Re: [PATCH v10 04/10] PCI: cadence: Add support for High Perf Architecture (HPA) controller

[Manivannan Sadhasivam]

On Sun, Nov 02, 2025 at 05:51:05AM +0000, Manikandan Karunakaran Pillai wrote:
> Hi Mani,
> 
> Pls find my comments below.
> 
> >> >> +			value |=
> >> >HPA_LM_RC_BAR_CFG_CTRL_PREF_MEM_64BITS(bar);
> >> >> +	} else {
> >> >> +		value |= HPA_LM_RC_BAR_CFG_CTRL_MEM_32BITS(bar);
> >> >> +		if ((flags & IORESOURCE_PREFETCH))
> >> >> +			value |=
> >> >HPA_LM_RC_BAR_CFG_CTRL_PREF_MEM_32BITS(bar);
> >> >> +	}
> >> >> +
> >> >> +	value |= HPA_LM_RC_BAR_CFG_APERTURE(bar, aperture);
> >> >> +	cdns_pcie_hpa_writel(pcie, REG_BANK_IP_CFG_CTRL_REG,
> >> >CDNS_PCIE_HPA_LM_RC_BAR_CFG, value);
> >> >> +
> >> >> +	return 0;
> >> >> +}
> >> >> +
> >> >> +static int cdns_pcie_hpa_host_bar_config(struct cdns_pcie_rc *rc,
> >> >> +					 struct resource_entry *entry)
> >> >
> >> >This and other functions are almost same as in 'pcie-cadence-host'. Why
> >don't
> >> >you reuse them in a common library?
> >>
> >> The function cdns_pcie_hpa_host_bar_config() calls functions
> >cdns_pcie_hpa_host_bar_ib_config()
> >> which is not common. All functions that are common between the two
> >architecture are moved to the
> >> common library file based on earlier comments.
> >>
> >
> >This is not a good reason to duplicate the whole function. You could just make
> >the common function accept the callback ib_config() and pass either
> >cdns_pcie_host_bar_ib_config() or cdns_pcie_hpa_host_bar_ib_config().
> >
> >This pattern could be done for other functions as well. Please audit all of them
> >and move them to common library. Currently, I could see a lot of duplications
> >that could be avoided.
> 
> The very first patch  for this feature included an ops struct  which was registered (very similar to a callback). Are are asking me to again implement the same design which was earlier rejected ?
> 

You didn't provide any link to the discussion, so how can I decide without
looking into it?

> Secondly except the names of the functions, the registers and their offset written and the sequence also changes for the implementations.
> 

I don't think so. From a quick look, at least cdns_pcie_hpa_host_bar_config(),
cdns_pcie_hpa_host_map_dma_ranges() are mostly similar. You can keep the
functions having different register configurations, but should try to move
others.

- Mani

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