diff mbox series

[RFC,04/12] types: Introduce [us]128

Message ID 20221219154119.087799661@infradead.org (mailing list archive)
State New
Headers show
Series Introduce cmpxchg128() -- aka. the demise of cmpxchg_double() | expand

Commit Message

Peter Zijlstra Dec. 19, 2022, 3:35 p.m. UTC
Introduce [us]128 (when available). Unlike [us]64, ensure they are
always naturally aligned.

This also enables 128bit wide atomics (which require natural
alignment) such as cmpxchg128().

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 include/linux/types.h      |    5 +++++
 include/uapi/linux/types.h |    4 ++++
 2 files changed, 9 insertions(+)

Comments

Pavel Machek Dec. 29, 2022, 8:30 a.m. UTC | #1
Hi!

> Introduce [us]128 (when available). Unlike [us]64, ensure they are
> always naturally aligned.
> 
> This also enables 128bit wide atomics (which require natural
> alignment) such as cmpxchg128().
> 
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> ---
>  include/linux/types.h      |    5 +++++
>  include/uapi/linux/types.h |    4 ++++
>  2 files changed, 9 insertions(+)
> 
> --- a/include/linux/types.h
> +++ b/include/linux/types.h
> @@ -10,6 +10,11 @@
>  #define DECLARE_BITMAP(name,bits) \
>  	unsigned long name[BITS_TO_LONGS(bits)]
>  
> +#ifdef __SIZEOF_INT128__
> +typedef __s128 s128;
> +typedef __u128 u128;
> +#endif

Should this come as a note here?

> Introduce [us]128 (when available). Unlike [us]64, ensure they are
> always naturally aligned.

BR,
							Pavel
diff mbox series

Patch

--- a/include/linux/types.h
+++ b/include/linux/types.h
@@ -10,6 +10,11 @@ 
 #define DECLARE_BITMAP(name,bits) \
 	unsigned long name[BITS_TO_LONGS(bits)]
 
+#ifdef __SIZEOF_INT128__
+typedef __s128 s128;
+typedef __u128 u128;
+#endif
+
 typedef u32 __kernel_dev_t;
 
 typedef __kernel_fd_set		fd_set;
--- a/include/uapi/linux/types.h
+++ b/include/uapi/linux/types.h
@@ -13,6 +13,10 @@ 
 
 #include <linux/posix_types.h>
 
+#ifdef __SIZEOF_INT128__
+typedef __signed__ __int128 __s128 __attribute__((aligned(16)));
+typedef unsigned __int128 __u128 __attribute__((aligned(16)));
+#endif
 
 /*
  * Below are truly Linux-specific types that should never collide with