[PATCH 1/2] x86/ACPI: Parse ACPI_FADT_LEGACY_DEVICES

[PATCH 1/2] x86/ACPI: Parse ACPI_FADT_LEGACY_DEVICES

[Anshuman Gupta]

From: "Luis R. Rodriguez" <mcgrof@kernel.org>

ACPI 5.2.9.3 IA-PC Boot Architecture flag ACPI_FADT_LEGACY_DEVICES
can be used to determine if a system has legacy devices LPC or
ISA devices. The x86 platform already has a struct which lists
known associated legacy devices, we start off careful only
by disabling root devices we should not regress with. The struct
and device list can be expanded with time to cover more root
legacy components.

Change-Id: I85ba7dfb405c7faefc0f8e6b43a6e7260a27a1c9
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: andrew.cooper3@citrix.com
Cc: andriy.shevchenko@linux.intel.com
Cc: bigeasy@linutronix.de
Cc: boris.ostrovsky@oracle.com
Cc: david.vrabel@citrix.com
Cc: ffainelli@freebox.fr
Cc: george.dunlap@citrix.com
Cc: glin@suse.com
Cc: jgross@suse.com
Cc: jlee@suse.com
Cc: josh@joshtriplett.org
Cc: julien.grall@linaro.org
Cc: konrad.wilk@oracle.com
Cc: kozerkov@parallels.com
Cc: lenb@kernel.org
Cc: lguest@lists.ozlabs.org
Cc: linux-acpi@vger.kernel.org
Cc: lv.zheng@intel.com
Cc: matt@codeblueprint.co.uk
Cc: mbizon@freebox.fr
Cc: rjw@rjwysocki.net
Cc: robert.moore@intel.com
Cc: rusty@rustcorp.com.au
Cc: tiwai@suse.de
Cc: toshi.kani@hp.com
Cc: xen-devel@lists.xensource.com
Link: http://lkml.kernel.org/r/1460592286-300-13-git-send-email-mcgrof@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/kernel/acpi/boot.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 8816102..7a25121 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -936,6 +936,10 @@ late_initcall(hpet_insert_resource);
 
 static int __init acpi_parse_fadt(struct acpi_table_header *table)
 {
+	if (!(acpi_gbl_FADT.boot_flags & ACPI_FADT_LEGACY_DEVICES)) {
+		pr_debug("ACPI: no legacy devices present\n");
+		x86_platform.legacy.devices.pnpbios = 0;
+	}
 
 	if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID &&
 	    !(acpi_gbl_FADT.boot_flags & ACPI_FADT_8042) &&
-- 
2.7.4


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Re: [PATCH 1/2] x86/ACPI: Parse ACPI_FADT_LEGACY_DEVICES

[Rajneesh Bhardwaj]

On Tue, Feb 27, 2018 at 11:47:45AM +0530, Anshuman Gupta wrote:
> From: "Luis R. Rodriguez" <mcgrof@kernel.org>
>

Anshuman, looks like you sent this by mistake. Please, be careful!

Everyone, kindly ignore this patch.
 
> ACPI 5.2.9.3 IA-PC Boot Architecture flag ACPI_FADT_LEGACY_DEVICES
> can be used to determine if a system has legacy devices LPC or
> legacy components.
> 
> 2.7.4
> 

-- 
Best Regards,
Rajneesh

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