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

[Hanjun Guo]

On 2021/7/28 15:13, Hanjun Guo wrote:
> On 2021/7/28 14:43, Kenneth Lee wrote:
> > From: Kenneth Lee <liguozhu@xxxxxxxxxxxxx>
> >
> > 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
> > this problem
> >
> > Signed-off-by: Kenneth Lee <liguozhu@xxxxxxxxxxxxx>
> > ---
> >   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);
>
> Just nit: I didn't see any driver in kernel refers to
> the riscv_global_pfn_base, can we just remove the EXPORT_SYMBOL()？

Sorry, I'm wrong, will be used by ARCH_PFN_OFFSET...