[PATCH 01/11] RISC-V: drivers/iommu: Add RISC-V IOMMU - Ziommu support.

[Baolu Lu]

On 2023/7/20 3:33, Tomasz Jeznach wrote:
> +struct riscv_iommu_domain {
> +	struct iommu_domain domain;
> +
> +	struct list_head endpoints;
> +	struct mutex lock;
> +	struct riscv_iommu_device *iommu;

How are domains and iommu devices connected? A domain can be attached to
multiple devices, which are possibly behind different iommu devices. So
a domain is possibly connected to multiple iommu devices.

Is it possible?

> +
> +	unsigned mode;		/* RIO_ATP_MODE_* enum */
> +	unsigned pscid;		/* RISC-V IOMMU PSCID */
> +
> +	pgd_t *pgd_root;	/* page table root pointer */
> +};
> +
> +/* Private dev_iommu_priv object, device-domain relationship. */
> +struct riscv_iommu_endpoint {
> +	struct device *dev;			/* platform or PCI endpoint device */
> +	unsigned devid;      			/* PCI bus:device:function number */
> +	unsigned domid;    			/* PCI domain number, segment */
> +	struct rb_node node;    		/* device tracking node (lookup by devid) */
> +	struct riscv_iommu_device *iommu;	/* parent iommu device */
> +
> +	struct mutex lock;
> +	struct list_head domain;		/* endpoint attached managed domain */
> +};

Best regards,
baolu