Re: [RFC PATCH v2 3/3] mm: make generic pXd_addr_end() macros inline functions

[Alexander Gordeev <agordeev@xxxxxxxxxxxxx>]

On Tue, Sep 08, 2020 at 07:19:38AM +0200, Christophe Leroy wrote:

[...]

> >diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
> >index 67ebc22cf83d..d9e7d16c2263 100644
> >--- a/include/linux/pgtable.h
> >+++ b/include/linux/pgtable.h
> >@@ -656,31 +656,35 @@ static inline int arch_unmap_one(struct mm_struct *mm,
> >   */
> >  #ifndef pgd_addr_end
> >-#define pgd_addr_end(pgd, addr, end)					\
> >-({	unsigned long __boundary = ((addr) + PGDIR_SIZE) & PGDIR_MASK;	\
> >-	(__boundary - 1 < (end) - 1)? __boundary: (end);		\
> >-})
> >+#define pgd_addr_end pgd_addr_end
> 
> I think that #define is pointless, usually there is no such #define
> for the default case.

Default pgd_addr_end() gets overriden on s390 (arch/s390/include/asm/pgtable.h):

#define pgd_addr_end pgd_addr_end
static inline unsigned long pgd_addr_end(pgd_t pgd, unsigned long addr, unsigned long end)
{
	return rste_addr_end_folded(pgd_val(pgd), addr, end);
}

> >+static inline unsigned long pgd_addr_end(pgd_t pgd, unsigned long addr, unsigned long end)
> >+{	unsigned long __boundary = (addr + PGDIR_SIZE) & PGDIR_MASK;
> >+	return (__boundary - 1 < end - 1) ? __boundary : end;
> >+}