Re: [PATCH 7/9] cxl-mailbox-utils: 0x5603 - FMAPI Get DC Region Extent Lists

[Jonathan Cameron <Jonathan.Cameron@huawei.com>]

On Mon, 17 Mar 2025 16:31:34 +0000
anisa.su887@gmail.com wrote:

> From: Anisa Su <anisa.su@samsung.com>
> 
> FM DCD Management command 0x5603 implemented per CXL r3.2 Spec Section 7.6.7.6.4
> Very similar to previously implemented command 0x4801.
> 
> Signed-off-by: Anisa Su <anisa.su@samsung.com>
> ---
>  hw/cxl/cxl-mailbox-utils.c | 84 ++++++++++++++++++++++++++++++++++++++
>  1 file changed, 84 insertions(+)
> 
> diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c
> index 51ead2b152..77cf0fdb15 100644
> --- a/hw/cxl/cxl-mailbox-utils.c
> +++ b/hw/cxl/cxl-mailbox-utils.c
> @@ -126,6 +126,7 @@ enum {
>          #define GET_DCD_INFO 0x0
>          #define GET_HOST_DC_REGION_CONFIG 0x1
>          #define SET_DC_REGION_CONFIG 0x2
> +        #define GET_DC_REGION_EXTENT_LIST 0x3
>  };
>  
>  /* CCI Message Format CXL r3.1 Figure 7-19 */
> @@ -3587,6 +3588,87 @@ static CXLRetCode cmd_fm_set_dc_region_config(const struct cxl_cmd *cmd,
>      return CXL_MBOX_SUCCESS;
>  }
>  
> +/*
> + * CXL r3.2 section 7.6.7.6.4 Get DC Region Extent Lists (Opcode 5603h)

Single line comment fine here.

> + */
> +static CXLRetCode cmd_fm_get_dc_region_extent_list(const struct cxl_cmd *cmd,
> +                                                   uint8_t *payload_in,
> +                                                   size_t len_in,
> +                                                   uint8_t *payload_out,
> +                                                   size_t *len_out,
> +                                                   CXLCCI *cci)
> +{
> +    struct {
> +        uint16_t host_id;
> +        uint8_t rsvd[2];
> +        uint32_t extent_cnt;
> +        uint32_t start_extent_id;
> +    } QEMU_PACKED *in = (void *)payload_in;
> +    struct {
> +        uint16_t host_id;
> +        uint8_t rsvd[2];
> +        uint32_t start_extent_id;
> +        uint32_t extents_returned;
> +        uint32_t total_extents;
> +        uint32_t list_generation_num;
> +        uint8_t rsvd2[4];
> +        CXLDCExtentRaw records[];
> +    } QEMU_PACKED *out = (void *)payload_out;
> +    QEMU_BUILD_BUG_ON(sizeof(*in) != 0xc);
> +    CXLType3Dev *ct3d = CXL_TYPE3(cci->d);
> +    CXLDCExtent *ent;
> +    CXLDCExtentRaw *out_rec;
> +    uint16_t record_count = 0, record_done = 0, i = 0;
> +    uint16_t out_pl_len, max_size;
> +
> +    if (ct3d->dc.num_regions == 0) {

As in previous.

> +        return CXL_MBOX_UNSUPPORTED;
> +    }
> +
> +    if (in->host_id != 0) {
> +        return CXL_MBOX_INVALID_INPUT;
> +    }
> +
> +    if (in->start_extent_id > ct3d->dc.total_extent_count) {
> +        return CXL_MBOX_INVALID_INPUT;
> +    }
> +
> +    record_count = MIN(in->extent_cnt,
> +                       ct3d->dc.total_extent_count - in->start_extent_id);
> +    max_size = CXL_MAILBOX_MAX_PAYLOAD_SIZE - sizeof(*out);
> +    record_count = MIN(record_count, max_size / sizeof(out->records[0]));
> +    out_pl_len = sizeof(*out) + record_count * sizeof(out->records[0]);
> +
> +    stw_le_p(&out->host_id, in->host_id);
> +    stl_le_p(&out->start_extent_id, in->start_extent_id);
> +    stl_le_p(&out->extents_returned, record_count);
> +    stl_le_p(&out->total_extents, ct3d->dc.total_extent_count);
> +    stl_le_p(&out->list_generation_num, ct3d->dc.ext_list_gen_seq);
> +
> +    if (record_count > 0) {
> +        out_rec = &out->records[record_done];

Given this isn't in the loop, record_done is always 0, so maybe just
use that here?
Or maybe drag that into the loop and...

> +
> +        QTAILQ_FOREACH(ent, &ct3d->dc.extents, node) {
> +            if (i++ < in->start_extent_id) {
> +                continue;
> +            }
> +            stq_le_p(&out_rec->start_dpa, ent->start_dpa);
> +            stq_le_p(&out_rec->len, ent->len);
> +            memcpy(&out_rec->tag, ent->tag, 0x10);
> +            stw_le_p(&out_rec->shared_seq, ent->shared_seq);
> +
> +            record_done++;
> +            out_rec++;

Then no need to increment out_rec here.

> +            if (record_done == record_count) {
> +                break;
> +            }
> +        }
> +    }
> +
> +    *len_out = out_pl_len;
> +    return CXL_MBOX_SUCCESS;
> +}
> +
>  static const struct cxl_cmd cxl_cmd_set[256][256] = {
>      [INFOSTAT][BACKGROUND_OPERATION_ABORT] = { "BACKGROUND_OPERATION_ABORT",
>          cmd_infostat_bg_op_abort, 0, 0 },
> @@ -3720,6 +3802,8 @@ static const struct cxl_cmd cxl_cmd_set_fm_dcd[256][256] = {
>           CXL_MBOX_CONFIG_CHANGE_CXL_RESET |
>           CXL_MBOX_IMMEDIATE_CONFIG_CHANGE |
>           CXL_MBOX_IMMEDIATE_DATA_CHANGE)},
> +    [FMAPI_DCD_MGMT][GET_DC_REGION_EXTENT_LIST] = { "GET_DC_REGION_EXTENT_LIST",
> +        cmd_fm_get_dc_region_extent_list, 12, 0},

space before }


>  };
>  
>  /*