On 9/11/24 2:04 AM, shiju.jose@xxxxxxxxxx wrote:
> From: Dave Jiang <dave.jiang@xxxxxxxxx>
>
> CXL spec r3.1 8.2.9.6.1 Get Supported Features (Opcode 0500h)
> The command retrieve the list of supported device-specific features
> (identified by UUID) and general information about each Feature.
>
> The driver will retrieve the feature entries in order to make checks and
> provide information for the Get Feature and Set Feature command. One of
> the main piece of information retrieved are the effects a Set Feature
> command would have for a particular feature.
>
> Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
> Signed-off-by: Shiju Jose <shiju.jose@xxxxxxxxxx>
> ---
> drivers/cxl/core/mbox.c | 175 +++++++++++++++++++++++++++++++++++
> drivers/cxl/cxlmem.h | 51 ++++++++++
> drivers/cxl/pci.c | 4 +
> include/uapi/linux/cxl_mem.h | 1 +
> 4 files changed, 231 insertions(+)
>
> diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
> index fa1ee495a4e3..fe965ec5802f 100644
> --- a/drivers/cxl/core/mbox.c
> +++ b/drivers/cxl/core/mbox.c
> @@ -67,6 +67,7 @@ static struct cxl_mem_command cxl_mem_commands[CXL_MEM_COMMAND_ID_MAX] = {
> CXL_CMD(SET_SHUTDOWN_STATE, 0x1, 0, 0),
> CXL_CMD(GET_SCAN_MEDIA_CAPS, 0x10, 0x4, 0),
> CXL_CMD(GET_TIMESTAMP, 0, 0x8, 0),
> + CXL_CMD(GET_SUPPORTED_FEATURES, 0x8, CXL_VARIABLE_PAYLOAD, 0),
> };
>
> /*
> @@ -790,6 +791,180 @@ static const uuid_t log_uuid[] = {
> [VENDOR_DEBUG_UUID] = DEFINE_CXL_VENDOR_DEBUG_UUID,
> };
>
> +static void cxl_free_features(void *features)
> +{
> + kvfree(features);
> +}
> +
> +static int cxl_get_supported_features_count(struct cxl_dev_state *cxlds)
> +{
> + struct cxl_mailbox *cxl_mbox = &cxlds->cxl_mbox;
> + struct cxl_mbox_get_sup_feats_out mbox_out;
> + struct cxl_mbox_get_sup_feats_in mbox_in;
> + struct cxl_mbox_cmd mbox_cmd;
> + int rc;
> +
> + memset(&mbox_in, 0, sizeof(mbox_in));
> + mbox_in.count = sizeof(mbox_out);
> + memset(&mbox_out, 0, sizeof(mbox_out));
> + mbox_cmd = (struct cxl_mbox_cmd) {
> + .opcode = CXL_MBOX_OP_GET_SUPPORTED_FEATURES,
> + .size_in = sizeof(mbox_in),
> + .payload_in = &mbox_in,
> + .size_out = sizeof(mbox_out),
> + .payload_out = &mbox_out,
> + .min_out = sizeof(mbox_out),
> + };
> + rc = cxl_internal_send_cmd(cxl_mbox, &mbox_cmd);
> + if (rc < 0)
> + return rc;
> +
> + cxlds->num_features = le16_to_cpu(mbox_out.supported_feats);
> + if (!cxlds->num_features)
> + return -ENOENT;
> +
> + return 0;
> +}
> +
> +int cxl_get_supported_features(struct cxl_dev_state *cxlds)
> +{
> + int remain_feats, max_size, max_feats, start, rc;
> + struct cxl_mailbox *cxl_mbox = &cxlds->cxl_mbox;
> + int feat_size = sizeof(struct cxl_feat_entry);
> + struct cxl_mbox_get_sup_feats_out *mbox_out;
> + struct cxl_mbox_get_sup_feats_in mbox_in;
> + int hdr_size = sizeof(*mbox_out);
> + struct cxl_mbox_cmd mbox_cmd;
> + struct cxl_mem_command *cmd;
> + void *ptr;
> +
> + /* Get supported features is optional, need to check */
> + cmd = cxl_mem_find_command(CXL_MBOX_OP_GET_SUPPORTED_FEATURES);
> + if (!cmd)
> + return -EOPNOTSUPP;
> + if (!test_bit(cmd->info.id, cxl_mbox->enabled_cmds))
> + return -EOPNOTSUPP;
> +
> + rc = cxl_get_supported_features_count(cxlds);
> + if (rc)
> + return rc;
> +
> + struct cxl_feat_entry *entries __free(kvfree) =
> + kvmalloc(cxlds->num_features * feat_size, GFP_KERNEL);
> +
> + if (!entries)
> + return -ENOMEM;
> +
> + cxlds->entries = no_free_ptr(entries);
> + rc = devm_add_action_or_reset(cxl_mbox->host, cxl_free_features,
> + cxlds->entries);
> + if (rc)
> + return rc;
> +
> + max_size = cxl_mbox->payload_size - hdr_size;
> + /* max feat entries that can fit in mailbox max payload size */
> + max_feats = max_size / feat_size;
> + ptr = &cxlds->entries[0];
> +
> + mbox_out = kvmalloc(cxl_mbox->payload_size, GFP_KERNEL);
> + if (!mbox_out)
> + return -ENOMEM;
> +
> + start = 0;
> + remain_feats = cxlds->num_features;
> + do {
> + int retrieved, alloc_size, copy_feats;
> +
> + if (remain_feats > max_feats) {
> + alloc_size = sizeof(*mbox_out) + max_feats * feat_size;
> + remain_feats = remain_feats - max_feats;
> + copy_feats = max_feats;
> + } else {
> + alloc_size = sizeof(*mbox_out) + remain_feats * feat_size;
> + copy_feats = remain_feats;
> + remain_feats = 0;
> + }
> +
> + memset(&mbox_in, 0, sizeof(mbox_in));
> + mbox_in.count = alloc_size;
> + mbox_in.start_idx = start;
> + memset(mbox_out, 0, alloc_size);
> + mbox_cmd = (struct cxl_mbox_cmd) {
> + .opcode = CXL_MBOX_OP_GET_SUPPORTED_FEATURES,
> + .size_in = sizeof(mbox_in),
> + .payload_in = &mbox_in,
> + .size_out = alloc_size,
> + .payload_out = mbox_out,
> + .min_out = hdr_size,
> + };
> + rc = cxl_internal_send_cmd(cxl_mbox, &mbox_cmd);
> + if (rc < 0) {
> + kfree(mbox_out);
> + return rc;
> + }
> + if (mbox_cmd.size_out <= hdr_size) {
> + rc = -ENXIO;
> + goto err;
> + }
> +
> + /*
> + * Make sure retrieved out buffer is multiple of feature
> + * entries.
> + */
> + retrieved = mbox_cmd.size_out - hdr_size;
> + if (retrieved % feat_size) {
> + rc = -ENXIO;
> + goto err;
> + }
> +
> + /*
> + * If the reported output entries * defined entry size !=
> + * retrieved output bytes, then the output package is incorrect.
> + */
> + if (mbox_out->num_entries * feat_size != retrieved) {
> + rc = -ENXIO;
> + goto err;
> + }
> +
> + memcpy(ptr, mbox_out->ents, retrieved);
> + ptr += retrieved;
> + /*
> + * If the number of output entries is less than expected, add the
> + * remaining entries to the next batch.
> + */
> + remain_feats += copy_feats - mbox_out->num_entries;
> + start += mbox_out->num_entries;
> + } while (remain_feats);
> +
> + kfree(mbox_out);
> + return 0;
> +
> +err:
> + kfree(mbox_out);
> + cxlds->num_features = 0;
> + return rc;
> +}
> +EXPORT_SYMBOL_NS_GPL(cxl_get_supported_features, CXL);
> +
> +int cxl_get_supported_feature_entry(struct cxl_dev_state *cxlds, const uuid_t *feat_uuid,
> + struct cxl_feat_entry *feat_entry_out)
> +{
> + struct cxl_feat_entry *feat_entry;
> + int count;
> +
> + /* Check CXL dev supports the feature */
> + feat_entry = &cxlds->entries[0];
> + for (count = 0; count < cxlds->num_features; count++, feat_entry++) {
> + if (uuid_equal(&feat_entry->uuid, feat_uuid)) {
> + memcpy(feat_entry_out, feat_entry, sizeof(*feat_entry_out));
> + return 0;
> + }
> + }
> +
> + return -EOPNOTSUPP;
> +}
> +EXPORT_SYMBOL_NS_GPL(cxl_get_supported_feature_entry, 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 d7c6ffe2a884..5d149e64c247 100644
> --- a/drivers/cxl/cxlmem.h
> +++ b/drivers/cxl/cxlmem.h
> @@ -389,6 +389,8 @@ struct cxl_dpa_perf {
> * @ram_res: Active Volatile memory capacity configuration
> * @serial: PCIe Device Serial Number
> * @type: Generic Memory Class device or Vendor Specific Memory device
> + * @features: number of supported features
> + * @entries: list of supported feature entries.
> */
> struct cxl_dev_state {
> struct device *dev;
> @@ -404,6 +406,8 @@ struct cxl_dev_state {
> u64 serial;
> enum cxl_devtype type;
> struct cxl_mailbox cxl_mbox;
> + int num_features;
> + struct cxl_feat_entry *entries;
Hi Shiju,
Going back and refactoring the fwctl code, I think this needs to stay with cxl_mailbox. Otherwise it makes it really hard to verify the feature effects for userspace. Preferably I don't think we want to expose 'struct cxl_dev_state' to fwctl if we don't need to.
DJ
> };
>
> /**
> @@ -482,6 +486,7 @@ 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,
> @@ -765,6 +770,48 @@ enum {
> CXL_PMEM_SEC_PASS_USER,
> };
>
> +/* Get Supported Features (0x500h) CXL r3.1 8.2.9.6.1 */
> +struct cxl_mbox_get_sup_feats_in {
> + __le32 count;
> + __le16 start_idx;
> + u8 reserved[2];
> +} __packed;
> +
> +/* 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_feat_entry {
> + uuid_t uuid;
> + __le16 id;
> + __le16 get_feat_size;
> + __le16 set_feat_size;
> + __le32 attr_flags;
> + u8 get_feat_ver;
> + u8 set_feat_ver;
> + __le16 set_effects;
> + u8 reserved[18];
> +} __packed;
> +
> +struct cxl_mbox_get_sup_feats_out {
> + __le16 num_entries;
> + __le16 supported_feats;
> + u8 reserved[4];
> + struct cxl_feat_entry ents[] __counted_by(le32_to_cpu(supported_feats));
> +} __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);
> @@ -824,4 +871,8 @@ struct cxl_hdm {
> struct seq_file;
> struct dentry *cxl_debugfs_create_dir(const char *dir);
> void cxl_dpa_debug(struct seq_file *file, struct cxl_dev_state *cxlds);
> +
> +int cxl_get_supported_features(struct cxl_dev_state *cxlds);
> +int cxl_get_supported_feature_entry(struct cxl_dev_state *cxlds, const uuid_t *feat_uuid,
> + struct cxl_feat_entry *feat_entry_out);
> #endif /* __CXL_MEM_H__ */
> diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
> index 3c73de475bf3..cec88e3a1754 100644
> --- a/drivers/cxl/pci.c
> +++ b/drivers/cxl/pci.c
> @@ -872,6 +872,10 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
> if (rc)
> return rc;
>
> + rc = cxl_get_supported_features(cxlds);
> + if (rc)
> + dev_dbg(&pdev->dev, "No features enumerated.\n");
> +
> rc = cxl_set_timestamp(mds);
> if (rc)
> return rc;
> diff --git a/include/uapi/linux/cxl_mem.h b/include/uapi/linux/cxl_mem.h
> index c6c0fe27495d..bd2535962f70 100644
> --- a/include/uapi/linux/cxl_mem.h
> +++ b/include/uapi/linux/cxl_mem.h
> @@ -50,6 +50,7 @@
> ___C(GET_LOG_CAPS, "Get Log Capabilities"), \
> ___C(CLEAR_LOG, "Clear Log"), \
> ___C(GET_SUP_LOG_SUBLIST, "Get Supported Logs Sub-List"), \
> + ___C(GET_SUPPORTED_FEATURES, "Get Supported Features"), \
> ___C(MAX, "invalid / last command")
>
> #define ___C(a, b) CXL_MEM_COMMAND_ID_##a
