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From: Ilya Leoshkevich <iii@linux.ibm.com>
To: Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Andrii Nakryiko <andrii@kernel.org>, Yonghong Song <yhs@fb.com>,
	Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: John Fastabend <john.fastabend@gmail.com>,
	bpf@vger.kernel.org, Heiko Carstens <heiko.carstens@de.ibm.com>,
	Vasily Gorbik <gor@linux.ibm.com>,
	Ilya Leoshkevich <iii@linux.ibm.com>
Subject: [PATCH v2 bpf-next 6/6] bpf: Document BTF_KIND_FLOAT in btf.rst
Date: Fri, 19 Feb 2021 03:25:43 +0100
Message-ID: <20210219022543.20893-7-iii@linux.ibm.com> (raw)
In-Reply-To: <20210219022543.20893-1-iii@linux.ibm.com>

Also document the expansion of the kind bitfield.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
 Documentation/bpf/btf.rst | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/Documentation/bpf/btf.rst b/Documentation/bpf/btf.rst
index 44dc789de2b4..4f25c992d442 100644
--- a/Documentation/bpf/btf.rst
+++ b/Documentation/bpf/btf.rst
@@ -84,6 +84,7 @@ sequentially and type id is assigned to each recognized type starting from id
     #define BTF_KIND_FUNC_PROTO     13      /* Function Proto       */
     #define BTF_KIND_VAR            14      /* Variable     */
     #define BTF_KIND_DATASEC        15      /* Section      */
+    #define BTF_KIND_FLOAT          16      /* Floating point       */
 
 Note that the type section encodes debug info, not just pure types.
 ``BTF_KIND_FUNC`` is not a type, and it represents a defined subprogram.
@@ -95,8 +96,8 @@ Each type contains the following common data::
         /* "info" bits arrangement
          * bits  0-15: vlen (e.g. # of struct's members)
          * bits 16-23: unused
-         * bits 24-27: kind (e.g. int, ptr, array...etc)
-         * bits 28-30: unused
+         * bits 24-28: kind (e.g. int, ptr, array...etc)
+         * bits 29-30: unused
          * bit     31: kind_flag, currently used by
          *             struct, union and fwd
          */
@@ -452,6 +453,18 @@ map definition.
   * ``offset``: the in-section offset of the variable
   * ``size``: the size of the variable in bytes
 
+2.2.16 BTF_KIND_FLOAT
+~~~~~~~~~~~~~~~~~~~~~
+
+``struct btf_type`` encoding requirement:
+ * ``name_off``: any valid offset
+ * ``info.kind_flag``: 0
+ * ``info.kind``: BTF_KIND_FLOAT
+ * ``info.vlen``: 0
+ * ``size``: the size of the float type in bytes.
+
+No additional type data follow ``btf_type``.
+
 3. BTF Kernel API
 *****************
 
-- 
2.29.2


  parent reply index

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-19  2:25 [PATCH v2 bpf-next 0/6] Add BTF_KIND_FLOAT support Ilya Leoshkevich
2021-02-19  2:25 ` [PATCH v2 bpf-next 1/6] bpf: Add BTF_KIND_FLOAT to uapi Ilya Leoshkevich
2021-02-19  2:25 ` [PATCH v2 bpf-next 2/6] libbpf: Add BTF_KIND_FLOAT support Ilya Leoshkevich
2021-02-19  4:22   ` Yonghong Song
2021-02-19 23:01     ` Ilya Leoshkevich
2021-02-19 23:35       ` Yonghong Song
2021-02-19 23:43         ` Ilya Leoshkevich
2021-02-19  2:25 ` [PATCH v2 bpf-next 3/6] tools/bpftool: " Ilya Leoshkevich
2021-02-19  2:25 ` [PATCH v2 bpf-next 4/6] bpf: " Ilya Leoshkevich
2021-02-19  4:04   ` kernel test robot
2021-02-19  4:13   ` kernel test robot
2021-02-19  2:25 ` [PATCH v2 bpf-next 5/6] selftest/bpf: Add BTF_KIND_FLOAT tests Ilya Leoshkevich
2021-02-19  5:38   ` Yonghong Song
2021-02-19  5:44   ` Yonghong Song
2021-02-19  2:25 ` Ilya Leoshkevich [this message]
2021-02-19  5:41   ` [PATCH v2 bpf-next 6/6] bpf: Document BTF_KIND_FLOAT in btf.rst Yonghong Song
2021-02-19 13:00     ` Ilya Leoshkevich
2021-02-19 15:26       ` Yonghong Song

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