[PATCH 1/8] powerpc: Add asm header 'papr_scm.h' describing the papr-scm interface

[Vaibhav Jain <vaibhav@linux.ibm.com>]

Add a new powerpc specific asm header named 'papr-scm.h' that descibes
the interface between PHYP and guest kernel running as an LPAR.

The HCALLs specific to managing SCM are descibed in Ref[1]. The asm
header introduced by this patch however describes the data structures
exchanged between PHYP and kernel during those HCALLs.

Future patches will use these structures to provide support for
retriving nvdimm health and performance stats in papr_scm kernel
module.

[1]: commit 58b278f568f0 ("powerpc: Provide initial documentation for
PAPR hcalls")

Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
---
 arch/powerpc/include/asm/papr_scm.h | 68 +++++++++++++++++++++++++++++
 1 file changed, 68 insertions(+)
 create mode 100644 arch/powerpc/include/asm/papr_scm.h

diff --git a/arch/powerpc/include/asm/papr_scm.h b/arch/powerpc/include/asm/papr_scm.h
new file mode 100644
index 000000000000..d893621063f3
--- /dev/null
+++ b/arch/powerpc/include/asm/papr_scm.h
@@ -0,0 +1,68 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Structures and defines needed to manage nvdimms for spapr guests.
+ */
+#ifndef _ASM_POWERPC_PAPR_SCM_H_
+#define _ASM_POWERPC_PAPR_SCM_H_
+
+#include <linux/types.h>
+#include <asm/bitsperlong.h>
+#include <linux/stringify.h>
+
+/* DIMM health bitmap bitmap indicators */
+/* SCM device is unable to persist memory contents */
+#define PAPR_SCM_DIMM_UNARMED			PPC_BIT(0)
+/* SCM device failed to persist memory contents */
+#define PAPR_SCM_DIMM_SHUTDOWN_DIRTY		PPC_BIT(1)
+/* SCM device contents are persisted from previous IPL */
+#define PAPR_SCM_DIMM_SHUTDOWN_CLEAN		PPC_BIT(2)
+/* SCM device contents are not persisted from previous IPL */
+#define PAPR_SCM_DIMM_EMPTY			PPC_BIT(3)
+/* SCM device memory life remaining is critically low */
+#define PAPR_SCM_DIMM_HEALTH_CRITICAL		PPC_BIT(4)
+/* SCM device will be garded off next IPL due to failure */
+#define PAPR_SCM_DIMM_HEALTH_FATAL		PPC_BIT(5)
+/* SCM contents cannot persist due to current platform health status */
+#define PAPR_SCM_DIMM_HEALTH_UNHEALTHY		PPC_BIT(6)
+/* SCM device is unable to persist memory contents in certain conditions */
+#define PAPR_SCM_DIMM_HEALTH_NON_CRITICAL	PPC_BIT(7)
+/* SCM device is encrypted */
+#define PAPR_SCM_DIMM_ENCRYPTED			PPC_BIT(8)
+/* SCM device has been scrubbed and locked */
+#define PAPR_SCM_DIMM_SCRUBBED_AND_LOCKED	PPC_BIT(9)
+
+/* Bits status indicators for health bitmap indicating unarmed dimm */
+#define PAPR_SCM_DIMM_UNARMED_MASK (PAPR_SCM_DIMM_UNARMED |	\
+					PAPR_SCM_DIMM_HEALTH_UNHEALTHY | \
+					PAPR_SCM_DIMM_HEALTH_NON_CRITICAL)
+
+/* Bits status indicators for health bitmap indicating unflushed dimm */
+#define PAPR_SCM_DIMM_BAD_SHUTDOWN_MASK (PAPR_SCM_DIMM_SHUTDOWN_DIRTY)
+
+/* Bits status indicators for health bitmap indicating unrestored dimm */
+#define PAPR_SCM_DIMM_BAD_RESTORE_MASK  (PAPR_SCM_DIMM_EMPTY)
+
+/* Bit status indicators for smart event notification */
+#define PAPR_SCM_DIMM_SMART_EVENT_MASK (PAPR_SCM_DIMM_HEALTH_CRITICAL | \
+					   PAPR_SCM_DIMM_HEALTH_FATAL | \
+					   PAPR_SCM_DIMM_HEALTH_UNHEALTHY | \
+					   PAPR_SCM_DIMM_HEALTH_NON_CRITICAL)
+
+#define PAPR_SCM_PERF_STATS_EYECATCHER __stringify(SCMSTATS)
+
+/* Struct holding a single performance metric */
+struct papr_scm_perf_stat {
+	__be64 statistic_id;
+	__be64 statistic_value;
+};
+
+/* Struct exchanged between kernel and ndctl reporting drc perf stats */
+struct papr_scm_perf_stats {
+	uint8_t eye_catcher[8];
+	__be32 stats_version;		/* Should be 0x01 */
+	__be32 num_statistics;		/* Number of stats following */
+	/* zero or more performance matrics */
+	struct papr_scm_perf_stat scm_statistics[];
+} __packed;
+
+#endif
-- 
2.24.1