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Subject[PATCH] docs: packing: move it to core-api book and adjust markups
Date
The packing.txt file was misplaced, as docs should be part of
a documentation book, and not at the root dir.

So, move it to the core-api directory and add to its index.

Also, ensure that the file will be properly parsed and the bitmap
ascii artwork will use a monotonic font.

Fixes: 554aae35007e ("lib: Add support for generic packing operations")
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
---
Documentation/core-api/index.rst | 1 +
.../{packing.txt => core-api/packing.rst} | 81 +++++++++++--------
2 files changed, 50 insertions(+), 32 deletions(-)
rename Documentation/{packing.txt => core-api/packing.rst} (61%)

diff --git a/Documentation/core-api/index.rst b/Documentation/core-api/index.rst
index d1e5b95bf86d..aebb16d7771f 100644
--- a/Documentation/core-api/index.rst
+++ b/Documentation/core-api/index.rst
@@ -25,6 +25,7 @@ Core utilities
librs
genalloc
errseq
+ packing
printk-formats
circular-buffers
generic-radix-tree
diff --git a/Documentation/packing.txt b/Documentation/core-api/packing.rst
similarity index 61%
rename from Documentation/packing.txt
rename to Documentation/core-api/packing.rst
index f830c98645f1..d8c341fe383e 100644
--- a/Documentation/packing.txt
+++ b/Documentation/core-api/packing.rst
@@ -30,6 +30,7 @@ The solution
------------

This API deals with 2 basic operations:
+
- Packing a CPU-usable number into a memory buffer (with hardware
constraints/quirks)
- Unpacking a memory buffer (which has hardware constraints/quirks)
@@ -49,10 +50,12 @@ What the examples show is where the logical bytes and bits sit.

1. Normally (no quirks), we would do it like this:

-63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32
-7 6 5 4
-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
-3 2 1 0
+::
+
+ 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32
+ 7 6 5 4
+ 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
+ 3 2 1 0

That is, the MSByte (7) of the CPU-usable u64 sits at memory offset 0, and the
LSByte (0) of the u64 sits at memory offset 7.
@@ -63,10 +66,12 @@ comments as "logical" notation.

2. If QUIRK_MSB_ON_THE_RIGHT is set, we do it like this:

-56 57 58 59 60 61 62 63 48 49 50 51 52 53 54 55 40 41 42 43 44 45 46 47 32 33 34 35 36 37 38 39
-7 6 5 4
-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
-3 2 1 0
+::
+
+ 56 57 58 59 60 61 62 63 48 49 50 51 52 53 54 55 40 41 42 43 44 45 46 47 32 33 34 35 36 37 38 39
+ 7 6 5 4
+ 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
+ 3 2 1 0

That is, QUIRK_MSB_ON_THE_RIGHT does not affect byte positioning, but
inverts bit offsets inside a byte.
@@ -74,10 +79,12 @@ inverts bit offsets inside a byte.

3. If QUIRK_LITTLE_ENDIAN is set, we do it like this:

-39 38 37 36 35 34 33 32 47 46 45 44 43 42 41 40 55 54 53 52 51 50 49 48 63 62 61 60 59 58 57 56
-4 5 6 7
-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
-0 1 2 3
+::
+
+ 39 38 37 36 35 34 33 32 47 46 45 44 43 42 41 40 55 54 53 52 51 50 49 48 63 62 61 60 59 58 57 56
+ 4 5 6 7
+ 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
+ 0 1 2 3

Therefore, QUIRK_LITTLE_ENDIAN means that inside the memory region, every
byte from each 4-byte word is placed at its mirrored position compared to
@@ -86,18 +93,22 @@ the boundary of that word.
4. If QUIRK_MSB_ON_THE_RIGHT and QUIRK_LITTLE_ENDIAN are both set, we do it
like this:

-32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63
-4 5 6 7
-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
-0 1 2 3
+::
+
+ 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63
+ 4 5 6 7
+ 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
+ 0 1 2 3


5. If just QUIRK_LSW32_IS_FIRST is set, we do it like this:

-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
-3 2 1 0
-63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32
-7 6 5 4
+::
+
+ 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
+ 3 2 1 0
+ 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32
+ 7 6 5 4

In this case the 8 byte memory region is interpreted as follows: first
4 bytes correspond to the least significant 4-byte word, next 4 bytes to
@@ -107,28 +118,34 @@ the more significant 4-byte word.
6. If QUIRK_LSW32_IS_FIRST and QUIRK_MSB_ON_THE_RIGHT are set, we do it like
this:

-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
-3 2 1 0
-56 57 58 59 60 61 62 63 48 49 50 51 52 53 54 55 40 41 42 43 44 45 46 47 32 33 34 35 36 37 38 39
-7 6 5 4
+::
+
+ 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
+ 3 2 1 0
+ 56 57 58 59 60 61 62 63 48 49 50 51 52 53 54 55 40 41 42 43 44 45 46 47 32 33 34 35 36 37 38 39
+ 7 6 5 4


7. If QUIRK_LSW32_IS_FIRST and QUIRK_LITTLE_ENDIAN are set, it looks like
this:

-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
-0 1 2 3
-39 38 37 36 35 34 33 32 47 46 45 44 43 42 41 40 55 54 53 52 51 50 49 48 63 62 61 60 59 58 57 56
-4 5 6 7
+::
+
+ 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
+ 0 1 2 3
+ 39 38 37 36 35 34 33 32 47 46 45 44 43 42 41 40 55 54 53 52 51 50 49 48 63 62 61 60 59 58 57 56
+ 4 5 6 7


8. If QUIRK_LSW32_IS_FIRST, QUIRK_LITTLE_ENDIAN and QUIRK_MSB_ON_THE_RIGHT
are set, it looks like this:

-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
-0 1 2 3
-32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63
-4 5 6 7
+::
+
+ 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
+ 0 1 2 3
+ 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63
+ 4 5 6 7


We always think of our offsets as if there were no quirk, and we translate
--
2.21.0
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