Date:   Mon, 6 Mar 2023 21:31:54 +0800
From:   Cai Huoqing <cai.huoqing@linux.dev>
To:     Serge Semin <fancer.lancer@gmail.com>
Cc:     Gustavo Pimentel <gustavo.pimentel@synopsys.com>,
        Vinod Koul <vkoul@kernel.org>,
        Jingoo Han <jingoohan1@gmail.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>,
        linux-kernel@vger.kernel.org, dmaengine@vger.kernel.org,
        linux-pci@vger.kernel.org
Subject: Re: [PATCH v5 1/4] dmaengine: dw-edma: Rename dw_edma_core_ops
 structure to dw_edma_plat_ops
Message-ID: <ZAXrSq1A8O7e55F6@chq-MS-7D45>
References: <20230303124642.5519-1-cai.huoqing@linux.dev>
 <20230303124642.5519-2-cai.huoqing@linux.dev>
 <20230303165125.fuymevji2jkybmbl@mobilestation>
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On 03 3月 23 19:51:25, Serge Semin wrote:
> On Fri, Mar 03, 2023 at 08:46:31PM +0800, Cai Huoqing wrote:
> > From: Cai huoqing <cai.huoqing@linux.dev>
> > 
> 
> > Rename dw_edma_core_ops structure to dw_edma_plat_ops, the ops is platform
> > specific operations: the DMA device environment configs like IRQs,
> > address translation, etc.
> > 
> > The dw_edma_plat_ops name was supposed to refer to the platform which
> > the DW eDMA engine is embedded to, like PCIe end-point (accessible via
> > the PCIe bus) or a PCIe root port (directly accessible by CPU).
> > Needless to say that for them the IRQ-vector and PCI-addresses are
> > differently determined. The suggested name has a connection with the
> > kernel platform device only as a private case of the eDMA/hDMA embedded
> > into the DW PCI Root ports, though basically it was supposed to refer to
> > any platform in which the DMA hardware lives.
> > 
> > Anyway the renaming was necessary to distinguish two types of
> > the implementation callbacks:
> > 1. DW eDMA/hDMA IP-core specific operations: device-specific CSR
> > setups in one or another aspect of the DMA-engine initialization.
> > 2. DW eDMA/hDMA platform specific operations: the DMA device
> > environment configs like IRQs, address translation, etc.
> > 
> > dw_edma_core_ops is supposed to be used for the case 1, and
> > dw_edma_plat_ops - for the case 2.
> 
> This text was my explanation to Bjorn of why the renaming was
> necessary. The patch log has a bit different context so I would
> change it to something like this:
> 
> "The dw_edma_core_ops structure contains a set of the operations:
> device IRQ numbers getter, CPU/PCI address translation. Based on the
> functions semantics the structure name "dw_edma_plat_ops" looks more
> descriptive since indeed the operations are platform-specific. The
> "dw_edma_core_ops" name shall be used for a structure with the IP-core
> specific set of callbacks in order to abstract out DW eDMA and DW HDMA
> setups. Such structure will be added in one of the next commit in the
> framework of the set of changes adding the DW HDMA device support."
OK

> 
> > 
> > Signed-off-by: Cai huoqing <cai.huoqing@linux.dev>
> > ---
> >   v4->v5:
> >     1.Revert the instance dw_edma_pcie_core_ops
> >     2.Move the change EDMA_MF_HDMA_NATIVE to patch[3/4] 
> > 
> >   v4 link:
> >   https://lore.kernel.org/lkml/20230221034656.14476-2-cai.huoqing@linux.dev/
> >  
> >  drivers/dma/dw-edma/dw-edma-pcie.c           | 2 +-
> >  drivers/pci/controller/dwc/pcie-designware.c | 2 +-
> >  include/linux/dma/edma.h                     | 4 ++--
> >  3 files changed, 4 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/dma/dw-edma/dw-edma-pcie.c b/drivers/dma/dw-edma/dw-edma-pcie.c
> > index 2b40f2b44f5e..190b32d8016d 100644
> > --- a/drivers/dma/dw-edma/dw-edma-pcie.c
> > +++ b/drivers/dma/dw-edma/dw-edma-pcie.c
> > @@ -109,7 +109,7 @@ static u64 dw_edma_pcie_address(struct device *dev, phys_addr_t cpu_addr)
> >  	return region.start;
> >  }
> >  
> 
> > -static const struct dw_edma_core_ops dw_edma_pcie_core_ops = {
> > +static const struct dw_edma_plat_ops dw_edma_pcie_core_ops = {
> 
> Please carefully note my comment to v4. I asked to add the prefix
> specific to the local naming convention:
> 
> -static const struct dw_edma_core_ops dw_edma_pcie_core_ops = {
> +static const struct dw_edma_plat_ops dw_edma_pcie_plat_ops = {
> 
> But besides of adding the correct prefix you changed the suffix to the
> improper one. Please get it back so the instance name would be
> "dw_edma_pcie_plat_ops".
Do you mean ditto
-	chip->ops = &dw_edma_pcie_core_ops;
+	chip->ops = &dw_edma_pcie_plat_ops;

> 
> -Serge(y)
> 
> >  	.irq_vector = dw_edma_pcie_irq_vector,
> >  	.pci_address = dw_edma_pcie_address,
> >  };
> > diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
> > index 53a16b8b6ac2..44e90b71d429 100644
> > --- a/drivers/pci/controller/dwc/pcie-designware.c
> > +++ b/drivers/pci/controller/dwc/pcie-designware.c
> > @@ -828,7 +828,7 @@ static int dw_pcie_edma_irq_vector(struct device *dev, unsigned int nr)
> >  	return platform_get_irq_byname_optional(pdev, name);
> >  }
> >  
> > -static struct dw_edma_core_ops dw_pcie_edma_ops = {
> > +static struct dw_edma_plat_ops dw_pcie_edma_ops = {
> >  	.irq_vector = dw_pcie_edma_irq_vector,
> >  };
> >  
> > diff --git a/include/linux/dma/edma.h b/include/linux/dma/edma.h
> > index d2638d9259dc..ed401c965a87 100644
> > --- a/include/linux/dma/edma.h
> > +++ b/include/linux/dma/edma.h
> > @@ -40,7 +40,7 @@ struct dw_edma_region {
> >   *			iATU windows. That will be done by the controller
> >   *			automatically.
> >   */
> > -struct dw_edma_core_ops {
> > +struct dw_edma_plat_ops {
> >  	int (*irq_vector)(struct device *dev, unsigned int nr);
> >  	u64 (*pci_address)(struct device *dev, phys_addr_t cpu_addr);
> >  };
> > @@ -80,7 +80,7 @@ enum dw_edma_chip_flags {
> >  struct dw_edma_chip {
> >  	struct device		*dev;
> >  	int			nr_irqs;
> > -	const struct dw_edma_core_ops   *ops;
> > +	const struct dw_edma_plat_ops	*ops;
> >  	u32			flags;
> >  
> >  	void __iomem		*reg_base;
> > -- 
> > 2.34.1
> >