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(SET_PARTITION_INFO, "Set Partition Information"),            \
33 	___C(SET_LSA, "Set Label Storage Area"),                          \
34 	___C(GET_ALERT_CONFIG, "Get Alert Configuration"),                \
35 	___C(SET_ALERT_CONFIG, "Set Alert Configuration"),                \
36 	___C(GET_SHUTDOWN_STATE, "Get Shutdown State"),                   \
37 	___C(SET_SHUTDOWN_STATE, "Set Shutdown State"),                   \
38 	___C(GET_POISON, "Get Poison List"),                              \
39 	___C(INJECT_POISON, "Inject Poison"),                             \
40 	___C(CLEAR_POISON, "Clear Poison"),                               \
41 	___C(GET_SCAN_MEDIA_CAPS, "Get Scan Media Capabilities"),         \
42 	___C(SCAN_MEDIA, "Scan Media"),                                   \
43 	___C(GET_SCAN_MEDIA, "Get Scan Media Results"),                   \
44 	___C(MAX, "invalid / last command")
45 
46 #define ___C(a, b) CXL_MEM_COMMAND_ID_##a
47 enum { CXL_CMDS };
48 
49 #undef ___C
50 #define ___C(a, b) { b }
51 static const struct {
52 	const char *name;
53 } cxl_command_names[] __attribute__((__unused__)) = { CXL_CMDS };
54 
55 /*
56  * Here's how this actually breaks out:
57  * cxl_command_names[] = {
58  *	[CXL_MEM_COMMAND_ID_INVALID] = { "Invalid Command" },
59  *	[CXL_MEM_COMMAND_ID_IDENTIFY] = { "Identify Command" },
60  *	...
61  *	[CXL_MEM_COMMAND_ID_MAX] = { "invalid / last command" },
62  * };
63  */
64 
65 #undef ___C
66 
67 /**
68  * struct cxl_command_info - Command information returned from a query.
69  * @id: ID number for the command.
70  * @flags: Flags that specify command behavior.
71  * @size_in: Expected input size, or ~0 if variable length.
72  * @size_out: Expected output size, or ~0 if variable length.
73  *
74  * Represents a single command that is supported by both the driver and the
75  * hardware. This is returned as part of an array from the query ioctl. The
76  * following would be a command that takes a variable length input and returns 0
77  * bytes of output.
78  *
79  *  - @id = 10
80  *  - @flags = 0
81  *  - @size_in = ~0
82  *  - @size_out = 0
83  *
84  * See struct cxl_mem_query_commands.
85  */
86 struct cxl_command_info {
87 	__u32 id;
88 
89 	__u32 flags;
90 #define CXL_MEM_COMMAND_FLAG_MASK GENMASK(0, 0)
91 
92 	__u32 size_in;
93 	__u32 size_out;
94 };
95 
96 /**
97  * struct cxl_mem_query_commands - Query supported commands.
98  * @n_commands: In/out parameter. When @n_commands is > 0, the driver will
99  *		return min(num_support_commands, n_commands). When @n_commands
100  *		is 0, driver will return the number of total supported commands.
101  * @rsvd: Reserved for future use.
102  * @commands: Output array of supported commands. This array must be allocated
103  *            by userspace to be at least min(num_support_commands, @n_commands)
104  *
105  * Allow userspace to query the available commands supported by both the driver,
106  * and the hardware. Commands that aren't supported by either the driver, or the
107  * hardware are not returned in the query.
108  *
109  * Examples:
110  *
111  *  - { .n_commands = 0 } // Get number of supported commands
112  *  - { .n_commands = 15, .commands = buf } // Return first 15 (or less)
113  *    supported commands
114  *
115  *  See struct cxl_command_info.
116  */
117 struct cxl_mem_query_commands {
118 	/*
119 	 * Input: Number of commands to return (space allocated by user)
120 	 * Output: Number of commands supported by the driver/hardware
121 	 *
122 	 * If n_commands is 0, kernel will only return number of commands and
123 	 * not try to populate commands[], thus allowing userspace to know how
124 	 * much space to allocate
125 	 */
126 	__u32 n_commands;
127 	__u32 rsvd;
128 
129 	struct cxl_command_info __user commands[]; /* out: supported commands */
130 };
131 
132 /**
133  * struct cxl_send_command - Send a command to a memory device.
134  * @id: The command to send to the memory device. This must be one of the
135  *	commands returned by the query command.
136  * @flags: Flags for the command (input).
137  * @raw: Special fields for raw commands
138  * @raw.opcode: Opcode passed to hardware when using the RAW command.
139  * @raw.rsvd: Must be zero.
140  * @rsvd: Must be zero.
141  * @retval: Return value from the memory device (output).
142  * @in: Parameters associated with input payload.
143  * @in.size: Size of the payload to provide to the device (input).
144  * @in.rsvd: Must be zero.
145  * @in.payload: Pointer to memory for payload input, payload is little endian.
146  * @out: Parameters associated with output payload.
147  * @out.size: Size of the payload received from the device (input/output). This
148  *	      field is filled in by userspace to let the driver know how much
149  *	      space was allocated for output. It is populated by the driver to
150  *	      let userspace know how large the output payload actually was.
151  * @out.rsvd: Must be zero.
152  * @out.payload: Pointer to memory for payload output, payload is little endian.
153  *
154  * Mechanism for userspace to send a command to the hardware for processing. The
155  * driver will do basic validation on the command sizes. In some cases even the
156  * payload may be introspected. Userspace is required to allocate large enough
157  * buffers for size_out which can be variable length in certain situations.
158  */
159 struct cxl_send_command {
160 	__u32 id;
161 	__u32 flags;
162 	union {
163 		struct {
164 			__u16 opcode;
165 			__u16 rsvd;
166 		} raw;
167 		__u32 rsvd;
168 	};
169 	__u32 retval;
170 
171 	struct {
172 		__u32 size;
173 		__u32 rsvd;
174 		__u64 payload;
175 	} in;
176 
177 	struct {
178 		__u32 size;
179 		__u32 rsvd;
180 		__u64 payload;
181 	} out;
182 };
183 
184 #endif
185