Re: [PATCH 4/5] asm-generic: use asm-generic/mman-common.h on parisc and alpha

[Lorenzo Stoakes]

On Wed, Sep 25, 2024 at 09:06:14PM +0000, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@xxxxxxxx>
>
> These two architectures each have their own set of MAP_* flags, like
> powerpc, mips and others do. In addition, the msync() flags are also
> different, here both define the same flags but in a different order.
> Finally, alpha also has a custom MADV_DONTNEED flag for madvise.
>
> Make the generic MADV_DONTNEED and MS_* definitions conditional on
> them already being defined and then include the common header
> header from both architectures, to remove the bulk of the contents.
>
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>

Lovely! Look at all that red :) Great work!

Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>

> ---
>  arch/alpha/include/uapi/asm/mman.h     | 68 +++-----------------------
>  arch/parisc/include/uapi/asm/mman.h    | 66 +------------------------
>  include/uapi/asm-generic/mman-common.h |  5 ++
>  3 files changed, 13 insertions(+), 126 deletions(-)
>
> diff --git a/arch/alpha/include/uapi/asm/mman.h b/arch/alpha/include/uapi/asm/mman.h
> index 1f1c03c047ce..fc8b74aa3f89 100644
> --- a/arch/alpha/include/uapi/asm/mman.h
> +++ b/arch/alpha/include/uapi/asm/mman.h
> @@ -2,18 +2,6 @@
>  #ifndef __ALPHA_MMAN_H__
>  #define __ALPHA_MMAN_H__
>
> -#define PROT_READ	0x1		/* page can be read */
> -#define PROT_WRITE	0x2		/* page can be written */
> -#define PROT_EXEC	0x4		/* page can be executed */
> -#ifndef PROT_SEM /* different on mips and xtensa */
> -#define PROT_SEM	0x8		/* page may be used for atomic ops */
> -#endif
> -/*			0x10		   reserved for arch-specific use */
> -/*			0x20		   reserved for arch-specific use */
> -#define PROT_NONE	0x0		/* page can not be accessed */
> -#define PROT_GROWSDOWN	0x01000000	/* mprotect flag: extend change to start of growsdown vma */
> -#define PROT_GROWSUP	0x02000000	/* mprotect flag: extend change to end of growsup vma */
> -
>  /* 0x01 - 0x03 are defined in linux/mman.h */
>  #define MAP_TYPE	0x0f		/* Mask for type of mapping (OSF/1 is _wrong_) */
>  #define MAP_FIXED	0x100		/* Interpret addr exactly */
> @@ -43,62 +31,18 @@
>  #define MCL_ONFAULT	32768		/* lock all pages that are faulted in */
>
>  /*
> - * Flags for mlock
> - */
> -#define MLOCK_ONFAULT	0x01		/* Lock pages in range after they are faulted in, do not prefault */
> -
> -/*
> - * Flags for msync
> + * Flags for msync, order is different from all others
>   */
>  #define MS_ASYNC	1		/* sync memory asynchronously */
>  #define MS_SYNC		2		/* synchronous memory sync */
>  #define MS_INVALIDATE	4		/* invalidate the caches */
>
> -#define MADV_NORMAL	0		/* no further special treatment */
> -#define MADV_RANDOM	1		/* expect random page references */
> -#define MADV_SEQUENTIAL	2		/* expect sequential page references */
> -#define MADV_WILLNEED	3		/* will need these pages */
> -#define MADV_DONTNEED	6		/* don't need these pages */
> +/*
> + * Flags for madvise, 1 through 3 are normal
> + */
>  /* originally MADV_SPACEAVAIL 5 */
> +#define MADV_DONTNEED	6		/* don't need these pages */
>
> -/* common parameters: try to keep these consistent across architectures */
> -#define MADV_FREE	8		/* free pages only if memory pressure */
> -#define MADV_REMOVE	9		/* remove these pages & resources */
> -#define MADV_DONTFORK	10		/* don't inherit across fork */
> -#define MADV_DOFORK	11		/* do inherit across fork */
> -
> -#define MADV_MERGEABLE   12		/* KSM may merge identical pages */
> -#define MADV_UNMERGEABLE 13		/* KSM may not merge identical pages */
> -
> -#define MADV_HUGEPAGE	14		/* Worth backing with hugepages */
> -#define MADV_NOHUGEPAGE	15		/* Not worth backing with hugepages */
> -
> -#define MADV_DONTDUMP   16		/* Explicity exclude from the core dump,
> -					   overrides the coredump filter bits */
> -#define MADV_DODUMP	17		/* Clear the MADV_DONTDUMP flag */
> -
> -#define MADV_WIPEONFORK 18		/* Zero memory on fork, child only */
> -#define MADV_KEEPONFORK 19		/* Undo MADV_WIPEONFORK */
> -
> -#define MADV_COLD	20		/* deactivate these pages */
> -#define MADV_PAGEOUT	21		/* reclaim these pages */
> -
> -#define MADV_POPULATE_READ	22	/* populate (prefault) page tables readable */
> -#define MADV_POPULATE_WRITE	23	/* populate (prefault) page tables writable */
> -
> -#define MADV_DONTNEED_LOCKED	24	/* like DONTNEED, but drop locked pages too */
> -
> -#define MADV_COLLAPSE	25		/* Synchronous hugepage collapse */
> -
> -#define MADV_HWPOISON	100		/* poison a page for testing */
> -#define MADV_SOFT_OFFLINE 101		/* soft offline page for testing */
> -
> -/* compatibility flags */
> -#define MAP_FILE	0
> -
> -#define PKEY_DISABLE_ACCESS	0x1
> -#define PKEY_DISABLE_WRITE	0x2
> -#define PKEY_ACCESS_MASK	(PKEY_DISABLE_ACCESS |\
> -				 PKEY_DISABLE_WRITE)
> +#include <asm-generic/mman-common.h>
>
>  #endif /* __ALPHA_MMAN_H__ */
> diff --git a/arch/parisc/include/uapi/asm/mman.h b/arch/parisc/include/uapi/asm/mman.h
> index 1cd5d816d4cf..3732950a5cd8 100644
> --- a/arch/parisc/include/uapi/asm/mman.h
> +++ b/arch/parisc/include/uapi/asm/mman.h
> @@ -2,19 +2,6 @@
>  #ifndef __PARISC_MMAN_H__
>  #define __PARISC_MMAN_H__
>
> -
> -#define PROT_READ	0x1		/* page can be read */
> -#define PROT_WRITE	0x2		/* page can be written */
> -#define PROT_EXEC	0x4		/* page can be executed */
> -#ifndef PROT_SEM /* different on mips and xtensa */
> -#define PROT_SEM	0x8		/* page may be used for atomic ops */
> -#endif
> -/*			0x10		   reserved for arch-specific use */
> -/*			0x20		   reserved for arch-specific use */
> -#define PROT_NONE	0x0		/* page can not be accessed */
> -#define PROT_GROWSDOWN	0x01000000	/* mprotect flag: extend change to start of growsdown vma */
> -#define PROT_GROWSUP	0x02000000	/* mprotect flag: extend change to end of growsup vma */
> -
>  /* 0x01 - 0x03 are defined in linux/mman.h */
>  #define MAP_TYPE	0x2b		/* Mask for type of mapping, includes bits 0x08 and 0x20 */
>  #define MAP_FIXED	0x04		/* Interpret addr exactly */
> @@ -43,61 +30,12 @@
>  #define MCL_ONFAULT	4		/* lock all pages that are faulted in */
>
>  /*
> - * Flags for mlock
> - */
> -#define MLOCK_ONFAULT	0x01		/* Lock pages in range after they are faulted in, do not prefault */
> -
> -/*
> - * Flags for msync
> + * Flags for msync, order is different from all others
>   */
>  #define MS_SYNC		1		/* synchronous memory sync */
>  #define MS_ASYNC	2		/* sync memory asynchronously */
>  #define MS_INVALIDATE	4		/* invalidate the caches */
>
> -#define MADV_NORMAL	0		/* no further special treatment */
> -#define MADV_RANDOM	1		/* expect random page references */
> -#define MADV_SEQUENTIAL	2		/* expect sequential page references */
> -#define MADV_WILLNEED	3		/* will need these pages */
> -#define MADV_DONTNEED	4		/* don't need these pages */
> -
> -/* common parameters: try to keep these consistent across architectures */
> -#define MADV_FREE	8		/* free pages only if memory pressure */
> -#define MADV_REMOVE	9		/* remove these pages & resources */
> -#define MADV_DONTFORK	10		/* don't inherit across fork */
> -#define MADV_DOFORK	11		/* do inherit across fork */
> -
> -#define MADV_MERGEABLE   12		/* KSM may merge identical pages */
> -#define MADV_UNMERGEABLE 13		/* KSM may not merge identical pages */
> -
> -#define MADV_HUGEPAGE	14		/* Worth backing with hugepages */
> -#define MADV_NOHUGEPAGE	15		/* Not worth backing with hugepages */
> -
> -#define MADV_DONTDUMP   16		/* Explicity exclude from the core dump,
> -					   overrides the coredump filter bits */
> -#define MADV_DODUMP	17		/* Clear the MADV_DONTDUMP flag */
> -
> -#define MADV_WIPEONFORK 18		/* Zero memory on fork, child only */
> -#define MADV_KEEPONFORK 19		/* Undo MADV_WIPEONFORK */
> -
> -#define MADV_COLD	20		/* deactivate these pages */
> -#define MADV_PAGEOUT	21		/* reclaim these pages */
> -
> -#define MADV_POPULATE_READ	22	/* populate (prefault) page tables readable */
> -#define MADV_POPULATE_WRITE	23	/* populate (prefault) page tables writable */
> -
> -#define MADV_DONTNEED_LOCKED	24	/* like DONTNEED, but drop locked pages too */
> -
> -#define MADV_COLLAPSE	25		/* Synchronous hugepage collapse */
> -
> -#define MADV_HWPOISON	100		/* poison a page for testing */
> -#define MADV_SOFT_OFFLINE 101		/* soft offline page for testing */
> -
> -/* compatibility flags */
> -#define MAP_FILE	0
> -
> -#define PKEY_DISABLE_ACCESS	0x1
> -#define PKEY_DISABLE_WRITE	0x2
> -#define PKEY_ACCESS_MASK	(PKEY_DISABLE_ACCESS |\
> -				 PKEY_DISABLE_WRITE)
> +#include <asm-generic/mman-common.h>
>
>  #endif /* __PARISC_MMAN_H__ */
> diff --git a/include/uapi/asm-generic/mman-common.h b/include/uapi/asm-generic/mman-common.h
> index 2911dd14ef2a..81a14ed99197 100644
> --- a/include/uapi/asm-generic/mman-common.h
> +++ b/include/uapi/asm-generic/mman-common.h
> @@ -27,15 +27,20 @@
>  /*
>   * Flags for msync
>   */
> +#ifndef MS_ASYNC /* different order on alpha and parisc */
>  #define MS_ASYNC	1		/* sync memory asynchronously */
>  #define MS_INVALIDATE	2		/* invalidate the caches */
>  #define MS_SYNC		4		/* synchronous memory sync */
> +#endif
>
>  #define MADV_NORMAL	0		/* no further special treatment */
>  #define MADV_RANDOM	1		/* expect random page references */
>  #define MADV_SEQUENTIAL	2		/* expect sequential page references */
>  #define MADV_WILLNEED	3		/* will need these pages */
> +/* 4 through 6 are different on alpha */
> +#ifndef MADV_DONTNEED
>  #define MADV_DONTNEED	4		/* don't need these pages */
> +#endif

Rather nice to have these differences both de-duplicated and documented
here...

>
>  /* common parameters: try to keep these consistent across architectures */
>  #define MADV_FREE	8		/* free pages only if memory pressure */
> --
> 2.39.2
>