Subject: Re: "Pick the right alignment default when creating dax devices" failed to build on powerpc

From: "Aneesh Kumar K.V" <[email-masked]>
Date: Fri, 20 Sep 2019 19:55:55 +0530

Qian Cai <[email-masked]> writes:

> The linux-next commit "libnvdimm/dax: Pick the right alignment default when
> creating dax devices" causes powerpc failed to build with this config. Reverted
> it fixed the issue.
>
> ERROR: "hash__has_transparent_hugepage" [drivers/nvdimm/libnvdimm.ko] undefined!
> ERROR: "radix__has_transparent_hugepage" [drivers/nvdimm/libnvdimm.ko]
> undefined!
> make[1]: *** [scripts/Makefile.modpost:93: __modpost] Error 1
> make: *** [Makefile:1305: modules] Error 2
>
> [1] https://patchwork.kernel.org/patch/11133445/
> [2] https://raw.githubusercontent.com/cailca/linux-mm/master/powerpc.config

Sorry for breaking the build. How about?

commit ea15fd8b5489e2c8e9f1b96d67248a7428ffb74a
Author: Aneesh Kumar K.V <[email-masked]>
Date:   Fri Sep 20 19:47:56 2019 +0530

    powerpc/book3s/nvdimm: Fix build error with nvdimm kernel module
    
    Fix the below comiple error.
    
    ERROR: "hash__has_transparent_hugepage" [drivers/nvdimm/libnvdimm.ko] undefined!
    ERROR: "radix__has_transparent_hugepage" [drivers/nvdimm/libnvdimm.ko] undefined!
    
    Signed-off-by: Aneesh Kumar K.V <[email-masked]>

diff --git a/arch/powerpc/include/asm/book3s/64/radix.h b/arch/powerpc/include/asm/book3s/64/radix.h
index e04a839cb5b9..65a6966f1de4 100644
--- a/arch/powerpc/include/asm/book3s/64/radix.h
+++ b/arch/powerpc/include/asm/book3s/64/radix.h
@@ -254,7 +254,13 @@ extern void radix__pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
 extern pgtable_t radix__pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp);
 extern pmd_t radix__pmdp_huge_get_and_clear(struct mm_struct *mm,
 				      unsigned long addr, pmd_t *pmdp);
-extern int radix__has_transparent_hugepage(void);
+static inline int radix__has_transparent_hugepage(void)
+{
+	/* For radix 2M at PMD level means thp */
+	if (mmu_psize_defs[MMU_PAGE_2M].shift == PMD_SHIFT)
+		return 1;
+	return 0;
+}
 #endif
 
 extern int __meminit radix__vmemmap_create_mapping(unsigned long start,
diff --git a/arch/powerpc/mm/book3s64/hash_pgtable.c b/arch/powerpc/mm/book3s64/hash_pgtable.c
index d1f390ac9cdb..64733b9cb20a 100644
--- a/arch/powerpc/mm/book3s64/hash_pgtable.c
+++ b/arch/powerpc/mm/book3s64/hash_pgtable.c
@@ -406,6 +406,8 @@ int hash__has_transparent_hugepage(void)
 
 	return 1;
 }
+EXPORT_SYMBOL_GPL(hash__has_transparent_hugepage);
+
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
 #ifdef CONFIG_STRICT_KERNEL_RWX
diff --git a/arch/powerpc/mm/book3s64/radix_pgtable.c b/arch/powerpc/mm/book3s64/radix_pgtable.c
index b4ca9e95e678..dc7a38f0a45b 100644
--- a/arch/powerpc/mm/book3s64/radix_pgtable.c
+++ b/arch/powerpc/mm/book3s64/radix_pgtable.c
@@ -1057,13 +1057,6 @@ pmd_t radix__pmdp_huge_get_and_clear(struct mm_struct *mm,
 	return old_pmd;
 }
 
-int radix__has_transparent_hugepage(void)
-{
-	/* For radix 2M at PMD level means thp */
-	if (mmu_psize_defs[MMU_PAGE_2M].shift == PMD_SHIFT)
-		return 1;
-	return 0;
-}
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
 void radix__ptep_set_access_flags(struct vm_area_struct *vma, pte_t *ptep,