[ndctl PATCH v3 1/6] libcxl: add GET_PARTITION_INFO mailbox command and accessors

[alison.schofield@intel.com]

From: Alison Schofield <alison.schofield@intel.com>

Users need access to the CXL GET_PARTITION_INFO mailbox command
to inspect and confirm changes to the partition layout of a memory
device.

Add libcxl APIs to create a new GET_PARTITION_INFO mailbox command,
the command output data structure (privately), and accessor APIs to
return the different fields in the partition info output.

Per the CXL 2.0 specification, devices report partition capacities
as multiples of 256MB. Define and use a capacity multiplier to
convert the raw data into bytes for user consumption. Use byte
format as the norm for all capacity values produced or consumed
using CXL Mailbox commands.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
---
 cxl/lib/libcxl.c   | 41 +++++++++++++++++++++++++++++++++++++++++
 cxl/lib/libcxl.sym |  5 +++++
 cxl/lib/private.h  | 10 ++++++++++
 cxl/libcxl.h       |  5 +++++
 util/size.h        |  1 +
 5 files changed, 62 insertions(+)

diff --git a/cxl/lib/libcxl.c b/cxl/lib/libcxl.c
index 3390eb9..58181c0 100644
--- a/cxl/lib/libcxl.c
+++ b/cxl/lib/libcxl.c
@@ -1160,6 +1160,47 @@ CXL_EXPORT ssize_t cxl_cmd_read_label_get_payload(struct cxl_cmd *cmd,
 	return length;
 }
 
+CXL_EXPORT struct cxl_cmd *cxl_cmd_new_get_partition_info(struct cxl_memdev *memdev)
+{
+	return cxl_cmd_new_generic(memdev,
+				   CXL_MEM_COMMAND_ID_GET_PARTITION_INFO);
+}
+
+#define cmd_partition_get_capacity_field(cmd, field)			\
+do {										\
+	struct cxl_cmd_get_partition_info *c =					\
+		(struct cxl_cmd_get_partition_info *)cmd->send_cmd->out.payload;\
+	int rc = cxl_cmd_validate_status(cmd,					\
+			CXL_MEM_COMMAND_ID_GET_PARTITION_INFO);			\
+	if (rc)									\
+		return ULLONG_MAX;							\
+	return le64_to_cpu(c->field) * CXL_CAPACITY_MULTIPLIER;			\
+} while (0)
+
+CXL_EXPORT unsigned long long
+cxl_cmd_partition_info_get_active_volatile_bytes(struct cxl_cmd *cmd)
+{
+	cmd_partition_get_capacity_field(cmd, active_volatile_cap);
+}
+
+CXL_EXPORT unsigned long long
+cxl_cmd_partition_info_get_active_persistent_bytes(struct cxl_cmd *cmd)
+{
+	cmd_partition_get_capacity_field(cmd, active_persistent_cap);
+}
+
+CXL_EXPORT unsigned long long
+cxl_cmd_partition_info_get_next_volatile_bytes(struct cxl_cmd *cmd)
+{
+	cmd_partition_get_capacity_field(cmd, next_volatile_cap);
+}
+
+CXL_EXPORT unsigned long long
+cxl_cmd_partition_info_get_next_persistent_bytes(struct cxl_cmd *cmd)
+{
+	cmd_partition_get_capacity_field(cmd, next_persistent_cap);
+}
+
 CXL_EXPORT int cxl_cmd_submit(struct cxl_cmd *cmd)
 {
 	struct cxl_memdev *memdev = cmd->memdev;
diff --git a/cxl/lib/libcxl.sym b/cxl/lib/libcxl.sym
index 077d104..e019c3c 100644
--- a/cxl/lib/libcxl.sym
+++ b/cxl/lib/libcxl.sym
@@ -70,6 +70,11 @@ global:
 	cxl_memdev_zero_label;
 	cxl_memdev_write_label;
 	cxl_memdev_read_label;
+	cxl_cmd_new_get_partition_info;
+	cxl_cmd_partition_info_get_active_volatile_bytes;
+	cxl_cmd_partition_info_get_active_persistent_bytes;
+	cxl_cmd_partition_info_get_next_volatile_bytes;
+	cxl_cmd_partition_info_get_next_persistent_bytes;
 local:
         *;
 };
diff --git a/cxl/lib/private.h b/cxl/lib/private.h
index a1b8b50..dd9234f 100644
--- a/cxl/lib/private.h
+++ b/cxl/lib/private.h
@@ -7,6 +7,7 @@
 #include <cxl/cxl_mem.h>
 #include <ccan/endian/endian.h>
 #include <ccan/short_types/short_types.h>
+#include <util/size.h>
 
 #define CXL_EXPORT __attribute__ ((visibility("default")))
 
@@ -104,6 +105,15 @@ struct cxl_cmd_get_health_info {
 	le32 pmem_errors;
 } __attribute__((packed));
 
+struct cxl_cmd_get_partition_info {
+	le64 active_volatile_cap;
+	le64 active_persistent_cap;
+	le64 next_volatile_cap;
+	le64 next_persistent_cap;
+} __attribute__((packed));
+
+#define CXL_CAPACITY_MULTIPLIER		SZ_256M
+
 /* CXL 2.0 8.2.9.5.3 Byte 0 Health Status */
 #define CXL_CMD_HEALTH_INFO_STATUS_MAINTENANCE_NEEDED_MASK		BIT(0)
 #define CXL_CMD_HEALTH_INFO_STATUS_PERFORMANCE_DEGRADED_MASK		BIT(1)
diff --git a/cxl/libcxl.h b/cxl/libcxl.h
index 89d35ba..08fd840 100644
--- a/cxl/libcxl.h
+++ b/cxl/libcxl.h
@@ -109,6 +109,11 @@ ssize_t cxl_cmd_read_label_get_payload(struct cxl_cmd *cmd, void *buf,
 		unsigned int length);
 struct cxl_cmd *cxl_cmd_new_write_label(struct cxl_memdev *memdev,
 		void *buf, unsigned int offset, unsigned int length);
+struct cxl_cmd *cxl_cmd_new_get_partition_info(struct cxl_memdev *memdev);
+unsigned long long cxl_cmd_partition_info_get_active_volatile_bytes(struct cxl_cmd *cmd);
+unsigned long long cxl_cmd_partition_info_get_active_persistent_bytes(struct cxl_cmd *cmd);
+unsigned long long cxl_cmd_partition_info_get_next_volatile_bytes(struct cxl_cmd *cmd);
+unsigned long long cxl_cmd_partition_info_get_next_persistent_bytes(struct cxl_cmd *cmd);
 
 #ifdef __cplusplus
 } /* extern "C" */
diff --git a/util/size.h b/util/size.h
index a0f3593..e72467f 100644
--- a/util/size.h
+++ b/util/size.h
@@ -15,6 +15,7 @@
 #define SZ_4M     0x00400000
 #define SZ_16M    0x01000000
 #define SZ_64M    0x04000000
+#define SZ_256M	  0x10000000
 #define SZ_1G     0x40000000
 #define SZ_1T 0x10000000000ULL
 
-- 
2.31.1