Re: [PATCH] riscv: fix the global name pfn_base confliction error

From: Mike Rapoport <rppt@kernel.org>
To: Kenneth Lee <nek.in.cn@gmail.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	Alexandre Ghiti <alex@ghiti.fr>, Anup Patel <anup@brainfault.org>,
	Atish Patra <atish.patra@wdc.com>,
	Kenneth Lee <liguozhu@hisilicon.com>,
	Kefeng Wang <wangkefeng.wang@huawei.com>,
	Vitaly Wool <vitaly.wool@konsulko.com>,
	Guo Ren <guoren@linux.alibaba.com>,
	Jisheng Zhang <jszhang@kernel.org>,
	Nick Kossifidis <mick@ics.forth.gr>,
	linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
	guohanjun@huawei.com, wangzhou1@hisilicon.com
Subject: Re: [PATCH] riscv: fix the global name pfn_base confliction error
Date: Wed, 28 Jul 2021 09:55:33 +0300	[thread overview]
Message-ID: <YQD/Zb0EszIWr6RJ@kernel.org> (raw)
In-Reply-To: <20210728064318.375747-1-nek.in.cn@gmail.com>

On Wed, Jul 28, 2021 at 02:43:18PM +0800, Kenneth Lee wrote:
> From: Kenneth Lee <liguozhu@hisilicon.com>
> 
> RISCV use a global variable pfn_base for page/pfn translation. But this
> is a common name and will be used elsewhere. In those case,
> the page-pfn macro which refer this name will refer to the local/input
> variable of those function (such as in vfio_pin_pages_remote). This make
> everything wrong.
> 
> This patch change the name from pfn_base to riscv_global_pfn_base to fix

I think global is excessive, just riscv_pfn_base should be ok for proper
namespacing.

> this problem
> 
> Signed-off-by: Kenneth Lee <liguozhu@hisilicon.com>
> ---
>  arch/riscv/include/asm/page.h | 4 ++--
>  arch/riscv/mm/init.c          | 6 +++---
>  2 files changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h
> index cca8764aed83..8711e415f37c 100644
> --- a/arch/riscv/include/asm/page.h
> +++ b/arch/riscv/include/asm/page.h
> @@ -79,8 +79,8 @@ typedef struct page *pgtable_t;
>  #endif
>  
>  #ifdef CONFIG_MMU
> -extern unsigned long pfn_base;
> -#define ARCH_PFN_OFFSET		(pfn_base)
> +extern unsigned long riscv_global_pfn_base;
> +#define ARCH_PFN_OFFSET		(riscv_global_pfn_base)
>  #else
>  #define ARCH_PFN_OFFSET		(PAGE_OFFSET >> PAGE_SHIFT)
>  #endif /* CONFIG_MMU */
> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
> index a14bf3910eec..2ce4e9a46ca0 100644
> --- a/arch/riscv/mm/init.c
> +++ b/arch/riscv/mm/init.c
> @@ -228,8 +228,8 @@ static struct pt_alloc_ops _pt_ops __initdata;
>  #define pt_ops _pt_ops
>  #endif
>  
> -unsigned long pfn_base __ro_after_init;
> -EXPORT_SYMBOL(pfn_base);
> +unsigned long riscv_global_pfn_base __ro_after_init;
> +EXPORT_SYMBOL(riscv_global_pfn_base);
>  
>  pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
>  pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
> @@ -572,7 +572,7 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa)
>  	kernel_map.va_kernel_pa_offset = kernel_map.virt_addr - kernel_map.phys_addr;
>  #endif
>  
> -	pfn_base = PFN_DOWN(kernel_map.phys_addr);
> +	riscv_global_pfn_base = PFN_DOWN(kernel_map.phys_addr);
>  
>  	/*
>  	 * Enforce boot alignment requirements of RV32 and
> -- 
> 2.25.1
> 

-- 
Sincerely yours,
Mike.