[PATCH v4 10/28] cxl/region: Add dynamic capacity decoder and region modes

[ira . weiny]

From: Navneet Singh <navneet.singh@xxxxxxxxx>

One or more decoders each pointing to a Dynamic Capacity (DC) partition
form a CXL software region.  The region mode reflects composition of
that entire software region.  Decoder mode reflects a specific DC
partition.  DC partitions are also known as DC regions per CXL
specification r3.1.

Define the new modes and helper functions required to make the
association between these new modes.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Reviewed-by: Fan Ni <fan.ni@xxxxxxxxxxx>
Signed-off-by: Navneet Singh <navneet.singh@xxxxxxxxx>
Co-developed-by: Ira Weiny <ira.weiny@xxxxxxxxx>
Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx>

---
Changes:
[iweiny: keep tags on simple patch]
[Fan: s/partitions/partition/]
[djiang: New wording for the commit message]
[iweiny: reword commit message more]
---
 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 f3a56003edc1..ab00203f285a 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -1870,6 +1870,8 @@ 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;
 }
@@ -3239,6 +3241,8 @@ cxl_decoder_to_region_mode(enum cxl_decoder_mode mode)
 		return CXL_REGION_RAM;
 	case CXL_DECODER_PMEM:
 		return CXL_REGION_PMEM;
+	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 5d74eb4ffab3..f931ebdd36d0 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -370,6 +370,14 @@ 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,
 };
@@ -380,6 +388,14 @@ 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",
 	};
 
@@ -388,10 +404,16 @@ 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,
 };
 
@@ -401,6 +423,7 @@ 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",
 	};
 

-- 
2.46.0