1/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2/*
3 * PAPR nvDimm Specific Methods (PDSM) and structs for libndctl
4 *
5 * (C) Copyright IBM 2020
6 *
7 * Author: Vaibhav Jain <vaibhav at linux.ibm.com>
8 */
9
10#ifndef _UAPI_ASM_POWERPC_PAPR_PDSM_H_
11#define _UAPI_ASM_POWERPC_PAPR_PDSM_H_
12
13#include <linux/types.h>
14#include <linux/ndctl.h>
15
16/*
17 * PDSM Envelope:
18 *
19 * The ioctl ND_CMD_CALL exchange data between user-space and kernel via
20 * envelope which consists of 2 headers sections and payload sections as
21 * illustrated below:
22 *  +-----------------+---------------+---------------------------+
23 *  |   64-Bytes      |   8-Bytes     |       Max 184-Bytes       |
24 *  +-----------------+---------------+---------------------------+
25 *  | ND-HEADER       |  PDSM-HEADER  |      PDSM-PAYLOAD         |
26 *  +-----------------+---------------+---------------------------+
27 *  | nd_family       |               |                           |
28 *  | nd_size_out     | cmd_status    |                           |
29 *  | nd_size_in      | reserved      |     nd_pdsm_payload       |
30 *  | nd_command      | payload   --> |                           |
31 *  | nd_fw_size      |               |                           |
32 *  | nd_payload ---> |               |                           |
33 *  +---------------+-----------------+---------------------------+
34 *
35 * ND Header:
36 * This is the generic libnvdimm header described as 'struct nd_cmd_pkg'
37 * which is interpreted by libnvdimm before passed on to papr_scm. Important
38 * member fields used are:
39 * 'nd_family'		: (In) NVDIMM_FAMILY_PAPR_SCM
40 * 'nd_size_in'		: (In) PDSM-HEADER + PDSM-IN-PAYLOAD (usually 0)
41 * 'nd_size_out'        : (In) PDSM-HEADER + PDSM-RETURN-PAYLOAD
42 * 'nd_command'         : (In) One of PAPR_PDSM_XXX
43 * 'nd_fw_size'         : (Out) PDSM-HEADER + size of actual payload returned
44 *
45 * PDSM Header:
46 * This is papr-scm specific header that precedes the payload. This is defined
47 * as nd_cmd_pdsm_pkg.  Following fields aare available in this header:
48 *
49 * 'cmd_status'		: (Out) Errors if any encountered while servicing PDSM.
50 * 'reserved'		: Not used, reserved for future and should be set to 0.
51 * 'payload'            : A union of all the possible payload structs
52 *
53 * PDSM Payload:
54 *
55 * The layout of the PDSM Payload is defined by various structs shared between
56 * papr_scm and libndctl so that contents of payload can be interpreted. As such
57 * its defined as a union of all possible payload structs as
58 * 'union nd_pdsm_payload'. Based on the value of 'nd_cmd_pkg.nd_command'
59 * appropriate member of the union is accessed.
60 */
61
62/* Max payload size that we can handle */
63#define ND_PDSM_PAYLOAD_MAX_SIZE 184
64
65/* Max payload size that we can handle */
66#define ND_PDSM_HDR_SIZE \
67	(sizeof(struct nd_pkg_pdsm) - ND_PDSM_PAYLOAD_MAX_SIZE)
68
69/* Various nvdimm health indicators */
70#define PAPR_PDSM_DIMM_HEALTHY       0
71#define PAPR_PDSM_DIMM_UNHEALTHY     1
72#define PAPR_PDSM_DIMM_CRITICAL      2
73#define PAPR_PDSM_DIMM_FATAL         3
74
75/* struct nd_papr_pdsm_health.extension_flags field flags */
76
77/* Indicate that the 'dimm_fuel_gauge' field is valid */
78#define PDSM_DIMM_HEALTH_RUN_GAUGE_VALID 1
79
80/*
81 * Struct exchanged between kernel & ndctl in for PAPR_PDSM_HEALTH
82 * Various flags indicate the health status of the dimm.
83 *
84 * extension_flags	: Any extension fields present in the struct.
85 * dimm_unarmed		: Dimm not armed. So contents wont persist.
86 * dimm_bad_shutdown	: Previous shutdown did not persist contents.
87 * dimm_bad_restore	: Contents from previous shutdown werent restored.
88 * dimm_scrubbed	: Contents of the dimm have been scrubbed.
89 * dimm_locked		: Contents of the dimm cant be modified until CEC reboot
90 * dimm_encrypted	: Contents of dimm are encrypted.
91 * dimm_health		: Dimm health indicator. One of PAPR_PDSM_DIMM_XXXX
92 * dimm_fuel_gauge	: Life remaining of DIMM as a percentage from 0-100
93 */
94struct nd_papr_pdsm_health {
95	union {
96		struct {
97			__u32 extension_flags;
98			__u8 dimm_unarmed;
99			__u8 dimm_bad_shutdown;
100			__u8 dimm_bad_restore;
101			__u8 dimm_scrubbed;
102			__u8 dimm_locked;
103			__u8 dimm_encrypted;
104			__u16 dimm_health;
105
106			/* Extension flag PDSM_DIMM_HEALTH_RUN_GAUGE_VALID */
107			__u16 dimm_fuel_gauge;
108		};
109		__u8 buf[ND_PDSM_PAYLOAD_MAX_SIZE];
110	};
111};
112
113/*
114 * Methods to be embedded in ND_CMD_CALL request. These are sent to the kernel
115 * via 'nd_cmd_pkg.nd_command' member of the ioctl struct
116 */
117enum papr_pdsm {
118	PAPR_PDSM_MIN = 0x0,
119	PAPR_PDSM_HEALTH,
120	PAPR_PDSM_MAX,
121};
122
123/* Maximal union that can hold all possible payload types */
124union nd_pdsm_payload {
125	struct nd_papr_pdsm_health health;
126	__u8 buf[ND_PDSM_PAYLOAD_MAX_SIZE];
127} __packed;
128
129/*
130 * PDSM-header + payload expected with ND_CMD_CALL ioctl from libnvdimm
131 * Valid member of union 'payload' is identified via 'nd_cmd_pkg.nd_command'
132 * that should always precede this struct when sent to papr_scm via CMD_CALL
133 * interface.
134 */
135struct nd_pkg_pdsm {
136	__s32 cmd_status;	/* Out: Sub-cmd status returned back */
137	__u16 reserved[2];	/* Ignored and to be set as '0' */
138	union nd_pdsm_payload payload;
139} __packed;
140
141#endif /* _UAPI_ASM_POWERPC_PAPR_PDSM_H_ */
142