Re: [RFC PATCH v9 04/11] cxl/mbox: Add GET_SUPPORTED_FEATURES mailbox command

[nifan . cxl]

On Tue, Jul 16, 2024 at 04:03:28PM +0100, shiju.jose@xxxxxxxxxx wrote:
> From: Shiju Jose <shiju.jose@xxxxxxxxxx>
> 
> Add support for GET_SUPPORTED_FEATURES mailbox command.
> 
> CXL spec 3.1 section 8.2.9.6 describes optional device specific features.
> CXL devices supports features with changeable attributes.
s/supports/support/

Fan
> Get Supported Features retrieves the list of supported device specific
> features. The settings of a feature can be retrieved using Get Feature
> and optionally modified using Set Feature.
> 
> Signed-off-by: Shiju Jose <shiju.jose@xxxxxxxxxx>
> ---
>  drivers/cxl/core/mbox.c | 27 ++++++++++++++++++
>  drivers/cxl/cxlmem.h    | 61 +++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 88 insertions(+)
> 
> diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
> index 2626f3fff201..9b9b1d26454e 100644
> --- a/drivers/cxl/core/mbox.c
> +++ b/drivers/cxl/core/mbox.c
> @@ -1324,6 +1324,33 @@ int cxl_set_timestamp(struct cxl_memdev_state *mds)
>  }
>  EXPORT_SYMBOL_NS_GPL(cxl_set_timestamp, CXL);
>  
> +int cxl_get_supported_features(struct cxl_memdev_state *mds,
> +			       u32 count, u16 start_index,
> +			       struct cxl_mbox_get_supp_feats_out *feats_out)
> +{
> +	struct cxl_mbox_get_supp_feats_in pi;
> +	struct cxl_mbox_cmd mbox_cmd;
> +	int rc;
> +
> +	pi.count = cpu_to_le32(count);
> +	pi.start_index = cpu_to_le16(start_index);
> +
> +	mbox_cmd = (struct cxl_mbox_cmd) {
> +		.opcode = CXL_MBOX_OP_GET_SUPPORTED_FEATURES,
> +		.size_in = sizeof(pi),
> +		.payload_in = &pi,
> +		.size_out = count,
> +		.payload_out = feats_out,
> +		.min_out = sizeof(*feats_out),
> +	};
> +	rc = cxl_internal_send_cmd(mds, &mbox_cmd);
> +	if (rc < 0)
> +		return rc;
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_NS_GPL(cxl_get_supported_features, CXL);
> +
>  int cxl_mem_get_poison(struct cxl_memdev *cxlmd, u64 offset, u64 len,
>  		       struct cxl_region *cxlr)
>  {
> diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
> index 19aba81cdf13..b0e1565b9d2e 100644
> --- a/drivers/cxl/cxlmem.h
> +++ b/drivers/cxl/cxlmem.h
> @@ -530,6 +530,7 @@ enum cxl_opcode {
>  	CXL_MBOX_OP_GET_LOG_CAPS	= 0x0402,
>  	CXL_MBOX_OP_CLEAR_LOG           = 0x0403,
>  	CXL_MBOX_OP_GET_SUP_LOG_SUBLIST = 0x0405,
> +	CXL_MBOX_OP_GET_SUPPORTED_FEATURES	= 0x0500,
>  	CXL_MBOX_OP_IDENTIFY		= 0x4000,
>  	CXL_MBOX_OP_GET_PARTITION_INFO	= 0x4100,
>  	CXL_MBOX_OP_SET_PARTITION_INFO	= 0x4101,
> @@ -699,6 +700,63 @@ struct cxl_mbox_set_timestamp_in {
>  
>  } __packed;
>  
> +/*
> + * Get Supported Features CXL 3.1 Spec 8.2.9.6.1
> + */
> +
> +/*
> + * Get Supported Features input payload
> + * CXL rev 3.1 section 8.2.9.6.1 Table 8-95
> + */
> +struct cxl_mbox_get_supp_feats_in {
> +	__le32 count;
> +	__le16 start_index;
> +	u8 rsvd[2];
> +} __packed;
> +
> +/*
> + * Get Supported Features Supported Feature Entry
> + * CXL rev 3.1 section 8.2.9.6.1 Table 8-97
> + */
> +/* Supported Feature Entry : Payload out attribute flags */
> +#define CXL_FEAT_ENTRY_FLAG_CHANGABLE	BIT(0)
> +#define CXL_FEAT_ENTRY_FLAG_DEEPEST_RESET_PERSISTENCE_MASK	GENMASK(3, 1)
> +#define CXL_FEAT_ENTRY_FLAG_PERSIST_ACROSS_FIRMWARE_UPDATE	BIT(4)
> +#define CXL_FEAT_ENTRY_FLAG_SUPPORT_DEFAULT_SELECTION	BIT(5)
> +#define CXL_FEAT_ENTRY_FLAG_SUPPORT_SAVED_SELECTION	BIT(6)
> +
> +enum cxl_feat_attr_value_persistence {
> +	CXL_FEAT_ATTR_VALUE_PERSISTENCE_NONE,
> +	CXL_FEAT_ATTR_VALUE_PERSISTENCE_CXL_RESET,
> +	CXL_FEAT_ATTR_VALUE_PERSISTENCE_HOT_RESET,
> +	CXL_FEAT_ATTR_VALUE_PERSISTENCE_WARM_RESET,
> +	CXL_FEAT_ATTR_VALUE_PERSISTENCE_COLD_RESET,
> +	CXL_FEAT_ATTR_VALUE_PERSISTENCE_MAX
> +};
> +
> +struct cxl_mbox_supp_feat_entry {
> +	uuid_t uuid;
> +	__le16 index;
> +	__le16 get_size;
> +	__le16 set_size;
> +	__le32 attr_flags;
> +	u8 get_version;
> +	u8 set_version;
> +	__le16 set_effects;
> +	u8 rsvd[18];
> +}  __packed;
> +
> +/*
> + * Get Supported Features output payload
> + * CXL rev 3.1 section 8.2.9.6.1 Table 8-96
> + */
> +struct cxl_mbox_get_supp_feats_out {
> +	__le16 nr_entries;
> +	__le16 nr_supported;
> +	u8 rsvd[4];
> +	struct cxl_mbox_supp_feat_entry feat_entries[];
> +} __packed;
> +
>  /* Get Poison List  CXL 3.0 Spec 8.2.9.8.4.1 */
>  struct cxl_mbox_poison_in {
>  	__le64 offset;
> @@ -830,6 +888,9 @@ void cxl_event_trace_record(const struct cxl_memdev *cxlmd,
>  			    enum cxl_event_type event_type,
>  			    const uuid_t *uuid, union cxl_event *evt);
>  int cxl_set_timestamp(struct cxl_memdev_state *mds);
> +int cxl_get_supported_features(struct cxl_memdev_state *mds,
> +			       u32 count, u16 start_index,
> +			       struct cxl_mbox_get_supp_feats_out *feats_out);
>  int cxl_poison_state_init(struct cxl_memdev_state *mds);
>  int cxl_mem_get_poison(struct cxl_memdev *cxlmd, u64 offset, u64 len,
>  		       struct cxl_region *cxlr);
> -- 
> 2.34.1
>