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 /* Indicate that the 'dimm_dsc' field is valid */
81 #define PDSM_DIMM_DSC_VALID 2
82 
83 /*
84  * Struct exchanged between kernel & ndctl in for PAPR_PDSM_HEALTH
85  * Various flags indicate the health status of the dimm.
86  *
87  * extension_flags	: Any extension fields present in the struct.
88  * dimm_unarmed		: Dimm not armed. So contents wont persist.
89  * dimm_bad_shutdown	: Previous shutdown did not persist contents.
90  * dimm_bad_restore	: Contents from previous shutdown werent restored.
91  * dimm_scrubbed	: Contents of the dimm have been scrubbed.
92  * dimm_locked		: Contents of the dimm cant be modified until CEC reboot
93  * dimm_encrypted	: Contents of dimm are encrypted.
94  * dimm_health		: Dimm health indicator. One of PAPR_PDSM_DIMM_XXXX
95  * dimm_fuel_gauge	: Life remaining of DIMM as a percentage from 0-100
96  */
97 struct nd_papr_pdsm_health {
98 	union {
99 		struct {
100 			__u32 extension_flags;
101 			__u8 dimm_unarmed;
102 			__u8 dimm_bad_shutdown;
103 			__u8 dimm_bad_restore;
104 			__u8 dimm_scrubbed;
105 			__u8 dimm_locked;
106 			__u8 dimm_encrypted;
107 			__u16 dimm_health;
108 
109 			/* Extension flag PDSM_DIMM_HEALTH_RUN_GAUGE_VALID */
110 			__u16 dimm_fuel_gauge;
111 
112 			/* Extension flag PDSM_DIMM_DSC_VALID */
113 			__u64 dimm_dsc;
114 		};
115 		__u8 buf[ND_PDSM_PAYLOAD_MAX_SIZE];
116 	};
117 };
118 
119 /*
120  * Methods to be embedded in ND_CMD_CALL request. These are sent to the kernel
121  * via 'nd_cmd_pkg.nd_command' member of the ioctl struct
122  */
123 enum papr_pdsm {
124 	PAPR_PDSM_MIN = 0x0,
125 	PAPR_PDSM_HEALTH,
126 	PAPR_PDSM_MAX,
127 };
128 
129 /* Maximal union that can hold all possible payload types */
130 union nd_pdsm_payload {
131 	struct nd_papr_pdsm_health health;
132 	__u8 buf[ND_PDSM_PAYLOAD_MAX_SIZE];
133 } __packed;
134 
135 /*
136  * PDSM-header + payload expected with ND_CMD_CALL ioctl from libnvdimm
137  * Valid member of union 'payload' is identified via 'nd_cmd_pkg.nd_command'
138  * that should always precede this struct when sent to papr_scm via CMD_CALL
139  * interface.
140  */
141 struct nd_pkg_pdsm {
142 	__s32 cmd_status;	/* Out: Sub-cmd status returned back */
143 	__u16 reserved[2];	/* Ignored and to be set as '0' */
144 	union nd_pdsm_payload payload;
145 } __packed;
146 
147 #endif /* _UAPI_ASM_POWERPC_PAPR_PDSM_H_ */
148