On 5/23/17 3:08 PM, Sudeep Holla wrote:
On 19/05/17 10:28, Mian Yousaf Kaukab wrote:
Low Power Idle(LPI) support added acpi_processor_ffh_lpi_probe() and
acpi_processor_ffh_lpi_enter() as __weak functions and arch code is
supposed to provide the actual callbacks. This breaks if
ACPI_PROCESSOR is configured as a module.
Add CONFIG_ARCH_HAS_ACPI_LPI configuration option to fix this.
Rafael didn't like the extra Kconfig option when I first posted
LPI patches.
Signed-off-by: Mian Yousaf Kaukab <yousaf.kau...@suse.com>
---
arch/arm64/Kconfig | 1 +
arch/arm64/kernel/cpuidle.c | 2 ++
drivers/acpi/Kconfig | 3 +++
drivers/acpi/processor_idle.c | 9 +++++++--
4 files changed, 13 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 848a34116c67..de2f2779cdf5 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -10,6 +10,7 @@ config ARM64
select ARCH_HAS_DEBUG_VIRTUAL
select ARCH_HAS_DEVMEM_IS_ALLOWED
select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
+ select ARCH_HAS_ACPI_LPI if ACPI
select ARCH_HAS_ELF_RANDOMIZE
select ARCH_HAS_GCOV_PROFILE_ALL
select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
diff --git a/arch/arm64/kernel/cpuidle.c b/arch/arm64/kernel/cpuidle.c
index fd691087dc9a..002d9cb890bd 100644
--- a/arch/arm64/kernel/cpuidle.c
+++ b/arch/arm64/kernel/cpuidle.c
@@ -51,9 +51,11 @@ int acpi_processor_ffh_lpi_probe(unsigned int cpu)
{
return arm_cpuidle_init(cpu);
}
+EXPORT_SYMBOL(acpi_processor_ffh_lpi_probe);
int acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
{
return CPU_PM_CPU_IDLE_ENTER(arm_cpuidle_suspend, lpi->index);
}
+EXPORT_SYMBOL(acpi_processor_ffh_lpi_enter);
Won't these 2 export suffice ? [...]
No, they don't suffice.
[...] I am just curious why that won't work.
I am not really sure. System.map shows the exported symbols as following:
ffff000008095898 T acpi_processor_ffh_lpi_probe
ffff0000080958f8 T acpi_processor_ffh_lpi_enter
ffff000008c19160 R __ksymtab_acpi_processor_ffh_lpi_enter
ffff000008c19170 R __ksymtab_acpi_processor_ffh_lpi_probe
ffff000008c357f0 r __kcrctab_acpi_processor_ffh_lpi_enter
ffff000008c357f8 r __kcrctab_acpi_processor_ffh_lpi_probe
ffff000008c4361b r __kstrtab_acpi_processor_ffh_lpi_enter
ffff000008c43638 r __kstrtab_acpi_processor_ffh_lpi_probe
and 'nm processor.ko' shows that they are defined as weak:
0000000000000d68 W acpi_processor_ffh_lpi_enter
0000000000000cc8 W acpi_processor_ffh_lpi_probe
But still weak symbols are happily used when the module is inserted.
Will weak function definitions be still picked when built as modules ?
Yes.
BR,
Yousaf