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1/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2/*
3 * CXL IOCTLs for Memory Devices
4 */
5
6#ifndef _UAPI_CXL_MEM_H_
7#define _UAPI_CXL_MEM_H_
8
9#include <linux/types.h>
10
11/**
12 * DOC: UAPI
13 *
14 * Not all of all commands that the driver supports are always available for use
15 * by userspace. Userspace must check the results from the QUERY command in
16 * order to determine the live set of commands.
17 */
18
19#define CXL_MEM_QUERY_COMMANDS _IOR(0xCE, 1, struct cxl_mem_query_commands)
20#define CXL_MEM_SEND_COMMAND _IOWR(0xCE, 2, struct cxl_send_command)
21
22#define CXL_CMDS \
23 ___C(INVALID, "Invalid Command"), \
24 ___C(IDENTIFY, "Identify Command"), \
25 ___C(RAW, "Raw device command"), \
26 ___C(GET_SUPPORTED_LOGS, "Get Supported Logs"), \
27 ___C(GET_FW_INFO, "Get FW Info"), \
28 ___C(GET_PARTITION_INFO, "Get Partition Information"), \
29 ___C(GET_LSA, "Get Label Storage Area"), \
30 ___C(GET_HEALTH_INFO, "Get Health Info"), \
31 ___C(GET_LOG, "Get Log"), \
32 ___C(MAX, "invalid / last command")
33
34#define ___C(a, b) CXL_MEM_COMMAND_ID_##a
35enum { CXL_CMDS };
36
37#undef ___C
38#define ___C(a, b) { b }
39static const struct {
40 const char *name;
41} cxl_command_names[] = { CXL_CMDS };
42
43/*
44 * Here's how this actually breaks out:
45 * cxl_command_names[] = {
46 * [CXL_MEM_COMMAND_ID_INVALID] = { "Invalid Command" },
47 * [CXL_MEM_COMMAND_ID_IDENTIFY] = { "Identify Command" },
48 * ...
49 * [CXL_MEM_COMMAND_ID_MAX] = { "invalid / last command" },
50 * };
51 */
52
53#undef ___C
54
55/**
56 * struct cxl_command_info - Command information returned from a query.
57 * @id: ID number for the command.
58 * @flags: Flags that specify command behavior.
59 * @size_in: Expected input size, or -1 if variable length.
60 * @size_out: Expected output size, or -1 if variable length.
61 *
62 * Represents a single command that is supported by both the driver and the
63 * hardware. This is returned as part of an array from the query ioctl. The
64 * following would be a command that takes a variable length input and returns 0
65 * bytes of output.
66 *
67 * - @id = 10
68 * - @flags = 0
69 * - @size_in = -1
70 * - @size_out = 0
71 *
72 * See struct cxl_mem_query_commands.
73 */
74struct cxl_command_info {
75 __u32 id;
76
77 __u32 flags;
78#define CXL_MEM_COMMAND_FLAG_MASK GENMASK(0, 0)
79
80 __s32 size_in;
81 __s32 size_out;
82};
83
84/**
85 * struct cxl_mem_query_commands - Query supported commands.
86 * @n_commands: In/out parameter. When @n_commands is > 0, the driver will
87 * return min(num_support_commands, n_commands). When @n_commands
88 * is 0, driver will return the number of total supported commands.
89 * @rsvd: Reserved for future use.
90 * @commands: Output array of supported commands. This array must be allocated
91 * by userspace to be at least min(num_support_commands, @n_commands)
92 *
93 * Allow userspace to query the available commands supported by both the driver,
94 * and the hardware. Commands that aren't supported by either the driver, or the
95 * hardware are not returned in the query.
96 *
97 * Examples:
98 *
99 * - { .n_commands = 0 } // Get number of supported commands
100 * - { .n_commands = 15, .commands = buf } // Return first 15 (or less)
101 * supported commands
102 *
103 * See struct cxl_command_info.
104 */
105struct cxl_mem_query_commands {
106 /*
107 * Input: Number of commands to return (space allocated by user)
108 * Output: Number of commands supported by the driver/hardware
109 *
110 * If n_commands is 0, kernel will only return number of commands and
111 * not try to populate commands[], thus allowing userspace to know how
112 * much space to allocate
113 */
114 __u32 n_commands;
115 __u32 rsvd;
116
117 struct cxl_command_info __user commands[]; /* out: supported commands */
118};
119
120/**
121 * struct cxl_send_command - Send a command to a memory device.
122 * @id: The command to send to the memory device. This must be one of the
123 * commands returned by the query command.
124 * @flags: Flags for the command (input).
125 * @raw: Special fields for raw commands
126 * @raw.opcode: Opcode passed to hardware when using the RAW command.
127 * @raw.rsvd: Must be zero.
128 * @rsvd: Must be zero.
129 * @retval: Return value from the memory device (output).
130 * @in: Parameters associated with input payload.
131 * @in.size: Size of the payload to provide to the device (input).
132 * @in.rsvd: Must be zero.
133 * @in.payload: Pointer to memory for payload input, payload is little endian.
134 * @out: Parameters associated with output payload.
135 * @out.size: Size of the payload received from the device (input/output). This
136 * field is filled in by userspace to let the driver know how much
137 * space was allocated for output. It is populated by the driver to
138 * let userspace know how large the output payload actually was.
139 * @out.rsvd: Must be zero.
140 * @out.payload: Pointer to memory for payload output, payload is little endian.
141 *
142 * Mechanism for userspace to send a command to the hardware for processing. The
143 * driver will do basic validation on the command sizes. In some cases even the
144 * payload may be introspected. Userspace is required to allocate large enough
145 * buffers for size_out which can be variable length in certain situations.
146 */
147struct cxl_send_command {
148 __u32 id;
149 __u32 flags;
150 union {
151 struct {
152 __u16 opcode;
153 __u16 rsvd;
154 } raw;
155 __u32 rsvd;
156 };
157 __u32 retval;
158
159 struct {
160 __s32 size;
161 __u32 rsvd;
162 __u64 payload;
163 } in;
164
165 struct {
166 __s32 size;
167 __u32 rsvd;
168 __u64 payload;
169 } out;
170};
171
172#endif