From: Al Stone ahs3@redhat.com
In order to deprecate the use of _OSI for arm64 or other new architectures, we need to make the default handler something we can change for various platforms. This patch moves the definition of acpi_osi_handler() -- the function used by ACPICA as a callback for evaluating _OSI -- into arch- dependent ACPI files. The declaration of acpi_os_handler() was moved in a previous patch.
Previously, _OSI behaved on arm64 as it did on x86. This patch changes _OSI so that on arm64 it will issue a warning if invoked, and tell the firmware that no features have been implemented (i.e., it will always return false).
In some distant future version of ACPI where _OSI has been completely deprecated, this implementation and all other architecture implementations should be removed.
Signed-off-by: Al Stone al.stone@linaro.org --- arch/arm64/kernel/acpi/Makefile | 2 +- arch/arm64/kernel/acpi/osi.c | 26 ++++++++++++++++++++++++++ 2 files changed, 27 insertions(+), 1 deletion(-) create mode 100644 arch/arm64/kernel/acpi/osi.c
diff --git a/arch/arm64/kernel/acpi/Makefile b/arch/arm64/kernel/acpi/Makefile index e049f94..15a6172 100644 --- a/arch/arm64/kernel/acpi/Makefile +++ b/arch/arm64/kernel/acpi/Makefile @@ -1 +1 @@ -obj-$(CONFIG_ACPI) += acpi.o +obj-$(CONFIG_ACPI) += acpi.o osi.o diff --git a/arch/arm64/kernel/acpi/osi.c b/arch/arm64/kernel/acpi/osi.c new file mode 100644 index 0000000..fa711dc --- /dev/null +++ b/arch/arm64/kernel/acpi/osi.c @@ -0,0 +1,26 @@ +/* + * ARM64 Specific ACPI _OSI Support + * + * Copyright (C) 2015, Linaro Ltd. + * Author: Al Stone al.stone@linaro.org + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#define pr_fmt(fmt) "ACPI: " fmt + +#include <linux/acpi.h> + +/* + * Consensus is to deprecate _OSI for all new ACPI-supported architectures. + * So, for arm64, reduce _OSI to a warning message, and tell the firmware + * nothing of value. + */ +u32 acpi_osi_handler(acpi_string interface, u32 supported) +{ + pr_warn("_OSI was called, but is deprecated for this architecture.\n"); + return false; +} +