linux-kernel - Re: [PATCH 2/4] microblaze: simplify pte_alloc_one

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Date:   Wed, 25 Aug 2021 14:13:45 +0200
From:   David Hildenbrand <david@...hat.com>
To:     Mike Rapoport <rppt@...nel.org>,
        Andrew Morton <akpm@...ux-foundation.org>
Cc:     Michal Simek <monstr@...str.eu>,
        Mike Rapoport <rppt@...ux.ibm.com>,
        linux-kernel@...r.kernel.org, linux-mm@...ck.org
Subject: Re: [PATCH 2/4] microblaze: simplify pte_alloc_one_kernel()

On 14.07.21 14:37, Mike Rapoport wrote:
> From: Mike Rapoport <rppt@...ux.ibm.com>
> 
> The microblaze's implementation of pte_alloc_one_kernel() used
> memblock_alloc_try_nid_raw() along with clear_page() to allocated a zeroed
> page during early setup.
> 
> Replace calls of these functions with a call to memblock_alloc_try_nid()
> that already returns zeroed page and respects the same allocation limits as
> memblock_alloc_try_nid_raw().
> 
> While on it drop early_get_page() wrapper that was only used in
> pte_alloc_one_kernel().
> 
> Signed-off-by: Mike Rapoport <rppt@...ux.ibm.com>
> ---
>   arch/microblaze/include/asm/pgtable.h |  2 --
>   arch/microblaze/mm/init.c             | 12 ------------
>   arch/microblaze/mm/pgtable.c          | 17 ++++++++---------
>   3 files changed, 8 insertions(+), 23 deletions(-)
> 
> diff --git a/arch/microblaze/include/asm/pgtable.h b/arch/microblaze/include/asm/pgtable.h
> index 71cd547655d9..c136a01e467e 100644
> --- a/arch/microblaze/include/asm/pgtable.h
> +++ b/arch/microblaze/include/asm/pgtable.h
> @@ -443,8 +443,6 @@ extern int mem_init_done;
>   
>   asmlinkage void __init mmu_init(void);
>   
> -void __init *early_get_page(void);
> -
>   #endif /* __ASSEMBLY__ */
>   #endif /* __KERNEL__ */
>   
> diff --git a/arch/microblaze/mm/init.c b/arch/microblaze/mm/init.c
> index ab55c70380a5..952f35b335b2 100644
> --- a/arch/microblaze/mm/init.c
> +++ b/arch/microblaze/mm/init.c
> @@ -265,18 +265,6 @@ asmlinkage void __init mmu_init(void)
>   	dma_contiguous_reserve(memory_start + lowmem_size - 1);
>   }
>   
> -/* This is only called until mem_init is done. */
> -void __init *early_get_page(void)
> -{
> -	/*
> -	 * Mem start + kernel_tlb -> here is limit
> -	 * because of mem mapping from head.S
> -	 */
> -	return memblock_alloc_try_nid_raw(PAGE_SIZE, PAGE_SIZE,
> -				MEMBLOCK_LOW_LIMIT, memory_start + kernel_tlb,
> -				NUMA_NO_NODE);
> -}
> -
>   void * __ref zalloc_maybe_bootmem(size_t size, gfp_t mask)
>   {
>   	void *p;
> diff --git a/arch/microblaze/mm/pgtable.c b/arch/microblaze/mm/pgtable.c
> index 38ccb909bc9d..c1833b159d3b 100644
> --- a/arch/microblaze/mm/pgtable.c
> +++ b/arch/microblaze/mm/pgtable.c
> @@ -33,6 +33,7 @@
>   #include <linux/init.h>
>   #include <linux/mm_types.h>
>   #include <linux/pgtable.h>
> +#include <linux/memblock.h>
>   
>   #include <asm/pgalloc.h>
>   #include <linux/io.h>
> @@ -242,15 +243,13 @@ unsigned long iopa(unsigned long addr)
>   
>   __ref pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
>   {
> -	pte_t *pte;
> -	if (mem_init_done) {
> -		pte = (pte_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
> -	} else {
> -		pte = (pte_t *)early_get_page();
> -		if (pte)
> -			clear_page(pte);
> -	}
> -	return pte;
> +	if (mem_init_done)
> +		return (pte_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
> +	else
> +		return memblock_alloc_try_nid(PAGE_SIZE, PAGE_SIZE,
> +					      MEMBLOCK_LOW_LIMIT,
> +					      memory_start + kernel_tlb,
> +					      NUMA_NO_NODE);
>   }
>   
>   void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t flags)
> 

Reviewed-by: David Hildenbrand <david@...hat.com>

-- 
Thanks,

David / dhildenb