Lines Matching +full:3 +full:- +full:byte
6 -----------------
10 One can memory-map a pointer to a carefully crafted struct over the hardware
23 were performed byte-by-byte. Also the code can easily get cluttered, and the
24 high-level idea might get lost among the many bit shifts required.
25 Many drivers take the bit-shifting approach and then attempt to reduce the
30 ------------
34 - Packing a CPU-usable number into a memory buffer (with hardware
36 - Unpacking a memory buffer (which has hardware constraints/quirks)
37 into a CPU-usable number.
44 perspective, bit 63 always means bit offset 7 of byte 7, albeit only
48 The byte offsets in the packed buffer are always implicitly 0, 1, ... 7.
57 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
58 3 2 1 0
60 That is, the MSByte (7) of the CPU-usable u64 sits at memory offset 0, and the
73 24 25 26 27 28 29 30 31 16 17 18 19 20 21 22 23 8 9 10 11 12 13 14 15 0 1 2 3 4 5 6 7
74 3 2 1 0
76 That is, QUIRK_MSB_ON_THE_RIGHT does not affect byte positioning, but
77 inverts bit offsets inside a byte.
80 3. If QUIRK_LITTLE_ENDIAN is set, we do it like this:
86 7 6 5 4 3 2 1 0 15 14 13 12 11 10 9 8 23 22 21 20 19 18 17 16 31 30 29 28 27 26 25 24
87 0 1 2 3
90 byte from each 4-byte word is placed at its mirrored position compared to
100 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
101 0 1 2 3
108 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
109 3 2 1 0
113 In this case the 8 byte memory region is interpreted as follows: first
114 4 bytes correspond to the least significant 4-byte word, next 4 bytes to
115 the more significant 4-byte word.
123 24 25 26 27 28 29 30 31 16 17 18 19 20 21 22 23 8 9 10 11 12 13 14 15 0 1 2 3 4 5 6 7
124 3 2 1 0
134 7 6 5 4 3 2 1 0 15 14 13 12 11 10 9 8 23 22 21 20 19 18 17 16 31 30 29 28 27 26 25 24
135 0 1 2 3
145 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
146 0 1 2 3
155 ------------
157 Drivers that opt to use this API first need to identify which of the above 3
160 xxx_packing() that calls it using the proper QUIRK_* one-hot bits set.
162 The packing() function returns an int-encoded error code, which protects the