Re: [PATCH v15 12/15] cxl/mbox: Add support for PERFORM_MAINTENANCE mailbox command

[Dave Jiang <dave.jiang@intel.com>]

On 11/1/24 2:17 AM, shiju.jose@huawei.com wrote:
> From: Shiju Jose <shiju.jose@huawei.com>
> 
> Add support for PERFORM_MAINTENANCE mailbox command.
> 
> CXL spec 3.1 section 8.2.9.7.1 describes the Perform Maintenance command.
> This command requests the device to execute the maintenance operation
> specified by the maintenance operation class and the maintenance operation
> subclass.
> 
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Signed-off-by: Shiju Jose <shiju.jose@huawei.com>

Reviewed-by: Dave Jiang <dave.jiang@intel.com>

> ---
>  drivers/cxl/core/mbox.c | 35 +++++++++++++++++++++++++++++++++++
>  drivers/cxl/cxlmem.h    | 17 +++++++++++++++++
>  2 files changed, 52 insertions(+)
> 
> diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
> index 4b9e62de164b..381cf9d61c85 100644
> --- a/drivers/cxl/core/mbox.c
> +++ b/drivers/cxl/core/mbox.c
> @@ -1084,6 +1084,41 @@ int cxl_set_feature(struct cxl_memdev_state *mds,
>  }
>  EXPORT_SYMBOL_NS_GPL(cxl_set_feature, CXL);
>  
> +int cxl_do_maintenance(struct cxl_memdev_state *mds,
> +		       u8 class, u8 subclass,
> +		       void *data_in, size_t data_in_size)
> +{
> +	struct cxl_mailbox *cxl_mbox = &mds->cxlds.cxl_mbox;
> +	struct cxl_memdev_maintenance_pi {
> +		struct cxl_mbox_do_maintenance_hdr hdr;
> +		u8 data[];
> +	}  __packed;
> +	struct cxl_mbox_cmd mbox_cmd;
> +	size_t hdr_size;
> +
> +	struct cxl_memdev_maintenance_pi *pi __free(kfree) =
> +					kmalloc(cxl_mbox->payload_size, GFP_KERNEL);
> +	pi->hdr.op_class = class;
> +	pi->hdr.op_subclass = subclass;
> +	hdr_size = sizeof(pi->hdr);
> +	/*
> +	 * Check minimum mbox payload size is available for
> +	 * the maintenance data transfer.
> +	 */
> +	if (hdr_size + data_in_size > cxl_mbox->payload_size)
> +		return -ENOMEM;
> +
> +	memcpy(pi->data, data_in, data_in_size);
> +	mbox_cmd = (struct cxl_mbox_cmd) {
> +		.opcode = CXL_MBOX_OP_DO_MAINTENANCE,
> +		.size_in = hdr_size + data_in_size,
> +		.payload_in = pi,
> +	};
> +
> +	return cxl_internal_send_cmd(cxl_mbox, &mbox_cmd);
> +}
> +EXPORT_SYMBOL_NS_GPL(cxl_do_maintenance, CXL);
> +
>  /**
>   * cxl_enumerate_cmds() - Enumerate commands for a device.
>   * @mds: The driver data for the operation
> diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
> index 9259c5d70a65..28290f7c89f7 100644
> --- a/drivers/cxl/cxlmem.h
> +++ b/drivers/cxl/cxlmem.h
> @@ -533,6 +533,7 @@ enum cxl_opcode {
>  	CXL_MBOX_OP_GET_SUPPORTED_FEATURES	= 0x0500,
>  	CXL_MBOX_OP_GET_FEATURE		= 0x0501,
>  	CXL_MBOX_OP_SET_FEATURE		= 0x0502,
> +	CXL_MBOX_OP_DO_MAINTENANCE	= 0x0600,
>  	CXL_MBOX_OP_IDENTIFY		= 0x4000,
>  	CXL_MBOX_OP_GET_PARTITION_INFO	= 0x4100,
>  	CXL_MBOX_OP_SET_PARTITION_INFO	= 0x4101,
> @@ -909,6 +910,19 @@ struct cxl_mbox_set_feat_hdr {
>  	u8 rsvd[9];
>  }  __packed;
>  
> +/*
> + * Perform Maintenance CXL 3.1 Spec 8.2.9.7.1
> + */
> +
> +/*
> + * Perform Maintenance input payload
> + * CXL rev 3.1 section 8.2.9.7.1 Table 8-102
> + */
> +struct cxl_mbox_do_maintenance_hdr {
> +	u8 op_class;
> +	u8 op_subclass;
> +}  __packed;
> +
>  int cxl_internal_send_cmd(struct cxl_mailbox *cxl_mbox,
>  			  struct cxl_mbox_cmd *cmd);
>  int cxl_dev_state_identify(struct cxl_memdev_state *mds);
> @@ -986,4 +1000,7 @@ int cxl_set_feature(struct cxl_memdev_state *mds,
>  		    const uuid_t feat_uuid, u8 feat_version,
>  		    void *feat_data, size_t feat_data_size,
>  		    u8 feat_flag);
> +int cxl_do_maintenance(struct cxl_memdev_state *mds,
> +		       u8 class, u8 subclass,
> +		       void *data_in, size_t data_in_size);
>  #endif /* __CXL_MEM_H__ */