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Date: Tue, 12 Mar 2024 12:04:17 +0300
From: Serge Semin <fancer.lancer@gmail.com>
To: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc: Jingoo Han <jingoohan1@gmail.com>, 
	Gustavo Pimentel <gustavo.pimentel@synopsys.com>, Lorenzo Pieralisi <lpieralisi@kernel.org>, 
	Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= <kw@linux.com>, Rob Herring <robh@kernel.org>, 
	Bjorn Helgaas <bhelgaas@google.com>, Marek Vasut <marek.vasut+renesas@gmail.com>, 
	Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>, Kishon Vijay Abraham I <kishon@kernel.org>, 
	linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-renesas-soc@vger.kernel.org, 
	linux-arm-msm@vger.kernel.org, mhi@lists.linux.dev, Siddharth Vadapalli <s-vadapalli@ti.com>, 
	Frank Li <Frank.Li@nxp.com>
Subject: Re: [PATCH v4 1/5] PCI: dwc: Refactor dw_pcie_edma_find_chip() API
Message-ID: <flwmqlr3irjuwfqpjn227qnrkyyayym57d5v3ksr4xqmfxshaj@ibdi3dyetkou>
References: <20240306-dw-hdma-v4-0-9fed506e95be@linaro.org>
 <20240306-dw-hdma-v4-1-9fed506e95be@linaro.org>
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In-Reply-To: <20240306-dw-hdma-v4-1-9fed506e95be@linaro.org>

Hi Mani

On Wed, Mar 06, 2024 at 03:51:57PM +0530, Manivannan Sadhasivam wrote:
> In order to add support for Hyper DMA (HDMA), let's refactor the existing
> dw_pcie_edma_find_chip() API by moving the common code to separate
> functions.
> 
> No functional change.
> 
> Suggested-by: Serge Semin <fancer.lancer@gmail.com>
> Reviewed-by: Siddharth Vadapalli <s-vadapalli@ti.com>
> Reviewed-by: Frank Li <Frank.Li@nxp.com>
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> ---
>  drivers/pci/controller/dwc/pcie-designware.c | 40 +++++++++++++++++++++++-----
>  1 file changed, 33 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
> index 250cf7f40b85..3a26dfc5368f 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.c
> +++ b/drivers/pci/controller/dwc/pcie-designware.c
> @@ -880,7 +880,17 @@ static struct dw_edma_plat_ops dw_pcie_edma_ops = {
>  	.irq_vector = dw_pcie_edma_irq_vector,
>  };
>  
> -static int dw_pcie_edma_find_chip(struct dw_pcie *pci)
> +static void dw_pcie_edma_init_data(struct dw_pcie *pci)
> +{
> +	pci->edma.dev = pci->dev;
> +
> +	if (!pci->edma.ops)
> +		pci->edma.ops = &dw_pcie_edma_ops;
> +
> +	pci->edma.flags |= DW_EDMA_CHIP_LOCAL;
> +}
> +
> +static int dw_pcie_edma_find_mf(struct dw_pcie *pci)
>  {
>  	u32 val;
>  
> @@ -902,8 +912,6 @@ static int dw_pcie_edma_find_chip(struct dw_pcie *pci)
>  
>  	if (val == 0xFFFFFFFF && pci->edma.reg_base) {
>  		pci->edma.mf = EDMA_MF_EDMA_UNROLL;
> -
> -		val = dw_pcie_readl_dma(pci, PCIE_DMA_CTRL);
>  	} else if (val != 0xFFFFFFFF) {
>  		pci->edma.mf = EDMA_MF_EDMA_LEGACY;
>  
> @@ -912,12 +920,17 @@ static int dw_pcie_edma_find_chip(struct dw_pcie *pci)
>  		return -ENODEV;
>  	}
>  
> -	pci->edma.dev = pci->dev;
> +	return 0;
> +}
>  
> -	if (!pci->edma.ops)
> -		pci->edma.ops = &dw_pcie_edma_ops;
> +static int dw_pcie_edma_find_channels(struct dw_pcie *pci)
> +{
> +	u32 val;
>  

> -	pci->edma.flags |= DW_EDMA_CHIP_LOCAL;
> +	if (pci->edma.mf == EDMA_MF_EDMA_LEGACY)
> +		val = dw_pcie_readl_dbi(pci, PCIE_DMA_VIEWPORT_BASE + PCIE_DMA_CTRL);
> +	else
> +		val = dw_pcie_readl_dma(pci, PCIE_DMA_CTRL);

Once again:

On Tue, Feb 27, 2024 at 01:04:55PM +0530, Manivannan Sadhasivam wrote:
> On Tue, Feb 27, 2024 at 12:00:41AM +0300, Serge Semin wrote:
> > The entire
> > 
> > +	if (pci->edma.mf == EDMA_MF_EDMA_LEGACY)
> > +		val = dw_pcie_readl_dbi(pci, PCIE_DMA_VIEWPORT_BASE + PCIE_DMA_CTRL);
> > +	else
> > +		val = dw_pcie_readl_dma(pci, PCIE_DMA_CTRL);
> > 
> > can be replaced with a single line
> > 
> > +	val = dw_pcie_readl_dma(pci, PCIE_DMA_CTRL);
> > 
> > since in the legacy case (reg_base = PCIE_DMA_VIEWPORT_BASE) the
> > pci->edma.reg_base has been initialized by now.
> > 
> 
> Ah okay, got it!

-Serge(y)

>  
>  	pci->edma.ll_wr_cnt = FIELD_GET(PCIE_DMA_NUM_WR_CHAN, val);
>  	pci->edma.ll_rd_cnt = FIELD_GET(PCIE_DMA_NUM_RD_CHAN, val);
> @@ -930,6 +943,19 @@ static int dw_pcie_edma_find_chip(struct dw_pcie *pci)
>  	return 0;
>  }
>  
> +static int dw_pcie_edma_find_chip(struct dw_pcie *pci)
> +{
> +	int ret;
> +
> +	dw_pcie_edma_init_data(pci);
> +
> +	ret = dw_pcie_edma_find_mf(pci);
> +	if (ret)
> +		return ret;
> +
> +	return dw_pcie_edma_find_channels(pci);
> +}
> +
>  static int dw_pcie_edma_irq_verify(struct dw_pcie *pci)
>  {
>  	struct platform_device *pdev = to_platform_device(pci->dev);
> 
> -- 
> 2.25.1
>