Re: [RFC PATCH 1/6] cxl/mbox: Add GET_SUPPORTED_FEATURES, GET_FEATURE and SET_FEATURE mailbox commands
From: Dave Jiang
Date: Wed Nov 15 2023 - 13:21:16 EST
On 11/14/23 05:56, shiju.jose@xxxxxxxxxx wrote:
> From: Shiju Jose <shiju.jose@xxxxxxxxxx>
>
> Add support for GET_SUPPORTED_FEATURES, GET_FEATURE and SET_FEATURE mailbox
> commands.
>
> CXL spec 3.0 section 8.2.9.6 describes optional device specific features.
> CXL devices supports features with changeable attributes.
> 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.
Maybe split this patch out into 3 for each of the individual commands you are enabling. That'll make git bisect easier for debugging.
A few nits but the rest LGTM.
>
> Signed-off-by: Shiju Jose <shiju.jose@xxxxxxxxxx>
> ---
> drivers/cxl/core/mbox.c | 74 ++++++++++++++++++++++++++++
> drivers/cxl/cxlmem.h | 95 ++++++++++++++++++++++++++++++++++++
> include/uapi/linux/cxl_mem.h | 3 ++
> 3 files changed, 172 insertions(+)
>
> diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
> index 36270dcfb42e..2a6d8ab927bd 100644
> --- a/drivers/cxl/core/mbox.c
> +++ b/drivers/cxl/core/mbox.c
> @@ -63,6 +63,9 @@ static struct cxl_mem_command cxl_mem_commands[CXL_MEM_COMMAND_ID_MAX] = {
> CXL_CMD(GET_SHUTDOWN_STATE, 0, 0x1, 0),
> CXL_CMD(SET_SHUTDOWN_STATE, 0x1, 0, 0),
> CXL_CMD(GET_SCAN_MEDIA_CAPS, 0x10, 0x4, 0),
> + CXL_CMD(GET_SUPPORTED_FEATURES, 0x8, CXL_VARIABLE_PAYLOAD, 0),
> + CXL_CMD(GET_FEATURE, 0x15, CXL_VARIABLE_PAYLOAD, 0),
> + CXL_CMD(SET_FEATURE, CXL_VARIABLE_PAYLOAD, 0, 0),
> };
>
> /*
> @@ -1303,6 +1306,77 @@ int cxl_set_timestamp(struct cxl_memdev_state *mds)
> }
> EXPORT_SYMBOL_NS_GPL(cxl_set_timestamp, CXL);
>
> +struct cxl_mbox_get_supp_feats_out *cxl_get_supported_features(struct cxl_memdev_state *mds,
> + struct cxl_mbox_get_supp_feats_in *pi)
> +{
> + int rc;
> + struct cxl_mbox_cmd mbox_cmd;
> + struct cxl_mbox_get_supp_feats_out *feats_out;
reverse xmas tree declarations
> +
> + feats_out = kvmalloc(pi->count, GFP_KERNEL);
> + if (!feats_out)
> + return ERR_PTR(-ENOMEM);
> +
> + mbox_cmd = (struct cxl_mbox_cmd) {
> + .opcode = CXL_MBOX_OP_GET_SUPPORTED_FEATURES,
> + .size_in = sizeof(*pi),
> + .payload_in = pi,
> + .size_out = pi->count,
> + .payload_out = feats_out,
> + .min_out = sizeof(struct cxl_mbox_get_supp_feats_out),
> + };
> + rc = cxl_internal_send_cmd(mds, &mbox_cmd);
> + if (rc < 0) {
> + kvfree(feats_out);
> + return ERR_PTR(rc);
> + }
> +
> + return feats_out;
> +}
> +EXPORT_SYMBOL_NS_GPL(cxl_get_supported_features, CXL);
> +
> +void *cxl_get_feature(struct cxl_memdev_state *mds, struct cxl_mbox_get_feat_in *pi)
> +{
> + int rc;
> + void *feat_out;
> + struct cxl_mbox_cmd mbox_cmd;
reverse xmas tree declarations
> +
> + feat_out = kvmalloc(pi->count, GFP_KERNEL);
> + if (!feat_out)
> + return ERR_PTR(-ENOMEM);
> +
> + mbox_cmd = (struct cxl_mbox_cmd) {
> + .opcode = CXL_MBOX_OP_GET_FEATURE,
> + .size_in = sizeof(*pi),
> + .payload_in = pi,
> + .size_out = pi->count,
> + .payload_out = feat_out,
> + .min_out = pi->count,
> + };
> + rc = cxl_internal_send_cmd(mds, &mbox_cmd);
> + if (rc < 0) {
> + kvfree(feat_out);
> + return ERR_PTR(rc);
> + }
> +
> + return feat_out;
> +}
> +EXPORT_SYMBOL_NS_GPL(cxl_get_feature, CXL);
> +
> +int cxl_set_feature(struct cxl_memdev_state *mds, void *feat_in, size_t size)
> +{
> + struct cxl_mbox_cmd mbox_cmd;
> +
> + mbox_cmd = (struct cxl_mbox_cmd) {
> + .opcode = CXL_MBOX_OP_SET_FEATURE,
> + .size_in = size,
> + .payload_in = feat_in,
> + };
> +
> + return cxl_internal_send_cmd(mds, &mbox_cmd);
> +}
> +EXPORT_SYMBOL_NS_GPL(cxl_set_feature, 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 a2fcbca253f3..fdac686560d4 100644
> --- a/drivers/cxl/cxlmem.h
> +++ b/drivers/cxl/cxlmem.h
> @@ -506,6 +506,9 @@ enum cxl_opcode {
> CXL_MBOX_OP_SET_TIMESTAMP = 0x0301,
> CXL_MBOX_OP_GET_SUPPORTED_LOGS = 0x0400,
> CXL_MBOX_OP_GET_LOG = 0x0401,
> + CXL_MBOX_OP_GET_SUPPORTED_FEATURES = 0x0500,
> + CXL_MBOX_OP_GET_FEATURE = 0x0501,
> + CXL_MBOX_OP_SET_FEATURE = 0x0502,
> CXL_MBOX_OP_IDENTIFY = 0x4000,
> CXL_MBOX_OP_GET_PARTITION_INFO = 0x4100,
> CXL_MBOX_OP_SET_PARTITION_INFO = 0x4101,
> @@ -740,6 +743,94 @@ struct cxl_mbox_set_timestamp_in {
>
> } __packed;
>
> +/* Get Supported Features CXL 3.0 Spec 8.2.9.6.1 */
> +/*
> + * Get Supported Features input payload
> + * CXL rev 3.0 section 8.2.9.6.1; Table 8-75
> + */
> +struct cxl_mbox_get_supp_feats_in {
> + __le32 count;
> + __le16 start_index;
> + u16 reserved;
> +} __packed;
> +
> +/*
> + * Get Supported Features Supported Feature Entry
> + * CXL rev 3.0 section 8.2.9.6.1; Table 8-77
> + */
> +/* 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_DEEPEST_RESET_PERSISTENCE_NONE 0x0
> +#define CXL_FEAT_ENTRY_FLAG_DEEPEST_RESET_PERSISTENCE_CXL_RESET 0x1
> +#define CXL_FEAT_ENTRY_FLAG_DEEPEST_RESET_PERSISTENCE_HOT_RESET 0x2
> +#define CXL_FEAT_ENTRY_FLAG_DEEPEST_RESET_PERSISTENCE_WARM_RESET 0x3
> +#define CXL_FEAT_ENTRY_FLAG_DEEPEST_RESET_PERSISTENCE_COLD_RESET 0x4
I think you can declare the flags as enums?
> +#define CXL_FEAT_ENTRY_FLAG_PERSISTENCE_ACROSS_FW_UPDATE_MASK BIT(4)
> +#define CXL_FEAT_ENTRY_FLAG_PERSISTENCE_DEFAULT_SEL_SUPPORT_MASK BIT(5)
> +#define CXL_FEAT_ENTRY_FLAG_PERSISTENCE_SAVED_SEL_SUPPORT_MASK BIT(6)
> +
> +struct cxl_mbox_supp_feat_entry {
> + uuid_t uuid;
> + __le16 feat_index;
> + __le16 get_feat_size;
> + __le16 set_feat_size;
> + __le32 attrb_flags;
> + u8 get_feat_version;
> + u8 set_feat_version;
> + __le16 set_feat_effects;
> + u8 rsvd[18];
> +} __packed;
> +
> +/*
> + * Get Supported Features output payload
> + * CXL rev 3.0 section 8.2.9.6.1; Table 8-76
> + */
> +struct cxl_mbox_get_supp_feats_out {
> + __le16 entries;
> + __le16 nsuppfeats_dev;
> + u32 reserved;
> + struct cxl_mbox_supp_feat_entry feat_entries[];
> +} __packed;
> +
> +/* Get Feature CXL 3.0 Spec 8.2.9.6.2 */
> +/*
> + * Get Feature input payload
> + * CXL rev 3.0 section 8.2.9.6.2; Table 8-79
> + */
> +/* Get Feature : Payload in selection */
> +#define CXL_GET_FEAT_CURRENT_VALUE 0x00
> +#define CXL_GET_FEAT_DEFAULT_VALUE 0x01
> +#define CXL_GET_FEAT_SAVED_VALUE 0x02
> +
> +struct cxl_mbox_get_feat_in {
> + uuid_t uuid;
> + __le16 offset;
> + __le16 count;
> + u8 selection;
> +} __packed;
> +
> +/* Set Feature CXL 3.0 Spec 8.2.9.6.3 */
> +/*
> + * Set Feature input payload
> + * CXL rev 3.0 section 8.2.9.6.3; Table 8-81
> + */
> +/* Set Feature : Payload in flags */
> +#define CXL_SET_FEAT_FLAG_ACTION_MASK GENMASK(2, 0)
> +#define CXL_SET_FEAT_FLAG_ACTION_FULL_DATA_TRANSFER 0x0
> +#define CXL_SET_FEAT_FLAG_ACTION_INITIATE_DATA_TRANSFER 0x1
> +#define CXL_SET_FEAT_FLAG_ACTION_CONTINUE_DATA_TRANSFER 0x2
> +#define CXL_SET_FEAT_FLAG_ACTION_FINISH_DATA_TRANSFER 0x3
> +#define CXL_SET_FEAT_FLAG_ACTION_ABORT_DATA_TRANSFER 0x4
> +#define CXL_SET_FEAT_FLAG_MOD_VALUE_SAVED_ACROSS_RESET BIT(3)
> +struct cxl_mbox_set_feat_in {
> + uuid_t uuid;
> + __le32 flags;
> + __le16 offset;
> + u8 version;
> + u8 rsvd[9];
> +} __packed;
> +
> /* Get Poison List CXL 3.0 Spec 8.2.9.8.4.1 */
> struct cxl_mbox_poison_in {
> __le64 offset;
> @@ -867,6 +958,10 @@ void clear_exclusive_cxl_commands(struct cxl_memdev_state *mds,
> unsigned long *cmds);
> void cxl_mem_get_event_records(struct cxl_memdev_state *mds, u32 status);
> int cxl_set_timestamp(struct cxl_memdev_state *mds);
> +struct cxl_mbox_get_supp_feats_out *cxl_get_supported_features(struct cxl_memdev_state *mds,
> + struct cxl_mbox_get_supp_feats_in *pi);
> +void *cxl_get_feature(struct cxl_memdev_state *mds, struct cxl_mbox_get_feat_in *pi);
> +int cxl_set_feature(struct cxl_memdev_state *mds, void *feat_in, size_t size);
> 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);
> diff --git a/include/uapi/linux/cxl_mem.h b/include/uapi/linux/cxl_mem.h
> index 14bc6e742148..8c89d323cc41 100644
> --- a/include/uapi/linux/cxl_mem.h
> +++ b/include/uapi/linux/cxl_mem.h
> @@ -46,6 +46,9 @@
> ___C(GET_SCAN_MEDIA_CAPS, "Get Scan Media Capabilities"), \
> ___DEPRECATED(SCAN_MEDIA, "Scan Media"), \
> ___DEPRECATED(GET_SCAN_MEDIA, "Get Scan Media Results"), \
> + ___C(GET_SUPPORTED_FEATURES, "Get Supported Features"), \
> + ___C(GET_FEATURE, "Get Feature"), \
> + ___C(SET_FEATURE, "Set Feature"), \
> ___C(MAX, "invalid / last command")
>
> #define ___C(a, b) CXL_MEM_COMMAND_ID_##a