* [PATCH -next] powerpc/book3s64: fix link error with CONFIG_PPC_RADIX_MMU=n
@ 2020-09-05 11:25 Yang Yingliang
2020-09-06 6:50 ` Christophe Leroy
0 siblings, 1 reply; 4+ messages in thread
From: Yang Yingliang @ 2020-09-05 11:25 UTC (permalink / raw)
To: linuxppc-dev, linux-kernel; +Cc: mpe, benh, yangyingliang
Fix link error when CONFIG_PPC_RADIX_MMU is disabled:
powerpc64-linux-gnu-ld: arch/powerpc/platforms/pseries/lpar.o:(.toc+0x0): undefined reference to `mmu_pid_bits'
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
---
arch/powerpc/mm/book3s64/mmu_context.c | 4 ++++
arch/powerpc/platforms/pseries/lpar.c | 2 ++
2 files changed, 6 insertions(+)
diff --git a/arch/powerpc/mm/book3s64/mmu_context.c b/arch/powerpc/mm/book3s64/mmu_context.c
index 0ba30b8b935b..a8e292cd88f0 100644
--- a/arch/powerpc/mm/book3s64/mmu_context.c
+++ b/arch/powerpc/mm/book3s64/mmu_context.c
@@ -152,6 +152,7 @@ void hash__setup_new_exec(void)
static int radix__init_new_context(struct mm_struct *mm)
{
+#ifdef CONFIG_PPC_RADIX_MMU
unsigned long rts_field;
int index, max_id;
@@ -177,6 +178,9 @@ static int radix__init_new_context(struct mm_struct *mm)
mm->context.hash_context = NULL;
return index;
+#else
+ return -ENOTSUPP;
+#endif
}
int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c
index baf24eacd268..e454e218dbba 100644
--- a/arch/powerpc/platforms/pseries/lpar.c
+++ b/arch/powerpc/platforms/pseries/lpar.c
@@ -1726,10 +1726,12 @@ void __init hpte_init_pseries(void)
void radix_init_pseries(void)
{
+#ifdef CONFIG_PPC_RADIX_MMU
pr_info("Using radix MMU under hypervisor\n");
pseries_lpar_register_process_table(__pa(process_tb),
0, PRTB_SIZE_SHIFT - 12);
+#endif
}
#ifdef CONFIG_PPC_SMLPAR
--
2.25.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH -next] powerpc/book3s64: fix link error with CONFIG_PPC_RADIX_MMU=n
2020-09-05 11:25 [PATCH -next] powerpc/book3s64: fix link error with CONFIG_PPC_RADIX_MMU=n Yang Yingliang
@ 2020-09-06 6:50 ` Christophe Leroy
2020-09-07 1:51 ` Yang Yingliang
0 siblings, 1 reply; 4+ messages in thread
From: Christophe Leroy @ 2020-09-06 6:50 UTC (permalink / raw)
To: Yang Yingliang, linuxppc-dev, linux-kernel
Le 05/09/2020 à 13:25, Yang Yingliang a écrit :
> Fix link error when CONFIG_PPC_RADIX_MMU is disabled:
> powerpc64-linux-gnu-ld: arch/powerpc/platforms/pseries/lpar.o:(.toc+0x0): undefined reference to `mmu_pid_bits'
>
> Reported-by: Hulk Robot <hulkci@huawei.com>
> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
> ---
> arch/powerpc/mm/book3s64/mmu_context.c | 4 ++++
In your commit log, you are just mentionning
arch/powerpc/platforms/pseries/lpar.o, which is right.
You shouldn't need to modify arch/powerpc/mm/book3s64/mmu_context.c at
all, see below.
> arch/powerpc/platforms/pseries/lpar.c | 2 ++
> 2 files changed, 6 insertions(+)
>
> diff --git a/arch/powerpc/mm/book3s64/mmu_context.c b/arch/powerpc/mm/book3s64/mmu_context.c
> index 0ba30b8b935b..a8e292cd88f0 100644
> --- a/arch/powerpc/mm/book3s64/mmu_context.c
> +++ b/arch/powerpc/mm/book3s64/mmu_context.c
> @@ -152,6 +152,7 @@ void hash__setup_new_exec(void)
>
> static int radix__init_new_context(struct mm_struct *mm)
> {
> +#ifdef CONFIG_PPC_RADIX_MMU
This shouldn't be required. radix__init_new_context() is only called
when radix_enabled() returns true.
As it is a static function, when it is not called it gets optimised
away, so you will never get an undefined reference to `mmu_pid_bits` there.
> unsigned long rts_field;
> int index, max_id;
>
> @@ -177,6 +178,9 @@ static int radix__init_new_context(struct mm_struct *mm)
> mm->context.hash_context = NULL;
>
> return index;
> +#else
> + return -ENOTSUPP;
> +#endif
> }
>
> int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
> diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c
> index baf24eacd268..e454e218dbba 100644
> --- a/arch/powerpc/platforms/pseries/lpar.c
> +++ b/arch/powerpc/platforms/pseries/lpar.c
> @@ -1726,10 +1726,12 @@ void __init hpte_init_pseries(void)
>
> void radix_init_pseries(void)
> {
> +#ifdef CONFIG_PPC_RADIX_MMU
This function is only called from
/arch/powerpc/mm/book3s64/radix_pgtable.c which is only built when
CONFIG_PPC_RADIX_MMU is selected.
So the entire function should be encloded in the #ifdef.
> pr_info("Using radix MMU under hypervisor\n");
>
> pseries_lpar_register_process_table(__pa(process_tb),
> 0, PRTB_SIZE_SHIFT - 12);
> +#endif
> }
>
> #ifdef CONFIG_PPC_SMLPAR
>
Christophe
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH -next] powerpc/book3s64: fix link error with CONFIG_PPC_RADIX_MMU=n
2020-09-06 6:50 ` Christophe Leroy
@ 2020-09-07 1:51 ` Yang Yingliang
2020-09-07 8:11 ` Christophe Leroy
0 siblings, 1 reply; 4+ messages in thread
From: Yang Yingliang @ 2020-09-07 1:51 UTC (permalink / raw)
To: Christophe Leroy, linuxppc-dev, linux-kernel
On 2020/9/6 14:50, Christophe Leroy wrote:
>
>
> Le 05/09/2020 à 13:25, Yang Yingliang a écrit :
>> Fix link error when CONFIG_PPC_RADIX_MMU is disabled:
>> powerpc64-linux-gnu-ld:
>> arch/powerpc/platforms/pseries/lpar.o:(.toc+0x0): undefined reference
>> to `mmu_pid_bits'
>>
>> Reported-by: Hulk Robot <hulkci@huawei.com>
>> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
>> ---
>> arch/powerpc/mm/book3s64/mmu_context.c | 4 ++++
>
> In your commit log, you are just mentionning
> arch/powerpc/platforms/pseries/lpar.o, which is right.
>
> You shouldn't need to modify arch/powerpc/mm/book3s64/mmu_context.c at
> all, see below.
>
>> arch/powerpc/platforms/pseries/lpar.c | 2 ++
>> 2 files changed, 6 insertions(+)
>>
>> diff --git a/arch/powerpc/mm/book3s64/mmu_context.c
>> b/arch/powerpc/mm/book3s64/mmu_context.c
>> index 0ba30b8b935b..a8e292cd88f0 100644
>> --- a/arch/powerpc/mm/book3s64/mmu_context.c
>> +++ b/arch/powerpc/mm/book3s64/mmu_context.c
>> @@ -152,6 +152,7 @@ void hash__setup_new_exec(void)
>> static int radix__init_new_context(struct mm_struct *mm)
>> {
>> +#ifdef CONFIG_PPC_RADIX_MMU
>
> This shouldn't be required. radix__init_new_context() is only called
> when radix_enabled() returns true.
> As it is a static function, when it is not called it gets optimised
> away, so you will never get an undefined reference to `mmu_pid_bits`
> there.
powerpc64-linux-gnu-ld:
arch/powerpc/mm/book3s64/mmu_context.o:(.toc+0x0): undefined reference
to `mmu_pid_bits'
powerpc64-linux-gnu-ld:
arch/powerpc/mm/book3s64/mmu_context.o:(.toc+0x8): undefined reference
to `mmu_base_pid'
mmu_context.c is always compiled, it uses mmu_pid_bits and mmu_base_pid.
>
>> unsigned long rts_field;
>> int index, max_id;
>> @@ -177,6 +178,9 @@ static int radix__init_new_context(struct
>> mm_struct *mm)
>> mm->context.hash_context = NULL;
>> return index;
>> +#else
>> + return -ENOTSUPP;
>> +#endif
>> }
>> int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
>> diff --git a/arch/powerpc/platforms/pseries/lpar.c
>> b/arch/powerpc/platforms/pseries/lpar.c
>> index baf24eacd268..e454e218dbba 100644
>> --- a/arch/powerpc/platforms/pseries/lpar.c
>> +++ b/arch/powerpc/platforms/pseries/lpar.c
>> @@ -1726,10 +1726,12 @@ void __init hpte_init_pseries(void)
>> void radix_init_pseries(void)
>> {
>> +#ifdef CONFIG_PPC_RADIX_MMU
>
> This function is only called from
> /arch/powerpc/mm/book3s64/radix_pgtable.c which is only built when
> CONFIG_PPC_RADIX_MMU is selected.
>
> So the entire function should be encloded in the #ifdef.
OK, I will send a v2 later.
>
>> pr_info("Using radix MMU under hypervisor\n");
>> pseries_lpar_register_process_table(__pa(process_tb),
>> 0, PRTB_SIZE_SHIFT - 12);
>> +#endif
>> }
>> #ifdef CONFIG_PPC_SMLPAR
>>
>
> Christophe
> .
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH -next] powerpc/book3s64: fix link error with CONFIG_PPC_RADIX_MMU=n
2020-09-07 1:51 ` Yang Yingliang
@ 2020-09-07 8:11 ` Christophe Leroy
0 siblings, 0 replies; 4+ messages in thread
From: Christophe Leroy @ 2020-09-07 8:11 UTC (permalink / raw)
To: Yang Yingliang, linuxppc-dev, linux-kernel
Le 07/09/2020 à 03:51, Yang Yingliang a écrit :
>
> On 2020/9/6 14:50, Christophe Leroy wrote:
>>
>>
>> Le 05/09/2020 à 13:25, Yang Yingliang a écrit :
>>> Fix link error when CONFIG_PPC_RADIX_MMU is disabled:
>>> powerpc64-linux-gnu-ld:
>>> arch/powerpc/platforms/pseries/lpar.o:(.toc+0x0): undefined reference
>>> to `mmu_pid_bits'
>>>
>>> Reported-by: Hulk Robot <hulkci@huawei.com>
>>> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
>>> ---
>>> arch/powerpc/mm/book3s64/mmu_context.c | 4 ++++
>>
>> In your commit log, you are just mentionning
>> arch/powerpc/platforms/pseries/lpar.o, which is right.
>>
>> You shouldn't need to modify arch/powerpc/mm/book3s64/mmu_context.c at
>> all, see below.
>>
>>> arch/powerpc/platforms/pseries/lpar.c | 2 ++
>>> 2 files changed, 6 insertions(+)
>>>
>>> diff --git a/arch/powerpc/mm/book3s64/mmu_context.c
>>> b/arch/powerpc/mm/book3s64/mmu_context.c
>>> index 0ba30b8b935b..a8e292cd88f0 100644
>>> --- a/arch/powerpc/mm/book3s64/mmu_context.c
>>> +++ b/arch/powerpc/mm/book3s64/mmu_context.c
>>> @@ -152,6 +152,7 @@ void hash__setup_new_exec(void)
>>> static int radix__init_new_context(struct mm_struct *mm)
>>> {
>>> +#ifdef CONFIG_PPC_RADIX_MMU
>>
>> This shouldn't be required. radix__init_new_context() is only called
>> when radix_enabled() returns true.
>> As it is a static function, when it is not called it gets optimised
>> away, so you will never get an undefined reference to `mmu_pid_bits`
>> there.
> powerpc64-linux-gnu-ld:
> arch/powerpc/mm/book3s64/mmu_context.o:(.toc+0x0): undefined reference
> to `mmu_pid_bits'
> powerpc64-linux-gnu-ld:
> arch/powerpc/mm/book3s64/mmu_context.o:(.toc+0x8): undefined reference
> to `mmu_base_pid'
>
>
> mmu_context.c is always compiled, it uses mmu_pid_bits and mmu_base_pid.
Yes, mmu_context.c is always compiled, but as I explained,
radix__init_new_context() is defined as 'static' so it is optimised out
when radix_enabled() returns false because there is no caller in that case.
I just made the test with ppc64_defconfig + CONFIG_PPC_RADIX_MMU=n (GCC 8.1)
The only failure I got was on lpar.c, which I fixed by enclosing the
entire radix_init_pseries() in an #ifdef.
Once this is fixed, the build is OK, without any modification to
mmu_context.c
powerpc64-linux-objdump -x arch/powerpc/mm/book3s64/mmu_context.o shows
only the following objects in the .toc:
RELOCATION RECORDS FOR [.toc]:
OFFSET TYPE VALUE
0000000000000000 R_PPC64_ADDR64 kmalloc_caches
0000000000000008 R_PPC64_ADDR64 vmemmap
0000000000000010 R_PPC64_ADDR64 __pmd_frag_nr
0000000000000018 R_PPC64_ADDR64 __pmd_frag_size_shift
mmu_pid_bits and mmu_base_pid are not part of the undefined objetcs:
0000000000000000 *UND* 0000000000000000 vmemmap
0000000000000000 *UND* 0000000000000000 .mm_iommu_init
0000000000000000 *UND* 0000000000000000 __pmd_frag_nr
0000000000000000 *UND* 0000000000000000 .ida_alloc_range
0000000000000000 *UND* 0000000000000000 .slb_setup_new_exec
0000000000000000 *UND* 0000000000000000 mmu_feature_keys
0000000000000000 *UND* 0000000000000000 .memset
0000000000000000 *UND* 0000000000000000 .memcpy
0000000000000000 *UND* 0000000000000000 .slice_init_new_context_exec
0000000000000000 *UND* 0000000000000000 ._mcount
0000000000000000 *UND* 0000000000000000 .__free_pages
0000000000000000 *UND* 0000000000000000 __pmd_frag_size_shift
0000000000000000 *UND* 0000000000000000 .slice_setup_new_exec
0000000000000000 *UND* 0000000000000000 .ida_free
0000000000000000 *UND* 0000000000000000 .pte_frag_destroy
0000000000000000 *UND* 0000000000000000 .kfree
0000000000000000 *UND* 0000000000000000 .pkey_mm_init
0000000000000000 *UND* 0000000000000000 .kmem_cache_alloc_trace
0000000000000000 *UND* 0000000000000000 .__warn_printk
0000000000000000 *UND* 0000000000000000 _mcount
0000000000000000 *UND* 0000000000000000 kmalloc_caches
Christophe
^ permalink raw reply [flat|nested] 4+ messages in thread
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