arch/powerpc/include/uapi/asm/papr_pdsm.h

   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  */
  94 struct 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  */
 117 enum 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 */
 124 union 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  */
 135 struct 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_ */