Re: [PATCH v1 6/9] PCI: microchip: Re-partition code between probe() and init()

[Conor Dooley <conor@kernel.org>]

On Wed, Nov 16, 2022 at 01:55:01PM +0000, daire.mcnamara@microchip.com wrote:
> From: Daire McNamara <daire.mcnamara@microchip.com>
> 
> Continuing to use pci_host_common_probe() for the PCIe root complex on
> PolarFire SoC was leading to an extremely large _init() function and
> some unnatural code flow. Re-partition so some tasks are done in
> a _probe() routine, which calls pci_host_common_probe() and then use a
> much smaller _init() function, mainly to enable interrupts after address
> translation tables are set up.
> 
> Signed-off-by: Daire McNamara <daire.mcnamara@microchip.com>
> Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
> ---
>  drivers/pci/controller/pcie-microchip-host.c | 55 ++++++++++++++------
>  1 file changed, 38 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/pci/controller/pcie-microchip-host.c b/drivers/pci/controller/pcie-microchip-host.c
> index faecf419ad6f..73856647f321 100644
> --- a/drivers/pci/controller/pcie-microchip-host.c
> +++ b/drivers/pci/controller/pcie-microchip-host.c
> @@ -381,6 +381,8 @@ static struct {
>  
>  static char poss_clks[][5] = { "fic0", "fic1", "fic2", "fic3" };
>  
> +static struct mc_pcie *port;
> +
>  static void mc_pcie_fixup_ecam(struct mc_pcie *port, void __iomem *ecam)
>  {
>  	struct mc_msi *msi = &port->msi;
> @@ -1095,7 +1097,34 @@ static int mc_platform_init(struct pci_config_window *cfg)
>  {
>  	struct device *dev = cfg->parent;
>  	struct platform_device *pdev = to_platform_device(dev);
> -	struct mc_pcie *port;
> +	void __iomem *bridge_base_addr =
> +		port->axi_base_addr + MC_PCIE_BRIDGE_ADDR;
> +	int ret;
> +
> +	/* Configure address translation table 0 for PCIe config space */
> +	mc_pcie_setup_window(bridge_base_addr, 0, cfg->res.start,
> +			     cfg->res.start,
> +			     resource_size(&cfg->res));
> +
> +	/* Need some fixups in config space */
> +	mc_pcie_fixup_ecam(port, cfg->win);
> +
> +	/* Configure non-config space outbound ranges */
> +	ret = mc_pcie_setup_windows(pdev, port);
> +	if (ret)
> +		return ret;
> +
> +	/* address translation is up; safe to enable interrupts */

I think that Bjorn mentioned it elsewhere, but consistent capitalisation
would be nice. Otherwise, code movement looks good to me.
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>

Thanks,
Conor.

> +	ret = mc_init_interrupts(pdev, port);
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static int mc_host_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
>  	void __iomem *bridge_base_addr;
>  	void __iomem *ctrl_base_addr;
>  	int ret;
> @@ -1104,13 +1133,8 @@ static int mc_platform_init(struct pci_config_window *cfg)
>  	port = devm_kzalloc(dev, sizeof(*port), GFP_KERNEL);
>  	if (!port)
>  		return -ENOMEM;
> -	port->dev = dev;
>  
> -	ret = mc_pcie_init_clks(dev);
> -	if (ret) {
> -		dev_err(dev, "failed to get clock resources, error %d\n", ret);
> -		return -ENODEV;
> -	}
> +	port->dev = dev;
>  
>  	port->axi_base_addr = devm_platform_ioremap_resource(pdev, 1);
>  	if (IS_ERR(port->axi_base_addr))
> @@ -1136,16 +1160,13 @@ static int mc_platform_init(struct pci_config_window *cfg)
>  	/* pick vector address from design */
>  	port->msi.vector_phy = readl_relaxed(bridge_base_addr + IMSI_ADDR);
>  
> -	/* Configure Address Translation Table 0 for PCIe config space */
> -	mc_pcie_setup_window(bridge_base_addr, 0, cfg->res.start & 0xffffffff,
> -			     cfg->res.start, resource_size(&cfg->res));
> -
> -	ret = mc_pcie_setup_windows(pdev, port);
> -	if (ret)
> -		return ret;
> +	ret = mc_pcie_init_clks(dev);
> +	if (ret) {
> +		dev_err(dev, "failed to get clock resources, error %d\n", ret);
> +		return -ENODEV;
> +	}
>  
> -	/* address translation is up; safe to enable interrupts */
> -	return mc_init_interrupts(pdev, port);
> +	return pci_host_common_probe(pdev);
>  }
>  
>  static const struct pci_ecam_ops mc_ecam_ops = {
> @@ -1168,7 +1189,7 @@ static const struct of_device_id mc_pcie_of_match[] = {
>  MODULE_DEVICE_TABLE(of, mc_pcie_of_match);
>  
>  static struct platform_driver mc_pcie_driver = {
> -	.probe = pci_host_common_probe,
> +	.probe = mc_host_probe,
>  	.driver = {
>  		.name = "microchip-pcie",
>  		.of_match_table = mc_pcie_of_match,
> -- 
> 2.25.1
> 
> 
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