Message-Id: <20150306202801.8BFE3C40AA9@trevor.secretlab.ca>
Date:	Fri, 06 Mar 2015 20:28:01 +0000
From:	Grant Likely <grant.likely@...aro.org>
To:	Hanjun Guo <hanjun.guo@...aro.org>,
	Catalin Marinas <catalin.marinas@....com>,
	"Rafael J. Wysocki" <rjw@...ysocki.net>,
	Will Deacon <will.deacon@....com>,
	Olof Johansson <olof@...om.net>
Cc:	Lorenzo Pieralisi <Lorenzo.Pieralisi@....com>,
	Arnd Bergmann <arnd@...db.de>,
	Mark Rutland <mark.rutland@....com>,
	Graeme Gregory <graeme.gregory@...aro.org>,
	Sudeep Holla <Sudeep.Holla@....com>,
	Jon Masters <jcm@...hat.com>,
	Marc Zyngier <marc.zyngier@....com>,
	Mark Brown <broonie@...nel.org>,
	Robert Richter <rric@...nel.org>,
	Timur Tabi <timur@...eaurora.org>,
	Ashwin Chaugule <ashwinc@...eaurora.org>,
	suravee.suthikulpanit@....com, linux-acpi@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
	linaro-acpi@...ts.linaro.org, Al Stone <al.stone@...aro.org>,
	Lorenzo Pieralisi <lorenzo.pieralisi@....com>,
	Tomasz Nowicki <tomasz.nowicki@...aro.org>,
	Hanjun Guo <hanjun.guo@...aro.org>
Subject: Re: [PATCH v9 05/21] ARM64 / ACPI: Get RSDP and ACPI boot-time
 tables

On Wed, 25 Feb 2015 16:39:45 +0800
, Hanjun Guo <hanjun.guo@...aro.org>
 wrote:
> From: Al Stone <al.stone@...aro.org>
> 
> As we want to get ACPI tables to parse and then use the information
> for system initialization, we should get the RSDP (Root System
> Description Pointer) first, it then locates Extended Root Description
> Table (XSDT) which contains all the 64-bit physical address that
> pointer to other boot-time tables.
> 
> Introduce acpi.c and its related head file in this patch to provide
> fundamental needs of extern variables and functions for ACPI core,
> and then get boot-time tables as needed.
>   - asm/acenv.h for arch specific ACPICA environments and
>     implementation, It is needed unconditionally by ACPI core;
>   - asm/acpi.h for arch specific variables and functions needed by
>     ACPI driver core;
>   - acpi.c for ARM64 related ACPI implementation for ACPI driver
>     core;
> 
> acpi_boot_table_init() is introduced to get RSDP and boot-time tables,
> it will be called in setup_arch() before paging_init(), so we should
> use eary_memremap() mechanism here to get the RSDP and all the table
> pointers.
> 
> FADT Major.Minor version was introduced in ACPI 5.1, it is the same
> as ACPI version.
> 
> In ACPI 5.1, some major gaps are fixed for ARM, such as updates in
> MADT table for GIC and SMP init, without those updates, we can not
> get the MPIDR for SMP init, and GICv2/3 related init information, so
> we can't boot arm64 ACPI properly with table versions predating 5.1.
> 
> If firmware provides ACPI tables with ACPI version less than 5.1,
> OS has no way to retrieve the configuration data that is necessary
> to init SMP boot protocol and the GIC properly, so disable ACPI if
> we get an FADT table with version less that 5.1 when acpi_boot_table_init()
> called.
> 
> CC: Catalin Marinas <catalin.marinas@....com>
> CC: Will Deacon <will.deacon@....com>
> CC: Lorenzo Pieralisi <lorenzo.pieralisi@....com>
> Tested-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@....com>
> Tested-by: Yijing Wang <wangyijing@...wei.com>
> Tested-by: Mark Langsdorf <mlangsdo@...hat.com>
> Tested-by: Jon Masters <jcm@...hat.com>
> Tested-by: Timur Tabi <timur@...eaurora.org>
> Tested-by: Robert Richter <rrichter@...ium.com>
> Acked-by: Robert Richter <rrichter@...ium.com>
> Signed-off-by: Al Stone <al.stone@...aro.org>
> Signed-off-by: Graeme Gregory <graeme.gregory@...aro.org>
> Signed-off-by: Tomasz Nowicki <tomasz.nowicki@...aro.org>
> Signed-off-by: Hanjun Guo <hanjun.guo@...aro.org>

Acked-by: Grant Likely <grant.likely@...aro.org>

> ---
>  arch/arm64/include/asm/acenv.h |  18 ++++++++
>  arch/arm64/include/asm/acpi.h  |  45 ++++++++++++++++++
>  arch/arm64/kernel/Makefile     |   1 +
>  arch/arm64/kernel/acpi.c       | 101 +++++++++++++++++++++++++++++++++++++++++
>  arch/arm64/kernel/setup.c      |   5 ++
>  5 files changed, 170 insertions(+)
>  create mode 100644 arch/arm64/include/asm/acenv.h
>  create mode 100644 arch/arm64/include/asm/acpi.h
>  create mode 100644 arch/arm64/kernel/acpi.c
> 
> diff --git a/arch/arm64/include/asm/acenv.h b/arch/arm64/include/asm/acenv.h
> new file mode 100644
> index 0000000..b49166f
> --- /dev/null
> +++ b/arch/arm64/include/asm/acenv.h
> @@ -0,0 +1,18 @@
> +/*
> + * ARM64 specific ACPICA environments and implementation
> + *
> + * Copyright (C) 2014, Linaro Ltd.
> + *   Author: Hanjun Guo <hanjun.guo@...aro.org>
> + *   Author: Graeme Gregory <graeme.gregory@...aro.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.
> + */
> +
> +#ifndef _ASM_ACENV_H
> +#define _ASM_ACENV_H
> +
> +/* It is required unconditionally by ACPI core, update it when needed. */
> +
> +#endif /* _ASM_ACENV_H */
> diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
> new file mode 100644
> index 0000000..8b837ab
> --- /dev/null
> +++ b/arch/arm64/include/asm/acpi.h
> @@ -0,0 +1,45 @@
> +/*
> + *  Copyright (C) 2013-2014, Linaro Ltd.
> + *	Author: Al Stone <al.stone@...aro.org>
> + *	Author: Graeme Gregory <graeme.gregory@...aro.org>
> + *	Author: Hanjun Guo <hanjun.guo@...aro.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;
> + */
> +
> +#ifndef _ASM_ACPI_H
> +#define _ASM_ACPI_H
> +
> +/* Basic configuration for ACPI */
> +#ifdef	CONFIG_ACPI
> +#define acpi_strict 1	/* No out-of-spec workarounds on ARM64 */
> +extern int acpi_disabled;
> +extern int acpi_noirq;
> +extern int acpi_pci_disabled;
> +
> +static inline void disable_acpi(void)
> +{
> +	acpi_disabled = 1;
> +	acpi_pci_disabled = 1;
> +	acpi_noirq = 1;
> +}
> +
> +/*
> + * It's used from ACPI core in kdump to boot UP system with SMP kernel,
> + * with this check the ACPI core will not override the CPU index
> + * obtained from GICC with 0 and not print some error message as well.
> + * Since MADT must provide at least one GICC structure for GIC
> + * initialization, CPU will be always available in MADT on ARM64.
> + */
> +static inline bool acpi_has_cpu_in_madt(void)
> +{
> +	return true;
> +}
> +
> +static inline void arch_fix_phys_package_id(int num, u32 slot) { }
> +
> +#endif /* CONFIG_ACPI */
> +
> +#endif /*_ASM_ACPI_H*/
> diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
> index bef04af..218eb7e 100644
> --- a/arch/arm64/kernel/Makefile
> +++ b/arch/arm64/kernel/Makefile
> @@ -34,6 +34,7 @@ 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
>  
>  obj-y					+= $(arm64-obj-y) vdso/
>  obj-m					+= $(arm64-obj-m)
> diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
> new file mode 100644
> index 0000000..f052e7a
> --- /dev/null
> +++ b/arch/arm64/kernel/acpi.c
> @@ -0,0 +1,101 @@
> +/*
> + *  ARM64 Specific Low-Level ACPI Boot Support
> + *
> + *  Copyright (C) 2013-2014, Linaro Ltd.
> + *	Author: Al Stone <al.stone@...aro.org>
> + *	Author: Graeme Gregory <graeme.gregory@...aro.org>
> + *	Author: Hanjun Guo <hanjun.guo@...aro.org>
> + *	Author: Tomasz Nowicki <tomasz.nowicki@...aro.org>
> + *	Author: Naresh Bhat <naresh.bhat@...aro.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>
> +#include <linux/bootmem.h>
> +#include <linux/cpumask.h>
> +#include <linux/init.h>
> +#include <linux/irq.h>
> +#include <linux/irqdomain.h>
> +#include <linux/memblock.h>
> +#include <linux/smp.h>
> +
> +int acpi_noirq;			/* skip ACPI IRQ initialization */
> +int acpi_disabled;
> +EXPORT_SYMBOL(acpi_disabled);
> +
> +int acpi_pci_disabled;		/* skip ACPI PCI scan and IRQ initialization */
> +EXPORT_SYMBOL(acpi_pci_disabled);
> +
> +/*
> + * __acpi_map_table() will be called before page_init(), so early_ioremap()
> + * or early_memremap() should be called here to for ACPI table mapping.
> + */
> +char *__init __acpi_map_table(unsigned long phys, unsigned long size)
> +{
> +	if (!phys || !size)
> +		return NULL;
> +
> +	return early_memremap(phys, size);
> +}
> +
> +void __init __acpi_unmap_table(char *map, unsigned long size)
> +{
> +	if (!map || !size)
> +		return;
> +
> +	early_memunmap(map, size);
> +}
> +
> +static int __init acpi_parse_fadt(struct acpi_table_header *table)
> +{
> +	struct acpi_table_fadt *fadt = (struct acpi_table_fadt *)table;
> +
> +	/*
> +	 * Revision in table header is the FADT Major revision, and there
> +	 * is a minor revision of FADT which was introduced by ACPI 5.1,
> +	 * we only deal with ACPI 5.1 or newer revision to get GIC and SMP
> +	 * boot protocol configuration data, or we will disable ACPI.
> +	 */
> +	if (table->revision > 5 ||
> +	    (table->revision == 5 && fadt->minor_revision >= 1))
> +		return 0;
> +
> +	pr_warn("Unsupported FADT revision %d.%d, should be 5.1+, will disable ACPI\n",
> +		table->revision, fadt->minor_revision);
> +	disable_acpi();
> +
> +	return -EINVAL;
> +}
> +
> +/*
> + * acpi_boot_table_init() called from setup_arch(), always.
> + *	1. find RSDP and get its address, and then find XSDT
> + *	2. extract all tables and checksums them all
> + *	3. check ACPI FADT revision
> + *
> + * We can parse ACPI boot-time tables such as MADT after
> + * this function is called.
> + */
> +void __init acpi_boot_table_init(void)
> +{
> +	/* If acpi_disabled, bail out */
> +	if (acpi_disabled)
> +		return;
> +
> +	/* Initialize the ACPI boot-time table parser. */
> +	if (acpi_table_init()) {
> +		disable_acpi();
> +		return;
> +	}
> +
> +	if (acpi_table_parse(ACPI_SIG_FADT, acpi_parse_fadt)) {
> +		/* disable ACPI if no FADT is found */
> +		disable_acpi();
> +		pr_err("Can't find FADT\n");
> +	}
> +}
> diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
> index e8420f6..4f1a014 100644
> --- a/arch/arm64/kernel/setup.c
> +++ b/arch/arm64/kernel/setup.c
> @@ -17,6 +17,7 @@
>   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
>   */
>  
> +#include <linux/acpi.h>
>  #include <linux/export.h>
>  #include <linux/kernel.h>
>  #include <linux/stddef.h>
> @@ -46,6 +47,7 @@
>  #include <linux/efi.h>
>  #include <linux/personality.h>
>  
> +#include <asm/acpi.h>
>  #include <asm/fixmap.h>
>  #include <asm/cpu.h>
>  #include <asm/cputype.h>
> @@ -380,6 +382,9 @@ void __init setup_arch(char **cmdline_p)
>  	efi_init();
>  	arm64_memblock_init();
>  
> +	/* Parse the ACPI tables for possible boot-time configuration */
> +	acpi_boot_table_init();
> +
>  	paging_init();
>  	request_standard_resources();
>  
> -- 
> 1.9.1
> 

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