[PATCH v2 1/2] powerpc/mm: Fix build break when PPC_NATIVE=n

[PATCH v2 1/2] powerpc/mm: Fix build break when PPC_NATIVE=n

[Michael Ellerman]

The recent commit to rework the hash MMU setup broke the build when
CONFIG_PPC_NATIVE=n. Fix it by adding an IS_ENABLED() check before
calling hpte_init_native().

Removing the else clause opens the possibility that we don't set any
ops, which would probably lead to a strange crash later. So add a check
that we correctly initialised at least one member of the struct.

Fixes: 166dd7d3fbf2 ("powerpc/64: Move MMU backend selection out of platform code")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
 arch/powerpc/mm/hash_utils_64.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index 341632471b9d..381b5894cc99 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -931,9 +931,12 @@ void __init hash__early_init_mmu(void)
 		ps3_early_mm_init();
 	else if (firmware_has_feature(FW_FEATURE_LPAR))
 		hpte_init_lpar();
-	else
+	else if IS_ENABLED(CONFIG_PPC_NATIVE)
 		hpte_init_native();
 
+	if (!mmu_hash_ops.hpte_insert)
+		panic("hash__early_init_mmu: No MMU hash ops defined!\n");
+
 	/* Initialize the MMU Hash table and create the linear mapping
 	 * of memory. Has to be done before SLB initialization as this is
 	 * currently where the page size encoding is obtained.
-- 
2.7.4

[PATCH v2 2/2] powerpc/mm: Rename hpte_init_lpar() and move the fallback to a header

[Michael Ellerman]

hpte_init_lpar() is part of the pseries platform, so name it as such.

Move the fallback implementation for when PSERIES=n into the header,
dropping the weak implementation. The panic() is now handled by the
calling code.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
 arch/powerpc/include/asm/book3s/64/mmu-hash.h | 7 ++++++-
 arch/powerpc/mm/hash_utils_64.c               | 7 +------
 arch/powerpc/platforms/pseries/lpar.c         | 2 +-
 3 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/64/mmu-hash.h b/arch/powerpc/include/asm/book3s/64/mmu-hash.h
index b0f4dffe12ae..450b017fdc19 100644
--- a/arch/powerpc/include/asm/book3s/64/mmu-hash.h
+++ b/arch/powerpc/include/asm/book3s/64/mmu-hash.h
@@ -391,8 +391,13 @@ int htab_remove_mapping(unsigned long vstart, unsigned long vend,
 extern void add_gpage(u64 addr, u64 page_size, unsigned long number_of_pages);
 extern void demote_segment_4k(struct mm_struct *mm, unsigned long addr);
 
+#ifdef CONFIG_PPC_PSERIES
+void hpte_init_pseries(void);
+#else
+static inline void hpte_init_pseries(void) { }
+#endif
+
 extern void hpte_init_native(void);
-extern void hpte_init_lpar(void);
 extern void hpte_init_beat(void);
 extern void hpte_init_beat_v3(void);
 
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index 381b5894cc99..1ff11c1bb182 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -885,11 +885,6 @@ static void __init htab_initialize(void)
 #undef KB
 #undef MB
 
-void __init __weak hpte_init_lpar(void)
-{
-	panic("FW_FEATURE_LPAR set but no LPAR support compiled\n");
-}
-
 void __init hash__early_init_mmu(void)
 {
 	/*
@@ -930,7 +925,7 @@ void __init hash__early_init_mmu(void)
 	if (firmware_has_feature(FW_FEATURE_PS3_LV1))
 		ps3_early_mm_init();
 	else if (firmware_has_feature(FW_FEATURE_LPAR))
-		hpte_init_lpar();
+		hpte_init_pseries();
 	else if IS_ENABLED(CONFIG_PPC_NATIVE)
 		hpte_init_native();
 
diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c
index 0e91388d0af9..86707e67843f 100644
--- a/arch/powerpc/platforms/pseries/lpar.c
+++ b/arch/powerpc/platforms/pseries/lpar.c
@@ -589,7 +589,7 @@ static int __init disable_bulk_remove(char *str)
 
 __setup("bulk_remove=", disable_bulk_remove);
 
-void __init hpte_init_lpar(void)
+void __init hpte_init_pseries(void)
 {
 	mmu_hash_ops.hpte_invalidate	 = pSeries_lpar_hpte_invalidate;
 	mmu_hash_ops.hpte_updatepp	 = pSeries_lpar_hpte_updatepp;
-- 
2.7.4

Re: [PATCH v2 2/2] powerpc/mm: Rename hpte_init_lpar() and move the fallback to a header

[Stephen Rothwell]

Hi Michael,

On Tue, 26 Jul 2016 13:38:38 +1000 Michael Ellerman <mpe@ellerman.id.au> wrote:
>
> hpte_init_lpar() is part of the pseries platform, so name it as such.
> 
> Move the fallback implementation for when PSERIES=n into the header,
> dropping the weak implementation. The panic() is now handled by the
> calling code.

Of course, this could have been handled the same way as the native one.

>  	else if (firmware_has_feature(FW_FEATURE_LPAR))
        else if (IS_ENABLED(CONFIG_PPC_PSERIES) && firmware_has_feature(FW_FEATURE_LPAR))
> -		hpte_init_lpar();
> +		hpte_init_pseries();

and no need to modify the header file.
-- 
Cheers,
Stephen Rothwell

Re: [PATCH v2 1/2] powerpc/mm: Fix build break when PPC_NATIVE=n

[Stephen Rothwell]

Hi Michael,

On Tue, 26 Jul 2016 13:38:37 +1000 Michael Ellerman <mpe@ellerman.id.au> wrote:
>
> The recent commit to rework the hash MMU setup broke the build when
> CONFIG_PPC_NATIVE=n. Fix it by adding an IS_ENABLED() check before
> calling hpte_init_native().
> 
> Removing the else clause opens the possibility that we don't set any
> ops, which would probably lead to a strange crash later. So add a check
> that we correctly initialised at least one member of the struct.
> 
> Fixes: 166dd7d3fbf2 ("powerpc/64: Move MMU backend selection out of platform code")
> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>
-- 
Cheers,
Stephen Rothwell

Re: [v2,1/2] powerpc/mm: Fix build break when PPC_NATIVE=n

[Michael Ellerman]

On Tue, 2016-26-07 at 03:38:37 UTC, Michael Ellerman wrote:
> The recent commit to rework the hash MMU setup broke the build when
> CONFIG_PPC_NATIVE=n. Fix it by adding an IS_ENABLED() check before
> calling hpte_init_native().
> 
> Removing the else clause opens the possibility that we don't set any
> ops, which would probably lead to a strange crash later. So add a check
> that we correctly initialised at least one member of the struct.
> 
> Fixes: 166dd7d3fbf2 ("powerpc/64: Move MMU backend selection out of platform code")
> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
> Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>

Series applied to powerpc next.

https://git.kernel.org/powerpc/c/7353644fa9df875aee778a802e

cheers