mmc, dma64, false);
>>   	if (ret)
>>   		goto cleanup;
>>   
>> diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c
>> index bff084f178c9..f98a468e8f43 100644
>> --- a/drivers/mmc/host/sdhci-tegra.c
>> +++ b/drivers/mmc/host/sdhci-tegra.c
>> @@ -1620,7 +1620,7 @@ static int sdhci_tegra_add_host(struct sdhci_host *host)
>>   	if (dma64)
>>   		cq_host->caps |= CQHCI_TASK_DESC_SZ_128;
>>   
>> -	ret = cqhci_init(cq_host, host->mmc, dma64);
>> +	ret = cqhci_init(cq_host, host->mmc, dma64, false);
>>   	if (ret)
>>   		goto cleanup;
>>   
>> diff --git a/drivers/mmc/host/sdhci_am654.c b/drivers/mmc/host/sdhci_am654.c
>> index 7ef828942df3..8e7fbee70e16 100644
>> --- a/drivers/mmc/host/sdhci_am654.c
>> +++ b/drivers/mmc/host/sdhci_am654.c
>> @@ -568,7 +568,7 @@ static int sdhci_am654_cqe_add_host(struct sdhci_host *host)
>>   
>>   	host->mmc->caps2 |= MMC_CAP2_CQE;
>>   
>> -	return cqhci_init(cq_host, host->mmc, 1);
>> +	return cqhci_init(cq_host, host->mmc, 1, false);
>>   }
>>   
>>   static int sdhci_am654_get_otap_delay(struct sdhci_host *host,

-- 
Regards,
Michael Wu