Re: [PATCH V2 7/7] PCI: host-generic: Add dwc PCIe controller based MSI controller usage

[Will Deacon <will@kernel.org>]

On Mon, Jul 15, 2024 at 11:13:35AM -0700, Mayank Rana wrote:
> Add usage of Synopsys Designware PCIe controller based MSI controller to
> support MSI functionality with ECAM compliant Synopsys Designware PCIe
> controller. To use this functionality add device compatible string as
> "snps,dw-pcie-ecam-msi".
> 
> Signed-off-by: Mayank Rana <quic_mrana@quicinc.com>
> ---
>  drivers/pci/controller/pci-host-generic.c | 92 ++++++++++++++++++++++++++++++-
>  1 file changed, 91 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/controller/pci-host-generic.c b/drivers/pci/controller/pci-host-generic.c
> index c2c027f..457ae44 100644
> --- a/drivers/pci/controller/pci-host-generic.c
> +++ b/drivers/pci/controller/pci-host-generic.c
> @@ -8,13 +8,73 @@
>   * Author: Will Deacon <will.deacon@arm.com>
>   */
>  
> -#include <linux/kernel.h>
>  #include <linux/init.h>
> +#include <linux/kernel.h>
>  #include <linux/module.h>
> +#include <linux/of_address.h>
>  #include <linux/pci-ecam.h>
>  #include <linux/platform_device.h>
>  #include <linux/pm_runtime.h>
>  
> +#include "dwc/pcie-designware-msi.h"
> +
> +struct dw_ecam_pcie {
> +	void __iomem *cfg;
> +	struct dw_msi *msi;
> +	struct pci_host_bridge *bridge;
> +};
> +
> +static u32 dw_ecam_pcie_readl(void *p_data, u32 reg)
> +{
> +	struct dw_ecam_pcie *ecam_pcie = (struct dw_ecam_pcie *)p_data;
> +
> +	return readl(ecam_pcie->cfg + reg);
> +}
> +
> +static void dw_ecam_pcie_writel(void *p_data, u32 reg, u32 val)
> +{
> +	struct dw_ecam_pcie *ecam_pcie = (struct dw_ecam_pcie *)p_data;
> +
> +	writel(val, ecam_pcie->cfg + reg);
> +}
> +
> +static struct dw_ecam_pcie *dw_pcie_ecam_msi(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct dw_ecam_pcie *ecam_pcie;
> +	struct dw_msi_ops *msi_ops;
> +	u64 addr;
> +
> +	ecam_pcie = devm_kzalloc(dev, sizeof(*ecam_pcie), GFP_KERNEL);
> +	if (!ecam_pcie)
> +		return ERR_PTR(-ENOMEM);
> +
> +	if (of_property_read_reg(dev->of_node, 0, &addr, NULL) < 0) {
> +		dev_err(dev, "Failed to get reg address\n");
> +		return ERR_PTR(-ENODEV);
> +	}
> +
> +	ecam_pcie->cfg = devm_ioremap(dev, addr, PAGE_SIZE);
> +	if (ecam_pcie->cfg == NULL)
> +		return ERR_PTR(-ENOMEM);
> +
> +	msi_ops = devm_kzalloc(dev, sizeof(*msi_ops), GFP_KERNEL);
> +	if (!msi_ops)
> +		return ERR_PTR(-ENOMEM);
> +
> +	msi_ops->readl_msi = dw_ecam_pcie_readl;
> +	msi_ops->writel_msi = dw_ecam_pcie_writel;
> +	msi_ops->pp = ecam_pcie;
> +	ecam_pcie->msi = dw_pcie_msi_host_init(pdev, msi_ops, 0);
> +	if (IS_ERR(ecam_pcie->msi)) {
> +		dev_err(dev, "dw_pcie_msi_host_init() failed\n");
> +		return ERR_PTR(-EINVAL);
> +	}
> +
> +	dw_pcie_msi_init(ecam_pcie->msi);
> +	return ecam_pcie;
> +}

Hmm. This looks like quite a lot of not-very-generic code to be adding
to pci-host-generic.c. The file is now, what, 50% designware logic?

Will