[3.16.y-ckt stable] Patch "x86/reboot: Add EFI reboot quirk for ACPI Hardware Reduced flag" has been added to staging queue
Luis Henriques
luis.henriques at canonical.com
Tue May 12 10:32:17 UTC 2015
This is a note to let you know that I have just added a patch titled
x86/reboot: Add EFI reboot quirk for ACPI Hardware Reduced flag
to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree
which can be found at:
http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue
This patch is scheduled to be released in version 3.16.7-ckt12.
If you, or anyone else, feels it should not be added to this tree, please
reply to this email.
For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable
Thanks.
-Luis
------
>From 694b7f5f8c724f237e38ea27bdc77e081be243e6 Mon Sep 17 00:00:00 2001
From: Matt Fleming <matt.fleming at intel.com>
Date: Fri, 13 Jun 2014 12:39:55 +0100
Subject: x86/reboot: Add EFI reboot quirk for ACPI Hardware Reduced flag
commit 44be28e9dd9880dca3e2cbf7a844f2114e67f2cb upstream.
It appears that the BayTrail-T class of hardware requires EFI in order
to powerdown and reboot and no other reliable method exists.
This quirk is generally applicable to all hardware that has the ACPI
Hardware Reduced bit set, since usually ACPI would be the preferred
method.
Cc: Len Brown <len.brown at intel.com>
Cc: Mark Salter <msalter at redhat.com>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki at intel.com>
Signed-off-by: Matt Fleming <matt.fleming at intel.com>
Cc: Ben Hutchings <ben at decadent.org.uk>
[ luis: backported to 3.16:
- move changes from quirks.c into efi.c
- adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
arch/x86/include/asm/efi.h | 7 +++++++
arch/x86/kernel/reboot.c | 18 ++++++++++++++++--
arch/x86/platform/efi/efi.c | 23 +++++++++++++++++++++++
drivers/firmware/efi/reboot.c | 8 ++++++++
include/linux/efi.h | 1 +
5 files changed, 55 insertions(+), 2 deletions(-)
diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h
index 1eb5f6433ad8..81396a9a9277 100644
--- a/arch/x86/include/asm/efi.h
+++ b/arch/x86/include/asm/efi.h
@@ -156,6 +156,9 @@ static inline efi_status_t efi_thunk_set_virtual_address_map(
return EFI_SUCCESS;
}
#endif /* CONFIG_EFI_MIXED */
+
+extern bool efi_reboot_required(void);
+
#else
/*
* IF EFI is not configured, have the EFI calls return -ENOSYS.
@@ -168,6 +171,10 @@ static inline efi_status_t efi_thunk_set_virtual_address_map(
#define efi_call5(_f, _a1, _a2, _a3, _a4, _a5) (-ENOSYS)
#define efi_call6(_f, _a1, _a2, _a3, _a4, _a5, _a6) (-ENOSYS)
static inline void parse_efi_setup(u64 phys_addr, u32 data_len) {}
+static inline bool efi_reboot_required(void)
+{
+ return false;
+}
#endif /* CONFIG_EFI */
#endif /* _ASM_X86_EFI_H */
diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
index 7c138543c500..587be13be0be 100644
--- a/arch/x86/kernel/reboot.c
+++ b/arch/x86/kernel/reboot.c
@@ -28,6 +28,7 @@
#include <linux/mc146818rtc.h>
#include <asm/realmode.h>
#include <asm/x86_init.h>
+#include <asm/efi.h>
/*
* Power off function, if any
@@ -411,12 +412,25 @@ static struct dmi_system_id __initdata reboot_dmi_table[] = {
static int __init reboot_init(void)
{
+ int rv;
+
/*
* Only do the DMI check if reboot_type hasn't been overridden
* on the command line
*/
- if (reboot_default)
- dmi_check_system(reboot_dmi_table);
+ if (!reboot_default)
+ return 0;
+
+ /*
+ * The DMI quirks table takes precedence. If no quirks entry
+ * matches and the ACPI Hardware Reduced bit is set, force EFI
+ * reboot.
+ */
+ rv = dmi_check_system(reboot_dmi_table);
+
+ if (!rv && efi_reboot_required())
+ reboot_type = BOOT_EFI;
+
return 0;
}
core_initcall(reboot_init);
diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 87fc96bcc13c..53a324606d11 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -44,6 +44,7 @@
#include <linux/io.h>
#include <linux/reboot.h>
#include <linux/bcd.h>
+#include <linux/acpi.h>
#include <asm/setup.h>
#include <asm/efi.h>
@@ -1340,3 +1341,25 @@ void __init efi_apply_memmap_quirks(void)
if (is_uv_system())
set_bit(EFI_OLD_MEMMAP, &efi.flags);
}
+
+/*
+ * For most modern platforms the preferred method of powering off is via
+ * ACPI. However, there are some that are known to require the use of
+ * EFI runtime services and for which ACPI does not work at all.
+ *
+ * Using EFI is a last resort, to be used only if no other option
+ * exists.
+ */
+bool efi_reboot_required(void)
+{
+ if (!acpi_gbl_reduced_hardware)
+ return false;
+
+ efi_reboot_quirk_mode = EFI_RESET_WARM;
+ return true;
+}
+
+bool efi_poweroff_required(void)
+{
+ return !!acpi_gbl_reduced_hardware;
+}
diff --git a/drivers/firmware/efi/reboot.c b/drivers/firmware/efi/reboot.c
index e9eeeb3c6345..9c59d1c795d1 100644
--- a/drivers/firmware/efi/reboot.c
+++ b/drivers/firmware/efi/reboot.c
@@ -5,6 +5,8 @@
#include <linux/efi.h>
#include <linux/reboot.h>
+int efi_reboot_quirk_mode = -1;
+
void efi_reboot(enum reboot_mode reboot_mode, const char *__unused)
{
int efi_mode;
@@ -22,6 +24,12 @@ void efi_reboot(enum reboot_mode reboot_mode, const char *__unused)
break;
}
+ /*
+ * If a quirk forced an EFI reset mode, always use that.
+ */
+ if (efi_reboot_quirk_mode != -1)
+ efi_mode = efi_reboot_quirk_mode;
+
efi.reset_system(efi_mode, EFI_SUCCESS, 0, NULL);
}
diff --git a/include/linux/efi.h b/include/linux/efi.h
index 2539aff31808..b3fac7c1656c 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -876,6 +876,7 @@ extern void efi_reserve_boot_services(void);
extern int efi_get_fdt_params(struct efi_fdt_params *params, int verbose);
extern struct efi_memory_map memmap;
+extern int efi_reboot_quirk_mode;
extern bool efi_poweroff_required(void);
/* Iterate through an efi_memory_map */
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