Re: [PATCH RFC v2 04/18] cxl/region: Add Dynamic Capacity decoder and region modes

From: Jonathan Cameron
Date: Tue Aug 29 2023 - 10:40:48 EST


On Mon, 28 Aug 2023 22:20:55 -0700
Ira Weiny <ira.weiny@xxxxxxxxx> wrote:

> Both regions and decoders will need a new mode to reflect the new type
> of partition they are targeting on a device. Regions reflect a dynamic
> capacity type which may point to different Dynamic Capacity (DC)
> Regions. Decoder mode reflects a specific DC Region.
>
> Define the new modes to use in subsequent patches and the helper
> functions associated with them.
>
> Co-developed-by: Navneet Singh <navneet.singh@xxxxxxxxx>
> Signed-off-by: Navneet Singh <navneet.singh@xxxxxxxxx>
> Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx>

Looks fine, though I'll be interested to see how it is used in later patches
as DC region does feel somewhat separate from the other types.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
>
> ---
> Changes for v2:
> [iweiny: split out from: Add dynamic capacity cxl region support.]
> ---
> drivers/cxl/core/region.c | 4 ++++
> drivers/cxl/cxl.h | 23 +++++++++++++++++++++++
> 2 files changed, 27 insertions(+)
>
> diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
> index 75041903b72c..69af1354bc5b 100644
> --- a/drivers/cxl/core/region.c
> +++ b/drivers/cxl/core/region.c
> @@ -1772,6 +1772,8 @@ static bool cxl_modes_compatible(enum cxl_region_mode rmode,
> return true;
> if (rmode == CXL_REGION_PMEM && dmode == CXL_DECODER_PMEM)
> return true;
> + if (rmode == CXL_REGION_DC && cxl_decoder_mode_is_dc(dmode))
> + return true;
>
> return false;
> }
> @@ -2912,6 +2914,8 @@ cxl_decoder_to_region_mode(enum cxl_decoder_mode mode)
> return CXL_REGION_PMEM;
> case CXL_DECODER_DEAD:
> return CXL_REGION_DEAD;
> + case CXL_DECODER_DC0 ... CXL_DECODER_DC7:
> + return CXL_REGION_DC;
> case CXL_DECODER_MIXED:
> default:
> return CXL_REGION_MIXED;
> diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
> index ed282dcd5cf5..d41f3f14fbe3 100644
> --- a/drivers/cxl/cxl.h
> +++ b/drivers/cxl/cxl.h
> @@ -356,6 +356,14 @@ enum cxl_decoder_mode {
> CXL_DECODER_NONE,
> CXL_DECODER_RAM,
> CXL_DECODER_PMEM,
> + CXL_DECODER_DC0,
> + CXL_DECODER_DC1,
> + CXL_DECODER_DC2,
> + CXL_DECODER_DC3,
> + CXL_DECODER_DC4,
> + CXL_DECODER_DC5,
> + CXL_DECODER_DC6,
> + CXL_DECODER_DC7,
> CXL_DECODER_MIXED,
> CXL_DECODER_DEAD,
> };
> @@ -366,6 +374,14 @@ static inline const char *cxl_decoder_mode_name(enum cxl_decoder_mode mode)
> [CXL_DECODER_NONE] = "none",
> [CXL_DECODER_RAM] = "ram",
> [CXL_DECODER_PMEM] = "pmem",
> + [CXL_DECODER_DC0] = "dc0",
> + [CXL_DECODER_DC1] = "dc1",
> + [CXL_DECODER_DC2] = "dc2",
> + [CXL_DECODER_DC3] = "dc3",
> + [CXL_DECODER_DC4] = "dc4",
> + [CXL_DECODER_DC5] = "dc5",
> + [CXL_DECODER_DC6] = "dc6",
> + [CXL_DECODER_DC7] = "dc7",
> [CXL_DECODER_MIXED] = "mixed",
> };
>
> @@ -374,10 +390,16 @@ static inline const char *cxl_decoder_mode_name(enum cxl_decoder_mode mode)
> return "mixed";
> }
>
> +static inline bool cxl_decoder_mode_is_dc(enum cxl_decoder_mode mode)
> +{
> + return (mode >= CXL_DECODER_DC0 && mode <= CXL_DECODER_DC7);
> +}
> +
> enum cxl_region_mode {
> CXL_REGION_NONE,
> CXL_REGION_RAM,
> CXL_REGION_PMEM,
> + CXL_REGION_DC,
> CXL_REGION_MIXED,
> CXL_REGION_DEAD,
> };
> @@ -388,6 +410,7 @@ static inline const char *cxl_region_mode_name(enum cxl_region_mode mode)
> [CXL_REGION_NONE] = "none",
> [CXL_REGION_RAM] = "ram",
> [CXL_REGION_PMEM] = "pmem",
> + [CXL_REGION_DC] = "dc",
> [CXL_REGION_MIXED] = "mixed",
> };
>
>