[PATCH v7 04/17] ARM64 / ACPI: Introduce early_param for "acpi" and pass acpi=force to enable ACPI

Hanjun Guo
2015-01-14T15:04:52Z

From: Al Stone <al.stone@linaro.org>

Introduce one early parameters "off" and "force" for "acpi", acpi=off
will be the default behavior for ARM64, so introduce acpi=force to
enable ACPI on ARM64.

Disable ACPI before early parameters parsed, and enable it to pass
"acpi=force" if people want use ACPI on ARM64. This ensures DT be
the prefer one if ACPI table and DT both are provided at this moment.

Tested-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Tested-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Al Stone <al.stone@linaro.org>
Signed-off-by: Graeme Gregory <graeme.gregory@linaro.org>
Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
---
Documentation/kernel-parameters.txt | 3 ++-
arch/arm64/include/asm/acpi.h | 9 +++++++++
arch/arm64/kernel/acpi.c | 17 +++++++++++++++++
arch/arm64/kernel/setup.c | 3 +++
4 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 4df73da..4adfd50 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -165,7 +165,7 @@ multipliers 'Kilo', 'Mega', and 'Giga', equalling 2^10, 2^20, and 2^30
bytes respectively. Such letter suffixes can also be entirely omitted.

- acpi= [HW,ACPI,X86]
+ acpi= [HW,ACPI,X86,ARM64]
Advanced Configuration and Power Interface
Format: { force | off | strict | noirq | rsdt }
force -- enable ACPI if default was off
@@ -175,6 +175,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
strictly ACPI specification compliant.
rsdt -- prefer RSDT over (default) XSDT
copy_dsdt -- copy DSDT to memory
+ For ARM64, ONLY "acpi=off" or "acpi=force" are available

See also Documentation/power/runtime_pm.txt, pci=noacpi

diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
index 8b837ab..496c33b 100644
--- a/arch/arm64/include/asm/acpi.h
+++ b/arch/arm64/include/asm/acpi.h
@@ -26,6 +26,13 @@ static inline void disable_acpi(void)
acpi_noirq = 1;
}

+static inline void enable_acpi(void)
+{
+ acpi_disabled = 0;
+ acpi_pci_disabled = 0;
+ acpi_noirq = 0;
+}
+
/*
* It's used from ACPI core in kdump to boot UP system with SMP kernel,
* with this check the ACPI core will not override the CPU index
@@ -40,6 +47,8 @@ static inline bool acpi_has_cpu_in_madt(void)

static inline void arch_fix_phys_package_id(int num, u32 slot) { }

+#else
+static inline void disable_acpi(void) { }
#endif /* CONFIG_ACPI */

#endif /*_ASM_ACPI_H*/
diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
index 9252f72..39a1655 100644
--- a/arch/arm64/kernel/acpi.c
+++ b/arch/arm64/kernel/acpi.c
@@ -67,3 +67,20 @@ void __init acpi_boot_table_init(void)
if (acpi_table_init())
disable_acpi();
}
+
+static int __init parse_acpi(char *arg)
+{
+ if (!arg)
+ return -EINVAL;
+
+ /* "acpi=off" disables both ACPI table parsing and interpreter */
+ if (strcmp(arg, "off") == 0)
+ disable_acpi();
+ else if (strcmp(arg, "force") == 0) /* force ACPI to be enabled */
+ enable_acpi();
+ else
+ return -EINVAL; /* Core will print when we return error */
+
+ return 0;
+}
+early_param("acpi", parse_acpi);
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index 726b019..4580ed3 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -62,6 +62,7 @@
#include <asm/memblock.h>
#include <asm/psci.h>
#include <asm/efi.h>
+#include <asm/acpi.h>

unsigned int processor_id;
EXPORT_SYMBOL(processor_id);
@@ -388,6 +389,8 @@ void __init setup_arch(char **cmdline_p)
early_fixmap_init();
early_ioremap_init();

+ disable_acpi();
+
parse_early_param();

/*
--
1.9.1