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kernel: add common infrastructure for unaligned access

PATCH Applied Harvey Harrison 2 participants 3 messages Apr 14, 2008 1 message not in the archive Generic include/asm header files

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Harvey Harrison

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PATCH v4 1/2 kernel: add common infrastructure for unaligned access

Create a linux/unaligned folder similar in spirit to the linux/byteorder folder to hold generic implementations collected from various arches.

Currently there are five implementations:
1) packed_struct.h: C-struct based, from asm-generic/unaligned.h
2) le_byteshift.h: Open coded byte-swapping, heavily based on asm-arm
3) be_byteshift.h: Open coded byte-swapping, heavily based on asm-arm
4) memmove.h: taken from multiple implementations in tree
5) access_ok.h: taken from x86 and others, unaligned access is ok.

All of the new implementations checks for sizes not equal to 1,2,4,8 and will fail to link.

API additions:

get_unaligned_{le16|le32|le64|be16|be32|be64}(p) which is meant to replace code of the form:
le16_to_cpu(get_unaligned((__le16 *)p));

put_unaligned_{le16|le32|le64|be16|be32|be64}(val, pointer) which is meant to replace code of the form:
put_unaligned(cpu_to_le16(val), (__le16 *)p);

The headers that arches should include from their asm/unaligned.h:

access_ok.h : Wrappers of the byteswapping functions in asm/byteorder

Choose a particular implementation for little-endian access:
le_byteshift.h
le_memmove.h (arch must be LE)
le_struct.h (arch must be LE)

Choose a particular implementation for big-endian access:
be_byteshift.h
be_memmove.h (arch must be BE)
be_struct.h (arch must be BE)

After including as needed from the above, include unaligned/generic.h and define your arch's get/put_unaligned as (for LE):

Signed-off-by Harvey Harrison <[email protected]>

---
Update to consistent #ifndef tests in each header file.

 include/linux/unaligned/access_ok.h     |   67 +++++++++++++++++++++++++++++
 include/linux/unaligned/be_byteshift.h  |   70 +++++++++++++++++++++++++++++++
 include/linux/unaligned/be_memmove.h    |   36 ++++++++++++++++
 include/linux/unaligned/be_struct.h     |   36 ++++++++++++++++
 include/linux/unaligned/generic.h       |   68 ++++++++++++++++++++++++++++++
 include/linux/unaligned/le_byteshift.h  |   70 +++++++++++++++++++++++++++++++
 include/linux/unaligned/le_memmove.h    |   36 ++++++++++++++++
 include/linux/unaligned/le_struct.h     |   36 ++++++++++++++++
 include/linux/unaligned/memmove.h       |   45 ++++++++++++++++++++
 include/linux/unaligned/packed_struct.h |   46 ++++++++++++++++++++
 10 files changed, 510 insertions(+), 0 deletions(-)
include/linux/unaligned/access_ok.h new file +67 -0
new file mode 100644
index 0000000..99c1b4d
@@ -0,0 +1,67 @@
+#ifndef _LINUX_UNALIGNED_ACCESS_OK_H
+#define _LINUX_UNALIGNED_ACCESS_OK_H
+
+#include <linux/kernel.h>
+#include <asm/byteorder.h>
+
+static inline u16 get_unaligned_le16(const void *p)
+{
+	return le16_to_cpup((__le16 *)p);
+}
+
+static inline u32 get_unaligned_le32(const void *p)
+{
+	return le32_to_cpup((__le32 *)p);
+}
+
+static inline u64 get_unaligned_le64(const void *p)
+{
+	return le64_to_cpup((__le64 *)p);
+}
+
+static inline u16 get_unaligned_be16(const void *p)
+{
+	return be16_to_cpup((__be16 *)p);
+}
+
+static inline u32 get_unaligned_be32(const void *p)
+{
+	return be32_to_cpup((__be32 *)p);
+}
+
+static inline u64 get_unaligned_be64(const void *p)
+{
+	return be64_to_cpup((__be64 *)p);
+}
+
+static inline void put_unaligned_le16(u16 val, void *p)
+{
+	*((__le16 *)p) = cpu_to_le16(val);
+}
+
+static inline void put_unaligned_le32(u32 val, void *p)
+{
+	*((__le32 *)p) = cpu_to_le32(val);
+}
+
+static inline void put_unaligned_le64(u64 val, void *p)
+{
+	*((__le64 *)p) = cpu_to_le64(val);
+}
+
+static inline void put_unaligned_be16(u16 val, void *p)
+{
+	*((__be16 *)p) = cpu_to_be16(val);
+}
+
+static inline void put_unaligned_be32(u32 val, void *p)
+{
+	*((__be32 *)p) = cpu_to_be32(val);
+}
+
+static inline void put_unaligned_be64(u64 val, void *p)
+{
+	*((__be64 *)p) = cpu_to_be64(val);
+}
+
+#endif /* _LINUX_UNALIGNED_ACCESS_OK_H */
include/linux/unaligned/be_byteshift.h new file +70 -0

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include/linux/unaligned/be_memmove.h new file +36 -0
new file mode 100644
index 0000000..c2a76c5
@@ -0,0 +1,36 @@
+#ifndef _LINUX_UNALIGNED_BE_MEMMOVE_H
+#define _LINUX_UNALIGNED_BE_MEMMOVE_H
+
+#include <linux/unaligned/memmove.h>
+
+static inline u16 get_unaligned_be16(const void *p)
+{
+	return __get_unaligned_memmove16((const u8 *)p);
+}
+
+static inline u32 get_unaligned_be32(const void *p)
+{
+	return __get_unaligned_memmove32((const u8 *)p);
+}
+
+static inline u64 get_unaligned_be64(const void *p)
+{
+	return __get_unaligned_memmove64((const u8 *)p);
+}
+
+static inline void put_unaligned_be16(u16 val, void *p)
+{
+	__put_unaligned_memmove16(val, p);
+}
+
+static inline void put_unaligned_be32(u32 val, void *p)
+{
+	__put_unaligned_memmove32(val, p);
+}
+
+static inline void put_unaligned_be64(u64 val, void *p)
+{
+	__put_unaligned_memmove64(val, p);
+}
+
+#endif /* _LINUX_UNALIGNED_LE_MEMMOVE_H */
include/linux/unaligned/be_struct.h new file +36 -0
new file mode 100644
index 0000000..1324158
@@ -0,0 +1,36 @@
+#ifndef _LINUX_UNALIGNED_BE_STRUCT_H
+#define _LINUX_UNALIGNED_BE_STRUCT_H
+
+#include <linux/unaligned/packed_struct.h>
+
+static inline u16 get_unaligned_be16(const void *p)
+{
+	return __get_unaligned_cpu16((const u8 *)p);
+}
+
+static inline u32 get_unaligned_be32(const void *p)
+{
+	return __get_unaligned_cpu32((const u8 *)p);
+}
+
+static inline u64 get_unaligned_be64(const void *p)
+{
+	return __get_unaligned_cpu64((const u8 *)p);
+}
+
+static inline void put_unaligned_be16(u16 val, void *p)
+{
+	__put_unaligned_cpu16(val, p);
+}
+
+static inline void put_unaligned_be32(u32 val, void *p)
+{
+	__put_unaligned_cpu32(val, p);
+}
+
+static inline void put_unaligned_be64(u64 val, void *p)
+{
+	__put_unaligned_cpu64(val, p);
+}
+
+#endif /* _LINUX_UNALIGNED_BE_STRUCT_H */
include/linux/unaligned/generic.h new file +68 -0

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include/linux/unaligned/le_byteshift.h new file +70 -0

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include/linux/unaligned/le_memmove.h new file +36 -0
new file mode 100644
index 0000000..269849b
@@ -0,0 +1,36 @@
+#ifndef _LINUX_UNALIGNED_LE_MEMMOVE_H
+#define _LINUX_UNALIGNED_LE_MEMMOVE_H
+
+#include <linux/unaligned/memmove.h>
+
+static inline u16 get_unaligned_le16(const void *p)
+{
+	return __get_unaligned_memmove16((const u8 *)p);
+}
+
+static inline u32 get_unaligned_le32(const void *p)
+{
+	return __get_unaligned_memmove32((const u8 *)p);
+}
+
+static inline u64 get_unaligned_le64(const void *p)
+{
+	return __get_unaligned_memmove64((const u8 *)p);
+}
+
+static inline void put_unaligned_le16(u16 val, void *p)
+{
+	__put_unaligned_memmove16(val, p);
+}
+
+static inline void put_unaligned_le32(u32 val, void *p)
+{
+	__put_unaligned_memmove32(val, p);
+}
+
+static inline void put_unaligned_le64(u64 val, void *p)
+{
+	__put_unaligned_memmove64(val, p);
+}
+
+#endif /* _LINUX_UNALIGNED_LE_MEMMOVE_H */
include/linux/unaligned/le_struct.h new file +36 -0
new file mode 100644
index 0000000..088c457
@@ -0,0 +1,36 @@
+#ifndef _LINUX_UNALIGNED_LE_STRUCT_H
+#define _LINUX_UNALIGNED_LE_STRUCT_H
+
+#include <linux/unaligned/packed_struct.h>
+
+static inline u16 get_unaligned_le16(const void *p)
+{
+	return __get_unaligned_cpu16((const u8 *)p);
+}
+
+static inline u32 get_unaligned_le32(const void *p)
+{
+	return __get_unaligned_cpu32((const u8 *)p);
+}
+
+static inline u64 get_unaligned_le64(const void *p)
+{
+	return __get_unaligned_cpu64((const u8 *)p);
+}
+
+static inline void put_unaligned_le16(u16 val, void *p)
+{
+	__put_unaligned_cpu16(val, p);
+}
+
+static inline void put_unaligned_le32(u32 val, void *p)
+{
+	__put_unaligned_cpu32(val, p);
+}
+
+static inline void put_unaligned_le64(u64 val, void *p)
+{
+	__put_unaligned_cpu64(val, p);
+}
+
+#endif /* _LINUX_UNALIGNED_LE_STRUCT_H */
include/linux/unaligned/memmove.h new file +45 -0

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include/linux/unaligned/packed_struct.h new file +46 -0

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Signature · 1 line
1.5.5.144.g3e42
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#1 lore raw
Quoted 2 lines · On Mon, 14 Apr 2008 10:50:06 -0700 Harvey Harrison…

Create a linux/unaligned folder similar in spirit to the linux/byteorder folder to hold generic implementations collected from various arches.

ooh, there's a cultural faux pas. I changed it to "directory" ;)

Quoted 1 line

[Andrew: I think we're getting close to something that could go into -mm]

I queued them up, thanks.

A message that is not in the archive (sent off-list or not yet received): 20080414151417.f8ab4365.akpm-de/[email protected]

author
#3 lore raw
Quoted 8 lines · Andrew Morton
Quoted 2 lines · On Mon, 14 Apr 2008 10:50:06 -0700 Harvey Harrison…

Create a linux/unaligned folder similar in spirit to the linux/byteorder folder to hold generic implementations collected from various arches.

ooh, there's a cultural faux pas. I changed it to "directory" ;)

Damn, I was hoping to hide some unfortunate mental damage early on in life ;)

Cheers,

Harvey