[PATCH v3 5/9] ACPI: move acpi_os_handler() so it can be made arch-dependent later
al.stone at linaro.org
al.stone at linaro.org
Tue Feb 24 16:36:21 PST 2015
From: Al Stone <al.stone at linaro.org>
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 a separate
file. Subsequent patches will change which files get built so that we can
then build the version of _OSI we need for a particular architecture.
There is no functional change.
Signed-off-by: Al Stone <al.stone at linaro.org>
---
drivers/acpi/Makefile | 2 +-
drivers/acpi/osi.c | 95 +++++++++++++++++++++++++++++++++++++++++++++++++++
drivers/acpi/osl.c | 24 -------------
include/linux/acpi.h | 1 +
4 files changed, 97 insertions(+), 25 deletions(-)
create mode 100644 drivers/acpi/osi.c
diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index 13536d8..97191eb 100644
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -18,7 +18,7 @@ obj-y += acpi.o \
acpica/
# All the builtin files are in the "acpi." module_param namespace.
-acpi-y += osl.o utils.o reboot.o
+acpi-y += osl.o utils.o reboot.o osi.o
acpi-y += nvs.o
# Power management related files
diff --git a/drivers/acpi/osi.c b/drivers/acpi/osi.c
new file mode 100644
index 0000000..f23aa70
--- /dev/null
+++ b/drivers/acpi/osi.c
@@ -0,0 +1,95 @@
+/*
+ * osi.c - _OSI implementation (moved from drivers/acpi/osl.c)
+ *
+ * Copyright (C) 2000 Andrew Henroid
+ * Copyright (C) 2001, 2002 Andy Grover <andrew.grover at intel.com>
+ * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh at intel.com>
+ * Copyright (c) 2008 Intel Corporation
+ * Author: Matthew Wilcox <willy at linux.intel.com>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ */
+
+#include <linux/acpi.h>
+
+#define _COMPONENT ACPI_OS_SERVICES
+ACPI_MODULE_NAME("osi");
+
+#define PREFIX "ACPI: "
+
+/*
+ * The story of _OSI(Linux)
+ *
+ * From pre-history through Linux-2.6.22,
+ * Linux responded TRUE upon a BIOS OSI(Linux) query.
+ *
+ * Unfortunately, reference BIOS writers got wind of this
+ * and put OSI(Linux) in their example code, quickly exposing
+ * this string as ill-conceived and opening the door to
+ * an un-bounded number of BIOS incompatibilities.
+ *
+ * For example, OSI(Linux) was used on resume to re-POST a
+ * video card on one system, because Linux at that time
+ * could not do a speedy restore in its native driver.
+ * But then upon gaining quick native restore capability,
+ * Linux has no way to tell the BIOS to skip the time-consuming
+ * POST -- putting Linux at a permanent performance disadvantage.
+ * On another system, the BIOS writer used OSI(Linux)
+ * to infer native OS support for IPMI! On other systems,
+ * OSI(Linux) simply got in the way of Linux claiming to
+ * be compatible with other operating systems, exposing
+ * BIOS issues such as skipped device initialization.
+ *
+ * So "Linux" turned out to be a really poor chose of
+ * OSI string, and from Linux-2.6.23 onward we respond FALSE.
+ *
+ * BIOS writers should NOT query _OSI(Linux) on future systems.
+ * Linux will complain on the console when it sees it, and return FALSE.
+ * To get Linux to return TRUE for your system will require
+ * a kernel source update to add a DMI entry,
+ * or boot with "acpi_osi=Linux"
+ */
+
+static struct osi_linux {
+ unsigned int enable:1;
+ unsigned int dmi:1;
+ unsigned int cmdline:1;
+ unsigned int default_disabling:1;
+} osi_linux = {0, 0, 0, 0};
+
+u32 acpi_osi_handler(acpi_string interface, u32 supported)
+{
+ if (!strcmp("Linux", interface)) {
+
+ pr_notice_once(FW_BUG PREFIX
+ "BIOS _OSI(Linux) query %s%s\n",
+ osi_linux.enable ? "honored" : "ignored",
+ osi_linux.cmdline ? " via cmdline" :
+ osi_linux.dmi ? " via DMI" : "");
+ }
+
+ if (!strcmp("Darwin", interface)) {
+ /*
+ * Apple firmware will behave poorly if it receives positive
+ * answers to "Darwin" and any other OS. Respond positively
+ * to Darwin and then disable all other vendor strings.
+ */
+ acpi_update_interfaces(ACPI_DISABLE_ALL_VENDOR_STRINGS);
+ supported = ACPI_UINT32_MAX;
+ }
+
+ return supported;
+}
diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index af6dda7..823a08f 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -136,30 +136,6 @@ static struct osi_linux {
unsigned int default_disabling:1;
} osi_linux = {0, 0, 0, 0};
-static u32 acpi_osi_handler(acpi_string interface, u32 supported)
-{
- if (!strcmp("Linux", interface)) {
-
- pr_notice_once(FW_BUG PREFIX
- "BIOS _OSI(Linux) query %s%s\n",
- osi_linux.enable ? "honored" : "ignored",
- osi_linux.cmdline ? " via cmdline" :
- osi_linux.dmi ? " via DMI" : "");
- }
-
- if (!strcmp("Darwin", interface)) {
- /*
- * Apple firmware will behave poorly if it receives positive
- * answers to "Darwin" and any other OS. Respond positively
- * to Darwin and then disable all other vendor strings.
- */
- acpi_update_interfaces(ACPI_DISABLE_ALL_VENDOR_STRINGS);
- supported = ACPI_UINT32_MAX;
- }
-
- return supported;
-}
-
static void __init acpi_request_region(struct acpi_generic_address *gas,
unsigned int length, char *desc)
{
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 9a01d5d..a7c402a 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -281,6 +281,7 @@ static inline int acpi_video_display_switch_support(void)
extern int acpi_blacklisted(void);
extern void acpi_dmi_osi_linux(int enable, const struct dmi_system_id *d);
extern void acpi_osi_setup(char *str);
+extern u32 acpi_osi_handler(acpi_string interface, u32 supported);
#ifdef CONFIG_ACPI_NUMA
int acpi_get_node(acpi_handle handle);
--
2.1.0
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