Re: [PATCH v2 7/9] PCI: apple: Convert to MSI parent infrastructure

[Alyssa Rosenzweig <alyssa@rosenzweig.io>]

Acked-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>

Le Tue , May 13, 2025 at 06:28:17PM +0100, Marc Zyngier a écrit :
> In an effort to move arm64 away from the legacy MSI setup,
> convert the apple PCIe driver to the MSI-parent infrastructure
> and let each device have its own MSI domain.
> 
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
>  drivers/pci/controller/Kconfig      |  1 +
>  drivers/pci/controller/pcie-apple.c | 62 ++++++++++-------------------
>  2 files changed, 22 insertions(+), 41 deletions(-)
> 
> diff --git a/drivers/pci/controller/Kconfig b/drivers/pci/controller/Kconfig
> index 9800b76810540..98a62f4559dfd 100644
> --- a/drivers/pci/controller/Kconfig
> +++ b/drivers/pci/controller/Kconfig
> @@ -40,6 +40,7 @@ config PCIE_APPLE
>  	depends on OF
>  	depends on PCI_MSI
>  	select PCI_HOST_COMMON
> +	select IRQ_MSI_LIB
>  	help
>  	  Say Y here if you want to enable PCIe controller support on Apple
>  	  system-on-chips, like the Apple M1. This is required for the USB
> diff --git a/drivers/pci/controller/pcie-apple.c b/drivers/pci/controller/pcie-apple.c
> index 18e11b9a7f464..6c88b4dd34151 100644
> --- a/drivers/pci/controller/pcie-apple.c
> +++ b/drivers/pci/controller/pcie-apple.c
> @@ -22,6 +22,7 @@
>  #include <linux/kernel.h>
>  #include <linux/iopoll.h>
>  #include <linux/irqchip/chained_irq.h>
> +#include <linux/irqchip/irq-msi-lib.h>
>  #include <linux/irqdomain.h>
>  #include <linux/list.h>
>  #include <linux/module.h>
> @@ -133,7 +134,6 @@ struct apple_pcie {
>  	struct mutex		lock;
>  	struct device		*dev;
>  	void __iomem            *base;
> -	struct irq_domain	*domain;
>  	unsigned long		*bitmap;
>  	struct list_head	ports;
>  	struct completion	event;
> @@ -162,27 +162,6 @@ static void rmw_clear(u32 clr, void __iomem *addr)
>  	writel_relaxed(readl_relaxed(addr) & ~clr, addr);
>  }
>  
> -static void apple_msi_top_irq_mask(struct irq_data *d)
> -{
> -	pci_msi_mask_irq(d);
> -	irq_chip_mask_parent(d);
> -}
> -
> -static void apple_msi_top_irq_unmask(struct irq_data *d)
> -{
> -	pci_msi_unmask_irq(d);
> -	irq_chip_unmask_parent(d);
> -}
> -
> -static struct irq_chip apple_msi_top_chip = {
> -	.name			= "PCIe MSI",
> -	.irq_mask		= apple_msi_top_irq_mask,
> -	.irq_unmask		= apple_msi_top_irq_unmask,
> -	.irq_eoi		= irq_chip_eoi_parent,
> -	.irq_set_affinity	= irq_chip_set_affinity_parent,
> -	.irq_set_type		= irq_chip_set_type_parent,
> -};
> -
>  static void apple_msi_compose_msg(struct irq_data *data, struct msi_msg *msg)
>  {
>  	msg->address_hi = upper_32_bits(DOORBELL_ADDR);
> @@ -226,8 +205,7 @@ static int apple_msi_domain_alloc(struct irq_domain *domain, unsigned int virq,
>  
>  	for (i = 0; i < nr_irqs; i++) {
>  		irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
> -					      &apple_msi_bottom_chip,
> -					      domain->host_data);
> +					      &apple_msi_bottom_chip, pcie);
>  	}
>  
>  	return 0;
> @@ -251,12 +229,6 @@ static const struct irq_domain_ops apple_msi_domain_ops = {
>  	.free	= apple_msi_domain_free,
>  };
>  
> -static struct msi_domain_info apple_msi_info = {
> -	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
> -		   MSI_FLAG_MULTI_PCI_MSI | MSI_FLAG_PCI_MSIX),
> -	.chip	= &apple_msi_top_chip,
> -};
> -
>  static void apple_port_irq_mask(struct irq_data *data)
>  {
>  	struct apple_pcie_port *port = irq_data_get_irq_chip_data(data);
> @@ -595,6 +567,18 @@ static int apple_pcie_setup_port(struct apple_pcie *pcie,
>  	return 0;
>  }
>  
> +static const struct msi_parent_ops apple_msi_parent_ops = {
> +	.supported_flags	= (MSI_GENERIC_FLAGS_MASK	|
> +				   MSI_FLAG_PCI_MSIX		|
> +				   MSI_FLAG_MULTI_PCI_MSI),
> +	.required_flags		= (MSI_FLAG_USE_DEF_DOM_OPS	|
> +				   MSI_FLAG_USE_DEF_CHIP_OPS	|
> +				   MSI_FLAG_PCI_MSI_MASK_PARENT),
> +	.chip_flags		= MSI_CHIP_FLAG_SET_EOI,
> +	.bus_select_token	= DOMAIN_BUS_PCI_MSI,
> +	.init_dev_msi_info	= msi_lib_init_dev_msi_info,
> +};
> +
>  static int apple_msi_init(struct apple_pcie *pcie)
>  {
>  	struct fwnode_handle *fwnode = dev_fwnode(pcie->dev);
> @@ -625,21 +609,17 @@ static int apple_msi_init(struct apple_pcie *pcie)
>  		return -ENXIO;
>  	}
>  
> -	parent = irq_domain_create_hierarchy(parent, 0, pcie->nvecs, fwnode,
> -					     &apple_msi_domain_ops, pcie);
> +	parent = msi_create_parent_irq_domain(&(struct irq_domain_info){
> +			.fwnode		= fwnode,
> +			.ops		= &apple_msi_domain_ops,
> +			.size		= pcie->nvecs,
> +			.host_data	= pcie,
> +			.parent		= parent,
> +		}, &apple_msi_parent_ops);
>  	if (!parent) {
>  		dev_err(pcie->dev, "failed to create IRQ domain\n");
>  		return -ENOMEM;
>  	}
> -	irq_domain_update_bus_token(parent, DOMAIN_BUS_NEXUS);
> -
> -	pcie->domain = pci_msi_create_irq_domain(fwnode, &apple_msi_info,
> -						 parent);
> -	if (!pcie->domain) {
> -		dev_err(pcie->dev, "failed to create MSI domain\n");
> -		irq_domain_remove(parent);
> -		return -ENOMEM;
> -	}
>  
>  	return 0;
>  }
> -- 
> 2.39.2
>