xref: /openbmc/linux/include/rdma/iba.h (revision fb574682)
1 /* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
2 /*
3  * Copyright (c) 2020, Mellanox Technologies inc.  All rights reserved.
4  */
5 #ifndef _IBA_DEFS_H_
6 #define _IBA_DEFS_H_
7 
8 #include <linux/kernel.h>
9 #include <linux/bitfield.h>
10 #include <asm/unaligned.h>
11 
12 static inline u32 _iba_get8(const u8 *ptr)
13 {
14 	return *ptr;
15 }
16 
17 static inline void _iba_set8(u8 *ptr, u32 mask, u32 prep_value)
18 {
19 	*ptr = (*ptr & ~mask) | prep_value;
20 }
21 
22 static inline u16 _iba_get16(const __be16 *ptr)
23 {
24 	return be16_to_cpu(*ptr);
25 }
26 
27 static inline void _iba_set16(__be16 *ptr, u16 mask, u16 prep_value)
28 {
29 	*ptr = cpu_to_be16((be16_to_cpu(*ptr) & ~mask) | prep_value);
30 }
31 
32 static inline u32 _iba_get32(const __be32 *ptr)
33 {
34 	return be32_to_cpu(*ptr);
35 }
36 
37 static inline void _iba_set32(__be32 *ptr, u32 mask, u32 prep_value)
38 {
39 	*ptr = cpu_to_be32((be32_to_cpu(*ptr) & ~mask) | prep_value);
40 }
41 
42 static inline u64 _iba_get64(const __be64 *ptr)
43 {
44 	/*
45 	 * The mads are constructed so that 32 bit and smaller are naturally
46 	 * aligned, everything larger has a max alignment of 4 bytes.
47 	 */
48 	return be64_to_cpu(get_unaligned(ptr));
49 }
50 
51 static inline void _iba_set64(__be64 *ptr, u64 mask, u64 prep_value)
52 {
53 	put_unaligned(cpu_to_be64((_iba_get64(ptr) & ~mask) | prep_value), ptr);
54 }
55 
56 #define _IBA_SET(field_struct, field_offset, field_mask, num_bits, ptr, value) \
57 	({                                                                     \
58 		field_struct *_ptr = ptr;                                      \
59 		_iba_set##num_bits((void *)_ptr + (field_offset), field_mask,  \
60 				   FIELD_PREP(field_mask, value));             \
61 	})
62 #define IBA_SET(field, ptr, value) _IBA_SET(field, ptr, value)
63 
64 #define _IBA_GET_MEM_PTR(field_struct, field_offset, type, num_bits, ptr)      \
65 	({                                                                     \
66 		field_struct *_ptr = ptr;                                      \
67 		(type *)((void *)_ptr + (field_offset));                       \
68 	})
69 #define IBA_GET_MEM_PTR(field, ptr) _IBA_GET_MEM_PTR(field, ptr)
70 
71 /* FIXME: A set should always set the entire field, meaning we should zero the trailing bytes */
72 #define _IBA_SET_MEM(field_struct, field_offset, type, num_bits, ptr, in,      \
73 		     bytes)                                                    \
74 	({                                                                     \
75 		const type *_in_ptr = in;                                      \
76 		WARN_ON(bytes * 8 > num_bits);                                 \
77 		if (in && bytes)                                               \
78 			memcpy(_IBA_GET_MEM_PTR(field_struct, field_offset,    \
79 						type, num_bits, ptr),          \
80 			       _in_ptr, bytes);                                \
81 	})
82 #define IBA_SET_MEM(field, ptr, in, bytes) _IBA_SET_MEM(field, ptr, in, bytes)
83 
84 #define _IBA_GET(field_struct, field_offset, field_mask, num_bits, ptr)        \
85 	({                                                                     \
86 		const field_struct *_ptr = ptr;                                \
87 		(u##num_bits) FIELD_GET(                                       \
88 			field_mask, _iba_get##num_bits((const void *)_ptr +    \
89 						       (field_offset)));       \
90 	})
91 #define IBA_GET(field, ptr) _IBA_GET(field, ptr)
92 
93 #define _IBA_GET_MEM(field_struct, field_offset, type, num_bits, ptr, out,     \
94 		     bytes)                                                    \
95 	({                                                                     \
96 		type *_out_ptr = out;                                          \
97 		WARN_ON(bytes * 8 > num_bits);                                 \
98 		if (out && bytes)                                              \
99 			memcpy(_out_ptr,                                       \
100 			       _IBA_GET_MEM_PTR(field_struct, field_offset,    \
101 						type, num_bits, ptr),          \
102 			       bytes);                                         \
103 	})
104 #define IBA_GET_MEM(field, ptr, out, bytes) _IBA_GET_MEM(field, ptr, out, bytes)
105 
106 /*
107  * The generated list becomes the parameters to the macros, the order is:
108  *  - struct this applies to
109  *  - starting offset of the max
110  *  - GENMASK or GENMASK_ULL in CPU order
111  *  - The width of data the mask operations should work on, in bits
112  */
113 
114 /*
115  * Extraction using a tabular description like table 106. bit_offset is from
116  * the Byte[Bit] notation.
117  */
118 #define IBA_FIELD_BLOC(field_struct, byte_offset, bit_offset, num_bits)        \
119 	field_struct, byte_offset,                                             \
120 		GENMASK(7 - (bit_offset), 7 - (bit_offset) - (num_bits - 1)),  \
121 		8
122 #define IBA_FIELD8_LOC(field_struct, byte_offset, num_bits)                    \
123 	IBA_FIELD_BLOC(field_struct, byte_offset, 0, num_bits)
124 
125 #define IBA_FIELD16_LOC(field_struct, byte_offset, num_bits)                   \
126 	field_struct, (byte_offset)&0xFFFE,                                    \
127 		GENMASK(15 - (((byte_offset) % 2) * 8),                        \
128 			15 - (((byte_offset) % 2) * 8) - (num_bits - 1)),      \
129 		16
130 
131 #define IBA_FIELD32_LOC(field_struct, byte_offset, num_bits)                   \
132 	field_struct, (byte_offset)&0xFFFC,                                    \
133 		GENMASK(31 - (((byte_offset) % 4) * 8),                        \
134 			31 - (((byte_offset) % 4) * 8) - (num_bits - 1)),      \
135 		32
136 
137 #define IBA_FIELD64_LOC(field_struct, byte_offset)                             \
138 	field_struct, byte_offset, GENMASK_ULL(63, 0), 64
139 /*
140  * In IBTA spec, everything that is more than 64bits is multiple
141  * of bytes without leftover bits.
142  */
143 #define IBA_FIELD_MLOC(field_struct, byte_offset, num_bits, type)              \
144 	field_struct, byte_offset, type, num_bits
145 
146 #endif /* _IBA_DEFS_H_ */
147