Date:   Mon, 6 Mar 2023 17:51:32 +0300
From:   Serge Semin <fancer.lancer@gmail.com>
To:     Cai Huoqing <cai.huoqing@linux.dev>
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: <20230306145132.wqzq7f6gsluqgp25@mobilestation>
References: <20230303124642.5519-1-cai.huoqing@linux.dev>
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 <20230303165125.fuymevji2jkybmbl@mobilestation>
 <ZAXrSq1A8O7e55F6@chq-MS-7D45>
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On Mon, Mar 06, 2023 at 09:31:54PM +0800, Cai Huoqing wrote:
> 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;

Yes, please.

-Serge(y)

> 
> > 
> > -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
> > >