* [PATCH] powerpc/64: option to force run-at-load to test relocation
@ 2016-10-12 6:57 Nicholas Piggin
2016-10-12 7:35 ` Balbir Singh
0 siblings, 1 reply; 5+ messages in thread
From: Nicholas Piggin @ 2016-10-12 6:57 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Nicholas Piggin
This adds a config option that can help exercise the case when
the kernel is not running at PAGE_OFFSET.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/Kconfig | 9 +++++++++
arch/powerpc/kernel/head_64.S | 4 ++++
arch/powerpc/kernel/setup-common.c | 3 +++
3 files changed, 16 insertions(+)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 65fba4c..5d43cb8 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -478,6 +478,15 @@ config RELOCATABLE
setting can still be useful to bootwrappers that need to know the
load address of the kernel (eg. u-boot/mkimage).
+config RELOCATABLE_TEST
+ bool "Test relocatable kernel"
+ depends on (PPC64 && RELOCATABLE)
+ default n
+ help
+ This runs the relocatable kernel at the address it was initially
+ loaded at, which tends to be non-zero and therefore test the
+ relocation code.
+
config CRASH_DUMP
bool "Build a kdump crash kernel"
depends on PPC64 || 6xx || FSL_BOOKE || (44x && !SMP)
diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index 79da0641..bc9ceac 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -111,8 +111,12 @@ __secondary_hold_acknowledge:
.globl __run_at_load
__run_at_load:
DEFINE_FIXED_SYMBOL(__run_at_load)
+#ifdef CONFIG_RELOCATABLE_TEST
+ .long 0x1 /* Test relocation, do not relocate to 0 */
+#else
.long 0x72756e30 /* "run0" -- relocate to 0 by default */
#endif
+#endif
. = 0x60
/*
diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index dba265c..18e0f19 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -795,6 +795,9 @@ static __init void print_system_info(void)
pr_info("mmu_features = 0x%08x\n", cur_cpu_spec->mmu_features);
#ifdef CONFIG_PPC64
pr_info("firmware_features = 0x%016lx\n", powerpc_firmware_features);
+
+ if (get_paca()->kernelbase != PAGE_OFFSET)
+ pr_info("kernelbase = 0x%llx\n", get_paca()->kernelbase);
#endif
#ifdef CONFIG_PPC_STD_MMU_64
--
2.9.3
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH] powerpc/64: option to force run-at-load to test relocation
2016-10-12 6:57 [PATCH] powerpc/64: option to force run-at-load to test relocation Nicholas Piggin
@ 2016-10-12 7:35 ` Balbir Singh
2016-10-13 2:25 ` Nicholas Piggin
2016-10-14 6:21 ` Michael Ellerman
0 siblings, 2 replies; 5+ messages in thread
From: Balbir Singh @ 2016-10-12 7:35 UTC (permalink / raw)
To: linuxppc-dev
On 12/10/16 17:57, Nicholas Piggin wrote:
> This adds a config option that can help exercise the case when
> the kernel is not running at PAGE_OFFSET.
>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
> arch/powerpc/Kconfig | 9 +++++++++
> arch/powerpc/kernel/head_64.S | 4 ++++
> arch/powerpc/kernel/setup-common.c | 3 +++
> 3 files changed, 16 insertions(+)
>
> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> index 65fba4c..5d43cb8 100644
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -478,6 +478,15 @@ config RELOCATABLE
> setting can still be useful to bootwrappers that need to know the
> load address of the kernel (eg. u-boot/mkimage).
>
> +config RELOCATABLE_TEST
> + bool "Test relocatable kernel"
> + depends on (PPC64 && RELOCATABLE)
> + default n
> + help
> + This runs the relocatable kernel at the address it was initially
> + loaded at, which tends to be non-zero and therefore test the
> + relocation code.
> +
> config CRASH_DUMP
> bool "Build a kdump crash kernel"
> depends on PPC64 || 6xx || FSL_BOOKE || (44x && !SMP)
> diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
> index 79da0641..bc9ceac 100644
> --- a/arch/powerpc/kernel/head_64.S
> +++ b/arch/powerpc/kernel/head_64.S
> @@ -111,8 +111,12 @@ __secondary_hold_acknowledge:
> .globl __run_at_load
> __run_at_load:
> DEFINE_FIXED_SYMBOL(__run_at_load)
> +#ifdef CONFIG_RELOCATABLE_TEST
> + .long 0x1 /* Test relocation, do not relocate to 0 */
> +#else
> .long 0x72756e30 /* "run0" -- relocate to 0 by default */
> #endif
> +#endif
Could we do something like
config RELOCATION_VALUE
default 0x72756e30
default 1 if CONFIG_RELOCTABLE_TEST
and then get
.long CONFIG_RELOCATION_VALUE
>
> . = 0x60
> /*
> diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
> index dba265c..18e0f19 100644
> --- a/arch/powerpc/kernel/setup-common.c
> +++ b/arch/powerpc/kernel/setup-common.c
> @@ -795,6 +795,9 @@ static __init void print_system_info(void)
> pr_info("mmu_features = 0x%08x\n", cur_cpu_spec->mmu_features);
> #ifdef CONFIG_PPC64
> pr_info("firmware_features = 0x%016lx\n", powerpc_firmware_features);
> +
> + if (get_paca()->kernelbase != PAGE_OFFSET)
> + pr_info("kernelbase = 0x%llx\n", get_paca()->kernelbase);
> #endif
>
Do we need this? We get physical_offset if we are relocated.
> #ifdef CONFIG_PPC_STD_MMU_64
>
Balbir Singh.
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] powerpc/64: option to force run-at-load to test relocation
2016-10-12 7:35 ` Balbir Singh
@ 2016-10-13 2:25 ` Nicholas Piggin
2016-10-14 0:39 ` Balbir Singh
2016-10-14 6:21 ` Michael Ellerman
1 sibling, 1 reply; 5+ messages in thread
From: Nicholas Piggin @ 2016-10-13 2:25 UTC (permalink / raw)
To: Balbir Singh; +Cc: linuxppc-dev
On Wed, 12 Oct 2016 18:35:21 +1100
Balbir Singh <bsingharora@gmail.com> wrote:
> On 12/10/16 17:57, Nicholas Piggin wrote:
> > This adds a config option that can help exercise the case when
> > the kernel is not running at PAGE_OFFSET.
> >
> > Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> > ---
> > arch/powerpc/Kconfig | 9 +++++++++
> > arch/powerpc/kernel/head_64.S | 4 ++++
> > arch/powerpc/kernel/setup-common.c | 3 +++
> > 3 files changed, 16 insertions(+)
> >
> > diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> > index 65fba4c..5d43cb8 100644
> > --- a/arch/powerpc/Kconfig
> > +++ b/arch/powerpc/Kconfig
> > @@ -478,6 +478,15 @@ config RELOCATABLE
> > setting can still be useful to bootwrappers that need to know the
> > load address of the kernel (eg. u-boot/mkimage).
> >
> > +config RELOCATABLE_TEST
> > + bool "Test relocatable kernel"
> > + depends on (PPC64 && RELOCATABLE)
> > + default n
> > + help
> > + This runs the relocatable kernel at the address it was initially
> > + loaded at, which tends to be non-zero and therefore test the
> > + relocation code.
> > +
> > config CRASH_DUMP
> > bool "Build a kdump crash kernel"
> > depends on PPC64 || 6xx || FSL_BOOKE || (44x && !SMP)
> > diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
> > index 79da0641..bc9ceac 100644
> > --- a/arch/powerpc/kernel/head_64.S
> > +++ b/arch/powerpc/kernel/head_64.S
> > @@ -111,8 +111,12 @@ __secondary_hold_acknowledge:
> > .globl __run_at_load
> > __run_at_load:
> > DEFINE_FIXED_SYMBOL(__run_at_load)
> > +#ifdef CONFIG_RELOCATABLE_TEST
> > + .long 0x1 /* Test relocation, do not relocate to 0 */
> > +#else
> > .long 0x72756e30 /* "run0" -- relocate to 0 by default */
> > #endif
> > +#endif
>
> Could we do something like
>
> config RELOCATION_VALUE
> default 0x72756e30
> default 1 if CONFIG_RELOCTABLE_TEST
>
> and then get
>
> .long CONFIG_RELOCATION_VALUE
Normally I'm up for reducing ifdefs in S and c files, but in this case
I'm not sure. I like being able to see the two possible values in the
source. I don't really mind though. If you or Michael feel strongly, I'm
happy to change it.
> > . = 0x60
> > /*
> > diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
> > index dba265c..18e0f19 100644
> > --- a/arch/powerpc/kernel/setup-common.c
> > +++ b/arch/powerpc/kernel/setup-common.c
> > @@ -795,6 +795,9 @@ static __init void print_system_info(void)
> > pr_info("mmu_features = 0x%08x\n", cur_cpu_spec->mmu_features);
> > #ifdef CONFIG_PPC64
> > pr_info("firmware_features = 0x%016lx\n", powerpc_firmware_features);
> > +
> > + if (get_paca()->kernelbase != PAGE_OFFSET)
> > + pr_info("kernelbase = 0x%llx\n", get_paca()->kernelbase);
> > #endif
> >
>
> Do we need this? We get physical_offset if we are relocated.
You're right, that hunk can go.
Thanks,
Nick
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] powerpc/64: option to force run-at-load to test relocation
2016-10-13 2:25 ` Nicholas Piggin
@ 2016-10-14 0:39 ` Balbir Singh
0 siblings, 0 replies; 5+ messages in thread
From: Balbir Singh @ 2016-10-14 0:39 UTC (permalink / raw)
To: Nicholas Piggin; +Cc: linuxppc-dev
On 13/10/16 13:25, Nicholas Piggin wrote:
> On Wed, 12 Oct 2016 18:35:21 +1100
> Balbir Singh <bsingharora@gmail.com> wrote:
>
>> On 12/10/16 17:57, Nicholas Piggin wrote:
>>> This adds a config option that can help exercise the case when
>>> the kernel is not running at PAGE_OFFSET.
>>>
>>> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
>>> ---
>>> arch/powerpc/Kconfig | 9 +++++++++
>>> arch/powerpc/kernel/head_64.S | 4 ++++
>>> arch/powerpc/kernel/setup-common.c | 3 +++
>>> 3 files changed, 16 insertions(+)
>>>
>>> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
>>> index 65fba4c..5d43cb8 100644
>>> --- a/arch/powerpc/Kconfig
>>> +++ b/arch/powerpc/Kconfig
>>> @@ -478,6 +478,15 @@ config RELOCATABLE
>>> setting can still be useful to bootwrappers that need to know the
>>> load address of the kernel (eg. u-boot/mkimage).
>>>
>>> +config RELOCATABLE_TEST
>>> + bool "Test relocatable kernel"
>>> + depends on (PPC64 && RELOCATABLE)
>>> + default n
>>> + help
>>> + This runs the relocatable kernel at the address it was initially
>>> + loaded at, which tends to be non-zero and therefore test the
>>> + relocation code.
>>> +
>>> config CRASH_DUMP
>>> bool "Build a kdump crash kernel"
>>> depends on PPC64 || 6xx || FSL_BOOKE || (44x && !SMP)
>>> diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
>>> index 79da0641..bc9ceac 100644
>>> --- a/arch/powerpc/kernel/head_64.S
>>> +++ b/arch/powerpc/kernel/head_64.S
>>> @@ -111,8 +111,12 @@ __secondary_hold_acknowledge:
>>> .globl __run_at_load
>>> __run_at_load:
>>> DEFINE_FIXED_SYMBOL(__run_at_load)
>>> +#ifdef CONFIG_RELOCATABLE_TEST
>>> + .long 0x1 /* Test relocation, do not relocate to 0 */
>>> +#else
>>> .long 0x72756e30 /* "run0" -- relocate to 0 by default */
>>> #endif
>>> +#endif
>>
>> Could we do something like
>>
>> config RELOCATION_VALUE
>> default 0x72756e30
>> default 1 if CONFIG_RELOCTABLE_TEST
>>
>> and then get
>>
>> .long CONFIG_RELOCATION_VALUE
>
> Normally I'm up for reducing ifdefs in S and c files, but in this case
> I'm not sure. I like being able to see the two possible values in the
> source. I don't really mind though. If you or Michael feel strongly, I'm
> happy to change it.
>
I guess it depends, for me parsing two .long's under #ifdef seems a little
more work than a .long with a constant depending on the configuration.
I don't feel too strongly about it either
Balbir Singh.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] powerpc/64: option to force run-at-load to test relocation
2016-10-12 7:35 ` Balbir Singh
2016-10-13 2:25 ` Nicholas Piggin
@ 2016-10-14 6:21 ` Michael Ellerman
1 sibling, 0 replies; 5+ messages in thread
From: Michael Ellerman @ 2016-10-14 6:21 UTC (permalink / raw)
To: Balbir Singh, linuxppc-dev
Balbir Singh <bsingharora@gmail.com> writes:
> On 12/10/16 17:57, Nicholas Piggin wrote:
>> diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
>> index 79da0641..bc9ceac 100644
>> --- a/arch/powerpc/kernel/head_64.S
>> +++ b/arch/powerpc/kernel/head_64.S
>> @@ -111,8 +111,12 @@ __secondary_hold_acknowledge:
>> .globl __run_at_load
>> __run_at_load:
>> DEFINE_FIXED_SYMBOL(__run_at_load)
>> +#ifdef CONFIG_RELOCATABLE_TEST
>> + .long 0x1 /* Test relocation, do not relocate to 0 */
>> +#else
>> .long 0x72756e30 /* "run0" -- relocate to 0 by default */
>> #endif
>> +#endif
>
> Could we do something like
>
> config RELOCATION_VALUE
> default 0x72756e30
> default 1 if CONFIG_RELOCTABLE_TEST
I'm not a fan of using kconfig logic when plain #defines would achieve
the same result, eg:
#ifdef CONFIG_RELOCATABLE_TEST
#define RUN_AT_LOAD_DEFAULT 1 /* Test relocation, do not relocate to 0 */
#else
#define RUN_AT_LOAD_DEFAULT 0x72756e30 /* "run0" -- relocate to 0 by default */
#endif
.globl __run_at_load
__run_at_load:
DEFINE_FIXED_SYMBOL(__run_at_load)
.long RUN_AT_LOAD_DEFAULT
Which is probably nicer to look at than Nick's version, but not by a
huge margin. I'd merge either.
cheers
^ permalink raw reply [flat|nested] 5+ messages in thread
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2016-10-12 6:57 [PATCH] powerpc/64: option to force run-at-load to test relocation Nicholas Piggin
2016-10-12 7:35 ` Balbir Singh
2016-10-13 2:25 ` Nicholas Piggin
2016-10-14 0:39 ` Balbir Singh
2016-10-14 6:21 ` Michael Ellerman
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