RE: [RFC PATCH v9 06/11] cxl/mbox: Add SET_FEATURE mailbox command
From: Shiju Jose
Date: Thu Jul 18 2024 - 05:15:16 EST
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>Sent: 17 July 2024 21:14
>To: Shiju Jose <shiju.jose@xxxxxxxxxx>
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>Subject: Re: [RFC PATCH v9 06/11] cxl/mbox: Add SET_FEATURE mailbox
>command
>
>On Tue, Jul 16, 2024 at 04:03:30PM +0100, shiju.jose@xxxxxxxxxx wrote:
>> From: Shiju Jose <shiju.jose@xxxxxxxxxx>
>>
>> Add support for SET_FEATURE mailbox command.
>>
>> CXL spec 3.1 section 8.2.9.6 describes optional device specific features.
>> CXL devices supports features with changeable attributes.
>> The settings of a feature can be optionally modified using Set Feature
>> command.
>
>Add more specific spec reference to the command here: 8.2.9.6.3.
>The same suggestions for get supported features and get feature commands.
Will do.
>
>>
>> Signed-off-by: Shiju Jose <shiju.jose@xxxxxxxxxx>
>> ---
>> drivers/cxl/core/mbox.c | 71
>+++++++++++++++++++++++++++++++++++++++++
>> drivers/cxl/cxlmem.h | 33 +++++++++++++++++++
>> 2 files changed, 104 insertions(+)
>>
>> diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c index
>> b1eeed508459..50ecd2bd7372 100644
>> --- a/drivers/cxl/core/mbox.c
>> +++ b/drivers/cxl/core/mbox.c
>> @@ -1388,6 +1388,77 @@ size_t cxl_get_feature(struct cxl_memdev_state
>> *mds, } EXPORT_SYMBOL_NS_GPL(cxl_get_feature, CXL);
>>
>> +/*
>> + * FEAT_DATA_MIN_PAYLOAD_SIZE - min extra number of bytes should be
>> + * available in the mailbox for storing the actual feature data so
>> +that
>> + * the feature data transfer would work as expected.
>> + */
>> +#define FEAT_DATA_MIN_PAYLOAD_SIZE 10 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)
>> +{
>> + struct cxl_memdev_set_feat_pi {
>> + struct cxl_mbox_set_feat_hdr hdr;
>> + u8 feat_data[];
>> + } __packed;
>> + size_t data_in_size, data_sent_size = 0;
>> + struct cxl_mbox_cmd mbox_cmd;
>> + size_t hdr_size;
>> + int rc = 0;
>> +
>> + struct cxl_memdev_set_feat_pi *pi __free(kfree) =
>> + kmalloc(mds->payload_size,
>GFP_KERNEL);
>> + pi->hdr.uuid = feat_uuid;
>> + pi->hdr.version = feat_version;
>> + feat_flag &= ~CXL_SET_FEAT_FLAG_DATA_TRANSFER_MASK;
>
>Although we may not support it yet, should we set bit[3] (saved across reset)
>since we already defined CXL_SET_FEAT_FLAG_DATA_SAVED_ACROSS_RESET
>and it is not used?
Will do.
>
>Fan
>> + hdr_size = sizeof(pi->hdr);
>> + /*
>> + * Check minimum mbox payload size is available for
>> + * the feature data transfer.
>> + */
>> + if (hdr_size + FEAT_DATA_MIN_PAYLOAD_SIZE > mds->payload_size)
>> + return -ENOMEM;
>> +
>> + if ((hdr_size + feat_data_size) <= mds->payload_size) {
>> + pi->hdr.flags = cpu_to_le32(feat_flag |
>> +
>CXL_SET_FEAT_FLAG_FULL_DATA_TRANSFER);
>> + data_in_size = feat_data_size;
>> + } else {
>> + pi->hdr.flags = cpu_to_le32(feat_flag |
>> +
>CXL_SET_FEAT_FLAG_INITIATE_DATA_TRANSFER);
>> + data_in_size = mds->payload_size - hdr_size;
>> + }
>> +
>> + do {
>> + pi->hdr.offset = cpu_to_le16(data_sent_size);
>> + memcpy(pi->feat_data, feat_data + data_sent_size,
>data_in_size);
>> + mbox_cmd = (struct cxl_mbox_cmd) {
>> + .opcode = CXL_MBOX_OP_SET_FEATURE,
>> + .size_in = hdr_size + data_in_size,
>> + .payload_in = pi,
>> + };
>> + rc = cxl_internal_send_cmd(mds, &mbox_cmd);
>> + if (rc < 0)
>> + return rc;
>> +
>> + data_sent_size += data_in_size;
>> + if (data_sent_size >= feat_data_size)
>> + return 0;
>> +
>> + if ((feat_data_size - data_sent_size) <= (mds->payload_size -
>hdr_size)) {
>> + data_in_size = feat_data_size - data_sent_size;
>> + pi->hdr.flags = cpu_to_le32(feat_flag |
>> +
>CXL_SET_FEAT_FLAG_FINISH_DATA_TRANSFER);
>> + } else {
>> + pi->hdr.flags = cpu_to_le32(feat_flag |
>> +
>CXL_SET_FEAT_FLAG_CONTINUE_DATA_TRANSFER);
>> + }
>> + } while (true);
>> +}
>> +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
>> 25698a6fbe66..c3cb8e2736b5 100644
>> --- a/drivers/cxl/cxlmem.h
>> +++ b/drivers/cxl/cxlmem.h
>> @@ -532,6 +532,7 @@ enum cxl_opcode {
>> CXL_MBOX_OP_GET_SUP_LOG_SUBLIST = 0x0405,
>> 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,
>> @@ -780,6 +781,34 @@ struct cxl_mbox_get_feat_in {
>> u8 selection;
>> } __packed;
>>
>> +/*
>> + * Set Feature CXL 3.1 Spec 8.2.9.6.3 */
>> +
>> +/*
>> + * Set Feature input payload
>> + * CXL rev 3.1 section 8.2.9.6.3 Table 8-101 */
>> +/* Set Feature : Payload in flags */
>> +#define CXL_SET_FEAT_FLAG_DATA_TRANSFER_MASK GENMASK(2, 0)
>> +enum cxl_set_feat_flag_data_transfer {
>> + CXL_SET_FEAT_FLAG_FULL_DATA_TRANSFER,
>> + CXL_SET_FEAT_FLAG_INITIATE_DATA_TRANSFER,
>> + CXL_SET_FEAT_FLAG_CONTINUE_DATA_TRANSFER,
>> + CXL_SET_FEAT_FLAG_FINISH_DATA_TRANSFER,
>> + CXL_SET_FEAT_FLAG_ABORT_DATA_TRANSFER,
>> + CXL_SET_FEAT_FLAG_DATA_TRANSFER_MAX
>> +};
>> +#define CXL_SET_FEAT_FLAG_DATA_SAVED_ACROSS_RESET BIT(3)
>> +
>> +struct cxl_mbox_set_feat_hdr {
>> + 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;
>> @@ -918,6 +947,10 @@ size_t cxl_get_feature(struct cxl_memdev_state
>*mds,
>> const uuid_t feat_uuid, void *feat_out,
>> size_t feat_out_size,
>> enum cxl_get_feat_selection selection);
>> +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_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
>>
Thanks,
Shiju