Re: [PATCH v5 0/2] cxl: Region bandwidth calculation for targets with shared upstream link

[Ira Weiny <ira.weiny@intel.com>]

Dave Jiang wrote:
> v5:
> - Adjust calculation of RPs under HB to only active RPs (Jonathan)
> - See patches for specific change log
> 
> This series provides recalculation of the CXL region bandwidth when the targets have
> shared upstream link by walking the toplogy from bottom up and clamp the bandwdith
> as the code trasverses up the tree. An example topology:

              traverses

> 
>  An example topology from Jonathan:
> 
>                  CFMWS 0
>                    |
>           _________|_________
>          |                   |
>      ACPI0017-0            ACPI0017-1
>    GP0/HB0/ACPI0016-0   GP1/HB1/ACPI0016-1
>      |          |        |           |
>     RP0        RP1      RP2         RP3
>      |          |        |           |
>    SW 0       SW 1     SW 2        SW 3
>    |   |      |   |    |   |       |   |
>   EP0 EP1    EP2 EP3  EP4  EP5    EP6 EP7
> 
>  Computation for the example topology:
> 
>  Min (GP0 to CPU BW,
>       Min(SW 0 Upstream Link to RP0 BW,
>           Min(SW0SSLBIS for SW0DSP0 (EP0), EP0 DSLBIS, EP0 Upstream Link) +
>           Min(SW0SSLBIS for SW0DSP1 (EP1), EP1 DSLBIS, EP1 Upstream link)) +
>       Min(SW 1 Upstream Link to RP1 BW,
>           Min(SW1SSLBIS for SW1DSP0 (EP2), EP2 DSLBIS, EP2 Upstream Link) +
>           Min(SW1SSLBIS for SW1DSP1 (EP3), EP3 DSLBIS, EP3 Upstream link))) +
>  Min (GP1 to CPU BW,
>       Min(SW 2 Upstream Link to RP2 BW,
>           Min(SW2SSLBIS for SW2DSP0 (EP4), EP4 DSLBIS, EP4 Upstream Link) +
>           Min(SW2SSLBIS for SW2DSP1 (EP5), EP5 DSLBIS, EP5 Upstream link)) +
>       Min(SW 3 Upstream Link to RP3 BW,
>           Min(SW3SSLBIS for SW3DSP0 (EP6), EP6 DSLBIS, EP6 Upstream Link) +
>           Min(SW3SSLBIS for SW3DSP1 (EP7), EP7 DSLBIS, EP7 Upstream link))))

Looks good,
Ira