[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [PATCH v8 5/7] xen/asm-generic: introduce generic device.h
Hi Oleksii, On 15/02/2024 16:54, Oleksii wrote: On 14/02/2024 09:32, Oleksii wrote:On Tue, 2024-02-13 at 18:09 +0000, Julien Grall wrote:+#ifdef CONFIG_HAS_PASSTHROUGH + struct iommu_fwspec *iommu_fwspec; /* per-device IOMMU instance data */ +#endif +}; + +typedef struct device device_t; + +#ifdef CONFIG_HAS_DEVICE_TREE + +#include <xen/device_tree.h> + +#define dev_is_dt(dev) ((dev)->type == DEV_DT) + +/** + * device_init - Initialize a device + * @dev: device to initialize + * @class: class of the device (serial, network...) + * @data: specific data for initializing the device + * + * Return 0 on success. + */ +int device_init(struct dt_device_node *dev, enum device_class class, + const void *data); + +/** + * device_get_type - Get the type of the device + * @dev: device to match + * + * Return the device type on success or DEVICE_ANY on failure + */ +enum device_class device_get_class(const struct dt_device_node *dev); + +#define DT_DEVICE_START(name_, namestr_, class_) \ +static const struct device_desc __dev_desc_##name_ __used \ +__section(".dev.info") = { \ + .name = namestr_, \ + .class = class_, + +#define DT_DEVICE_END \ +}; + +#else /* !CONFIG_HAS_DEVICE_TREE */ +#define dev_is_dt(dev) ((void)(dev), false) +#endif /* CONFIG_HAS_DEVICE_TREE */ + +#define dev_is_pci(dev) ((dev)->type == DEV_PCI) + +struct device_desc { + /* Device name */ + const char *name; + /* Device class */ + enum device_class class; + +#ifdef CONFIG_HAS_DEVICE_TREE + + /* List of devices supported by this driver */ + const struct dt_device_match *dt_match; + /* + * Device initialization. + * + * -EAGAIN is used to indicate that device probing is deferred. + */ + int (*init)(struct dt_device_node *dev, const void *data); + +#endif +};I am not sure I fully understand why "device_desc" is not protected by CONFIG_HAS_DEVICE_TREE. The structure doesn't mean much when the config is disabled. Can you clarify?I thought that one day struct device_desc and acpi_device_desc will be "merged", and so decided just to #ifdef only DEVICE_TREE specific fields.It might be possible to merge the two if we were using an union for the ACPI/DT specific part. However the majority of the parsing code needs to differ. So I am not convinced there would be any value to merge the two structures.In this case, let's have two separate structures. This is not the current situation, and I don't have a specific example. It appears that all architectures will use Device Tree or ACPI. However, does it make sense to keep 'struct device_desc' more generic to accommodate non-DT or non-ACPI cases? I am not entirely sure what else to say. As I wrote before yes it could be made generic. But right now I don't see any values. If you have any idea how to share the structure. Then feel free to make a proposal and I will review it. Cheers, -- Julien Grall
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