diff mbox

[v3,8/9] ACPI: arm64: use an arch-specific ACPI _OSI method and ACPI blacklist

Message ID 1424824585-6405-9-git-send-email-al.stone@linaro.org
State New
Headers show

Commit Message

Al Stone Feb. 25, 2015, 12:36 a.m. UTC 
From: Al Stone <al.stone@linaro.org>

Now that all of the _OSI functionality has been separated out, we can
provide arch-specific functionality for it.  This also allows us to do
the same for the acpi_blacklisted() function.  We also make sure the
defaults for the arm64 kernel are set so that the arch-specific _OSI
method and blacklist are always used for ACPI.

For arm64, any use of _OSI will issue a warning that it is deprecated.
All use of _OSI will return false -- i.e., it will return no useful
information to any firmware using it.  The ability to temporarily turn
on _OSI, or turn off _OSI, or affect it in other ways from the command
line is no longer available for arm64, either.  The blacklist for ACPI
on arm64 is empty.  This will, of course, require ACPI to be enabled
for arm64.

Signed-off-by: Al Stone <al.stone@linaro.org>
---
 arch/arm64/Kconfig                 |  1 +
 arch/arm64/kernel/Makefile         |  2 +-
 arch/arm64/kernel/acpi-blacklist.c | 20 ++++++++++++++++++++
 arch/arm64/kernel/acpi-osi.c       | 25 +++++++++++++++++++++++++
 4 files changed, 47 insertions(+), 1 deletion(-)
 create mode 100644 arch/arm64/kernel/acpi-blacklist.c
 create mode 100644 arch/arm64/kernel/acpi-osi.c

Comments

Al Stone March 2, 2015, 7 p.m. UTC | #1 
On 03/02/2015 10:29 AM, Will Deacon wrote:
> Hi Al,
> 
> On Wed, Feb 25, 2015 at 12:36:24AM +0000, al.stone@linaro.org wrote:
>> diff --git a/arch/arm64/kernel/acpi-blacklist.c b/arch/arm64/kernel/acpi-blacklist.c
>> new file mode 100644
>> index 0000000..1be6a56
>> --- /dev/null
>> +++ b/arch/arm64/kernel/acpi-blacklist.c
>> @@ -0,0 +1,20 @@
>> +/*
>> + *  ARM64 Specific ACPI Blacklist 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>
>> +
>> +/* The arm64 ACPI blacklist is currently empty.  */
>> +int __init acpi_blacklisted(void)
>> +{
>> +	return 0;
>> +}
>> diff --git a/arch/arm64/kernel/acpi-osi.c b/arch/arm64/kernel/acpi-osi.c
>> new file mode 100644
>> index 0000000..bb351f4
>> --- /dev/null
>> +++ b/arch/arm64/kernel/acpi-osi.c
>> @@ -0,0 +1,25 @@
>> +/*
>> + *  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;
>> +}
> 
> This kinda feels backwards to me. If _OSI is going away, then the default
> should be "the architecture doesn't need to do anything", rather than have
> new architectures defining a bunch of empty, useless stub code.
> 
> Anyway we could make this the default in core code and have architectures
> that *do* want _OSI override that behaviour, instead of the other way around?
> 
> Cheers,
> 
> Will
> 

We could do that; I personally don't have a strong preference either way,
so I'm inclined to make it whatever structure Rafael thinks is proper since
it affects ACPI code most.  That being said, the current patch structure
made sense to me since it wasn't distorting existing code much -- and given
the pure number of x86/ia64 machines vs ARM machines using ACPI, that seemed
the more cautious approach.

@Rafael: do you have an opinion/preference?
diff mbox

Patch

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 3f08727..e441d28 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -7,6 +7,7 @@  config ARM64
 	select ARCH_HAS_SG_CHAIN
 	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
 	select ARCH_USE_CMPXCHG_LOCKREF
+	select ARCH_SPECIFIC_ACPI_OSI if ACPI
 	select ARCH_SUPPORTS_ATOMIC_RMW
 	select ARCH_WANT_OPTIONAL_GPIOLIB
 	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index 79bdd3b..b5e1268 100644
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -35,7 +35,7 @@  arm64-obj-$(CONFIG_KGDB)		+= kgdb.o
 arm64-obj-$(CONFIG_EFI)			+= efi.o efi-stub.o efi-entry.o
 arm64-obj-$(CONFIG_PCI)			+= pci.o
 arm64-obj-$(CONFIG_ARMV8_DEPRECATED)	+= armv8_deprecated.o
-arm64-obj-$(CONFIG_ACPI)		+= acpi.o
+arm64-obj-$(CONFIG_ACPI)		+= acpi.o acpi-osi.o acpi-blacklist.o
 
 obj-y					+= $(arm64-obj-y) vdso/
 obj-m					+= $(arm64-obj-m)
diff --git a/arch/arm64/kernel/acpi-blacklist.c b/arch/arm64/kernel/acpi-blacklist.c
new file mode 100644
index 0000000..1be6a56
--- /dev/null
+++ b/arch/arm64/kernel/acpi-blacklist.c
@@ -0,0 +1,20 @@ 
+/*
+ *  ARM64 Specific ACPI Blacklist 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>
+
+/* The arm64 ACPI blacklist is currently empty.  */
+int __init acpi_blacklisted(void)
+{
+	return 0;
+}
diff --git a/arch/arm64/kernel/acpi-osi.c b/arch/arm64/kernel/acpi-osi.c
new file mode 100644
index 0000000..bb351f4
--- /dev/null
+++ b/arch/arm64/kernel/acpi-osi.c
@@ -0,0 +1,25 @@ 
+/*
+ *  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;
+}