[PATCH] arm64/acpi: make ACPI boot preference configurable
From: Jonathan Toppins <hidden>
Date: 2018-02-27 06:05:37
Also in:
lkml
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
This patch allows a user to configure ACPI to be preferred over device-tree. Currently for ACPI to be used a user either has to set acpi=on on the kernel command line or make sure any device tree passed to the kernel is empty. If the dtb passed to the kernel is non-empty then device-tree will be chosen as the boot method of choice even if it is not correct. To prevent this situation where a system is only intended to be booted via ACPI a user can set this kernel configuration so it ignores device-tree settings unless ACPI table checks fail. Signed-off-by: Jonathan Toppins <redacted> --- arch/arm64/Kconfig | 13 +++++++++++++ arch/arm64/kernel/acpi.c | 2 +- 2 files changed, 14 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 7381eeb7ef8e..da8d9ab62825 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig@@ -1170,6 +1170,19 @@ config ARM64_ACPI_PARKING_PROTOCOL protocol even if the corresponding data is present in the ACPI MADT table. +config ARM64_PREFER_ACPI + bool "Prefer usage of ACPI boot tables over device-tree" + depends on ACPI + help + Normally device-tree is preferred over ACPI on arm64 unless + explicitly preferred via kernel command line, something like: acpi=on + This configuration changes this default behaviour by pretending + the user set acpi=on on the command line. This configuration still + allows the user to turn acpi table parsing off via acpi=off. If + for some reason the table checks fail the system will still fall + back to using device-tree unless the user explicitly sets acpi=force + on the command line. + config CMDLINE string "Default kernel command string" default ""
diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
index 7b09487ff8fb..315b001c45f1 100644
--- a/arch/arm64/kernel/acpi.c
+++ b/arch/arm64/kernel/acpi.c@@ -44,7 +44,7 @@ int acpi_pci_disabled = 1; /* skip ACPI PCI scan and IRQ initialization */ EXPORT_SYMBOL(acpi_pci_disabled); static bool param_acpi_off __initdata; -static bool param_acpi_on __initdata; +static bool param_acpi_on __initdata = IS_ENABLED(CONFIG_ARM64_PREFER_ACPI); static bool param_acpi_force __initdata; static int __init parse_acpi(char *arg)
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2.13.6