From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751540AbeB0GFh (ORCPT ); Tue, 27 Feb 2018 01:05:37 -0500 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:38146 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750770AbeB0GFg (ORCPT ); Tue, 27 Feb 2018 01:05:36 -0500 From: Jonathan Toppins To: linux-arm-kernel@lists.infradead.org Cc: jtoppins@redhat.com, astone@redhat.com, jcm@redhat.com, catalin.marinas@arm.com, will.deacon@arm.com, rafael.j.wysocki@intel.com, mingo@kernel.org, prarit@redhat.com, james.morse@arm.com, andriy.shevchenko@linux.intel.com, bhsharma@redhat.com, linux-kernel@vger.kernel.org, rhkernel-list@redhat.com Subject: [PATCH] arm64/acpi: make ACPI boot preference configurable Date: Tue, 27 Feb 2018 01:05:32 -0500 Message-Id: <85047448dc1d2d3c725b6b78d5ef2a89fc81b83b.1519659254.git.jtoppins@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch allows a user to configure ACPI to be preferred over device-tree. Currently for ACPI to be used a user either has to set acpi=on on the kernel command line or make sure any device tree passed to the kernel is empty. If the dtb passed to the kernel is non-empty then device-tree will be chosen as the boot method of choice even if it is not correct. To prevent this situation where a system is only intended to be booted via ACPI a user can set this kernel configuration so it ignores device-tree settings unless ACPI table checks fail. Signed-off-by: Jonathan Toppins --- arch/arm64/Kconfig | 13 +++++++++++++ arch/arm64/kernel/acpi.c | 2 +- 2 files changed, 14 insertions(+), 1 deletion(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 7381eeb7ef8e..da8d9ab62825 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -1170,6 +1170,19 @@ config ARM64_ACPI_PARKING_PROTOCOL protocol even if the corresponding data is present in the ACPI MADT table. +config ARM64_PREFER_ACPI + bool "Prefer usage of ACPI boot tables over device-tree" + depends on ACPI + help + Normally device-tree is preferred over ACPI on arm64 unless + explicitly preferred via kernel command line, something like: acpi=on + This configuration changes this default behaviour by pretending + the user set acpi=on on the command line. This configuration still + allows the user to turn acpi table parsing off via acpi=off. If + for some reason the table checks fail the system will still fall + back to using device-tree unless the user explicitly sets acpi=force + on the command line. + config CMDLINE string "Default kernel command string" default "" diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c index 7b09487ff8fb..315b001c45f1 100644 --- a/arch/arm64/kernel/acpi.c +++ b/arch/arm64/kernel/acpi.c @@ -44,7 +44,7 @@ int acpi_pci_disabled = 1; /* skip ACPI PCI scan and IRQ initialization */ EXPORT_SYMBOL(acpi_pci_disabled); static bool param_acpi_off __initdata; -static bool param_acpi_on __initdata; +static bool param_acpi_on __initdata = IS_ENABLED(CONFIG_ARM64_PREFER_ACPI); static bool param_acpi_force __initdata; static int __init parse_acpi(char *arg) -- 2.13.6 From mboxrd@z Thu Jan 1 00:00:00 1970 From: jtoppins@redhat.com (Jonathan Toppins) Date: Tue, 27 Feb 2018 01:05:32 -0500 Subject: [PATCH] arm64/acpi: make ACPI boot preference configurable Message-ID: <85047448dc1d2d3c725b6b78d5ef2a89fc81b83b.1519659254.git.jtoppins@redhat.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org This patch allows a user to configure ACPI to be preferred over device-tree. Currently for ACPI to be used a user either has to set acpi=on on the kernel command line or make sure any device tree passed to the kernel is empty. If the dtb passed to the kernel is non-empty then device-tree will be chosen as the boot method of choice even if it is not correct. To prevent this situation where a system is only intended to be booted via ACPI a user can set this kernel configuration so it ignores device-tree settings unless ACPI table checks fail. Signed-off-by: Jonathan Toppins --- arch/arm64/Kconfig | 13 +++++++++++++ arch/arm64/kernel/acpi.c | 2 +- 2 files changed, 14 insertions(+), 1 deletion(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 7381eeb7ef8e..da8d9ab62825 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -1170,6 +1170,19 @@ config ARM64_ACPI_PARKING_PROTOCOL protocol even if the corresponding data is present in the ACPI MADT table. +config ARM64_PREFER_ACPI + bool "Prefer usage of ACPI boot tables over device-tree" + depends on ACPI + help + Normally device-tree is preferred over ACPI on arm64 unless + explicitly preferred via kernel command line, something like: acpi=on + This configuration changes this default behaviour by pretending + the user set acpi=on on the command line. This configuration still + allows the user to turn acpi table parsing off via acpi=off. If + for some reason the table checks fail the system will still fall + back to using device-tree unless the user explicitly sets acpi=force + on the command line. + config CMDLINE string "Default kernel command string" default "" diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c index 7b09487ff8fb..315b001c45f1 100644 --- a/arch/arm64/kernel/acpi.c +++ b/arch/arm64/kernel/acpi.c @@ -44,7 +44,7 @@ int acpi_pci_disabled = 1; /* skip ACPI PCI scan and IRQ initialization */ EXPORT_SYMBOL(acpi_pci_disabled); static bool param_acpi_off __initdata; -static bool param_acpi_on __initdata; +static bool param_acpi_on __initdata = IS_ENABLED(CONFIG_ARM64_PREFER_ACPI); static bool param_acpi_force __initdata; static int __init parse_acpi(char *arg) -- 2.13.6