include/rdma/iba.h

   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_ */