kbuild test robot [off-list ref] writes:

Hi Christophe,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on powerpc/next]
[also build test ERROR on v4.17-rc2 next-20180426]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Christophe-Leroy/powerpc-nohash-remove-hash-related-code-from-nohash-headers/20180425-182026
base:   https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
config: powerpc-ppc64e_defconfig (attached as .config)
compiler: powerpc64-linux-gnu-gcc (Debian 7.2.0-11) 7.2.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        make.cross ARCH=powerpc 

All errors (new ones prefixed by >>):

   In file included from arch/powerpc/include/asm/nohash/pgtable.h:6:0,
                    from arch/powerpc/include/asm/pgtable.h:19,
                    from include/linux/memremap.h:8,
                    from include/linux/mm.h:27,
                    from include/linux/mman.h:5,
                    from arch/powerpc/kernel/asm-offsets.c:22:
   arch/powerpc/include/asm/nohash/64/pgtable.h: In function '__ptep_test_and_clear_young':

quoted

quoted

arch/powerpc/include/asm/nohash/64/pgtable.h:214:6: error: implicit declaration of function 'pte_young'; did you mean 'pte_pud'? [-Werror=implicit-function-declaration]

     if (pte_young(*ptep))
         ^~~~~~~~~
         pte_pud

Urk.

There's a circular dependency here.

I fixed it with the patch below, which seems to be the least worst
solution. Possibly we can clean things up further in future.

cheers

diff --git a/arch/powerpc/include/asm/nohash/32/pgtable.h b/arch/powerpc/include/asm/nohash/32/pgtable.h
index 140f8e74b478..987a658b18e1 100644
--- a/arch/powerpc/include/asm/nohash/32/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/32/pgtable.h

@@ -267,6 +267,11 @@ static inline void __ptep_set_access_flags(struct mm_struct *mm,
 	pte_update(ptep, clr, set);
 }
 
+static inline int pte_young(pte_t pte)
+{
+	return pte_val(pte) & _PAGE_ACCESSED;
+}
+
 #define __HAVE_ARCH_PTE_SAME
 #define pte_same(A,B)	((pte_val(A) ^ pte_val(B)) == 0)
 

diff --git a/arch/powerpc/include/asm/nohash/64/pgtable.h b/arch/powerpc/include/asm/nohash/64/pgtable.h
index e8de7cb4d3fb..6ac8381f4c7a 100644
--- a/arch/powerpc/include/asm/nohash/64/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/64/pgtable.h

@@ -204,6 +204,11 @@ static inline unsigned long pte_update(struct mm_struct *mm,
 	return old;
 }
 
+static inline int pte_young(pte_t pte)
+{
+	return pte_val(pte) & _PAGE_ACCESSED;
+}
+
 static inline int __ptep_test_and_clear_young(struct mm_struct *mm,
 					      unsigned long addr, pte_t *ptep)
 {

diff --git a/arch/powerpc/include/asm/nohash/pgtable.h b/arch/powerpc/include/asm/nohash/pgtable.h
index 077472640b35..2160be2e4339 100644
--- a/arch/powerpc/include/asm/nohash/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/pgtable.h

@@ -17,7 +17,6 @@ static inline int pte_write(pte_t pte)
 }
 static inline int pte_read(pte_t pte)		{ return 1; }
 static inline int pte_dirty(pte_t pte)		{ return pte_val(pte) & _PAGE_DIRTY; }
-static inline int pte_young(pte_t pte)		{ return pte_val(pte) & _PAGE_ACCESSED; }
 static inline int pte_special(pte_t pte)	{ return pte_val(pte) & _PAGE_SPECIAL; }
 static inline int pte_none(pte_t pte)		{ return (pte_val(pte) & ~_PTE_NONE_MASK) == 0; }
 static inline pgprot_t pte_pgprot(pte_t pte)	{ return __pgprot(pte_val(pte) & PAGE_PROT_BITS); }