Re: [PATCH v2 1/3] cxl: support Type2 when initializing cxl_dev_state

[Jonathan Cameron <jonathan.cameron@huawei.com>]

On Wed, 25 Feb 2026 12:14:28 +0000
alejandro.lucero-palau@amd.com wrote:

> From: Alejandro Lucero <alucerop@amd.com>
> 
> In preparation for type2 drivers add function and macro for
> differentiating CXL memory expanders (type 3) from CXL device
> accelerators (type 2) helping accel drivers to embed cxl_dev_state

Slight preference for 

"to embed struct cxl_dev_state"

> inside a private struct.
I'd be tempted to call this "a driver specific structure".

private is a little too much of a guide to how this 'might' be used
in the long run.

> 
> Update type3 driver for using this same initialization.
> 
> Signed-off-by: Alejandro Lucero <alucerop@amd.com>
> Reviewed-by: Dave Jiang <dave.jiang@intel.com>
> Reviewed-by: Alison Schofield <alison.schofield@intel.com>

One minor wording comment below.

Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>

> diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
> index e21d744d639b..9daf4bc42692 100644
> --- a/drivers/cxl/cxlmem.h
> +++ b/drivers/cxl/cxlmem.h
> @@ -523,6 +523,37 @@ to_cxl_memdev_state(struct cxl_dev_state *cxlds)
>  	return container_of(cxlds, struct cxl_memdev_state, cxlds);
>  }
>  
> +struct cxl_dev_state *_devm_cxl_dev_state_create(struct device *dev,
> +						 enum cxl_devtype type,
> +						 u64 serial, u16 dvsec,
> +						 size_t size, bool has_mbox);
> +
> +/**
> + * cxl_dev_state_create - safely create and cast a cxl dev state embedded in a
> + * driver specific struct.
> + *
> + * @parent: device behind the request
> + * @type: CXL device type
> + * @serial: device identification
> + * @dvsec: dvsec capability offset
> + * @drv_struct: driver struct embedding a cxl_dev_state struct
> + * @member: drv_struct member as cxl_dev_state

 * @member: name of the struct cxl_dev_state member in drv_struct

("as" to me implies a cast, which had me briefly confused).

> + * @mbox: true if mailbox supported
> + *
> + * Returns a pointer to the drv_struct allocated and embedding a cxl_dev_state
> + * struct initialized.
> + *
> + * Introduced for Type2 driver support.
> + */
> +#define devm_cxl_dev_state_create(parent, type, serial, dvsec, drv_struct, member, mbox)	\
> +	({										\
> +		static_assert(__same_type(struct cxl_dev_state,				\
> +			      ((drv_struct *)NULL)->member));				\
> +		static_assert(offsetof(drv_struct, member) == 0);			\
> +		(drv_struct *)_devm_cxl_dev_state_create(parent, type, serial, dvsec,	\
> +						      sizeof(drv_struct), mbox);	\
> +	})
> +