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Date:   Sat, 24 Feb 2018 17:22:26 +1000
From:   Nicholas Piggin <npiggin@gmail.com>
To:     Christophe Leroy <christophe.leroy@c-s.fr>
Cc:     Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Scott Wood <oss@buserror.net>, aneesh.kumar@linux.vnet.ibm.com,
        linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH v5 2/6] powerpc/mm/slice: create header files dedicated
 to slices
Message-ID: <20180224172226.777c78bd@roar.ozlabs.ibm.com>
In-Reply-To: <d73e104992133e8fd17c798d817687bf2ea8b50a.1519305410.git.christophe.leroy@c-s.fr>
References: <455276187b369bf019e91715b7488e86cd932d49.1519305410.git.christophe.leroy@c-s.fr>
        <d73e104992133e8fd17c798d817687bf2ea8b50a.1519305410.git.christophe.leroy@c-s.fr>
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On Thu, 22 Feb 2018 15:27:22 +0100 (CET)
Christophe Leroy <christophe.leroy@c-s.fr> wrote:

> In preparation for the following patch which will enhance 'slices'
> for supporting PPC32 in order to fix an issue on hugepages on 8xx,
> this patch takes out of page*.h all bits related to 'slices' and put
> them into newly created slice.h header files.
> While common parts go into asm/slice.h, subarch specific
> parts go into respective books3s/64/slice.c and nohash/64/slice.c
> 'slices'
> 
> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>

I don't see a problem with this. Even by itself it seems like
a good cleanup.

Reviewed-by: Nicholas Piggin <npiggin@gmail.com>

> ---
>  v5: new - come from a split of patch 2 of v4
> 
>  arch/powerpc/include/asm/book3s/64/slice.h | 27 ++++++++++++++
>  arch/powerpc/include/asm/nohash/64/slice.h | 12 ++++++
>  arch/powerpc/include/asm/page.h            |  1 +
>  arch/powerpc/include/asm/page_64.h         | 59 ------------------------------
>  arch/powerpc/include/asm/slice.h           | 40 ++++++++++++++++++++
>  5 files changed, 80 insertions(+), 59 deletions(-)
>  create mode 100644 arch/powerpc/include/asm/book3s/64/slice.h
>  create mode 100644 arch/powerpc/include/asm/nohash/64/slice.h
>  create mode 100644 arch/powerpc/include/asm/slice.h
> 
> diff --git a/arch/powerpc/include/asm/book3s/64/slice.h b/arch/powerpc/include/asm/book3s/64/slice.h
> new file mode 100644
> index 000000000000..db0dedab65ee
> --- /dev/null
> +++ b/arch/powerpc/include/asm/book3s/64/slice.h
> @@ -0,0 +1,27 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef _ASM_POWERPC_BOOK3S_64_SLICE_H
> +#define _ASM_POWERPC_BOOK3S_64_SLICE_H
> +
> +#ifdef CONFIG_PPC_MM_SLICES
> +
> +#define SLICE_LOW_SHIFT		28
> +#define SLICE_LOW_TOP		(0x100000000ul)
> +#define SLICE_NUM_LOW		(SLICE_LOW_TOP >> SLICE_LOW_SHIFT)
> +#define GET_LOW_SLICE_INDEX(addr)	((addr) >> SLICE_LOW_SHIFT)
> +
> +#define SLICE_HIGH_SHIFT	40
> +#define SLICE_NUM_HIGH		(H_PGTABLE_RANGE >> SLICE_HIGH_SHIFT)
> +#define GET_HIGH_SLICE_INDEX(addr)	((addr) >> SLICE_HIGH_SHIFT)
> +
> +#else /* CONFIG_PPC_MM_SLICES */
> +
> +#define get_slice_psize(mm, addr)	((mm)->context.user_psize)
> +#define slice_set_user_psize(mm, psize)		\
> +do {						\
> +	(mm)->context.user_psize = (psize);	\
> +	(mm)->context.sllp = SLB_VSID_USER | mmu_psize_defs[(psize)].sllp; \
> +} while (0)
> +
> +#endif /* CONFIG_PPC_MM_SLICES */
> +
> +#endif /* _ASM_POWERPC_BOOK3S_64_SLICE_H */
> diff --git a/arch/powerpc/include/asm/nohash/64/slice.h b/arch/powerpc/include/asm/nohash/64/slice.h
> new file mode 100644
> index 000000000000..ad0d6e3cc1c5
> --- /dev/null
> +++ b/arch/powerpc/include/asm/nohash/64/slice.h
> @@ -0,0 +1,12 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef _ASM_POWERPC_NOHASH_64_SLICE_H
> +#define _ASM_POWERPC_NOHASH_64_SLICE_H
> +
> +#ifdef CONFIG_PPC_64K_PAGES
> +#define get_slice_psize(mm, addr)	MMU_PAGE_64K
> +#else /* CONFIG_PPC_64K_PAGES */
> +#define get_slice_psize(mm, addr)	MMU_PAGE_4K
> +#endif /* !CONFIG_PPC_64K_PAGES */
> +#define slice_set_user_psize(mm, psize)	do { BUG(); } while (0)
> +
> +#endif /* _ASM_POWERPC_NOHASH_64_SLICE_H */
> diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
> index 8da5d4c1cab2..d5f1c41b7dba 100644
> --- a/arch/powerpc/include/asm/page.h
> +++ b/arch/powerpc/include/asm/page.h
> @@ -344,5 +344,6 @@ typedef struct page *pgtable_t;
>  
>  #include <asm-generic/memory_model.h>
>  #endif /* __ASSEMBLY__ */
> +#include <asm/slice.h>
>  
>  #endif /* _ASM_POWERPC_PAGE_H */
> diff --git a/arch/powerpc/include/asm/page_64.h b/arch/powerpc/include/asm/page_64.h
> index 56234c6fcd61..af04acdb873f 100644
> --- a/arch/powerpc/include/asm/page_64.h
> +++ b/arch/powerpc/include/asm/page_64.h
> @@ -86,65 +86,6 @@ extern u64 ppc64_pft_size;
>  
>  #endif /* __ASSEMBLY__ */
>  
> -#ifdef CONFIG_PPC_MM_SLICES
> -
> -#define SLICE_LOW_SHIFT		28
> -#define SLICE_HIGH_SHIFT	40
> -
> -#define SLICE_LOW_TOP		(0x100000000ul)
> -#define SLICE_NUM_LOW		(SLICE_LOW_TOP >> SLICE_LOW_SHIFT)
> -#define SLICE_NUM_HIGH		(H_PGTABLE_RANGE >> SLICE_HIGH_SHIFT)
> -
> -#define GET_LOW_SLICE_INDEX(addr)	((addr) >> SLICE_LOW_SHIFT)
> -#define GET_HIGH_SLICE_INDEX(addr)	((addr) >> SLICE_HIGH_SHIFT)
> -
> -#ifndef __ASSEMBLY__
> -struct mm_struct;
> -
> -extern unsigned long slice_get_unmapped_area(unsigned long addr,
> -					     unsigned long len,
> -					     unsigned long flags,
> -					     unsigned int psize,
> -					     int topdown);
> -
> -extern unsigned int get_slice_psize(struct mm_struct *mm,
> -				    unsigned long addr);
> -
> -extern void slice_set_user_psize(struct mm_struct *mm, unsigned int psize);
> -extern void slice_set_range_psize(struct mm_struct *mm, unsigned long start,
> -				  unsigned long len, unsigned int psize);
> -
> -#endif /* __ASSEMBLY__ */
> -#else
> -#define slice_init()
> -#ifdef CONFIG_PPC_BOOK3S_64
> -#define get_slice_psize(mm, addr)	((mm)->context.user_psize)
> -#define slice_set_user_psize(mm, psize)		\
> -do {						\
> -	(mm)->context.user_psize = (psize);	\
> -	(mm)->context.sllp = SLB_VSID_USER | mmu_psize_defs[(psize)].sllp; \
> -} while (0)
> -#else /* !CONFIG_PPC_BOOK3S_64 */
> -#ifdef CONFIG_PPC_64K_PAGES
> -#define get_slice_psize(mm, addr)	MMU_PAGE_64K
> -#else /* CONFIG_PPC_64K_PAGES */
> -#define get_slice_psize(mm, addr)	MMU_PAGE_4K
> -#endif /* !CONFIG_PPC_64K_PAGES */
> -#define slice_set_user_psize(mm, psize)	do { BUG(); } while(0)
> -#endif /* CONFIG_PPC_BOOK3S_64 */
> -
> -#define slice_set_range_psize(mm, start, len, psize)	\
> -	slice_set_user_psize((mm), (psize))
> -#endif /* CONFIG_PPC_MM_SLICES */
> -
> -#ifdef CONFIG_HUGETLB_PAGE
> -
> -#ifdef CONFIG_PPC_MM_SLICES
> -#define HAVE_ARCH_HUGETLB_UNMAPPED_AREA
> -#endif
> -
> -#endif /* !CONFIG_HUGETLB_PAGE */
> -
>  #define VM_DATA_DEFAULT_FLAGS \
>  	(is_32bit_task() ? \
>  	 VM_DATA_DEFAULT_FLAGS32 : VM_DATA_DEFAULT_FLAGS64)
> diff --git a/arch/powerpc/include/asm/slice.h b/arch/powerpc/include/asm/slice.h
> new file mode 100644
> index 000000000000..17c5a5d8c418
> --- /dev/null
> +++ b/arch/powerpc/include/asm/slice.h
> @@ -0,0 +1,40 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef _ASM_POWERPC_SLICE_H
> +#define _ASM_POWERPC_SLICE_H
> +
> +#ifdef CONFIG_PPC_BOOK3S_64
> +#include <asm/book3s/64/slice.h>
> +#else
> +#include <asm/nohash/64/slice.h>
> +#endif
> +
> +#ifdef CONFIG_PPC_MM_SLICES
> +
> +#ifdef CONFIG_HUGETLB_PAGE
> +#define HAVE_ARCH_HUGETLB_UNMAPPED_AREA
> +#endif
> +#define HAVE_ARCH_UNMAPPED_AREA
> +#define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
> +
> +#ifndef __ASSEMBLY__
> +
> +struct mm_struct;
> +
> +unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len,
> +				      unsigned long flags, unsigned int psize,
> +				      int topdown);
> +
> +unsigned int get_slice_psize(struct mm_struct *mm, unsigned long addr);
> +
> +void slice_set_user_psize(struct mm_struct *mm, unsigned int psize);
> +void slice_set_range_psize(struct mm_struct *mm, unsigned long start,
> +			   unsigned long len, unsigned int psize);
> +#endif /* __ASSEMBLY__ */
> +
> +#else /* CONFIG_PPC_MM_SLICES */
> +
> +#define slice_set_range_psize(mm, start, len, psize)	\
> +	slice_set_user_psize((mm), (psize))
> +#endif /* CONFIG_PPC_MM_SLICES */
> +
> +#endif /* _ASM_POWERPC_SLICE_H */